U.S. patent application number 15/525868 was filed with the patent office on 2017-11-09 for terminal device, base station device, mme, and communication control method.
This patent application is currently assigned to SHARP KABUSHIKI KAISHA. The applicant listed for this patent is SHARP KABUSHIKI KAISHA. Invention is credited to Masafumi ARAMOTO, Masayuki ENOMOTO.
Application Number | 20170325055 15/525868 |
Document ID | / |
Family ID | 55954340 |
Filed Date | 2017-11-09 |
United States Patent
Application |
20170325055 |
Kind Code |
A1 |
ENOMOTO; Masayuki ; et
al. |
November 9, 2017 |
TERMINAL DEVICE, BASE STATION DEVICE, MME, AND COMMUNICATION
CONTROL METHOD
Abstract
An MME detects that a PDN connection is not effective and
changes from a non-optimal gateway to a bearer established in a PDN
connection using a more optimal gateway as an endpoint node. This
configuration allows an already-established PDN connection to
switch to a new PDN connection using the more optimal gateway,
which achieves optimal communication control for continuing
communication of UE.
Inventors: |
ENOMOTO; Masayuki; (Sakai
City, JP) ; ARAMOTO; Masafumi; (Sakai City,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SHARP KABUSHIKI KAISHA |
Sakai City, Osaka |
|
JP |
|
|
Assignee: |
SHARP KABUSHIKI KAISHA
Sakai City, Osaka
JP
|
Family ID: |
55954340 |
Appl. No.: |
15/525868 |
Filed: |
November 9, 2015 |
PCT Filed: |
November 9, 2015 |
PCT NO: |
PCT/JP2015/081456 |
371 Date: |
May 10, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 76/22 20180201;
H04W 60/04 20130101; H04W 36/125 20180801; H04W 76/10 20180201;
H04W 4/029 20180201; H04W 88/16 20130101; H04W 4/02 20130101; H04W
80/04 20130101 |
International
Class: |
H04W 4/02 20090101
H04W004/02; H04W 60/00 20090101 H04W060/00; H04W 80/04 20090101
H04W080/04; H04W 88/16 20090101 H04W088/16 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 11, 2014 |
JP |
2014-228505 |
Claims
1. A terminal device configured to: establish a Packet Data Network
(PDN) connection by transmitting an Access Point Name (APN) to a
core network; establish a PDN connection, the PDN connection having
a communication path thereof constituted of a communication path to
a first gateway device and a communication path to a second gateway
device; transmit and receive user data to and from the first
gateway device using the PDN connection; initiate a service request
procedure or a tracking area update procedure by transmitting, to a
base station device, a SERVICE REQUEST message to make a transition
from an idle state to an active state or a TRACKING AREA UPDATE
REQUEST message to update a tracking area; and transmit and receive
user data to and from the second gateway device using the PDN
connection in accordance with the service request procedure or the
tracking area update procedure.
2. The terminal device according to claim 1, wherein the APN is
associated with permission information allowing a change of a
gateway device from the first gateway device to the second gateway
device, the terminal device transmitting and receiving user data to
and from the gateway device using the PDN connection.
3. The terminal device according to claim 1, configured to: obtain,
from the core network, a first and second IP addresses associated
with the PDN connection; transmit and receive, using the first IP
address, user data to and from the first gateway device using the
PDN connection; and transmit and receive, using the second IP
address, user data to and from the second gateway device using the
PDN connection.
4. The terminal device according to claim 3, configured to:
receive, from the base station device, identification information
indicating use of the second IP address in accordance with the
service request procedure or the tracking area procedure; and
transmit and receive, using the second IP address in accordance
with the identification information, user data to and from the
second gateway device using the PDN connection.
5. The terminal device according to claim 1, wherein the first
gateway device is a Local Gateway (LGW) located for offloading, and
the second gateway device is a Packet Data Gateway (PGW) located in
the core network.
6. A Mobility Management Entity (MME) configured to: receive, from
a base station device, a SERVICE REQUEST message transmitted by a
terminal device to make a transition from an idle state to an
active state, or a TRACKING AREA UPDATE REQUEST message transmitted
by the terminal device to update a tracking area; initiate a
gateway change procedure for a Packet Data Network (PDN) connection
in response to reception of the SERVICE REQUEST message or the
TRACKING AREA UPDATE REQUEST message, the PDN connection having a
communication path thereof constituted of a communication path to a
first gateway device and a communication path to a second gateway
device, the PDN connection being established by the terminal
device, the gateway change procedure being a procedure for changing
a communication path to be used for communication using the PDN
connection from the communication path to the first gateway device
to the communication path to the second gateway device; and
transmit, to a base station device in the gateway change procedure,
at least notification information for switching communication
paths.
7. The MME according to claim 6, wherein the PDN connection is
established using an Access Point Name (APN), the APN being
associated with at least permission information allowing
establishment of the PDN connection constituting the communication
path to the first gateway device and the communication path to the
second gateway device.
8. The MME according to claim 7, configured to: receive the APN
from the terminal device in accordance with an attach procedure;
select the first gateway device and the second gateway device in
accordance with the APN; transmit a first Create Session request
message for establishing the communication path to the first
gateway device, to a Serving Gateway (SGW) or the first gateway
device connecting the base station device and a core network; and
transmit a second Create Session request message for establishing
the communication path to the second gateway device, to the SGW or
the second gateway device.
9. The MME according to claim 6, wherein the first gateway device
is a Local Gateway (LGW) located for offloading, and the second
gateway device is a Packet Data Gateway (PGW) located in a core
network.
10. A base station device configured to: in accordance with an
attach procedure initiated by a terminal device, receive, from a
core network, an ATTACH ACCEPT message including a first and second
IP addresses associated with a Packet Data Network (PDN) connection
and allocated to the terminal device, the PDN connection having a
communication path thereof constituted of a communication path to a
first gateway device and a communication path to a second gateway
device; and transmit the ATTACH ACCEPT message to the terminal
device.
11. The base station device according to claim 10, configured to
notify the terminal device of identification information indicating
use of the first IP address or the second IP address in a service
procedure or a tracking area procedure initiated by the terminal
device.
12. A communication control method for a terminal device, the
method comprising the steps of: establishing a Packet Data Network
(PDN) connection by transmitting an Access Point Name (APN) to a
core network, the PDN connection having a communication path
thereof constituted of a communication path to a first gateway
device and a communication path to a second gateway device;
transmitting and receiving user data to and from the first gateway
device using the PDN connection; initiating a service request
procedure or a tracking area update procedure by transmitting, to a
base station device, a SERVICE REQUEST message to make a transition
from an idle state to an active state or a TRACKING AREA UPDATE
REQUEST message to update a tracking area; and transmitting and
receiving user data to and from the second gateway device using the
PDN connection in accordance with the service request procedure or
the tracking area update procedure.
13. The communication control method for a terminal device
according to claim 12, wherein the APN is associated with
permission information allowing a change of a gateway device from
the first gateway device to the second gateway device, the terminal
device transmitting and receiving user data to and from the gateway
device using the PDN connection.
14. The communication control method for a terminal device
according to claim 12, the method further comprising the steps of:
obtaining, from the core network, a first and second IP addresses
associated with the PDN connection; transmit and receive, using the
first IP address, user data to and from the first gateway device
using the PDN connection; and transmit and receive, using the
second IP address, user data to and from the second gateway device
using the PDN connection.
15. The communication control method for a terminal device
according to claim 14, the method further comprising the steps of:
receiving, from the base station device, identification information
indicating use of the second IP address in accordance with the
service request procedure or the tracking area procedure; and
selecting, in accordance with the identification information, the
second IP address as an IP address to be used for transmission and
reception of user data to and from the second gateway device using
the PDN connection.
16. The communication control method for a terminal device
according to claim 12, wherein the first gateway device is a Local
Gateway (LGW) located for offloading, and the first gateway device
is a Packet Data Gateway (PGW) located in the core network.
17. A communication control method for a Mobility Management Entity
(MME), the method comprising the steps of: receiving, from a base
station device, a SERVICE REQUEST message transmitted by a terminal
device to make a transition from an idle state to an active state,
or a TRACKING AREA UPDATE REQUEST message transmitted by the
terminal device to update a tracking area; initiating a gateway
change procedure for a Packet Data Network (PDN) connection in
response to reception of the SERVICE REQUEST message or the
TRACKING AREA UPDATE REQUEST message, the PDN connection having a
communication path thereof constituted of a communication path to a
first gateway device and a communication path to a second gateway
device, the PDN connection being established by the terminal
device, the gateway change procedure being a procedure for changing
a communication path to be used for communication using the PDN
connection from the communication path to the first gateway device
to the communication path to the second gateway device; and
transmitting, to a base station device in the gateway change
procedure, at least notification information for switching
communication paths.
18. The communication control method for an MME according to claim
17, wherein the PDN connection is established using an Access Point
Name (APN), the APN being associated with at least permission
information allowing establishment of a PDN connection constituting
the communication path to the first gateway device and the
communication path to the second gateway device.
19. The communication control method for an MME according to claim
18, the method further comprising the steps of: receiving the APN
from the terminal device in accordance with an attach procedure;
selecting the first gateway device and the second gateway device in
accordance with the APN; transmitting a first Create Session
request message for establishing the communication path to the
first gateway device, to a Serving Gateway (SGW) or the first
gateway device connecting the base station device and a core
network; and transmitting a second Create Session request message
for establishing the communication path to the second gateway
device, to the SGW or the second gateway device.
20. The communication control method for an MME according to claim
17, wherein the first gateway device is a Local Gateway (LGW)
located for offloading, and the second gateway device is a Packet
Data Gateway (PGW) located in a core network.
21. A communication control method for a base station device, the
method comprising the steps of: in accordance with an attach
procedure initiated by a terminal device, receiving, from a core
network, an ATTACH ACCEPT message including a first and second IP
addresses associated with a Packet Data Network (PDN) connection
and allocated to the terminal device, the PDN connection having a
communication path thereof constituted of a communication path to a
first gateway device and a communication path to a second gateway
device; and transmitting the ATTACH ACCEPT message to the terminal
device.
22. The communication control method for a base station device
according to claim 21, the method further comprising the step of
notifying the terminal device of identification information
indicating use of the first IP address or the second IP address in
a service procedure or a tracking area procedure initiated by the
terminal device.
Description
TECHNICAL FIELD
[0001] The present invention relates to a terminal device, a base
station device, an MME, and a communication control method.
BACKGROUND ART
[0002] The 3rd Generation Partnership Project (3GPP), which is a
group for standardizing mobile communication systems, is advancing
the process of formulating specifications for the Evolved Packet
System (EPS), which is described in NPL 1 below, as a
next-generation mobile communication system.
[0003] The following NPL 2 discloses a method for realizing the
Selected IP Traffic Offload (SIPTO). SIPTO is a function that
provides an offload communication path through which User Equipment
(UE, terminal device) connects to an eNodeB (eNB, base station
device) without the use of the core network of a mobile
communication system. In this configuration, the UE establishes an
offload communication path for SIPTO with a gateway device that is
close in location to the UE.
[0004] 3GPP has been discussing that with a Local GW (LGW) set as a
gateway device used for an offload communication path for SIPTO, UE
connecting to an eNB establishes a PDN connection for SIPTO with
the LGW, and transmits and receives, via a broadband network, data
to and from a device in the network using the PDN connection for
SIPTO. At the time of establishing the PDN connection for SIPTO,
the UE can establish a communication path with an LGW that is close
in location to the UE, which enables communication using an optimal
offload communication path.
[0005] The UE can continue to communicate while changing eNBs while
moving. In this case, the UE maintains the PDN connection for SIPTO
established with the LGW and can continue offload communication
using the PDN connection.
[0006] However, it is assumed that multiple LGWs are provided in a
communication system. Therefore, as the UE moves, an LGW closer in
location to the UE than an LGW selected at the time of establishing
the PDN connection for SIPTO may be present.
[0007] An offload communication path provides greater offload
effect as the offload is realized by the use of a gateway that is
closer in location to the UE. Hence, the PDN connection for SIPTO
established by the UE may no longer be an optimal communication
path as a result of the moving of the UE.
[0008] In light of such circumstances, as in NPL 3, 3GPP, which
standardizes mobile communication systems, has set, as a
requirement, that communication is continued by switching an
already-established PDN connection to a new PDN connection using a
more optimal gateway device.
CITATION LIST
Non Patent Literature
[0009] NPL 1: 3GPP TS 23.401 General Packet Radio Service (GPRS)
enhancements for Evolved Universal Terrestrial Radio Access Network
(E-UTRAN) access
[0010] NPL 2: 3GPP TR 23.829 Local IP Access and Selected IP
Traffic Offload
[0011] NPL 3: 3GPP TR 22.828 Study on Co-ordinated P-GW change for
SIPTO
SUMMARY OF INVENTION
Technical Problem
[0012] However, currently, no concrete means for continuing
communication by switching an already-established PDN connection to
a new PDN connection using a more optimal gateway device has been
introduced.
[0013] In addition, it is required that the method for switching a
communication path have high seamlessness to minimize disconnection
of the communication.
[0014] In light of such circumstances, an object of the present
invention is to provide a communication system and the like
intended to provide optimal communication control for continuing
communication of UE by switching an already-established PDN
connection to a new PDN connection using a more optimal
gateway.
Solution to Problem
[0015] In order to accomplish the object described above, the
present invention is contrived to provide the following means.
[0016] A terminal device is configured to: establish a first Packet
Data Network (PDN) connection with a first gateway device, the
first PDN connection being capable of changing a communication path
thereof from a communication path to the first gateway device to a
communication path to a second gateway device; initiate a service
request procedure by transmitting a SERVICE REQUEST message to a
base station device to make a transition from an idle state to an
active state; change the communication path of the first PDN
connection from the first gateway device to the second gateway
device in accordance with the service request procedure; and
perform communication using the first PDN connection.
[0017] The terminal device is configured to transmit a first Access
Point Name (APN) to a core network to establish the first PDN
connection. The first APN is associated with permission information
allowing a change of the communication path of the first PDN
connection from the first gateway device to the second gateway
device.
[0018] The terminal device is configured to transmit and receive,
using a first IP address, user data through the first PDN
connection; receive a second IP address from the core network in
accordance with the service procedure; change the first IP address
to the second IP address; and transmit and receive, using the
second IP address, user data through the first PDN connection.
[0019] The terminal device is configured to: transmit a second APN
to the core network to establish a second PDN connection with the
first gateway device, the second APN being different from the first
APN and not associated with the permission information allowing a
change of a communication path of the second PDN connection from
the first gateway device to the second gateway device; initiate the
service request procedure by transmitting the SERVICE REQUEST
message to the base station device to make a transition from the
idle state to the active state; receive a SERVICE REJECT message
that is a response to the SERVICE REQUEST message and rejects the
service request; and transmit the second APN to the core network to
establish a third PDN connection with the second gateway device in
response to the reception of the SERVICE REJECT message.
[0020] The first gateway device is a Local Gateway (LGW) located
for offloading, and the second gateway device is a Packet Data
Gateway (PGW) located in the core network.
[0021] A Mobility Management Entity (MME) is configured to:
receive, from a base station device, a SERVICE REQUEST message
transmitted by a terminal device to make a transition from an idle
state to an active state, and in a case that the terminal device
has established at least a first PDN connection, initiate a control
procedure to change a communication path of the first PDN
connection from the first gateway device to a second gateway device
in accordance with the service request procedure, the first PDN
connection being capable of changing the communication path thereof
from the communication path to the first gateway device to the
communication path to the second gateway device.
[0022] The first PDN connection is established using a first Access
Point Name (APN), and the first APN is associated with permission
information allowing a change of the communication path of the
first PDN connection from the first gateway device to the second
gateway device.
[0023] The MME is configured to: in a case that the terminal device
has established at least a second PDN connection, transmit a
SERVICE REJECT message in response to the reception of the SERVICE
REQUEST message, the SERVICE REJECT message being a response to the
SERVICE REQUEST message and rejecting the service request; and
request the terminal device to initiate an attach procedure by
transmitting the SERVICE REJECT message. The second PDN connection
is established using the second APN, and the second APN is
different from the first APN and not associated with the permission
information allowing a change of a communication path of the PDN
connection from the first gateway device to the second gateway
device.
[0024] The first gateway device is a Local Gateway (LGW) located
for offloading, and the second gateway device is a Packet Data
Gateway (PGW) located in the core network.
[0025] A base station device is configured to: receive, from a
terminal device, a SERVICE REQUEST message transmitted to make a
transition from an idle state to an active state; transmit the
SERVICE REQUEST message to a core network; receive an IP address to
be allocated to the terminal device from the core network; and
notify the terminal device of the IP address.
[0026] A base station device is configured to: receive, from a
terminal device, a SERVICE REQUEST message transmitted to make a
transition from an idle state to an active state; transmit the
SERVICE REQUEST message to the core network; receive first
identification information from the core network, the first
identification information indicating that the terminal device
needs to obtain an IP address again; and notify the terminal device
of the first identification information.
[0027] A communication control method for a terminal device
includes the steps of: establishing a first Packet Data Network
(PDN) connection with a first gateway device, the first PDN
connection being capable of changing a communication path of the
first PDN connection from a communication path to the first gateway
device to a communication path to a second gateway device;
initiating a service request procedure by transmitting a SERVICE
REQUEST message to a base station device to make a transition from
an idle state to an active state; changing the communication path
of the first PDN connection from the first gateway device to the
second gateway device in accordance with the service request
procedure; and performing communication using the first PDN
connection.
[0028] The communication control method further includes the step
of transmitting a first Access Point Name (APN) to a core network
to establish the first PDN connection. The first APN is associated
with permission information allowing a change of the communication
path of the first PDN connection from the first gateway device to
the second gateway device.
[0029] The communication control method further includes the step
of: transmitting and receiving, using a first IP address, user data
through the first PDN connection; receiving a second IP address
from the core network in accordance with the service procedure;
changing the first IP address to the second IP address; and
transmitting and receiving, using the second IP address, the user
data through the first PDN connection.
[0030] The communication control method further includes the step
of: transmitting a second APN to the core network to establish a
second PDN connection with the first gateway device, the second APN
being different from the first APN and not associated with the
permission information allowing a change of a communication path of
the PDN connection from the first gateway device to the second
gateway device; initiate the service request procedure by
transmitting a SERVICE REQUEST message to the base station device
to make a transition from the idle state to the active state;
receiving a SERVICE REJECT message that is a response to the
SERVICE REQUEST message and rejects the service request; and
transmitting the second APN to the core network to establish a
third PDN connection with the second gateway device in response to
the reception of the SERVICE REJECT message.
[0031] The first gateway device is a Local Gateway (LGW) located
for offloading, and the second gateway device is a packet data
gateway (PGW) located in the core network.
