U.S. patent application number 16/690699 was filed with the patent office on 2020-03-19 for method and apparatus for providing congestion control for application in wireless communication system.
The applicant listed for this patent is Samsung Electronics Co., Ltd.. Invention is credited to Songyean CHO, Sunghoon KIM, Sung Hwan WON.
Application Number | 20200092778 16/690699 |
Document ID | / |
Family ID | 56848929 |
Filed Date | 2020-03-19 |
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United States Patent
Application |
20200092778 |
Kind Code |
A1 |
WON; Sung Hwan ; et
al. |
March 19, 2020 |
METHOD AND APPARATUS FOR PROVIDING CONGESTION CONTROL FOR
APPLICATION IN WIRELESS COMMUNICATION SYSTEM
Abstract
The present disclosure relates to a communication method and
system for converging a 5th-Generation (5G) communication system
for supporting higher data rates beyond a 4th-Generation (4G)
system with a technology for Internet of Things (IoT). The present
disclosure may be applied to intelligent services based on the 5G
communication technology and the IoT-related technology, such as
smart home, smart building, smart city, smart car, connected car,
health care, digital education, smart retail, security and safety
services. Methods and apparatuses provide a service to user
equipment through a dedicated core network. In one method, a base
station, also referred to as eNB, receives a non-access stratum
(NAS) message from user equipment (UE), and transmits a first
initial UE message having the NAS message to a first mobility
management entity (MME). Also, the base station receives a
redirection request message having the NAS message from the first
MME, and transmits a second initial UE message having the NAS
message to a second MME. In another method, the MME receives the
first initial UE message having the NAS message from the base
station, and transmits the redirection request message having the
NAS message when the MME fails to support a dedicated core network
according to UE usage type information. If the redirection request
message is transmitted, a second initial UE message having the NAS
message is transmitted to a dedicated MME.
Inventors: |
WON; Sung Hwan; (Seoul,
KR) ; KIM; Sunghoon; (Suwon-si, KR) ; CHO;
Songyean; (Seoul, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Samsung Electronics Co., Ltd. |
Suwon-si |
|
KR |
|
|
Family ID: |
56848929 |
Appl. No.: |
16/690699 |
Filed: |
November 21, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15935727 |
Mar 26, 2018 |
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16690699 |
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15058794 |
Mar 2, 2016 |
9930591 |
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15935727 |
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62126917 |
Mar 2, 2015 |
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62202406 |
Aug 7, 2015 |
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62232100 |
Sep 24, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 8/065 20130101;
H04W 36/12 20130101; H04W 28/02 20130101; H04W 48/06 20130101; H04W
36/0011 20130101; H04W 48/16 20130101; H04W 48/02 20130101; H04W
4/06 20130101; H04L 67/12 20130101 |
International
Class: |
H04W 36/12 20060101
H04W036/12; H04W 36/00 20060101 H04W036/00; H04W 8/06 20060101
H04W008/06; H04L 29/08 20060101 H04L029/08 |
Claims
1. A method performed by a base station in a wireless communication
system, the method comprising: receiving, from a terminal, a
non-access stratum (NAS) message; transmitting, toward a first
mobility management entity, a first initial UE message including
the NAS message; receiving a reroute message including the first
initial UE message transmitted from the first mobility management
entity, in case that a reroute is determined by the first mobility
management entity; identifying a second mobility management entity
supporting a dedicated core network for the UE, based on the
reroute message; and transmitting, to the second mobility
management entity, a second initial UE message including the NAS
message supporting the dedicated core network for the UE, wherein
the second mobility management entity is selected based on a
selected public land mobile network (PLMN).
2. The method of claim 1, wherein the selected PLMN is stored in
the base station.
3. The method of claim 1, wherein identifying the second mobility
management entity comprises identifying the second mobility
management entity, based on at least one of a mobility management
entity group identifier, a null-network resource identifier
(null-NRI)/serving node group identifier, or an additional globally
unique temporary UE identity (GUTI)/P-temporary mobile subscriber
identity (P-TMSI), all of which are contained in the reroute
message.
4. The method of claim 1, wherein the NAS message includes at least
one of an attach request message, a tracking area update message,
or a routing area update message.
5. A base station in a wireless communication system, the base
station comprising: a transceiver; and a controller coupled with
the transceiver and configured to control the transceiver to:
receive, from a user equipment (UE), a non-access stratum (NAS)
message, transmit, toward a first mobility management entity, a
first initial UE message including the NAS message, receive a
reroute message including the first initial UE message transmitted
from the first mobility management entity, in case that a reroute
is determined by the first mobility management entity, identify a
second mobility management entity supporting a dedicated core
network for the UE, based on the reroute message, and transmit, to
a second mobility management entity, a second initial UE message
including the NAS message supporting the dedicated core network for
the UE, wherein the second mobility management entity