[0032] A communication control method for a mobility management
entity (MME) includes the steps of: receiving, from a base station
device, a SERVICE REQUEST message transmitted by a terminal device
to make a transition from an idle state to an active state; and in
a case that the terminal device has established at least a first
PDN connection, initiating a control procedure to change a
communication path of the first PDN connection from a first gateway
device to a second gateway device in accordance with the service
request procedure. The first PDN connection is capable of changing
the communication path thereof from the communication path to the
first gateway device to the communication path to the second
gateway device.
[0033] The first PDN connection is established using a first Access
Point Name (APN), and the first APN is associated with permission
information allowing a change of the communication path of the
first PDN connection from the first gateway device to the second
gateway device.
[0034] The communication control method further includes the steps
of: in a case that the terminal device has established at least a
second PDN connection, transmitting a SERVICE REJECT message in
response to the reception of the SERVICE REQUEST message, the
SERVICE REJECT message being a response to the SERVICE REQUEST
message and rejecting the service request; and requesting the
terminal device to initiate an attach procedure by transmitting the
SERVICE REJECT message. The second PDN connection is established
using the second APN, and the second APN is different from the
first APN and not associated with the permission information
allowing a change of a communication path of the PDN connection
from the first gateway device to the second gateway device.
[0035] The first gateway device is a Local Gateway (LGW) located
for offloading, and the second gateway device is a Packet Data
Gateway (PGW) located in a core network.
[0036] A communication control method for a base station device
includes the steps of: receiving, from a terminal device, a SERVICE
REQUEST message transmitted to make a transition from an idle state
to an active state; transmitting the SERVICE REQUEST message to a
core network; receiving an IP address to be allocated to the
terminal device from the core network; and notifying the terminal
device of the IP address.
[0037] A communication control method for a base station device
includes the steps of: receiving, from a terminal device, a SERVICE
REQUEST message transmitted to making a transition from an idle
state to an active state; transmitting the SERVICE REQUEST message
to the core network; receiving first identification information
from the core network, the first identification information
indicating that the terminal device needs to obtain an IP address
again; and notifying the terminal device of the first
identification information.
Advantageous Effects of Invention
[0038] According to the present invention, UE can continue to
communicate by switching an already-established PDN connection
using a gateway to a new PDN connection using a more optimal
gateway.
BRIEF DESCRIPTION OF DRAWINGS
[0039] FIGS. 1A and 1B are diagrams illustrating an overview of a
mobile communication system 1 according to a first embodiment.
[0040] FIG. 2 is a diagram illustrating a functional configuration
of UE according to the embodiment.
[0041] FIG. 3 is a diagram illustrating a storage of the UE
according to the embodiment.
[0042] FIG. 4 is a diagram illustrating a functional configuration
of an eNB according to the embodiment.
[0043] FIG. 5 is a diagram illustrating a storage of the eNB
according to the embodiment.
[0044] FIG. 6 is a diagram illustrating a functional configuration
of an MME according to the embodiment.
[0045] FIG. 7 is a diagram illustrating a storage of the MME
according to the embodiment.
[0046] FIG. 8 is a diagram illustrating a PDN connection to be
established.
[0047] FIG. 9 is a diagram illustrating an attach procedure
according to the embodiment.
[0048] FIGS. 10A, 10B, and 10C are diagrams illustrating a create
session procedure according to the embodiment.
[0049] FIG. 11 is a diagram illustrating a PDN connectivity
procedure according to the embodiment.
[0050] FIG. 12 is a diagram illustrating a service request
procedure according to the embodiment.
[0051] FIG. 13 is a diagram illustrating subsequent steps in the
service request procedure according to the embodiment.
[0052] FIG. 14 is a diagram illustrating subsequent steps in the
service request procedure according to the embodiment.
[0053] FIG. 15 is a diagram illustrating a tracking area update
procedure according to the embodiment.
[0054] FIGS. 16A, 16B, and 16C are diagrams illustrating an
overview of a mobile communication system 2.
DESCRIPTION OF EMBODIMENTS
[0055] Hereinafter, embodiments for carrying out the present
invention will be described with reference to the drawings. Note
that for the present embodiment, an embodiment of a mobile
communication system to which the present invention is applied will
be described in detail as an example, with reference to the
drawings.
1. First Embodiment
[0056] A first embodiment to which the present invention has been
applied will be described with reference to the drawings.
1.1 Overview of Mobile Communication System
[0057] FIGS. 1A and 1B are diagrams illustrating an overview of a
mobile communication system 1 according to the present embodiment.
As illustrated in FIG. 1A, the mobile communication system 1 is
constituted of UE (terminal device) 10 and a Packet Data Network
(PDN) 90. The UE 10 and the PDN 90 connect to each other via an IP
mobile communication network 5. The UE 10 connects to the IP mobile
communication network 5, and the IP mobile communication network 5
is connected with the PDN 90.
[0058] The IP mobile communication network 5 may be a network
constituted of a radio access network and a core network managed by
a mobile network operator, or may be a broadband network managed by
a fixed network operator, for example. Here, the broadband network
may be an IP communication network that is managed by a network
operator and provides high-speed communication using a digital line
such as optical fiber using asymmetric digital subscriber line
(ADSL) or the like. Alternatively, the broadband network may be,
without being limited to such a network, a network for radio access
using worldwide interoperability for microwave access (WiMAX) or
the like.
[0059] The UE 10 is a communication terminal that establishes a
connection using an access system, such as long term evolution
(LTE) or a wireless LAN (WLAN). The UE 10 includes a 3GPP LTE
communication interface, a WLAN communication interface, or the
like and is capable of establishing a connection to an IP access
network using such an interface.
[0060] Specifically, the UE 10 is a mobile phone terminal or a
smartphone, or a tablet computer, a personal computer, or a home
appliance with a communication function.
[0061] The PDN 90 is a network that provides network services for
transmitting and receiving data in the form of packets. Examples of
the PDN 90 include the Internet and an IP multimedia subsystem
(IMS). The PDN 90 may be a network that provides group
communication services, such as a group call.
[0062] The UE 10 connects to the IP mobile communication network to
establish a communication path, thereby establishing connectivity
with the PDN 90. This configuration allows the UE 10 to transmit
and receive data to and from the PDN 90.
[0063] The PDN 90 is connected to an IP access network using a
wired line or the like. For example, the PDN 90 is constructed by
ADSL, optical fiber, or the like. However, the PDN 90 maybe,
without being limited to such a configuration, a radio access
network such as LTE, WLAN, or WiMAX.
1.1.1 Configuration Example of IP Mobile Communication Network
[0064] As illustrated in FIGS. 1A and 1B, the mobile communication
system 1 is constituted of the UE 10, the IP mobile communication
network 5, and the PDN 90.
[0065] The IP mobile communication network 5 is constituted of a
core network 7 and a radio access network.
[0066] The core network 7 is constituted of a mobile management
entity (MME) 30, a Local Gateway (LGW) 40, a serving gateway (SGW)
50, an access control device (PGW) 60, a home subscriber server
(HSS) 70, and a policy and charging rules function (PCRF) 80.
[0067] In the core network 7, multiple MMEs 30, such as an MME 30A
and an MME 30B, may be provided.
[0068] In the core network 7, multiple SGWs 50, such as an SGW 50A
and an SGW 50B, may be provided.
[0069] In the core network 7, multiple PGWs 60, such as a PGW 60A
and a PGW 60B, may be provided.
[0070] In the core network 7, multiple LGWs 40, such as an LGW 40A
and an LGW 40B, may be provided. Furthermore, the LGW 40 may be
provided within the core network or may be provided within the
radio access network 9.
[0071] Note that although the LGW 40 is provided in the core
network 7 in FIG. 1A, the LGW 40 may be a gateway device provided
near the LTE_AN 9 and connecting the LTE_AN 9 to the Internet or a
broadband network, as illustrated in FIGS. 16A, 16B, and 16C. The
MME 30 may select, depending on a base station device to which the
UE 10 connects, an LGW 40 provided near the base station device, as
the endpoint node of the PDN connection established by the UE
10.
[0072] Here, as illustrated in FIG. 16C, the LGW 40 may be integral
with an eNB 20. Alternatively, as illustrated in FIG. 16B, the LGW
40 may be separate from the eNB 20.
[0073] When no LGW is provided near the base station device, the
MME 30 may select the PGW 60 as a gateway device that serves as the
endpoint node of the PDN connection established by the UE 10.
[0074] Note that such gateway selection performed by the MME 30 may
be performed in accordance with APN permission information
transmitted by the UE 10 to establish a PDN connection.
[0075] Here, the APN is identification information for selecting a
PDN to be connected by the UE 10. Note that multiple PDNs may be
provided. For example, multiple PDNs may be provided for respective
services, such as the Internet and a voice call service network
(IMS network). Moreover, the UE 10 may store multiple APNs. When
the UE 10 notifies the core network of the APN, the MME 30 selects
the PDN corresponding to the APN and selects a gateway device used
for connecting to the PDN.
[0076] As described above, the APN is identification information
for selecting a PDN to be connected by the UE 10, and may be
identification information for selecting a gateway device to be
used for connecting to the PDN.
[0077] The MME 30 also gives approval to the connection to the PDN
and the establishment of the PDN connection in accordance with the
APN transmitted to the UE 10. Hence, the APN is identification
information that also serves as authentication information for the
UE 10 to connect to the PDN or to establish the PDN connection.
[0078] The radio access network 9 is connected to the core network
7. Furthermore, the UE 10 can wirelessly connect to the radio
access network.
[0079] The radio access network may be constituted of an LTE access
network 9 (LTE AN) capable of establishing a connection using an
LTE access system. The LTE AN 9 is a network including a base
station device using the LTE access system. The LTE AN 9 may be a
public access network or a home network established at home.
[0080] Note that each of the devices has a similar configuration to
those of existing devices in a mobile communication system using an
EPS, which eliminates the need for detailed description thereof. To
describe the functions briefly, the PGW 60 is connected to the PDN
90, the SGW 50, and the PCRF 80 and routes user data by functioning
as a gateway device between the PDN 90 and the core network 7.
[0081] The SGW 50 is connected to the PGW 60, the MME 30, and the
LTE AN 9. The SGW 50 serving as a gateway device between the core
network 7 and the LTE AN 9 routes user data.
[0082] The PGW 60 serving as a gateway device connecting the core
network 7 and the PDN 90 routes user data. Note that the PGW 60
establishes a PDN connection with the UE 10 and enables data
transmission and reception between the UE 10 and a communication
device provided in the PDN 60, using the PDN connection.
[0083] The LGW 40 is connected to the SGW 50, the LTE AN 9, and the
PDN 90. The LGW 40 serving as a gateway device for the PDN 90
routes user data. The LGW 40 may be connected to a broadband
network and connected to the PDN 90 via the broadband network. As
described above, the LGW 40 is a gateway device for establishing a
communication path for offloading with the UE 10. In other words,
the LGW 40 is an endpoint node of the PDN connection for SIPTO
established by the UE 10 and is a device that performs offloading
to the broadband network and the PDN 90.
[0084] The MME 30 is connected to the SGW 50, the LTE AN 9, and the
LGW 40 and is a control device that performs location management
and access control of the UE 10 via the LTE AN 9.
[0085] The HSS 70 is connected to the SGW 50 and an AAA 55 and
manages subscriber information.
[0086] The PCRF 80 is connected to the PGW 60 and manages QoS
management for data routing.
[0087] In addition, as illustrated in FIG. 1B, the radio access
network includes devices such as a base station device to which the
UE 10 actually connects, and the like. Although various devices
adapted to the radio access network are conceivable as the devices
used for the connections, the LTE AN 9 is configured to include the
eNB 20 in the present embodiment. The eNB 20 is a radio base
station to which the UE 10 connects using an LTE access system. The
LTE AN 9 may be configured to include one or multiple radio base
stations.
[0088] Note that, herein, the UE 10 being connected to a radio
access network refers to the UE 10 being connected to a base
station device included in the radio access network, and data,
signals, and the like are also transmitted and received through the
base station device.
[0089] For example, the UE 10 being connected to the LTE AN 9
refers to the UE 10 being connected via the eNB 20.
1.2 Device Configuration
[0090] Next, the configuration of each of the devices will be
described briefly with reference to the drawings.
1.2.1 Configuration of UE
[0091] A functional configuration of the UE 10 according to the
present embodiment will be described with reference to FIG. 2. In
the UE 10, a first interface unit 110 and a storage 140 are
connected to a control unit 100 via a bus.
[0092] The control unit 100 is a function unit for controlling the
UE 10. The control unit 100 implements various processes by reading
out various kinds of information and various programs stored in the
storage 140 and executing the programs.
[0093] The first interface unit 110 is a function unit for
establishing a connection to the LTE AN 9 in compliance with an LTE
access scheme and transmitting and receiving data using radio
communication. An external antenna 112 for transmitting and
receiving data in compliance with the LTE access scheme is
connected to the first interface unit 110.
[0094] The storage 140 is a function unit for storing programs,
data, and the like necessary for various operations of the UE 10.
The storage 140 is constituted of, for example, a semiconductor
memory, a hard disk drive (HDD), or the like. Furthermore, the
storage 140 stores an APN list and UE communication path context
142.
[0095] The APN list stores APNs that the UE 10 can use. The UE 10
may store multiple APNs in the APN list.
[0096] The access point name (APN) is identification information
used by the MME 30 to select a gateway device that serves as an
endpoint node of the PDN connection to be established by the UE 10
over the IP mobile communication network 5. The APN may be
identification information associated with the PDN 90. When a
different PDN 90 is configured for each of the services, such as
IMS and video streaming, the APN can also be used as identification
information identifying the corresponding service. Note that an APN
capable of establishing a PDN connection for SIPTO and an APN that
does not perform offload communication may be managed as different
APNs. In this case, a gateway selected in accordance with an APN
for offloading may be the LGW 40, while a gateway selected in
accordance with an APN that does not perform offload communication
may be the PGW 60 configured in the core network 7.
[0097] Each of the APNs may be associated with permission
information allowing a switch to a PDN connection using a different
gateway as an endpoint node.
[0098] For example, APN1 may be an APN capable of establishing a
PDN connection for SIPTO as well as an APN that is not allowed to
switch to a PDN connection using a different gateway as an endpoint
node. APN2 may be an APN that is capable of establishing a PDN
connection for SIPTO and is allowed to switch to a PDN connection
using a different gateway as an endpoint node. APN3 may be an APN
that is unable to establish a PDN connection for SIPTO and is not
allowed to switch to a PDN connection using a different gateway as
an endpoint node. APN4 may be an APN that is unable to establish a
PDN connection for SIPTO and is allowed to switch to a PDN
connection using a different gateway as an endpoint node. APN5 may
be an APN that capable of establishing a PDN connection for SIPTO
and is allowed to have multiple connectivity using different
gateways as endpoint nodes. APN5 may be an APN capable of
simultaneously establishing multiple bearers using different
gateways as endpoint nodes using a single PDN connection.
[0099] The UE communication path context 142 is a group of
information pieces stored in association with a communication path
established by the UE. In the UE communication path context 142, a
communication path context is stored for each PDN connection. A
concrete example of the UE communication path context 142 is
illustrated in FIG. 3. FIG. 3 illustrates an example of each of
information elements managed by the UE 10 for the PDN connection
established using APN5.
[0100] As illustrated in FIG. 3, when having established a PDN
connection, the UE 10 manages the APN used for establishing the PDN
connection, the allocated PDN type, the IP address, and the default
bearer, as information elements managed for each effective PDN
connection. In addition, when having established the PDN
connection, the UE 10 manages an EPS bearer ID and an EPS bearer
QoS as information elements managed for each EPS bearer in the PDN
connection.
[0101] Note that the UE 10 may hold multiple APNs and establish a
PDN connection corresponding to each of the APNs. Furthermore, the
information elements managed for each PDN connection may be stored
for each of the PDN connections established with each of the APNs.
Each of the information elements may be different among PDN
connections. This configuration allows the UE 10 to establish
multiple PDN connections.
[0102] For example, the UE 10 may establish a PDN connection for
offloading using APN1, a PDN connection for communication via the
core network 7 using APN3, and a PDN connection capable of
offloading and having multiple connectivity to different gateways.
Note that APN3 may be an APN that is not allowed to select the LGW
40 as an endpoint node of a PDN connection and that is not allowed
to establish an offload communication path. In this case, the UE 10
establishes a PDN connection with the PGW 60 using APN3 to connect
to the PDN.
[0103] Note that the establishment of a PDN connection using an APN
may correspond to the establishment of a PDN connection in
accordance with an attach request including at least an APN
transmitted by the UE 10 to the MME 30. Note that the UE 10 may
transmit the APN to the MME 30, with the APN included in an ATTACH
REQUEST message for initiating an attach procedure or may transmit
the APN to the MME, with the APN included in another control
message in the attach procedure.
[0104] Alternatively, the establishment of a PDN connection using
an APN may correspond to the establishment of a PDN connection in
accordance with a PDN connectivity request including at least an
APN transmitted by the UE 10 to the MME 30. Note that the UE 10 may
transmit the APN to the MME 30, with the APN included in a PDN
CONNECTIVITY REQUEST message for initiating a PDN connectivity
procedure or may transmit the APN to the MME, with the APN included
in another control message in the PDN connectivity procedure.
[0105] The allocated PDN type is information indicating the version
of an IP address allocated to the UE 10. The version of the IP
address is either IPv4 or IPv6. Here, the UE 10 is notified of the
allocated PDN type together with the IP address in an attach accept
and manages the notified PDN type as the allocated PDN type.
[0106] Here, the UE 10 can request the version of IP address to be
allocated, by including the PDN type, which is information
indicating the version of IP address, in the attach request.
[0107] The UE 10 is notified of the allocated PDN type together
with the IP address in a PDN connectivity accept and manages the
notified PDN type as the allocated PDN type.
[0108] Here, the UE 10 can request the version of an IP address to
be allocated, by including the PDN type, which is information
indicating the version of the IP address, in the PDN connectivity
request.
[0109] The IP address is an IP address allocated to the UE 10. The
UE 10 transmits uplink data and receives downlink data using the
allocated IP address. Note that a single or multiple IP addresses
may be managed for each effective PDN connection. Multiple IP
addresses may be managed when a PDN connection with multiple
connectivity to different gateways is established. However, when a
PDN connection with multiple connectivity to different gateways is
established but the same IP address can be used for the different
gateways, a single IP address may be managed.
[0110] The default bearer is information identifying a radio bearer
that is a radio communication path established between the UE 10
and the eNB 20 when the UE 10 connects to the eNB 20 in the LTE AN
9.
[0111] The default bearer may be an EPS bearer ID, a radio bearer
ID, or a linked bearer ID (LBI). Note that the LBI is information
associated with a bearer ID.
[0112] The UE 10 may manage the APN, the allocated PDN type, the IP
address, and the default bearer in association with each other as
information elements managed for each effective PDN connection.
[0113] The EPS bearer ID is information identifying a radio bearer
that is a radio communication path established between the UE 10
and the eNB 20 when the UE 10 connects to the eNB 20 in the LTE AN
9.
[0114] The EPS bearer ID may be a radio bearer ID or a linked
bearer ID (LBI). Note that the LBI is information associated with a
bearer ID.
[0115] The UE 10 may manage, as the default bearer, a bearer ID of
a bearer allocated when connecting to the PDN for the first time,
and may manage, as the EPS bearer ID, a bearer ID when a different
bearer is allocated in the same PDN connection.
[0116] The EPS bearer QoS is information indicating the quality of
service (QoS) associated along with the EPS bearer ID. The EPS
bearer QoS is not associated with the default bearer and is
information indicating the QoS when an EPS bearer different from
the default bearer is allocated in the PDN connection.
[0117] The UE 10 may manage the EPS bearer ID and the EPS bearer
QoS in association with each other as information elements managed
for each EPS bearer in the PDN connection.
[0118] The UE 10 may manage the information elements managed for
each effective PDN connection and the information elements managed
for each EPS bearer in the PDN connection in association with each
other. In other words, the UE 10 may manage the APN, the allocated
PDN type, the IP address, the default bearer, the EPS bearer ID,
and the EPS bearer QoS in association with each other.
[0119] Note that the UE 10 may establish multiple communication
paths. Specifically, the UE 10 may create and manage the UE
communication path context 142 for each established PDN
connection.
[0120] The UE 10 may manage base station identification information
and service identification information, in addition to the
above-described information.
[0121] The base station identification information may be
information identifying the eNB 20. The base station identification
information may be constituted of a combination of an operator
identification code identifying the mobile network operator
providing the communication service and the base station
identification code. This configuration allows the base station
identification information to be unique identification information
in multiple mobile communication networks provided by multiple
mobile network operators.
[0122] The service identification information is information
identifying a service provided in the IP communication network 5 by
a mobile network operator. The service identification information
may be an APN or may be service domain identification information,
such as a fully qualified domain name (FQDN). The service
identification information may be, without being limited to such
information, any identification information associated with the
service. Furthermore, the service may include a voice call service
or video streaming service based on IMS, and a service providing
group communication. The service identification information is
identification information identifying such a service.
1.2.2 Configuration of eNB
[0123] With reference to FIG. 4, a functional configuration of the
eNB 20 according to the present embodiment will be illustrated. In
the eNB 20, a first interface unit 210, a second interface unit
220, a data transfer unit 230, and a storage 240 are connected to a
control unit 200 via a bus.
[0124] The control unit 200 is a function unit for controlling the
eNB 20. The control unit 200 implements various processes by
reading out various kinds of information and various programs
stored in the storage 240 and executing the programs.
[0125] The first interface unit 210 is a function unit for
establishing a radio communication path with the UE 10 in
compliance with an LTE access scheme and transmitting and receiving
data using radio communication. An external antenna 212 is
connected to the first interface unit 210.
[0126] The second interface unit 220 is connected to the core
network 7 to the core network through wired connection. The
connection to the core network 7 may be established over Ethernet
(registered trademark), an optical fiber cable, or the like.
[0127] The storage 240 is a function unit for storing programs,
data, and the like necessary for various operations of the eNB 20.
The storage 240 is constituted of, for example, a semiconductor
memory, a hard disk drive (HDD), or the like. Furthermore, the
storage 240 stores an eNB communication path context 242.
[0128] The eNB communication path context 242 is a group of
information pieces stored in association with a communication path
established by the eNB 20. FIG. 5 illustrates a concrete example of
the eNB communication path context 242. FIG. 5 illustrates
information elements managed by the eNB 20 when a PDN connection
has been established using APN5.
[0129] As illustrated in FIG. 5, the eNB 20 manages an MME UE S1 AP
ID, a GUMMEI, a global eNB ID, a tracking area ID, an E-RAB ID, and
a UE ID, as information elements managed for each effective PDN
connection.
[0130] When having established a PDN connection, the eNB 20 manages
an EPS bearer ID, an EPS bearer QoS, and a transport address as
information elements managed for each EPS bearer in the PDN
connection.
[0131] Note that the eNB 20 may manage multiple EPS bearers for a
single PDN connection. When the eNB 20 manages multiple EPS bearers
for a single PDN connection, the eNB 20 may manage the EPS bearer
ID, the EPS bearer QoS, and the transport address for each EPS
bearer.
[0132] The MME UE S1 AP ID is identification information allocated
for identifying the UE on the S1 interface. Note that the eNB 20
may receive the MME UE S1 AP ID from the MME 30 and manage the MME
UE S1 AP ID. The eNB 20 may receive the MME UE S1 AP ID from the
MME 30 by S1-AP signalling.
[0133] The GUMMEI is the identification number of the MME 30. The
eNB 20 can transfer a message from the UE 10 to the MME 30 with the
GUMMEI. Note that MME identification information to be used for
selecting an MME when the eNB 20 selects a destination of the
control message may be an MMEI (MME ID) instead of the GUMMEI.
[0134] The global eNB ID is identification information identifying
the eNB 20. The global eNB ID may be constituted of a combination
of an operator identification code identifying the mobile network
operator providing the communication service and the base station
identification code. This configuration allows the global eNB ID to
be unique identification information in multiple mobile
communication networks provided by multiple mobile network
operators.
[0135] The tracking area ID is identification information
identifying the tracking area to which the eNB 20 belongs. The
tracking area is information indicating the location of the eNB
20.
[0136] The E-UTRAN radio access bearer ID (E-RAB ID) is
identification information identifying the radio access bearer in
the E-UTRAN. When establishing a radio connection with the UE 10,
the eNB 20 allocates the E-RAB ID to the UE 10. Note that the E-RAB
ID may be a radio bearer ID, an EPS bearer ID, or a default
bearer.
[0137] The UE ID is identification information identifying a UE.
The eNB 20 manages the identification information on the UE 10 that
has established a radio connection with the UE 10. Note that a
concrete UE ID may be an international mobile subscriber identity
(IMSI). Alternatively, the UE ID may be a globally unique temporary
identity (GUTI). Alternatively, the UE ID may be a SAE temporary
mobile subscriber identity (S-TMSI), or an IP address of the UE. At
least one of these information elements may be stored. These
information elements may be combined. Note that such pieces of
identification information may be obtained from the core
network.
[0138] The EPS bearer ID is identification information identifying
an EPS bearer. Here, the EPS bearer ID may be an identifier
indicating the EPS bearer between the eNB 20 and the SGW 50. The
EPS bearer ID may be an identifier indicating the EPS bearer
between the eNB 20 and the LGW 40.
[0139] The transport address is information indicating the transfer
destination of uplink data from the UE 10. When having established
a radio connection with the UE 10, the eNB 20 manages the transfer
destination of the uplink data. The transport address may be the IP
address of the SGW 50, the TEID of the SGW 50, the IP address of
the LGW, the correlation ID or the LHN ID of the LGW 40. The tunnel
endpoint ID (TEID) is identification information of a tunnel
communication path for transport of user data constituting the PDN
connection. The TEID may be identification information on a tunnel
communication path established in accordance with a GTP protocol, a
mobile IP protocol, or a proxy mobile IP protocol.
[0140] The correlation ID is identification information on the
tunnel communication path in the LGW 40 corresponding to the TEID
in the SGW 50. Note that the correlation ID may be a SIPTO
correlation ID specifying that SIPTO is provided. Note that the
invention is intended for SIPTO; thus, the correlation ID is a
correlation ID providing SIPTO in the present invention unless
otherwise stated.
[0141] The local HeNB network ID (LHN ID) is identification
information identifying the network to which the LGW 40
belongs.
[0142] When managing the LGW 40, the eNB 20 may notify the MME 30
of the identification information on the LGW 40 in the attach
procedure. When managing the LGW 40, the eNB 20 may notify the MME
30 of the identification information on the LGW 40 in the service
request procedure. When managing the LGW 40, the eNB 20 may notify
the MME 30 of the identification information on the LGW 40 in the
PDN connectivity procedure.
[0143] The eNB communication path context 242 may be held for each
communication path. For example, when multiple communication paths
established with the UE 10 are present, the eNB communication path
context 242 may be held for each of the communication paths.
[0144] Here, the base station information on the eNB communication
path context may include information identifying the UE 10 and
information identifying the eNB 20.
[0145] The data transfer unit 230 is a function unit for
transferring received data received from the UE 10 via the first
interface unit 210, to the IP mobile communication network via the
second interface unit 220 and also transferring received data
addressed to the UE 10 received via the second interface unit 220,
to the UE 10 via the first interface unit 210.
[0146] Note that the eNB 20 may establish multiple bearers for a
single PDN connection and store information elements corresponding
to each of the bearers. The first bearer established for the single
PDN connection may be a bearer for offload communication connected
to the LGW configured for offload communication. A second bearer
may be a bearer connected to the PGW included in the core network
7.
[0147] Note that the first bearer may be a bearer connecting the
eNB 20 and the LGW 40 or may be a combination of a bearer
connecting the eNB and the SGW and a bearer connecting the SGW 50
and the LGW 40.
[0148] The second bearer may be a bearer connecting the eNB 20 and
the SGW 50 and a bearer combining the SGW 50 and the PGW 60.
[0149] Alternatively, the eNB 20 may manage a radio bearer between
the UE 10 and the eNB 20 and/or a bearer between the eNB 20 and the
SGW 50 as common bearers and may manage the first bearer as the
bearer connecting the SGW 50 and the LGW 40 while managing the
second bearer as the bearer connecting the SGW 50 and the PGW 60.
In this way, the MME 30 may manage bearers connecting to different
gateways in association with the PDN connections.
1.2.3 Configuration of MME
[0150] The MME 30 is a control device that determines whether or
not to give permission regarding establishment of a communication
path or provision of a service for the UE 10.
[0151] FIG. 6 illustrates a functional configuration of the MME 30.
In the MME 30, the IP mobile communication network interface unit
410 and a storage 440 are connected to a control unit 400 via a
bus.
[0152] The control unit 300 is a function unit for controlling the
UE 10. The control unit 300 implements various processes by reading
out and executing various programs stored in the storage 340.
[0153] The IP mobile communication network interface unit 310 is a
function unit through which the MME 30 connects to the IP mobile
communication network 5.
[0154] The storage 340 is a function unit for recording programs,
data, and the like necessary for various operations of the UE 10.
The storage 340 is constituted of, for example, a semiconductor
memory, a hard disk drive (HDD), or the like. Furthermore, the
storage 340 stores MME communication path context 342.
[0155] The MME communication path context 342 is a group of
information pieces stored in association with a communication path
established between the UE 10 and the PGW 60. FIG. 7 illustrates a
concrete example of the MME communication path context 342. FIG. 7
illustrates information elements managed by the MME 30 when the UE
10 has established a PDN connection using APN5.
[0156] As illustrated in FIG. 7, when the UE 10 has established a
PDN connection, the MME 30 may manage an APN, a PDN type, an IP
address, SIPTO permission information, a LHN ID, a PDN GW address
(C-plane), a PGW TEID (C-plane), a default bearer, and the like, as
information elements managed for each effective PDN connection.
[0157] When the PDN connection has been established, the MME 30
manages an EPS bearer ID, an SGW IP address (S1-u), an SGW TEID
(S1-u), a PGW IP address (u-plane), a PGW TEID (u-plane), an EPS
bearer QoS, and the like as information elements managed for each
EPS bearer in the PDN connection.
[0158] Note that the MME 30 may manage multiple EPS bearers for a
single PDN connection. When managing multiple EPS bearers for a
single PDN connection, the MME 30 may manage an EPS bearer ID, an
SGW IP address (S1-u), an SGW TEID (S1-u), a PGW IP address
(u-plane), a PGW TEID (u-plane), and an EPS bearer QoS for each EPS
bearer.
[0159] Note that the first bearer established for the single PDN
connection may be a bearer for offload communication connected to
the LGW configured for offload communication. The second bearer may
be a bearer connected to the PGW included in the core network
7.
[0160] Note that the first bearer may be a bearer connecting the
eNB 20 and the LGW 40 or may be a combination of a bearer
connecting the eNB and the SGW and a bearer connecting the SGW 50
and the LGW 40.
[0161] The second bearer may be a bearer connecting the eNB 20 and
the SGW 50 and a bearer combining the SGW 50 and the PGW 60.
[0162] Alternatively, the MME 30 may manage a bearer between the
eNB 20 and the SGW 50 as a common bearer, manage the first bearer
as a bearer connecting the SGW 50 and the LGW 40, and manage the
second bearer as the bearer connecting the SGW 50 and the PGW
60.
[0163] In this way, the MME 30 may manage bearers connecting to
different gateways in association with the PDN connections.
[0164] The access point name (APN) is identification information
used for selection of a gateway device that serves as an endpoint
node of the PDN connection established by the UE 10 in the IP
mobile communication network 5. The APN may be identification
information associated with the PDN 90. When a different PDN 90 is
configured for each of the services, such as IMS and video
streaming, the APN can also be used as identification information
identifying the corresponding service. Note that an APN for offload
communication that is capable of establishing a SIPTO-enabled PDN
connection and an APN that does not perform offload communication
may be managed as different APNs. In this case, a gateway selected
in accordance with the APN for offloading may be the LGW 40, while
a gateway selected in accordance with the APN that does not perform
offload communication may be the PGW 60 configured in the core
network 7.
[0165] Each of the APNs may be associated with permission
information allowing a switch to a PDN connection using a different
gateway as an endpoint node.
[0166] For example, APN1 may be an APN capable of establishing a
PDN connection for SIPTO as well as APN that is not allowed to
switch to a PDN connection using a different gateway as an endpoint
node. APN2 may be an APN that is capable of establishing a PDN
connection for SIPTO and is allowed to switch to a PDN connection
using a different gateway as an endpoint node. APN3 may be an APN
that is unable to establish a PDN connection for SIPTO and is not
allowed to switch to a PDN connection using a different gateway as
an endpoint node. APN4 may be an APN that is unable to establish a
PDN connection for SIPTO and is allowed to switch to a PDN
connection using a different gateway as an endpoint node. APN5 may
be an APN that is capable of establishing a PDN connection for
SIPTO as well as an APN that is allowed to have multiple
connectivity using different gateways as endpoint nodes. APN5 may
be an APN that simultaneously establishes multiple bearers using
different gateways as endpoint nodes for a single PDN
connection.
[0167] The MME 30 manages, for each UE, an APN available to the UE.
Multiple APNs available to the UE may be provided. For example, the
MME 30 may manage that the UE 10 is allowed to establish
connections using APN1, APN3, APN4, and APN5.
[0168] The PDN type is information indicating the version of the IP
address allocated to the UE 10. The version of the IP address is
either IPv4 or IPv6. Here, the MME 30 may notify the UE 10 of the
PDN type together with the IP address in an attach accept and
manage the notified PDN type. The MME 30 may notify the UE 10 of
the PDN type together with the IP address in a PDN connectivity
accept and manage the notified PDN type.
[0169] The IP address is an IP address allocated to the UE 10. The
UE 10 can transmit uplink data and receive downlink data with the
allocated IP address.
[0170] The MME 30 may manage the IP address of the UE 10 in
advance. The MME 30 may manage the IP address notified by the PGW
30. Further, the MME 30 may manage the IP address notified by the
LGW 40.
[0171] The permission of SIPTO includes information indicating that
the associated APN allows SIPTO. Here, the SIPTO permission
information may be subdivided permission information. For example,
the SIPTO permission information may include permission information
indicating that establishment of a PDN connection for SIPTO is
prohibited, permission information indicating that establishment of
a PDN connection for SIPTO other than SIPTO@LN is allowed,
permission information indicating that establishment of a PDN
connection for SIPTO including SIPTO@LN is allowed, or permission
information indicating that establishment of a PDN connection only
for SIPTO@LN is allowed.
[0172] Here, SIPTO@LN may indicate that the UE 10 establishes a PDN
connection with the LGW included in the access network, and SIPTO
other than SIPTO@LN may indicate that the UE 10 establishes a PDN
connection with the LGW included in the core network.
[0173] Note that in the present embodiment, allowing establishment
of a PDN connection for SIPTO including SIPTO@LN described above is
expressed as allowing SIPTO and SIPTO@LN.
[0174] The permission of SIPOTO may include, in addition to the
above permission information, permission information indicating
that establishment of a PDN connection for SIPTO@LN and SIPTO is
possible and a switch to a PDN connection using a different gateway
as an endpoint node is allowed. Further, the permission of SIPTO
may include permission information indicating that establishment of
a PDN connection for SIPTO is possible and having multiple
connectivity using different gateways as endpoint nodes is
allowed.
[0175] Note that in the present embodiment, the above-described
permission information indicating that establishment of a PDN
connection for SIPTO@LN and SIPTO is possible and having multiple
connectivity using different gateways as endpoint nodes is allowed
is indicated as permission for co-ordinated P-GW change for SIPTO
(CSIPTO).
[0176] The LHN ID is identification information identifying the
network that is managed by the eNB 20 and to which the LGW 40
belongs. The MME 30 may manage the LHN ID when a gateway as an
endpoint node of the PDN connection established by the UE 10 is the
LGW 40.
[0177] The PDN GW address (C-plane) is an IP address for
transmitting and receiving control information in the PGW 60. The
MME 30 manages the IP address of the LGW 40 and the IP address of
the PGW 60 in the PDN GW address (C-plane). Here, the C-plane
indicates control information. The PDN GW address (C-plane) is an
IP address of the PGW 60 for transmitting and receiving control
information. In the PGW 60, a PGW transmitting and receiving
control information and a PGW transmitting and receiving user data
may be integrally or separately configured.
[0178] The PDN GW TEID (C-plane) is identification information on
the tunnel communication path in the PGW 60. The PDN GW TEID is
identification information on a tunnel communication path
established in accordance with a GTP protocol, a mobile IP
protocol, or a proxy mobile IP protocol.
[0179] The PDN GW TEID (C-plane) may be a TEID of the PGW 60 for
transmitting and receiving control information. In other words, in
the PGW 60, the TEID of the PGW transmitting and receiving control
information and the TEID of the PGW transmitting and receiving user
data may be different from each other.
[0180] The PDN GW TEID (C-plane) may include a correlation ID. The
correlation ID is identification information on the tunnel
communication path in the LGW 40. Note that the correlation ID may
be a SIPTO correlation ID specifying that SIPTO is provided.
[0181] The default bearer is information identifying a radio bearer
that is a radio communication path established between the UE 10
and the eNB 20 when the UE 10 connects to the eNB 20 in the LTE AN
9.
[0182] The default bearer may be an EPS bearer ID, a radio bearer
ID, or a linked bearer ID (LBI). Note that the LBI is information
associated with a bearer ID.
[0183] The MME 30 may manage an APN, a PDN type, an IP address,
SIPTO permission information, a LHN ID, a PDN GW address (C-plane),
a PDN GW TEID (C-plane), and a default bearer in association with
each other, as information elements managed for each effective PDN
connection.
[0184] The EPS bearer ID may be information identifying the radio
bearer that is the radio communication path established between the
UE 10 and the eNB 20 when the UE 10 connects to the eNB 20 in the
LTE AN 9. The EPS bearer ID may be an identifier indicating the EPS
bearer between the eNB 20 and the SGW 50. The EPS bearer ID may be
an identifier indicating the EPS bearer between the eNB 20 and the
LGW 40.
[0185] The EPS bearer ID may be a radio bearer ID or a linked
bearer ID (LBI). Note that the LBI is information associated with a
bearer ID.
[0186] The MME 30 may manage, as the default bearer, the bearer ID
of the bearer allocated when connecting to the PDN for the first
time, and may manage, when a different bearer is allocated in the
same PDN connection, the different bearer as the EPS bearer ID.
[0187] The SGW IP address (S1-u) is the IP address of the SGW 50
for transmitting and receiving user data. S1-u indicates the
interface for transmitting and receiving user data between the SGW
50 and the eNB 20. Note that the SGW 50 transmits and receives user
data to and from the eNB 20 but neither transmits nor receives
control information to and from the eNB 20.
[0188] Note that when the SGW 50 is not included in an established
PDN connection, the MME 30 does not need to manage the IP address
of the SGW 50.
[0189] The SGW TEID (S1-u) is identification information on the
tunnel communication path between the eNB 20 and the SGW 50 for
transmitting and receiving user data. Note that the SGW 50
transmits and receives user data to and from the eNB 20 but neither
transmits nor receives control information to and from the eNB
20.
[0190] The SGW TEID (S1-u) may be identification information on a
tunnel communication path established in accordance with a GTP
protocol, a mobile IP protocol, or a proxy mobile IP protocol. Note
that when the SGW 50 is not included in an established PDN
connection, the MME 30 does not need to manage the TEID of the SGW
50.
[0191] The PGW IP address (U-plane) is the IP address of the PGW 60
transmitting and receiving user data. The MME 30 manages the IP
address of the LGW 40 and the IP address of the PGW 60 in the PGW
IP address (U-plane). Note that, in the PGW 60, a PGW transmitting
and receiving user data and a PGW transmitting and receiving
control information may be integrally or separately configured.
[0192] The PGW TEID (U-plane) is identification information on the
tunnel communication path in the PGW 60 transmitting and receiving
user data. The PGW TEID (U-plane) is identification information on
a tunnel communication path established in accordance with a GTP
protocol, a mobile IP protocol, or a proxy mobile IP protocol. Note
that, in the PGW 60, a PGW transmitting and receiving user data and
a PGW transmitting and receiving control information may be
integrally or separately configured.
[0193] Note that the PDN GW TEID (U-plane) may include a PGW TEID
and a correlation ID. The correlation ID is identification
information on the tunnel communication path in the LGW 40. Note
that the correlation ID may be a SIPTO correlation ID specifying
that SIPTO is provided.
[0194] The EPS bearer QoS is information indicating the quality of
service (QoS) associated together with the EPS bearer ID. The EPS
bearer QoS is not associated with the default bearer and is
information indicating the QoS when an EPS bearer different from
the default bearer is allocated in the PDN connection.
[0195] The MME 30 may manage an EPS bearer ID, an SGW IP address
(S1-u), an SGW TEID (S1-u), a PGW IP address (U-plane), a PGW TEID
(U-plane), and an EPS bearer QoS, as information elements managed
for each EPS bearer in the PDN connection in association with each
other.
[0196] The MME 30 may manage the information elements managed for
each effective PDN connection and the information elements managed
for each EPS bearer in the PDN connection in association with each
other. Specifically, the MME 30 may manage an APN, a PDN type, an
IP address, permission of SIPTO, a LHN ID, a PDN GW address
(C-plane), a PDN GW TEID (C-plane), a default bearer, an EPS bearer
ID, an SGW IP address (S1-u), an SGW TEID (S1-u), a PGW IP address
(U-plane), a PGW TEID (U-plane), and an EPS bearer QoS in
association with each other.
[0197] Note that the MME 30 may establish multiple communication
paths. Specifically, the MME 30 may create and manage the MME
communication path context 342 for each established PDN
connection.
[0198] The MME 30 may manage base station identification
information and service identification information, in addition to
the above-described information.
[0199] The base station identification information may be
information identifying the eNB 20. The base station identification
information may be constituted of an operator identification code
identifying the mobile network operator providing the communication
service and the base station identification code. This
configuration allows the base station identification information to
be unique identification information in multiple mobile
communication networks provided by multiple mobile network
operators.
[0200] The service identification information is information
identifying a service provided in the IP communication network 5 by
a mobile network operator. The service identification information
may be an APN or may be service domain identification information,
such as a fully qualified domain name (FQDN). The service
identification information may be, without being limited to such
information, any identification information associated with the
service. Furthermore, the service may include a voice call service
or video streaming service based on IMS, and a service providing
group communication. The service identification information is
identification information identifying such a service.
[0201] The MME communication path context 342 may be held for each
communication path. For example, when the UE 10 establishes
multiple communication paths with the eNB 20, the MME communication
path context 342 may be held for each of the communication
paths.
1.3 Description of Processing
[0202] Next, description will be given of concrete PDN connection
establishment and method of selecting a bearer in the
above-described mobile communication system. With reference to FIG.
8, description will be given of a PDN connection and a bearer to be
established and a method of selecting a bearer in the present
embodiment.
[0203] In FIG. 8, first, the UE 10 establishes a PDN connection and
performs data communication with a terminal to communicate with on
the network, using the PDN connection.
[0204] Here, the PDN connection may be a PDN connection for offload
communication. The established PDN connection may be constituted of
a first connection established between the UE 10 and the LGW 40 and
a second connection established between the UE 10 and the PGW 60
via the eNB 20. The established PDN connection may be constituted
of a first bearer established between the UE 10 and the LGW 40 and
a second bearer established between the UE 10 and the PGW 60 via
the eNB 20.
[0205] Here, the MME 30 first requests a first optimal gateway (LGW
40) to establish a session for a single PDN connection. Here, the
MME 30 may request the selected optimal gateway (LGW 40) to
allocate an IP address.
[0206] Then, the MME 30 requests a second optimal gateway (PGW 60)
to establish a session for the single PDN connection. Here, the MME
30 may request the selected optimal gateway (PGW 60) to allocate an
IP address.
[0207] Here, when the UE 10 is located at least in the serving area
of the eNB 20, the UE 10 can maintain the PDN connection including
a first bearer between the eNB 20 and the LGW 40 and a second
bearer between the UE 10 and the PGW 60 via the eNB 20.
[0208] Here, when the UE 10 is located at least in the serving area
of the eNB 20, the UE 10 can transmit and receive data using the
first bearer via the LGW 40 used as the optimal gateway.
[0209] Then, as the UE 10 moves, the UE 10 changes the serving base
station. For example, the UE 10 changes the serving base station
from an eNB 20A to an eNB 20B.
[0210] As the UE 10 moves, the serving base station is changed from
the eNB 20A to the eNB 20B. In a conventional system, even when
changing the serving base station from the eNB 20A to the eNB 20B,
the UE 10 maintains the PDN connection for which the LGW 40 has
been selected, unless the PDN connection is canceled and another
PDN connection is reestablished. In other words, the UE 10
maintains the PDN connection to the LGW 40 via the eNB 20B. Here,
when the UE 10 is located in the serving area of the eNB 20B, the
LGW 40 may not necessarily be the optimal gateway for offloading,
and hence the PDN connection to the LGW 40 may not be the PDN
connection for which the optimal gateway has been selected.
[0211] In the present embodiment, the UE 10 does not have
connectivity having a single gateway as an endpoint node in a
single PDN connection as in the conventional system, but has
multiple connectivity using multiple gateways as endpoint nodes in
a single PDN connection. For the PDN connection established here, a
bearer may be established for each of the gateways.
[0212] Specifically, the UE 10 may establish the first bearer
between the UE 10 and the LGW 40 and the second bearer between the
UE 10 and the PGW 60 via the eNB 20 in the single PDN
connection.
[0213] Here, even when the UE 10 has moved to the eNB 20B, an
optimal communication control is performed for UE communication by
switching to a connection using the optimal gateway via the PGW 60,
instead of using a connection via the LGW 40, which is no longer
the optimal gateway, in the already-established PDN connection.
[0214] Furthermore, even when the UE 10 has moved to the eNB 20B,
optimal communication control may be performed for UE communication
by switching to the second bearer using the optimal gateway,
instead of using the first bearer using the optimal gateway that is
no longer optimal, in the already-established PDN connection.
[0215] Note that in the conventional system, when the MME 30
detects that the already-established PDN connection is not the
optimal communication path, the MME 30 transmits, to the UE 10, a
PDN connectivity reestablishment request for a PDN connection. Upon
receiving the PDN connectivity reestablishment request from the MME
30, the UE 10 performs a PDN connectivity reestablishment
procedure.
[0216] In the present embodiment, when the MME 30 detects that the
connection via the LGW 40 is not the optimal communication path in
the already-established PDN connection, the MME 30 selects the PGW
50 as the optimal gateway in the already-established PDN connection
and performs a procedure for changing the gateway in the PDN
connection, instead of requesting the UE 10 to reestablish a PDN
connection.
[0217] Here, when the MME 30 detects that the communication path is
not optimal in the first EPS bearer in the already-established PDN
connection, the MME 30 may select the second EPS bearer in the PDN
connection of the UE 10 and performs a procedure for changing the
gateway in the PDN connection.
[0218] Here, the MME 30 may switch the connection from the first
connection (the first bearer) using the LGW 40 as the endpoint node
to the second connection (the second bearer) using the PGW 60 as
the endpoint node, with a single IP address.
[0219] Here, the MME 30 may switch the connection from the first
connection (the first bearer) using the LGW 40 as the endpoint node
to the second connection (the second bearer) using the PGW 60 as
the endpoint node, with multiple IP addresses.
[0220] The MME 30 may notify the UE 10 of the IP address received
from the optimal gateway (PGW 60). The UE 10 may receive the IP
address from the MME 30 and update the IP address managed for the
PDN connection.
[0221] The above-described procedure makes it possible to change
from the first EPS bearer in the PDN connection between the UE 10
and the LGW 40, which is no longer the optimal gateway, to the
second EPS bearer in the PDN connection between the UE 10 and the
PGW 60, which is the optimal gateway.
[0222] In other words, the UE 10 can switch the communication path
thereof from the communication path to the LGW 40 to the
communication path to the PGW 60 in the established PDN
connection.
[0223] Even during a change of an EPS bearer in the core network 7,
the UE 10 is able to reduce packet loss and the like and delay
caused by switching of the communication path without noticing the
PDN connection for which the EPS bearer is being changed, which
improves seamlessness.
1.3.1 Attach Procedure
[0224] First, an attach procedure in the UE 10 will be described
with reference to FIG. 9. Note that the attach procedure allows the
UE 10 to establish a PDN connection using APN5. The UE 10 can
transmit and receive data to and from a corresponding node included
in the PDN 90 using the PDN connection. Note that APN5 is an APN
capable of establishing a PDN connection for SIPTO and allowed to
have multiple connectivity using different gateways as endpoint
nodes.
[0225] First, the UE 10 transmits an attach request to the eNB 20
to initiate an attach request procedure (S902). The UE 10 transmits
an APN, with the APN included in the attach request. The UE 10 may
transmit a PDN type, with the PDN type included in the attach
request to specify the version of the IP address allocated to the
UE 10. Note that the UE 10 may transmit the APN to the MME 30, with
the APN included in an ATTACH REQUEST message for initiating the
attach procedure or may transmit the APN to the MME, with the APN
included in another control message in the attach procedure.
[0226] The UE 10 may request the establishment of the second PDN
connection using APN5 to establish a PDN connection that is a PDN
connection for SIPTO and has multiple connectivity using different
gateways as endpoint nodes.
[0227] Then, the eNB 20 transmits, to the MME 30, the attach
request transmitted by the UE 10 (S904). Here, the eNB 20 may
include identification information on a neighboring gateway managed
by the eNB 20, such as the LGW 40, in the attach request to be
transmitted to the MME 30. The eNB 20 may include the LHN ID
indicating the network of the LGW 40, in the attach request to be
transmitted to the MME 30.
[0228] The eNB 20 may notify the MME 30 of such information in
advance, instead of using the attach request.
[0229] For example, the eNB 20 may notify the MME 30 of the LHN ID,
with the LHN ID included in an initial UE message or an uplink NAS
transport message, separate from the attach request. The eNB 20 may
notify the MME 30 of the information identifying the neighboring
gateway, such as the LGW address of the LGW 40, with the
information included in the initial UE message or the uplink NAS
transport message, separate from the attach request.
[0230] The MME 30 receives the attach request from the UE 10 or the
eNB 20. Upon receiving the attach request, the MME 30 detects that
the UE 10 is to establish the PDN connection.
[0231] Here, the information indicating that the UE 10 will
establish a PDN connection may be an APN included in the attach
request and/or a control message in the attach procedure. In other
words, the MME 30 may detect the establishment in accordance with
the APN included in the attach request and/or a control message in
the attach procedure. The MME 30 may detect the establishment of
the PDN connection in accordance with permission information or
capability information on the UE 10.
[0232] Furthermore, the MME 30 may perform GW selection for
establishing the PDN connection in accordance with the APN included
in the attach request and/or a control message in the attach
procedure. Here, the GW selection is to select a gateway device
serving as the endpoint node of the PDN connection to be
established by the UE 10.
[0233] The MME 30 selects a gateway device in the neighbor eNB 20,
such as the LGW 40. Note that the MME 30 may select a gateway
device in the neighbor eNB 20, such as the LGW 40, instead of the
PGW 60, when APN5 is allowed for SIPTO. Further, when receiving an
APN, such as APN5, allowed to establish a PDN connection for SIPTO
and allowed to have multiple connectivity using different gateways
as endpoint nodes, the MME 30 may select multiple gateways such as
the PGW 60 included in the core network 7 and the LGW 40 included
in the access network 9.
[0234] Here, the MME 30 may query the HSS 70 to select the gateway.
The MME 30 may transmit the APN and location information to the HSS
70 and receive identification information on the PGW 60, the LGW
40, and the like.
[0235] Note that the MME 30 may select a gateway in the neighbor
eNB 20 and establish a PDN connection. The MME 30 may select a
gateway in the neighbor eNB 20 using the LGW address of the LGW 40
notified by the eNB 20. The MME 30 may select a gateway in the
neighbor eNB 20 using the LHN ID of the LGW 40 notified by the eNB
20.
[0236] Here, the MME 30 selects the LGW 40, which is a gateway in
the neighbor eNB 20, and the PGW 60 as a gateway in the core
network 7.
[0237] Then, the MME 30 performs a create session procedure with
the selected gateway. Note that when the MME 30 selects multiple
gateways for the establishment of a single PDN connection, the MME
30 may perform the create session procedure for each of the
selected gateways.
[0238] In other words, the MME 30 may perform multiple create
session procedures. In this way, the MME 30 may establish multiple
bearers using different gateways, for the single PDN
connection.
[0239] Specifically, the MME 30 may perform the create session
procedure with the LGW 40 (S910) and perform the create session
procedure with the PGW 60 (S906). Note that either of the session
procedures may be performed first. Furthermore, the MME 30 may
initiate the second session procedure after the completion of the
first session procedure or may initiate the second session
procedure without waiting for the completion of the first session
establishment procedure.
[0240] An example of the create session procedure between the MME
30 and the PGW 60 will be described with reference to FIG. 10A.
This session procedure causes the SGW 50 and the PGW 60 to
establish therebetween a bearer to be associated with the PDN
connection.
[0241] First, the MME 30 transmits a Create Session request to the
SGW 40 (S1002). Here, the MME 30 may select, by an SGW selection
function in advance, the SGW 40 to which the MME 30 transmits the
Create Session request. In the SGW selection function, the location
information on the UE may be used for the selection of the SGW 50.
For the selection of the SGW 50, an operator policy specified by
the mobile network operator may be used.
[0242] The MME 30 may include a PGW address, an APN, a PDN type,
and an EPS bearer ID in the Create Session request.
[0243] Here, the PDN GW address may be identification information
on the gateway selected by the MME 30 in the GW selection.
Specifically, the PDN GW address may include the identification
information identifying the LGW 40 and the identification
information identifying the PGW 60. Here, the PDN GW address
includes the identification information identifying the PGW 60.
[0244] Description will be given in which the MME 30 is assumed to
include APN5 as the APN. Note that APN5 may indicate establishment
of a PDN connection that is a PDN connection for SIPTO and has
multiple connectivity using different gateways as endpoint
nodes.
[0245] The PDN type may be determined by the MME 30 in accordance
with the contract information of the user of the UE 10. The MME 30
may authenticate the PDN type included in the attach request
transmitted from the UE 10 to determine the PDN type.
[0246] The EPS bearer ID may be bearer identification information
allocated by the MME 30 to the UE 10. Note that the EPS bearer ID
may be identification information identifying the default
bearer.
[0247] The SGW 50 transmits a Create Session request to the PGW 40
(S1004). Here, the SGW 50 may determine the PGW 60 to which the SGW
50 transmits the Create Session request in accordance with the
identification information on the PDN GW address included in the
Create Session request transmitted from the MME 30 to the SGW 50.
The SGW 50 may include an APN, an SGW address (U-plane), an SGW
TEID (U-plane), an SGW TEID (C-plane), a PDN type, and an EPS
bearer ID in the Create Session request.
[0248] For the APN, the PDN type, and the EPS bearer ID, the APN,
the PDN type, the PDN address, and the EPS bearer ID included in
the Create Session request transmitted from the MME 30 may be used,
respectively.
[0249] Note that the PDN address is an IP address allocated to the
UE 10 and used by the UE 10 to transmit and receive user data.
[0250] The SGW address (U-plane), the SGW TEID (U-plane), and the
SGW TEID (C-plane) may be information managed by the SGW 50 in
advance.
[0251] The PGW 60 that has received the Create Session request may
perform an IP address allocation process (S1006). Here, when the
PGW 60 causes a third server device (using DHCP or stateless
address configuration) to allocate an IP address, the third server
device may provide information indicating the allocation.
[0252] The PGW 60 may perform a session establishment procedure.
Here, in the session establishment procedure, the PGW 60 may
establish a communication path with the default QoS or may
establish a communication path with EPS bearer QoS different from
the default QoS.
[0253] The PGW 60 transmits a Create Session response to the SGW 50
(S1008). The LGW 40 may include a PGW address (U-plane), a PGW TEID
(U-plane), a PGW TEID (C-plane), a PDN type, a PDN address, an EPS
bearer ID, and an EPS bearer QoS in the Create Session
response.
[0254] The PGW address (U-plane), the PGW TEID (U-plane), and the
PGW TEID (C-plane) may be information managed by the PGW 60 in
advance.
[0255] The PDN type may be the PDN type included in the Create
Session request (S1004) transmitted from the SGW 50.
[0256] The PDN address may be an IP address allocated by the PGW 60
to the UE 10. Here, when the allocation of the IP address is
performed by the third server device, the third server device may
include information indicating the allocation.
[0257] The EPS bearer ID and the EPS bearer QoS may be information
elements on the case of establishing QoS different from that of the
default bearer.
[0258] Furthermore, the SGW 50 transmits a Create Session response
to the MME 30 (S1010). Here, the SGW 50 may include a PDN type, a
PDN address, an SGW address (U-plane), an SGW TEID (U-plane), and
an SGW TEID (C-plane), an EPS bearer ID, an EPS bearer QoS, a PGW
address (U-plane), and a PGW TEID in the Create Session
response.
[0259] Here, the PDN type, the PDN address, the EPS bearer ID, the
EPS bearer QoS, the PGW address (U-plane), and the PGW TEID may be
information elements included in the Create Session response
transmitted from the PGW 60 (S1008).
[0260] The SGW address (U-plane), the SGW TEID (U-plane), and the
SGW TEID (C-plane) may be information elements managed by the SGW
50.
[0261] The MME 30 receives the Create Session response. The MME 30
may manage the PDN type, the PDN address, the SGW address
(U-plane), the SGW TEID (U-plane), the SGW TEID (C-plane), the EPS
bearer ID, the EPS bearer QoS, the PGW address (U-plane), and the
PGW TEID included in the Create Session response, together with the
APN, the SIPTO permission information, and the LHN ID.
[0262] The MME 30 can manage information elements managed for each
effective PDN connection before move of the UE in the MME
communication path context 342 illustrated in FIG. 7, and
information elements managed for the second EPS bearer in the PDN
connection.
[0263] Next, an example of the create session procedure (S910)
between the MME 30 and the LGW 40 will be described with reference
to FIG. 10B. This session procedure causes the SGW 50 and the LGW
40 to establish therebetween a bearer that is to be associated with
the PDN connection.
[0264] First, the MME 30 transmits a Create Session request to the
SGW 50 (S1020). Here, the MME 30 may select, in advance, the SGW 50
to which the MME 30 transmits the Create Session request, by the
SGW selection function. In the SGW selection function, the SGW 50
may be selected using UE location information. For the selection of
the SGW 50, an operator policy specified by the mobile network
operator may be used.
[0265] The MME 30 may include a PDN GW address, an APN, a PDN type,
and an EPS bearer ID in the Create Session request.
[0266] Here, the PDN GW address may be identification information
on the gateway selected by the MME 30 in the GW selection.
Specifically, the PDN GW address may include the identification
information identifying the LGW 40 and the identification
information identifying the PGW 60. Here, the PDN GW address
includes the identification information identifying the LGW 40.
[0267] A description will be given in which the MME 30 is assumed
to include APN5 as the APN. Note that APN5 may indicate to
establish a PDN connection that is a PDN connection for SIPTO and
has multiple connectivity using different gateways as endpoint
nodes.
[0268] The PDN type may be determined by the MME 30 in accordance
with the contract information of the user of the UE 10. The MME 30
may authenticate the PDN type included in the attach request
transmitted from the UE 10 to determine the PDN type.
[0269] The EPS bearer ID may be bearer identification information
allocated by the MME 30 to the UE 10. Note that the EPS bearer ID
may be identification information identifying the default
bearer.
[0270] The MME 30 may include an indicator indicating whether to
allocate an IP address to the LGW 40. Note that the indicator
indicating whether to allocate an IP address may be an IP address
allocated by the PGW 60. The indicator indicating whether to
allocate an IP address may be an APN.
[0271] The SGW 50 transmits a Create Session request to the LGW 40
(S1022). Here, the SGW 50 may determine the LGW 40 to which the SGW
50 transmits the Create Session request in accordance with the
identification information on the PDN GW address included in the
Create Session request transmitted from the MME 30 to the SGW 50.
The SGW 50 may include an APN, an SGW address (U-plane), an SGW
TEID (U-plane), an SGW TEID (C-plane), a PDN type, and an EPS
bearer ID in the Create Session request.
[0272] For the APN, the PDN type, and the EPS bearer ID, the APN,
the PDN type, the PDN address, and the EPS bearer ID included in
the Create Session request transmitted from the MME 30 may be used,
respectively.
[0273] The SGW address (U-plane), the SGW TEID (U-plane), and the
SGW TEID (C-plane) may be information managed by the SGW 50 in
advance.
[0274] The LGW 40 that has received the Create Session request may
perform an IP address allocation process (S1024). Here, the LGW 40
may determine not to allocate an IP address depending on the APN
included in the Create Session request. The LGW 40 may determine
not to allocate an IP address depending on the indicator included
in the Create Session request transmitted by the MME 30.
[0275] The LGW 40 may determine to allocate an IP address depending
on the indicator included in the Create Session request transmitted
by the MME 30.
[0276] Here, when the LGW 40 determines to allocate an IP address
and causes a third server device (using DHCP or stateless address
configuration) to allocate the IP address, the third server device
may provide information indicating the allocation.
[0277] The LGW 40 may perform a session establishment procedure.
Here, in the session establishment procedure, the LGW 40 may
establish a communication path with the default QoS, or may
establish a communication path with the EPS bearer QoS different
from the default QoS.
[0278] The LGW 40 transmits a Create Session response to the SGW 50
(S1026). The LGW 40 may include a PGW address (U-plane), a PGW TEID
(U-plane), a PGW TEID (C-plane), a PDN type, a PDN address, an EPS
bearer ID, and an EPS bearer QoS in the Create Session
response.
[0279] The PGW address (U-plane), the PGW TEID (U-plane), and the
PGW TEID (C-plane) may be information managed by the LGW 40 in
advance. Here, the PGW address (U-plane) may be identification
information identifying the LGW 40. Each of the PGW TEID (U-plane)
and the PGW TEID (C-plane) may be a correlation ID. The correlation
ID is identification information on the tunnel communication path
in the LGW 40. Note that the correlation ID may be a SIPTO
correlation ID specifying that SIPTO is provided.
[0280] The PDN type may be the PDN type included in the Create
Session request (S1022) transmitted from the SGW 50.
[0281] The PDN address may be an IP address allocated by the LGW 40
to the UE 10. Here, when the allocation of the IP address is
performed by the third server device, the third server device may
include information indicating the allocation.
[0282] The EPS bearer ID and the EPS bearer QoS may be information
elements on the case of establishing QoS different from that of the
default bearer.
[0283] Furthermore, the SGW 50 transmits a Create Session response
to the MME 30 (S1028). Here, the SGW 50 may include a PDN type, a
PDN address, an SGW address (U-plane), an SGW TEID (U-plane), an
SGW TEID (C-plane), an EPS bearer ID, an EPS bearer QoS, a PGW
address (U-plane), and a PGW TEID in the Create Session
response.
[0284] Here, the PDN type, the PDN address, the EPS bearer ID, the
EPS bearer QoS, the PGW address (U-plane), and the PGW TEID may be
information elements included in the Create Session response
(S1026) transmitted from the LGW 40.
[0285] The SGW address (U-plane), the SGW TEID (U-plane), and the
SGW TEID (C-plane) may be information elements managed by the SGW
50.
[0286] The MME 30 receives the Create Session response. The MME 30
may manage the PDN type, the PDN address, the SGW address
(U-plane), the SGW TEID (U-plane), the SGW TEID (C-plane), the EPS
bearer ID, the EPS bearer QoS, the PGW address (U-plane), and the
PGW TEID included in the Create Session response, together with the
APN, the SIPTO permission information, and the LHN ID.
[0287] The MME 30 can manage information elements managed for each
effective PDN connection before move of the UE, and information
elements managed for each of the first EPS bearers in the PDN
connection, in the MME communication path context 342 illustrated
in FIG. 7.
[0288] Note that the bearer established for the LGW 40 does not
need to be the bearer between the SGW 50 and the LGW 40. For
example, the bearer established for the LGW 40 may be a bearer
established directly by the eNB 20 and the LGW 40.
[0289] In this case, the create session procedure performed by the
MME 30 may be a procedure different from the procedure described
with reference to FIG. 10B.
[0290] An example of the create session procedure (S910) in this
case will be described with reference to FIG. 10C. Although the
Create Session request is transmitted to the LGW 40 via the SGW 50
in FIG. 10B, the MME 30 may transmit the Create Session request
directly to the LGW 40. The SGW 50 may be integrally configured
with the LGW 40.
[0291] First, the MME 30 transmits a Create Session request to the
LGW 40 (S1030). Here, the MME 30 may include a PDN GW address, an
APN, a PDN type, and an EPS bearer ID in the Create Session
request.
[0292] Here, the PDN GW address may be identification information
on the gateway selected by the MME 30 in the GW selection.
Specifically, the PDN GW address may include the identification
information identifying the LGW 40 and the identification
information identifying the PGW 60. Here, the PDN GW address may
include the identification information identifying the LGW 40.
[0293] A description will be given in which the MME 30 is assumed
to include APN5 as the APN. APN5 may indicate establishment of a
PDN connection that is a PDN connection for SIPTO and has multiple
connectivity having different gateways as endpoint nodes.
[0294] The PDN type may be determined by the MME 30 in accordance
with the contract information of the user of the UE 10 or the like.
The MME 30 may authenticate the PDN type included in the attach
request transmitted from the UE 10 to determine the PDN type.
[0295] The EPS bearer ID may be bearer identification information
allocated by the MME 30 to the UE 10. Note that the EPS bearer ID
may be identification information identifying the default
bearer.
[0296] The MME 30 may include an indicator indicating whether to
allocate an IP address to the LGW 40. The indicator indicating
whether to allocate an IP address may be an IP address allocated by
the PGW 60. The indicator indicating whether to allocate an IP
address may be an APN.
[0297] Here, the MME 30 may select, in advance by the SGW selection
function, the SGW 50 that is integrally configured with the LGW 40.
The SGW selection function may select the SGW 50 with reference to
UE location information. For the selection of the SGW 50, an
operator policy specified by the mobile network operator may be
used.
[0298] The LGW 40 that has received the Create Session request may
perform an IP address allocation process (S1024). Here, the LGW 40
may determine not to allocate an IP address depending on the APN
included in the Create Session request. The LGW 40 may determine
not to allocate an IP address depending on the indicator included
in the Create Session request transmitted by the MME 30.
[0299] The LGW 40 may determine to allocate an IP address depending
on the indicator included in the Create Session request transmitted
by the MME 30.
[0300] Here, when the LGW 40 determines to allocate an IP address
and causes a third server device (using DHCP or stateless address
configuration) to allocate the IP address, the third server device
may provide information indicating the allocation.
[0301] The LGW 40 may perform a session establishment procedure.
Here, in the session establishment procedure, the LGW 40 may
establish a communication path with the default QoS, or may
establish a communication path with the EPS bearer QoS different
from the default QoS.
[0302] The LGW 40 transmits a Create Session response to the MME 30
(S1032). The LGW 40 may include a PGW address (U-plane), a PGW TEID
(U-plane), a PGW TEID (C-plane), a PDN type, a PDN address, an EPS
bearer ID, and an EPS bearer QoS in the Create Session
response.
[0303] The PGW address (U-plane), the PGW TEID (U-plane), and the
PGW TEID (C-plane) may be information managed by the LGW 40 in
advance. Here, the PGW address (U-plane) may be identification
information identifying the LGW 40. Each of the PGW TEID (U-plane)
and the PGW TEID (C-plane) may be a correlation ID. The correlation
ID is identification information on the tunnel communication path
in the LGW 40. Note that the correlation ID may be a SIPTO
correlation ID specifying that SIPTO is provided.
[0304] The PDN type may be the PDN type included in the Create
Session request (S1022) transmitted from the SGW 50.
[0305] The PDN address may be an IP address allocated by the LGW 40
to the UE 10. Here, when the allocation of the IP address is
performed by the third server device, the third server device may
include information indicating the allocation.
[0306] The EPS bearer ID and the EPS bearer QoS may be information
elements on the case of establishing QoS different from that of the
default bearer.
[0307] Furthermore, the SGW 50 transmits a Create Session response
to the MME 30 (S1028). Here, the SGW 50 may include a PDN type, a
PDN address, an SGW address (U-plane), an SGW TEID (U-plane), an
SGW TEID (C-plane), an EPS bearer ID, an EPS bearer QoS, a PGW
address (U-plane), and a PGW TEID in the Create Session
response.
[0308] Here, the PDN type, the PDN address, the EPS bearer ID, the
EPS bearer QoS, the PGW address (U-plane), and the PGW TEID may be
information elements included in the Create Session response
(S1026) transmitted from the LGW 40.
[0309] The SGW address (U-plane), the SGW TEID (U-plane), and the
SGW TEID (C-plane) may be information elements managed by the LGW
40.
[0310] The MME 30 receives the Create Session response. The MME 30
may manage the PDN type, the PDN address, the SGW address
(U-plane), the SGW TEID (U-plane), the SGW TEID (C-plane), the EPS
bearer ID, the EPS bearer QoS, the PGW address (U-plane), and the
PGW TEID included in the Create Session response, together with the
APN, the SIPTO permission information, and the LHN ID.
[0311] The MME 30 can manage information elements managed for each
effective PDN connection before move of the UE, and information
elements managed for each of the first EPS bearers in the PDN
connection, in the MME communication path context 342 illustrated
in FIG. 7.
[0312] As described above, the MME 30 can manage information on a
PDN connection, information elements managed for each of the first
EPS bearers, and information elements managed for each of the
second EPS bearers.
[0313] Note that a different IP address may be allocated to the UE
10 in each of the session procedures. Hence, the MME 30 and/or each
of the gateways may allocate multiple IP addresses for a single PDN
connection.
[0314] Alternatively, the same IP address may be allocated to the
UE 10 in each of the session procedures. Hence, the MME 30 and/or
each of the gateways may allocate a single IP address to a single
PDN connection.
[0315] A method of allocating the same IP address to the UE 10 in
each of the session procedures may be the following method.
[0316] For example, a configuration may be made in which the
gateway devices obtain the same IP address from a third server
device, such as a DHCP server.
[0317] Alternatively, at the time of initiating the second session
procedure after the completion of the first session procedure, the
MME 30 may transmit a Create Session request including the IP
address obtained in the first session procedure, to request the
allocation of the same IP address. Furthermore, the gateway
receiving the Create Session request in the second session
procedure may allocate the IP address transmitted by the MME
30.
[0318] The above-described procedures allow the SGW 50 to establish
a communication path to the PGW 60 and a communication path to the
LGW 40 for the PDN connection.
[0319] These communication paths can be selected by the SGW 50 and
can be selected, for example, at the time of transferring data
transmitted by the UE 10 and received from the eNB 20. A
communication path selection means of the SGW 50 may be performed
in accordance with SGW configuration information. The configuration
information may be information obtained from the MME 30. More
specifically, the MME 30 may transmit information indicating
selection of a communication path for offloading, to the SGW 50.
The MME 30 may make this notification at the time of establishing
the PDN connection, for example, by transmitting the information,
with the information included in a Create Session message.
[0320] Alternatively, the MME 30 may make the notification at any
timing after establishment of the PDN connection.
[0321] More specifically, the information indicating that the MME
30 selects a communication path for offloading may be a correlation
ID.
[0322] For example, when having obtained the correlation ID from
the MME 30, the SGW 50 may select the communication path to the LGW
40. When having not received the correlation ID, the SGW 50 may
select the communication path to the PGW 60.
[0323] Alternatively, the information may be a correlation ID for
SIPTO or a special correlation ID for CSIPTO different from the
correlation ID for SIPTO.
[0324] Alternatively, the information may be different
identification information indicating selection of an offload
communication path.
[0325] Note that these communication paths may be bearers connected
to the devices, such as the LGW 40 and the PGW 60.
[0326] Through the above-described procedure, the create session
procedure is completed.
[0327] Returning to FIG. 9, description will be given of the
subsequent steps of the attach procedure. The MME 30 transmits an
initial context setup request/attach accept to the eNB 20A
(S914).
[0328] Note that the MME 30 makes a notification of information on
the first EPS bearer and information on the second EPS bearer in a
PDN connection that is to be newly established, with the
information included in the initial context setup request/attach
accept.
[0329] The attach accept may include the APN, the PDN type, the PDN
address, the EPS bearer ID, and the EPS bearer QoS. Here, the PDN
address may include the IP addresses allocated to the first EPS
bearer and the second EPS bearer.
[0330] The initial context setup request may include the EPS bearer
QoS, the EPS bearer ID, the SGW TEID (U-plane), the SGW address
(U-plane). When a PDN connection using an LGW as an end point node
(a PDN connection for SIPTO@LN) is established, the initial context
request may include a SIPTO correlation ID.
[0331] Here, the EPS bearer QoS, the EPS bearer ID, the SGW TEID
(U-plane), and the SGW address (U-plane) included in the initial
context setup request may be included for each EPS bearer.
Specifically, the initial context setup request may include the EPS
bearer QoS, the EPS bearer ID, the SGW TEID (U-plane), and the SGW
address (U-plane) of the first EPS bearer, and the EPS bearer QoS,
the EPS bearer ID, the SGW TEID (U-plane), and the SGW address
(U-plane) of the second EPS bearer.
[0332] The eNB 20 receives the initial context setup request/attach
accept. The eNB 20 determines to establish a radio bearer with the
UE 10, in accordance with the EPS bearer ID and the EPS bearer QoS
included in the initial context setup request. Here, the eNB 20 may
determine an E-RAB ID in accordance with the EPS bearer ID and the
EPS bearer QoS.
[0333] Note that when managing the LGW 40 as a neighboring gateway,
the eNB 20 may establish a radio bearer in accordance with the
information elements associated with the LGW 40. Here, the eNB 20
may establish a radio bearer with the UE 10 in accordance with the
EPS bearer ID including the correlation ID and the EPS bearer
QoS.
[0334] The eNB 20 may manage an SGW TEID (U-plane), an SGW address
(U-plane), and a SIPTO correlation ID included in a modify bearer
request.
[0335] The above procedure allows the eNB 20 to manage an MME UE S1
AP ID, a GUMMEI, a global eNB ID, a tracking area ID, an E-RAB ID,
and a UE ID, as information elements managed for each PDN
connection in the eNB communication path context 242 illustrated in
FIG. 5. The eNB 20 can manage an EPS bearer ID, an EPS bearer QoS,
and a transport address as information elements managed for each
EPS bearer in the PDN connection.
[0336] In this way, the eNB 20 may establish a communication path
to the SGW 50 and a communication path to the LGW 40. Note that the
communication path to the LGW 40 may be established in response to
receipt of a correlation ID from the MME 30.
[0337] These communication paths can be selected by the eNB 20 and
can be selected, for example, at the time of transferring data
received from the UE 10. A communication path selection means of
the eNB 20 may be performed in accordance with eNB configuration
information. The configuration information may be information
obtained from the MME 30. More specifically, the MME 30 may
transmit, to the eNB 20, information indicating selection of a
communication path for offloading. The MME 30 may make this
notification at the time of establishing the PDN connection, for
example, by transmitting the information, with the information
included in a Create Session response message.
[0338] Alternatively, the MME 30 may make the notification at any
timing after establishment of the PDN connection.
[0339] More specifically, the information indicating that the MME
30 selects a communication path for offloading may be a correlation
ID.
[0340] For example, when having obtained the correlation ID from
the MME 30, the eNB 20 may select the communication path to the LGW
40. When having not received the correlation ID, the eNB 20 may
select the communication path to the SGW 50 connecting to the PGW
60.
[0341] Alternatively, the information may be a correlation ID for
SIPTO or a special correlation ID for CSIPTO different from the
correlation ID for SIPTO.
[0342] Alternatively, the information may be different
identification information indicating selection of an offload
communication path.
[0343] These communication paths may be bearers connected to the
devices, such as the LGW 40 and the SGW 50. Next, the eNB 20
transmits an RRC connection reconfiguration to the UE 10 (S916).
Note that the eNB 20 includes an attach accept in an RRC connection
reconfiguration notification destined for the UE 10. Here, the eNB
20 may include the attach accept, separate from the RRC connection
reconfiguration notification destined for the UE 10. In other
words, the eNB 20 makes a notification of the information on the
newly established PDN connection by transferring the attach
accept.
[0344] The UE 10 receives the RRC connection reconfiguration and
the attach accept from the eNB 20. Here, the UE 10 detects the
information on the newly established PDN connection included in the
attach accept from the eNB 20, and manages the information.
[0345] Note that the information on the PDN connection may be an
APN, a PDN type, a PDN address, an EPS bearer ID, and an EPS bearer
QoS. Next, the UE 10 performs an IP address obtainment process
(S917). Here, the UE 10 may obtain the PDN address included in the
attach accept as an IP address. Note that when multiple PDN
addresses are included in an ATTACH ACCEPT message, multiple IP
addresses may be stored for the PDN connection.
[0346] When the PDN address included in the attach accept includes
information indicating obtainment of an IP address in accordance
with DHCP, the UE 10 may obtain the IP address from the DHCP
server. Here, the DHCP server may be an external server different
from the core network 7 or the LGW 40.
[0347] Note that the UE 10 may obtain multiple IP addresses for the
PDN connection from the DHCP server and store the IP addresses.
[0348] When the PDN address included in the attach accept includes
information indicating obtainment of an IP address in accordance
with the stateless address auto-configuration, the UE 10 may
receive a router advertisement (RA) from a router device and obtain
the IP address in accordance with the router advertisement. Here,
the router device may be an external server different from the core
network 7 or may be the LGW 40.
[0349] Note that the UE 10 may obtain multiple IP addresses for the
PDN connection from the router device and manage the IP
addresses.
[0350] When the UE 10 stores multiple IP addresses for a single PDN
connection, the UE 10 may select and use these IP addresses at the
time of transmitting user data.
[0351] An IP address selection means may be performed in accordance
with configuration information of the UE 10. The configuration
information may be information obtained from the MME 30 or the eNB
20. More specifically, the MME 30 or the eNB 20 may transmit
information indicating selection of a communication path for
offloading, to the UE 10. The MME 30 may make this notification at
the time of establishing the PDN connection, for example, by
transmitting the information, with the information included in an
ATTACH ACCEPT message.
[0352] Alternatively, the MME 30 may make the notification at any
timing after establishment of the PDN connection.
[0353] More specifically, the information indicating that the MME
30 selects a communication path for offloading may be priority
information configured for each IP address.
[0354] Alternatively, the information may be a correlation ID for
SIPTO or a special correlation ID for CSIPTO different from the
correlation ID for SIPTO.
[0355] Alternatively, the information may be different
identification information indicating selection of an offload
communication path.
[0356] The UE 10 may select an IP address to be used for
transmission of user data, in accordance with such information. The
UE 10 obtains the IP address in the above-described method, and
manages the IP address as the PDN connection. The UE 10 can manage
information on the PDN connection in the UE communication path
context 142 indicated in (a) before move in FIG. 3 and can transmit
uplink data in the PDN connection.
[0357] The UE 10 transmits an RRC connection reconfiguration
complete (S918). The eNB 20 receives the RRC connection
reconfiguration complete as a response to the RRC connection
reconfiguration (S916) and transmits an initial context setup
response to the MME 30 (S920).
[0358] The UE 10 also transmits direct transfer to the eNB 20
(S922). Here, an attach complete may be included in the direct
transfer. The EPS bearer ID may be included in the attach
complete.
[0359] The eNB 20 receives the direct transfer from the UE 10 and
transfers the attach complete included in the direct transfer to
the MME 30 (S924). The MME 30 that has received the initial context
setup response and the attach complete transmits a modify bearer
request to the SGW 50 (S926). The SGW 50 receives the modify bearer
request from the MME 30 and transmits a modify bearer response to
the MME 30 (S928).
[0360] The above procedure allows the PDN connection to be
established between the UE 10 and each of the PGW 60 and the LGW
40. In other words, the UE 10 can manage an APN, an allocated PDN
type, an IP address, a default bearer, an EPS bearer ID, and an EPS
bearer QoS in the UE communication path context 142 illustrated in
FIG. 3, as information on the PDN connection.
[0361] The eNB 20 can manage an MME UE S1 AP ID, a GUMMEI, a global
eNB ID, a tracking area ID, an E-RAB ID, and a UE ID in the eNB
communication path context 242 illustrated in FIG. 5, as
information on the PDN connection. The eNB 20 can manage an EPS
bearer ID, an ESP bearer QoS, and a transport address as
information elements managed for the EPS bearer in the PDN
connection. Note that the transport address may be the IP address
of the SGW, the TEID of the SGW, or the IP address or the
correlation ID of the LGW.
[0362] Furthermore, the MME 30 can manage an APN, a PDN type, an IP
address, SIPTO permission (information), a LHN ID, a PDN GW address
(C-plane), a PDN GW TEID (C-plane), and a default bearer in the MME
communication path context 342 illustrated in FIG. 7, as
information on the PDN connection.
[0363] The MME 30 can manage an EPS bearer ID, an SGW IP address
(S1-u), an SGW TEID (S1-u), a PGW IP address (U-plane), a PGW TEID
(U-plane), and an EPS bearer QoS as information elements managed
for each EPS bearer in the PDN connection.
[0364] Through the above, the UE 10 can transmit and receive data
via the PGW 60 or LGW 40 using the PDN connection. In other words,
the UE 10, the eNB 20, and/or the SGW 50 can establish a PDN
connection constituted of a communication path to the LGW 40 and a
communication path to the PGW 60.
[0365] Note that for the communication of the UE 10 using the PDN
connection, the communication path connected to the LGW 40 can be
preferentially selected in accordance with the configuration
information on the UE 10, the eNB 20, and/or the SGW 50. Hence, the
communication of the UE 10 using the PDN connection can be
performed using the communication path connected to the LGW 40, in
accordance with the configuration information on the UE 10, the eNB
20, and/or the SGW 50.
[0366] Note that when having established a PDN connection by
performing an attach procedure using APN5, the UE 10 manages APN5
as the APN, PDN type 1 as the allocated PDN type, IP address 1 and
IP address 2 as the IP address, and EPS bearer ID 1 as the default
bearer, and manages EPS bearer ID 5 as the EPS bearer ID and EPS
bearer QoS 1 as the EPS bearer QoS among information elements
managed for each EPS bearer in the PDN connection, as illustrated
in the UE communication path context 142 in FIG. 3.
[0367] Note that when multiple IP addresses are not obtained at the
time of establishing a PDN connection, the UE 10 may manage IP
address 1 only.
[0368] In this case, as illustrated in the eNB communication path
context 242 in FIG. 5, the eNB 20 manages MME UE S1 AP ID 1 as the
MME UE S1 AP ID, GUMMEI1 as the GUMMEI, global eNB ID 1, tracking
area ID 1 as the tracking area ID, E-RAB ID 1 as the E-RAB ID, and
UE ID 1 as the UE ID, manages EPS bearer ID 1 as the EPS bearer ID,
EPS bearer QoS 1 as the EPS bearer QoS, and transport address 1
(such as a PGW address, a PGW TEID, an LGW address, or a
correlation ID) as the transport address among information elements
managed for the first EPS bearer, and manages EPS bearer ID 2 as
the EPS bearer ID, EPS bearer QoS 2 as the EPS bearer QoS, and
transport address 2 as the transport address (such as a PGW
address, a PGW TEID, an LGW address, or a correlation ID) among
information elements managed for the second EPS bearer.
[0369] As illustrated in the MME communication path context 342 in
FIG. 7, the MME 30 manages APN 5 as the APN, PDN type 1 as the PDN
type, IP address 1 and IP address 2 as the IP address, permission
of CSIPTO as the permission of SIPTO, LHN ID 1 as the LHN ID, LGW
address 1 and PGW address 1 as the PDN GW address (C-plane),
correlation ID 1 and PGW TEID 1 as the PDN GW TEID (C-plane), and
EPS bearer ID 1 as the default bearer, manages EPS bearer ID 5 as
the EPS bearer ID, LGW IP address 1 as the PGW IP address
(U-plane), correlation ID 1 as the PGW TEID (U-plane), and EPS
bearer QoS 1 as the EPS bearer QoS among the information elements
managed for the first EPS bearer, and manages EPS bearer ID 7 as
the EPS bearer ID, SGW IP address 1 as the SGW IP address (S1-u),
SGW TEID 1 as the SGW TEID (S1-u), PGW IP address 1 as the PGW IP
address (U-plane), PGW TEID 1 as the PGW TEID (U-plane), and EPS
bearer QoS 2 as the EPS bearer QoS among information elements
managed for the second EPS bearer.
1.3.2 PDN Connectivity Procedure
[0370] Establishment of a PDN connection using APN5 can also be
established in accordance with a PDN connectivity procedure without
being limited to the attach procedure. Note that when a PDN
connection for SIPTO can be established and a PDN connection having
multiple connectivity using different gateways as endpoint nodes
has been established, in the attach procedure, the PDN connectivity
procedure does not need to be performed.
[0371] A UE-initiated PDN connectivity procedure will be described
with reference to FIG. 11. First, the UE 10 transmits a PDN
connectivity request to the MME 30 (S1102).
[0372] The UE 10 may transmit the APN and the PDN type included at
the time of establishing the PDN connection, with the APN and the
PDN type included in the PDN connectivity request.
[0373] Here, the UE 10 may request the establishment of a second
PDN connection using APN5 to establish a PDN connection that is a
PDN connection for SIPTO and is allowed to have multiple
connectivity using different gateways as endpoint nodes.
[0374] Note that the PDN connectivity request transmitted by the UE
10 is transmitted via the eNB 20. Here, the eNB 20 may include
identification information on a neighboring gateway managed by the
eNB 20, such as the LGW 40, in the PDN connectivity request to be
transmitted to the MME 30. The eNB 20 may include the LHN ID
indicating the network of the LGW 40, in the PDN connectivity
request to be transmitted to the MME 30.
[0375] Here, when the eNB 20 does not manage the LGW 40, the eNB 20
does not need to include the identification information on the
neighboring gateway. When the eNB 20 does not manage the LGW 40,
the eNB 20 does not need to include the LHN ID indicating the
network of the LGW 40, in the PDN connectivity request.
[0376] The eNB 20 may notify the MME 30 of such information in
advance, instead of using the PDN connectivity request.
[0377] For example, the eNB 20 may notify the MME 30 of the LHN ID,
with the LHN ID included in an initial UE message or an uplink NAS
transport message, separate from the PDN CONNECTIVITY REQUEST
message. The eNB 20 may notify the MME 30 of the information
identifying the neighboring gateway, such as the LGW address of the
LGW 40, with the information included in an initial UE message or
an uplink NAS transport message, separate from the PDN CONNECTIVITY
REQUEST message.
[0378] The MME 30 receives the PDN connectivity request from the UE
10 or the eNB 20. The MME 30 may perform GW selection for
establishing the PDN connection in accordance with the APN included
in the PDN connectivity request. The MME 30 may detect the
establishment of the PDN connection in accordance with permission
information or capability information on the UE 10.
[0379] The MME 30 selects a gateway device in the neighbor eNB 20,
such as the LGW 40. Note that the MME 30 may select a gateway
device in the neighbor eNB 20, such as the LGW 40, instead of the
PGW 60, when SIPTO is allowed for APN5. Further, when having
received an APN allowed to establish a PDN connection for SIPTO and
allowed to have multiple connectivity using different gateways as
endpoint nodes, such as APN5, the MME 30 may select multiple
gateways such as the PGW 60 included in the core network 7 and the
LGW 40 included in the access network 9.
[0380] The MME 30 may query the HSS 70 to select the gateway. The
MME 30 may transmit the APN to the HSS 70 and receive the
identification information on the PGW 60.
[0381] Note that the MME 30 may select a gateway in the neighbor
eNB 20 to establish a PDN connection. The MME 30 may select a
gateway in the neighbor eNB 20 using the LGW address of the LGW 40
notified by the eNB 20. The MME 30 may select a gateway in the
neighbor eNB 20 using the LHN ID of the LGW 40 notified by the eNB
20.
[0382] Here, the MME 30 selects the LGW 40, which is a gateway in
the neighbor eNB 20, and the PGW 60 as a gateway in the core
network 7.
[0383] Then, the MME 30 performs a create session procedure with
the selected gateway. Note that when having selected multiple
gateways for the establishment of a single PDN connection, the MME
30 may perform the create session procedure for each of the
selected gateways.
[0384] In other words, the MME 30 may perform multiple create
session procedures. In this way, the MME 30 may establish multiple
bearers using different gateways, for the single PDN
connection.
[0385] Specifically, the MME 30 may perform the create session
procedure with the LGW 40 (S1108) and perform the create session
procedure with the PGW 60 (S1106). Note that either of the session
procedures may be performed first. Furthermore, the MME 30 may
initiate the second session procedure after the completion of the
first session procedure or may initiate the second session
procedure without waiting for the completion of the first session
establishment procedure.
[0386] Note that the same procedure as that described with
reference to FIG. 10A can be used for the create session procedure
between the MME 30 and the PGW 60 (S1106), and therefore the
detailed description thereof is omitted. The same procedure as that
described with reference to FIG. 10B or FIG. 10C can be used for
the create session procedure between the MME 30 and the LGW 40
(S1108), and therefore the detailed description thereof is
omitted.
[0387] Subsequently, the MME 30 transmits a bearer setup
request/PDN connectivity accept to the eNB 20B (S1112). Note that
the MME 30 makes a notification of information on the first EPS
bearer and the second EPS bearer in a PDN connection that is to be
newly established, with the information included in the bearer
setup request/PDN connectivity accept.
[0388] The bearer generation request may include an EPS bearer QoS,
a PDN connectivity accept, an SGW TEID (U-plane), and an SGW
address (U-plane).
[0389] When a PDN connection using an LGW as an endpoint node (PDN
connection for SIPTO@LN) is established, the initial context
request may include an SIPTO correlation ID.
[0390] Here, the EPS bearer QoS, the EPS bearer ID, the SGW TEID
(U-plane), and the SGW address (U-plane) included in the initial
context setup request may be included for each EPS bearer.
Specifically, the initial context setup request may include the EPS
bearer QoS, the EPS bearer ID, the SGW TEID (U-plane), and the SGW
address (U-plane) of the first EPS bearer, the EPS bearer QoS, the
EPS bearer ID, the SGW TEID (U-plane), and the SGW address
(U-plane) of the second EPS bearer, the EPS bearer QoS, the EPS
bearer ID, the SGW TEID (U-plane), and the SGW address (U-plane) of
the second EPS bearer, and the EPS bearer QoS, the EPS bearer ID,
the SGW TEID (U-plane), and the SGW address (U-plane) of the second
EPS bearer.
[0391] The PDN connectivity accept may include an APN, a PDN type,
a PDN address, and an EPS bearer ID.
[0392] The eNB 20 receives the bearer setup request/PDN
connectivity accept. The eNB 20B determines establishment of a
radio bearer with the UE 10 in accordance with the EPS bearer ID
and the EPS bearer QoS included in the bearer setup request. Here,
the eNB 20A may determine the E-RAB ID in accordance with the EPS
bearer ID and the EPS bearer QoS.
[0393] Note that when managing the LGW 40 as a neighboring gateway,
the eNB 20 may establish a radio bearer in accordance with the
information elements associated with the LGW 40. Here, the eNB 20
may establish a radio bearer with the UE 10 in accordance with the
EPS bearer ID including the correlation ID and the EPS bearer
QoS.
[0394] The eNB 20 may manage an SGW TEID (U-plane) and an SGW
address (U-plane) included in a modify bearer request.
[0395] The above procedure allows the eNB 20 to manage an MME UE S1
AP ID, a GUMMEI, a global eNB ID, a tracking area ID, an E-RAB ID,
and a UE ID, as information elements managed for each PDN
connection in the eNB communication path context 242 illustrated in
FIG. 5. The eNB 20 can manage an EPS bearer ID, an EPS bearer QoS,
and a transport address as information elements managed for each
EPS bearer in the PDN connection.
[0396] In this way, the eNB 20 may establish a communication path
to the SGW 50 and a communication path to the LGW 40. Note that the
communication path to the LGW 40 may be established in response to
receipt of a correlation ID from the MME 30.
[0397] These communication paths can be selected by the eNB 20 and
can be selected, for example, at the time of transferring data
received from the UE 10. A communication path selection means of
the eNB 20 may be performed in accordance with eNB configuration
information. The configuration information may be information
obtained from the MME 30. More specifically, the MME 30 may
transmit information indicating selection of a communication path
for offloading, to the eNB 20. The MME 30 may make this
notification at the time of establishing the PDN connection, for
example, by transmitting the information, with the information
included in a Create Session response message.
[0398] Alternatively, the MME 30 may make the notification at any
timing after establishment of the PDN connection.
[0399] More specifically, the information indicating that the MME
30 selects a communication path for offloading may be a correlation
ID.
[0400] For example, when having obtained the correlation ID from
the MME 30, the eNB 20 may select the communication path to the LGW
40. When having not received the correlation ID, the eNB 20 may
select the communication path to the SGW 50 connecting to the PGW
60.
[0401] Alternatively, the information may be a correlation ID for
SIPTO or a special correlation ID for CSIPTO different from the
correlation ID for SIPTO.
[0402] Alternatively, the information may be different
identification information indicating selection of an offload
communication path.
[0403] Note that these communication paths may be bearers connected
to the devices, such as the LGW 40 and the SGW 50.
[0404] Subsequently, the eNB 20B transmits an RRC connection
reconfiguration to the UE 10 (S1114). Note that the eNB 20B
includes a PDN connectivity accept in the RRC connection
reconfiguration destined for the UE 10. Here, the eNB 20B may
include the PDN connectivity accept in a notification different
from the RRC connection reconfiguration notification destined for
the UE 10. In other words, the eNB 20 makes a notification of
information on the newly established PDN connection by transferring
the PDN connectivity accept.
[0405] The UE 10 receives the RRC connection reconfiguration and
the PDN connectivity accept from the eNB 20. Here, the UE 10
detects the information on the newly established PDN connection
included in the PDN connectivity accept from the eNB 20B, and
manages the information.
[0406] Note that the information on the PDN connection may be an
APN, a PDN type, a PDN address, an EPS bearer ID, and an EPS bearer
QoS.
[0407] Subsequently, the UE 10 performs an IP address obtaining
process (S1115). Here, the UE 10 may obtain, as the IP address, the
PDN address included in the PDN connectivity accept. Here, the UE
10 may obtain multiple IP addresses. Note that when multiple PDN
addresses are included in the ATTACH ACCEPT message, multiple IP
addresses may be stored for the PDN connection.
[0408] When the PDN address included in the PDN connectivity accept
includes information indicating obtainment of an IP address in
accordance with DHCP, the UE 10 may obtain the IP address from the
DHCP server. Here, the DHCP server may be an external server
different from the core network 7, or may be the PGW 60.
[0409] Note that the UE 10 may obtain multiple IP addresses for the
PDN connection from the DHCP server and store the IP addresses.
[0410] When the PDN address included in the PDN connectivity accept
includes information indicating obtainment of an IP address through
stateless address auto-configuration, the UE 10 may receive a
router advertisement (RA) from a router device and obtain the IP
address in accordance with the router advertisement. Here, the
router device may be an external server different from the core
network 7, or may be the PGW 60.
[0411] Note that the UE 10 may obtain multiple IP addresses for the
PDN connection from the router device and store the IP
addresses.
[0412] When the UE 10 stores multiple IP addresses for a single PDN
connection, the UE 10 may select and use these IP addresses at the
time of transmitting user data.
[0413] An IP address selection means may be performed in accordance
with configuration information of the UE 10. The configuration
information may be information obtained from the MME 30 or the eNB
20. More specifically, the MME 30 or the eNB 20 may transmit
information indicating selection of a communication path for
offloading, to the UE 10. The MME 30 may make this notification at
the time of establishing the PDN connection, for example, by
transmitting the information, with the information included in an
ATTACH ACCEPT message.
[0414] Alternatively, the MME 30 may make the notification at any
timing after establishment of the PDN connection.
[0415] More specifically, the information indicating that the MME
30 selects a communication path for offloading may be priority
information configured for each IP address.
[0416] Alternatively, the information may be a correlation ID for
SIPTO or a special correlation ID for CSIPTO different from the
correlation ID for SIPTO, or the like.
[0417] Alternatively, the information may be different
identification information indicating selection of an offload
communication path.
[0418] The UE 10 may select an IP address to be used for
transmission of user data, in accordance with such information.
[0419] The UE 10 obtains the IP address by the above method and
manages the IP address as the second PDN connection therein. The UE
10 can manage information on the PDN connection in the UE
communication path context 142 illustrated in FIG. 3 and can
transmit uplink data in the second PDN connection.
[0420] The UE 10 transmits an RRC connection reconfiguration
complete to the eNB 20B (S1116). The eNB 20B receives the RRC
connection reconfiguration complete as a response to the RRC
connection reconfiguration (S1114) and transmits a bearer setup
response to the MME 30 (S1118).
[0421] The UE 10 transmits direct transfer to the eNB 20B (S1120).
Here, a PDN connectivity complete may be included in the direct
transfer. An EPS bearer ID may be included in the PDN connectivity
complete.
[0422] The eNB 20B receives the direct transfer from the UE 10 and
transfers the PDN connectivity complete included in the direct
transfer to the MME 30 (S1122). The MME 30 that has received the
bearer setup response and the PDN connectivity complete transmits a
modify bearer request to the SGW 50 (S1124).
[0423] The SGW 50 transmits the modify bearer request to the PGW 60
in response to receipt of the modify bearer request (S1126).
[0424] The PGW 60 receives the modify bearer request and transmits,
as a response to the modify bearer request, a modify bearer
response to the SGW 50 (S1128).
[0425] The SGW 50 transmits, as a response to the modify bearer
request transmitted by the MME 30, a modify bearer response to the
MME 30 (S1130).
[0426] The above procedure allows the UE 10 to establish a PDN
connection between the UE 10 and each of the PGW 60 and the LGW 40.
In other words, the UE 10 can manage an APN, an allocated PDN type,
an IP address, a default bearer, an EPS bearer ID, and an EPS
bearer QoS in the UE communication path context 142 illustrated in
FIG. 3, as information on the second PDN connection.
[0427] The eNB 20 can manage an MME UE S1 AP ID, a GUMMEI, a global
eNB ID, a tracking area ID, an E-RAB ID, a UE ID, and a transport
address in the eNB communication path context 242 illustrated in
FIG. 5, as information on the second PDN connection. The eNB 20 can
manage an EPS bearer ID, an ESP bearer QoS, and a transport address
as information elements managed for the EPS bearer in the PDN
connection. Note that the transport address may be the IP address
of the SGW, the TEID of the SGW, or the IP address or the
correlation ID of the LGW.
[0428] Furthermore, the MME 30 can manage an APN, a PDN type, an IP
address, permission (information) of SIPTO, a PDN GW address
(C-plane), a PDN GW TEID (C-plane), and a default bearer in the MME
communication path context 342 illustrated in FIG. 7, as
information on the PDN connection.
[0429] The MME 30 can manage an EPS bearer ID, an SGW IP address
(S1-u), an SGW TEID (S1-u), a PGW IP address (U-plane), a PGW TEID
(U-plane), and an EPS bearer QoS as information elements managed
for each EPS bearer in the PDN connection.
[0430] Through the above, the UE 10 can transmit and receive data
via the PGW 60 or LGW 40 using the second PDN connection. In other
words, the UE 10, the eNB 20, and/or the SGW 50 can establish a PDN
connection constituted of a communication path to the LGW 40 and a
communication path to the PGW 60.
[0431] Note that for the communication of the UE 10 using the PDN
connection, the communication path connected to the LGW 40 can be
preferentially selected in accordance with the configuration
information on the UE 10, the eNB 20, and/or the SGW 50. Hence, the
communication of the UE 10 using the PDN connection can be
performed using the communication path connected to the LGW 40, in
accordance with the configuration information on the UE 10, the eNB
20, and/or the SGW 50. Note that when having performed a PDN
connectivity procedure using APN5 to establish a PDN connection,
the UE 10 manages APN5 as the APN, PDN type 1 as the allocated PDN
type, IP address 1 and IP address 2 as the IP address, and EPS
bearer ID 1 as the default bearer, and manages EPS bearer ID 5 as
the EPS bearer ID and EPS bearer QoS 1 as the EPS bearer QoS among
information elements managed for each EPS bearer in the PDN
connection, as illustrated in the UE communication path context 142
in FIG. 3.
[0432] Note that when multiple IP addresses are not obtained at the
time of establishing a PDN connection, the UE 10 may store IP
address 1 only.
[0433] In this case, as illustrated in the eNB communication path
context 242 in FIG. 5, the eNB 20 manages MME UE S1 AP ID 1 as the
MME UE S1 AP ID, GUMMEI1 as the GUMMEI, global eNB ID 1, tracking
area ID 1 as the tracking area ID, E-RAB ID 1 as the E-RAB ID, and
UE ID 1 as the UE ID, manages EPS bearer ID 1 as the EPS bearer ID,
EPS bearer QoS 1 as the EPS bearer QoS, and transport address 1
(such as a PGW address, a PGW TEID, an LGW address, or a
correlation ID) as the transport address among information elements
managed for the first EPS bearer, and manages EPS bearer ID 2 as
the EPS bearer ID, EPS bearer QoS 2 as the EPS bearer QoS, and
transport address 2 as the transport address (such as a PGW
address, a PGW TEID, an LGW address, or a correlation ID) among
information elements managed for the second EPS bearer.
[0434] As illustrated in the MME communication path context 342 in
FIG. 7, the MME 30 manages APN 5 as the APN, PDN type 1 as the PDN
type, IP address 1 and IP address 2 as the IP address, permission
of CSIPTO as the permission of SIPTO, LHN ID 1 as the LHN ID, LGW
address 1 and PGW address 1 as PDN GW address (C-plane),
correlation ID 1 and PGW TEID 1 as the PDN GW TEID (C-plane), and
EPS bearer ID 1 as the default bearer, manages EPS bearer ID 5 as
the EPS bearer ID, LGW IP address 1 as the PGW IP address
(U-plane), correlation ID 1 as the PGW TEID (U-plane), and EPS
bearer QoS 1 as the EPS bearer QoS among the information elements
managed for the first EPS bearer, and manages EPS bearer ID 7 as
the EPS bearer ID, SGW IP address 1 as the SGW IP address (S1-u),
SGW TEID 1 as the SGW TEID (S1-u), PGW IP address 1 as the PGW IP
address (U-plane), PGW TEID 1 as the PGW TEID (U-plane), and EPS
bearer QoS 2 as the EPS bearer QoS among information elements
managed for the second EPS bearer.
1.3.3 Service Request Procedure
[0435] Next, the UE 10 performs a service request procedure to
resume data transmission and reception using a PDN connection
established by the UE 10 and each of the PGW 60 and the LGW 40 in
the attach procedure or the PDN connectivity procedure. Here, when
having completed data transmission and reception in the PDN
connection, the UE 10 makes a transition from a connected state
(active state) to an idle state. When performing the service
request procedure, the UE 10 can make a transition from the idle
state to the connected state and initiate data transmission and
reception using the PDN connection. Note that the idle state may be
a state in which the radio bearer and/or radio resource between the
UE 10 and the eNB 20 has been released.
[0436] Note that in the service request procedure described in the
present embodiment, the UE 10, the eNB 20, the SGW 50, and/or the
MME 30 can select a bearer that delivers user data from among the
multiple bearers constituting the PDN connection. In other words,
the UE 10, the eNB 20, the SGW 50, and/or the MME 30 can change the
bearer that delivers user data. The service request procedure in
the UE 10 will be described with reference to FIG. 12.
[0437] First, the UE 10 transmits a service request to the eNB 20
(S1202). Here, the UE 10 may transmit the service request to the
eNB 20, with the service request included in the RRC message. Here,
the service request may be a tracking area update request.
[0438] Subsequently, the eNB 20 transfers the service request to
the MME 30 (S1204). Here, the eNB 20 may transmit the service
request to the MME 30, with the service request included in the
initial UE message. The initial UE message may include a SIPTO LGW
transport address and the LHN ID managed by the eNB 20. Here, when
the eNB 20 does not manage the LGW 40, the initial UE message need
not include the SIPTO LGW transport address (the LGW address of the
LGW 40) or the LHN ID. Here, the service request may be a tracking
area update request.
[0439] The MME 30 receives the service request or the tracking area
update request from the UE 10 or the eNB 20. Here, the MME 30
performs a PDN connection change detection process (S1206). Here,
the MME 30 determines whether to change the bearer used for PDN
connection communication, in accordance with the service request
transmitted from the UE 10. Specifically, the MME 30 determines
whether to change the communication path used for the PDN
connection from the first EPS bearer to the second EPS bearer.
[0440] Note that the first bearer may be a bearer for offload
communication established with the LGW 40, and the second bearer
may be a bearer established with the PGW 60.
[0441] More specifically, the first bearer may be a bearer
established by the SGW 50 and the LGW 40, and the second bearer may
be a bearer established by the SGW 50 and the PGW 60. Other bearers
constituting other PDN connections and information on the bearers
need not be changed.
[0442] Alternatively, the first bearer may be a bearer established
by the eNB 20 and the LGW 40, and the second bearer may be a bearer
established by the SGW 50 and the PGW 60. Other bearers
constituting other PDN connections and information on the bearers
need not be changed.
[0443] As described above, the bearer that is changed may be one or
some of the bearers configured for data transmission and reception
through communication using the PDN connection.
[0444] Furthermore, bearers which can be changed may be established
by a separate create session procedure, and the bearers may be
managed as different sessions. Hence, it can be said that the
bearer change performed through this procedure is the same as
changing one or some of the sessions constituting the PDN
connection.
[0445] Here, the MME 30 may determine whether to change the bearer
by detecting that the first EPS bearer in the PDN connection is
effective. Here, the first EPS bearer in the effective PDN
connection may be detected on the basis of the UE 10 not having
changed the base station device to which the UE 10 is connected, or
the LGW 40 being the optimal gateway device for the offloading even
when the UE 10 has changed the base station device to which the UE
10 is connected.
[0446] More specifically, whether the first EPS bearer in the PDN
connection is effective may be detected in accordance with the LHN
ID or the SIPTO LGW transport address (the LGW address of the LGW
40) included in the initial UE message transmitted from the eNB
20.
[0447] The MME 30 may detect the effectiveness by the LHN ID
managed in the MME communication path context 342 managed by the
MME 30, or by the LGW IP address in the PGW IP address
(U-plane).
[0448] The MME 30 may detect that the first EPS bearer in the PDN
connection is effective, by comparing the LHN ID or the SIPTO LGW
transport address (the LGW address of the LGW 40) included in the
initial UE message transmitted from the eNB 20 and the LHN ID or
the LGW IP address in the PGW IP address (U-plane) managed in the
MME communication path context 342.
[0449] Here, when not detecting that the first EPS bearer in the
PDN connection is effective, the MME 30 may determine to change the
first EPS bearer to the second EPS bearer in the PDN
connection.
[0450] For example, the MME 30 may detect that the first EPS bearer
in the PDN connection is not effective, for example, when the MME
30 detects that the LGW 40 is not the optimal gateway for
offloading, when the MME 30 detects an optimal gateway device
different from the LGW 40, or on the basis of a factor that the
base station device to which the UE 10 connects is not allowed to
establish a PDN connection for SIPTO using the LGW as an endpoint
node.
[0451] On the other hand, when the APN managed in the MME
communication path context 342 is APN5 and the permission of SIPTO
includes information indicating permission of CSIPTO, the MME 30
may determine to change the first EPS bearer to the second EPS
bearer in the PDN connection. As described above, the EPS bearer
may be changed on the basis of the fact that the PDN connection is
established using APN5. Here, changing the first EPS bearer to the
second EPS bearer in the PDN connection may be the same as changing
the endpoint node of the gateway device from the LGW 40 (or the
communication path to the LGW 40) to the PGW 60 (or the
communication path to the PGW 60).
[0452] Note that the change procedure for changing the first EPS
bearer to the second EPS bearer in the PDN connection may be
performed in accordance with determination made by the operator,
such as the policy of the network operator, regardless of which APN
is used to establish the PDN connection.
1.3.3.1 Continuation of Service Request Procedure
[0453] A description will be given of a case in which the MME 30
detects that the first EPS bearer in the PDN connection is
effective in the modify bearer detection process (S1206) and
determines to continue the service request procedure. The
subsequent steps of the service request procedure will be described
with reference to FIG. 13.
[0454] FIG. 13 illustrates the procedure for the UE 10 to continue
the service request procedure when the UE 10 does not move from the
eNB 20A for which the attach procedure or the PDN connectivity
procedure has been performed. However, even when moving to another
eNB 20, the UE 10 may initiate the service request procedure as
long as the first EPS bearer is effective.
[0455] The MME 30 that has detected that the first EPS bearer in
the PDN connection is effective transmits an initial context setup
request to the eNB 20 (S1302). The initial context setup request
may include the SGW address, the SGW TEID, the EPS bearer QoS, and
the SIPTO correlation ID. Here, the MME 30 may transmit
identification information for selecting a bearer and/or
identification information requesting to change the bearer to be
selected with the identification information included in the
initial context request. Specifically, the identification
information may be information indicating not changing from the
first EPS bearer. The identification information may be information
identifying the first EPS bearer. The identification information
may be a group of information elements associated with the first
EPS bearer. For example, the group of information elements may
include an EPS bearer ID, an SGW IP address, an SGW TEID, a PGW IP
address, a PGW TEID (SIPTO correlation ID), an EPS bearer QoS, and
an IP address.
[0456] The eNB 20 receives the initial context setup request. The
eNB 20 may select a bearer in accordance with the received
identification information. Note that the eNB 20 may manage the SGW
address, the SGW TEID, the EPS bearer QoS, and the SIPTO
correlation ID included in the initial context setup request.
[0457] Note that the eNB 20 may determine to use the EPS bearer
configured by the first EPS bearer, in accordance with the
information indicating not changing from the first EPS bearer, the
information indicating the first EPS bearer, or the information
associated with the first EPS bearer, included in the initial
context setup request.
[0458] Subsequently, the eNB 20 establishes a radio bearer with the
UE 10 (S1304). The eNB 20 may establish a radio bearer in
accordance with the EPS bearer QoS. Furthermore, the eNB 20 may
generate a radio parameter for establishing the radio bearer in
accordance with the EPS bearer QoS.
[0459] Here, the eNB 20 may transmit, to the UE 10, identification
information for selecting an IP address and/or identification
information requesting to change the IP address to be selected.
Specifically, the identification information may be information
indicating not changing from the first IP address. The
identification information may be information identifying IP
address 1. The identification information may be a group of
information elements associated with IP address 1. For example, the
group of information elements may include an EPS bearer ID, an SGW
IP address, an SGW TEID, a PGW IP address, a PGW TEID (SIPTO
correlation ID), an EPS bearer QoS, and IP address 1. In this case,
the MME 30 may transmit such identification information to the UE
10 with the identification information included in control
information to be transmitted to the UE 10 to establish the radio
link.
[0460] The UE 10 may receive the identification information and
select an IP address in accordance with the received identification
information.
[0461] The UE 10 that has established the radio bearer transmits
uplink data to the eNB 20. Note that the eNB 20 transfers the
uplink data from the UE 10 to the LGW 40. The LGW 40 transfers the
uplink data from the eNB 20 to the PDN 90.
[0462] The eNB 20 that has established the radio bearer transmits
the initial context setup complete to the MME 30 (S1306).
[0463] The eNB 20 may transmit identification information for
selecting a bearer and/or identification information requesting to
change the bearer to be selected with the identification
information included in the initial context setup complete.
Specifically, the identification information may be information
indicating not changing from the first EPS bearer. The
identification information may be information identifying the first
EPS bearer. The identification information may be a group of
information elements associated with the first EPS bearer. For
example, the group of information elements may include an EPS
bearer ID, an SGW IP address, an SGW TEID, a PGW IP address, a PGW
TEID (SIPTO correlation ID), an EPS bearer QoS, and an IP
address.
[0464] Furthermore, an eNB address, a list of accepted EPS bearers,
a list of rejected EPS bearers, and an SGW TEID may be included in
the initial context setup complete. Here, the eNB 20 may include at
least identification information identifying the PDN connection in
the list of accepted EPS bearers.
[0465] The MME 30 receives the initial context setup complete from
the eNB 20. When the list of rejected EPS bearers is included,
information on each of the corresponding PDN connections may be
deleted.
[0466] Subsequently, the MME 30 transmits a modify bearer request
(S1308).
[0467] The MME 30 may transmit identification information for
selecting a bearer and/or identification information for requesting
to change the bearer that is selected, by including the information
in the modify bearer request. Specifically, the identification
information may be information indicating not changing from the
first EPS bearer. The identification information may be information
identifying the first EPS bearer. The identification information
may be a group of information elements associated with the first
EPS bearer. For example, the group of information elements may
include an EPS bearer ID, an SGW IP address, an SGW TEID, a PGW IP
address, a PGW TEID (SIPTO correlation ID), an EPS bearer QoS, and
an IP address.
[0468] The MME 30 may also include an eNB address and an S1 TEID in
the modify bearer request. Note that the eNB address and the S1
TEID included in the modify bearer request may be information
elements by which the MME 30 is associated with the PDN
connection.
[0469] The SGW 50 receives the modify bearer request from the MME
30. The SGW 50 may select a bearer in accordance with the received
identification information. More specifically, the SGW 50 may
select a first bearer for communication using the PDN
connection.
[0470] The SGW 50 can transmit downlink data destined for the UE 10
in the PDN connection corresponding to the eNB address and the S1
TEID, on the basis of the eNB address and the S1 TEID included in
the modify bearer request.
[0471] The SGW 50 transmits, as a response to the modify bearer
request, a modify bearer response to the MME 30 (S1310).
[0472] The above-described procedure allows data to be transmitted
and received using the first EPS bearer in the PDN connection
between the UE 10 and the LGW 40.
1.3.3.2 Bearer Change in Service Request Procedure
[0473] Description will be given of a case in which the MME 30 does
not detect that the first EPS bearer in the PDN connection is
effective in the modify bearer detection process (S1206) and
determines to change the first bearer to the second bearer in the
service request procedure. The EPS modify bearer procedure using
the service request procedure will be described with reference to
FIG. 14.
[0474] FIG. 14 illustrates the EPS modify bearer procedure using
the service request procedure in which the UE 10 moves from the eNB
20 for which the UE 10 has performed the attach procedure or the
PDN connectivity procedure. However, even when moving to another
eNB 20, the UE 10 may perform the EPS bearer change using the
service request procedure as long as the first EPS bearer in the
PDN connection is not effective.
[0475] Here, changing the first bearer may be the same as changing
the first EPS bearer using the LGW 40 in the PDN connection as an
endpoint node to the second EPS bearer using the PGW 60 in the PDN
connection as an endpoint node.
[0476] Furthermore, performing the EPS modify bearer procedure in
the service request procedure allows for transmission and reception
of user data using the second EPS bearer using the PGW 60 as the
endpoint node, instead of transmission and reception of user data
using the first EPS bearer using the LGW 40 as the endpoint
node.
[0477] The MME 30 that has not detected that the first EPS bearer
in the PDN connection is effective transmits an initial context
setup request to the eNB 20 (S1402).
[0478] An SGW address, an SGW TEID, and an EPS bearer QoS may be
included in the initial context setup request. Here, the MME 30 may
transmit identification information for selecting a bearer and/or
identification information requesting to change the bearer that is
to be selected with the identification information included in the
initial context request. Specifically, the identification
information may be information indicating a change to the second
EPS bearer. The identification information may be information
identifying the second EPS bearer. The identification information
may be a group of information elements associated with the second
EPS bearer. For example, the group of information elements may
include an EPS bearer ID, an SGW IP address, an SGW TEID, a PGW IP
address, a PGW TEID (SIPTO correlation ID), an EPS bearer QoS, and
an IP address.
[0479] The eNB 20 receives the initial context setup request. The
eNB 20 may select a bearer in accordance with the received
identification information. Note that the eNB 20 may manage the SGW
address, the SGW TEID, and the EPS bearer QoS included in the
initial context setup request.
[0480] Note that the eNB 20 may determine to use the EPS bearer
configured by the second EPS bearer, in accordance with the
information indicating changing from the first EPS bearer, the
information indicating the second EPS bearer, or the information
associated with the second EPS bearer included in the initial
context setup request.
[0481] Subsequently, the eNB 20 establishes a radio bearer with the
UE 10 (S1404). The eNB 20 may establish a radio bearer in
accordance with the EPS bearer QoS. Furthermore, the eNB 20 may
generate a radio parameter for establishing the radio bearer in
accordance with the EPS bearer QoS.
[0482] Here, the eNB 20 may transmit, to the UE 10, identification
information for selecting an IP address and/or identification
information requesting to change the IP address that is selected.
Specifically, the identification information may be information
indicating changing from the first IP address. The identification
information may be information identifying IP address 2. The
identification information may be a group of information elements
associated with IP address 2. For example, the group of information
elements may include an EPS bearer ID, an SGW IP address, an SGW
TEID, a PGW IP address, a PGW TEID (SIPTO correlation ID), an EPS
bearer QoS, and IP address 2. In this case, the MME 30 may transmit
such identification information to the UE 10 with the
identification information included in control information that is
transmitted to the UE 10 to establish the radio link.
[0483] The UE 10 may receive the identification information and
select an IP address in accordance with the received identification
information.
[0484] Here, the eNB 20 may notify the UE 10 of the IP address
included in the initial context setup request.
[0485] On the other hand, for the establishment of the radio bearer
with the eNB 20, the UE 10 may perform an IP address change process
(S1405). Here, upon notification of the IP address from the eNB 20,
the UE 10 may change the IP address in the information elements
managed for the PDN connection. The UE 10 may perform transmission
and reception of data using the notified IP address.
[0486] The UE 10 that has established the radio bearer transmits
uplink data to the eNB 20. Note that the eNB 20 transfers the
uplink data from the UE 10 to the LGW 40. The LGW 40 transfers the
uplink data from the eNB 20 to the PDN 90.
[0487] The eNB 20 that has established the radio bearer transmits
the initial context setup complete to the MME 30 (S1406).
[0488] The eNB 20 may transmit identification information for
selecting a bearer and/or identification information requesting to
change the bearer that is selected with the identification
information included in the initial context setup complete.
Specifically, the identification information may be information
indicating changing from the first EPS bearer. The identification
information may be information identifying the second EPS bearer.
The identification information may be a group of information
elements associated with the second EPS bearer. For example, the
group of information elements may include an EPS bearer ID, an SGW
IP address, an SGW TEID, a PGW IP address, a PGW TEID (SIPTO
correlation ID), an EPS bearer QoS, and an IP address.
[0489] Furthermore, an eNB address, a list of accepted EPS bearers,
a list of rejected EPS bearers, and an SGW TEID may be included in
the initial context setup complete. Here, the eNB 20 may include at
least identification information identifying the PDN connection in
the list of accepted EPS bearers.
[0490] The MME 30 receives the initial context setup complete from
the eNB 20. When the list of rejected EPS bearers is included,
information on each of the corresponding PDN connections may be
deleted.
[0491] Subsequently, the MME 30 transmits a modify bearer request
(S1408).
[0492] The MME 30 may transmit identification information for
selecting a bearer and/or identification information requesting to
change the bearer that is selected with the identification
information included in the modify bearer request. Specifically,
the identification information may be information indicating a
change from the first EPS bearer. The identification information
may be information identifying the second EPS bearer. The
identification information may be a group of information elements
associated with the second EPS bearer. For example, the group of
information elements may include an EPS bearer ID, an SGW IP
address, an SGW TEID, a PGW IP address, a PGW TEID (SIPTO
correlation ID), an EPS bearer QoS, and an IP address.
[0493] The MME 30 may also include an eNB address and an S1 TEID in
the modify bearer request. Note that the eNB address and the S1
TEID included in the modify bearer request may be information
elements by which the MME 30 is associated with the PDN
connection.
[0494] The SGW 50 receives the modify bearer request from the MME
30. The SGW 50 may select a bearer in accordance with the received
identification information. More specifically, the SGW 50 may
select a second bearer for communication using the PDN
connection.
[0495] The SGW 50 can transmit downlink data destined for the UE 10
in the PDN connection corresponding to the eNB address and the S1
TEID, on the basis of the eNB address and the S1 TEID included in
the modify bearer request.
[0496] The SGW 50 transmits, as a response to the modify bearer
request, a modify bearer response to the MME 30 (S1410).
[0497] The above procedure allows data to be transmitted and
received using the second EPS bearer in the PDN connection between
the UE 10 and the LGW 40.
1.3.3.3 Bearer Change in Tracking Area Update Procedure
[0498] The service request transmitted by the UE 10 (S1202) may be
a tracking area update request, and the service request transmitted
by the eNB 20 may be a tracking area update request.
[0499] The MME 30 that has received the tracking area update
request may perform the PDN connection change process (S1206). Note
that a description of the PDN connection change process has already
been given, and hence a detailed description thereof is
omitted.
[0500] The MME 30 may transmit, to the SGW 50, identification
information for selecting a bearer and/or identification
information requesting to change the bearer to be selected, in
response to receipt of the tracking area update request.
Specifically, the identification information may be information
indicating not changing from the first EPS bearer. The
identification information may be information identifying the first
EPS bearer. The identification information may be a group of
information elements associated with the first EPS bearer. For
example, the group of information elements may include an EPS
bearer ID, an SGW IP address, an SGW TEID, a PGW IP address, a PGW
TEID (SIPTO correlation ID), an EPS bearer QoS, and an IP
address.
[0501] More specifically, the MME 30 may transmit the
identification information, with the identification information
included in a Create Session request or a modify bearer request
(S1508).
[0502] The SGW 50 receives the identification information from the
MME 30. The SGW 50 may select a bearer in accordance with the
received identification information. More specifically, the SGW 50
may select a first bearer for communication using the PDN
connection.
[0503] The SGW 50 receives the modify bearer request or the Create
Session request from the MME 30 and transmits the modify bearer
response or the Create Session response to the MME 30 (S1510).
[0504] The MME 30 may also transmit, to the eNB 20, identification
information for selecting a bearer and/or identification
information requesting to change the bearer that is selected.
Specifically, the identification information may be information
indicating not changing from the first EPS bearer. The
identification information may be information identifying the first
EPS bearer. The identification information may be a group of
information elements associated with the first EPS bearer. For
example, the group of information elements may include an EPS
bearer ID, an SGW IP address, an SGW TEID, a PGW IP address, a PGW
TEID (SIPTO correlation ID), an EPS bearer QoS, and an IP
address.
[0505] The eNB 20 receives the initial context setup request. The
eNB 20 may select a bearer in accordance with the received
identification information.
[0506] The eNB 20 may receive the identification information and
select a bearer in accordance with the received identification
information.
[0507] Subsequently, the MME 30 transmits a tracking area accept to
the UE 10 (S1506).
[0508] Here, the information elements that the MME 30 includes in
the tracking area accept may vary depending on whether the first
EPS bearer is used or the second EPS bearer is used in the PDN
connection.
[0509] First, a case of using the first EPS bearer will be
described. Note that a description on determination to use the
first EPS bearer in the PDN connection change detection process
(S1206) has already been given, and hence a detailed description
thereof is omitted.
[0510] The MME 30 may transmit identification information for
selecting an IP address and/or identification information
requesting to change the IP address that is selected. Specifically,
the identification information may be information indicating not
changing from the first IP address. The identification information
may be information identifying IP address 1. The identification
information may be a group of information elements associated with
IP address 1. For example, the group of information elements may
include an EPS bearer ID, an SGW IP address, an SGW TEID, a PGW IP
address, a PGW TEID (SIPTO correlation ID), an EPS bearer QoS, and
IP address 1. In this case, the MME 30 may transmit such
identification information to the UE 10 with the information
included in the tracking area accept.
[0511] The UE 10 may receive the identification information and
select an IP address in accordance with the received identification
information.
[0512] The information indicating not changing from the first EPS
bearer may be included. The MME 30 may include information
indicating the first EPS bearer in the tracking area accept. The
MME 30 may include information elements associated with the first
EPS bearer in the tracking area accept. For example, the EPS bearer
ID or the IP address may be included.
[0513] The above procedure allows for a change to the first EPS
bearer between the UE 10 and the LGW 40 in the PDN connection.
[0514] Next, a case of using the second EPS bearer will be
described. Note that a description on determination to use the
second EPS bearer in the PDN connection change detection process
(S1206) has already been given of, and hence a detailed description
thereof is omitted.
[0515] The MME 30 may transmit, to the SGW 50, identification
information for selecting a bearer and/or identification
information requesting to change the bearer that is selected, in
response to receipt of the tracking area update request.
Specifically, the identification information may be information
indicating changing from the first EPS bearer. The identification
information may be information identifying the second EPS bearer.
The identification information may be a group of information
elements associated with the second EPS bearer. For example, the
group of information elements may include an EPS bearer ID, an SGW
IP address, an SGW TEID, a PGW IP address, a PGW TEID (SIPTO
correlation ID), an EPS bearer QoS, and an IP address.
[0516] More specifically, the MME 30 may transmit the
identification information, with the identification information
included in a Create Session request or a modify bearer request
(S1508).
[0517] The SGW 50 receives the identification information from the
MME 30. The SGW 50 may select a bearer in accordance with the
received identification information. More specifically, the SGW 50
may select a first bearer for communication using the PDN
connection.
[0518] The SGW 50 receives the modify bearer request or the Create
Session request from the MME 30 and transmits the modify bearer
response or the Create Session response to the MME 30 (S1510).
[0519] The MME 30 may also transmit, to the eNB 20, identification
information for selecting a bearer and/or identification
information requesting to change the bearer that is selected.
Specifically, the identification information may be information
indicating changing from the first EPS bearer. The identification
information may be information identifying the second EPS bearer.
The identification information may be a group of information
elements associated with the second EPS bearer. For example, the
group of information elements may include an EPS bearer ID, an SGW
IP address, an SGW TEID, a PGW IP address, a PGW TEID (SIPTO
correlation ID), an EPS bearer QoS, and an IP address.
[0520] The eNB 20 receives the initial context setup request. The
eNB 20 may select a bearer in accordance with the received
identification information.
[0521] The eNB 20 may receive the identification information and
select a bearer in accordance with the received identification
information.
[0522] Subsequently, the MME 30 transmits the tracking area accept
to the UE 10 (S1506).
[0523] In this transmission, the MME 30 may transmit identification
information for selecting an IP address and/or identification
information requesting to change the IP address that is selected.
Specifically, the identification information may be information
indicating changing from the first IP address. The identification
information may be information identifying IP address 2. The
identification information may be a group of information elements
associated with IP address 2. For example, the group of information
elements may include an EPS bearer ID, an SGW IP address, an SGW
TEID, a PGW IP address, a PGW TEID (SIPTO correlation ID), an EPS
bearer QoS, and IP address 2.
[0524] The eNB 20 receives the initial context setup request. The
eNB 20 may select a bearer in accordance with the received
identification information. In this case, the MME 30 may transmit
such identification information to the UE 10 with the
identification information included in the tracking area
accept.
[0525] The UE 10 may receive the identification information and
select an IP address in accordance with the received identification
information. Note that the MME 30 may transmit such identification
information with the information included in the tracking area
accept.
[0526] The above procedure allows for a change to the second EPS
bearer in the PDN connection between the UE 10 and the PGW 60.
Here, a change to the second bearer may be the same as a change
from the first EPS bearer using the LGW 40 in the PDN connection as
an endpoint node to the second EPS bearer using the PGW 60 in the
PDN connection as an endpoint node.
[0527] Furthermore, performing the EPS modify bearer procedure in
the service request procedure allows for transmission and reception
of user data using the second EPS bearer using the PGW 60 as the
endpoint node in the established PDN connection, instead of
transmission and reception of user data using the first EPS bearer
using the LGW 40 as the endpoint node. The above-described
procedures according to the present embodiment allows the UE 10,
the MME 30, the eNB 20, the SGW 30, and/or the gateway devices,
such as the LGW 40 and the PGW 60, to change one or some of
communication paths and/or one or some of sessions to be used for
communication in the PDN connection. Furthermore, this change
allows the gateway to be changed. More specifically, this change
allows for a change to a communication path and/or a session with a
different gateway.
[0528] Note that such a change may be triggered by the service
request procedure and/or the tracking area update procedure
initiated by the UE 10.
[0529] The PDN connection on which such a change is performed may
be a PDN connection established using an APN associated with
special permission information, such as APN5. Hence, a PDN
connection established using an APN, such as APN1, not associated
with permission information corresponding to such a change need not
change to a communication path and/or a session with a different
gateway at the time of performing the service request procedure
and/or the tracking area update procedure.
[0530] Hence, whether to perform the change may be determined in
accordance with APN and permission information.
[0531] Note that the UE 10 may establish, with multiple APNs,
multiple PDN connections for the respective APNs.
2. Modified Example
[0532] As described above, the method described in the above
embodiment can be applied to the stored information and the process
in each of the devices including the UE 10, and hence detailed
description thereof is omitted.
[0533] The embodiment and multiple modified examples relating to
the embodiments have been described above. The modified examples
may be individually applied to the embodiment. The embodiment of
the invention has been described in detail thus far with reference
to the drawings, but the specific configuration is not limited to
the embodiment. Other designs and the like that do not depart from
the essential spirit of the invention also fall within the scope of
the patent claims.
[0534] Additionally, the program run on each of the devices in the
embodiments is a program that controls a CPU (program that causes a
computer to function) to realize the functions of the
above-described embodiments. The information handled by these
devices is temporarily held in a transitory storage device (RAM,
for example) at the time of processing, and is then stored in
various storage devices such as a ROM and an HDD, read out by the
CPU as necessary, and edited and written.
[0535] Here, a semiconductor medium (a ROM, a non-volatile memory
card, or the like, for example), an optical recording
medium/magneto-optical recording medium (a digital versatile disc
(DVD), a magneto optical disc (MO), a mini disc (MD), a compact
disc (CD), a BD, or the like, for example), a magnetic recording
medium (magnetic tape, a flexible disk, or the like, for example),
and the like can be given as examples of recording media for
storing the programs. In addition to realizing the functions of the
above-described embodiments by executing programs that have been
loaded, there are also cases where the functions of the present
invention are realized by the programs running cooperatively with
an operating system, other application programs, or the like in
accordance with instructions included in those programs.
[0536] When delivering these programs to market, the programs can
be stored in a portable recording medium, or transferred to a
server computer connected via a network such as the Internet. In
this case, the storage device serving as the server computer is of
course also included in the present invention.
[0537] Additionally, each device in the above-described embodiments
may be partially or completely realized as a large scale
integration (LSI) circuit, which is a typical integrated circuit.
The functional blocks of each device may be individually realized
as chips, or may be partially or completely integrated into a chip.
The circuit integration technique is not limited to LSI, and the
integrated circuits for the functional blocks may be realized as
dedicated circuits or a general-purpose processor. Furthermore, if
advances in semiconductor technology produce circuit integration
technology capable of replacing LSI, it is of course possible to
use integrated circuits based on the technology.
REFERENCE SIGNS LIST
[0538] 1 Mobile communication system [0539] 5 IP mobile
communication network [0540] 7 Core network [0541] 9 LTE access
network [0542] 10 UE [0543] 20 eNB [0544] 30 MME [0545] 40 LGW
[0546] 50 SGW [0547] 60 PGW [0548] 70 HSS [0549] 80 PCRF [0550] 90
PDN
* * * * *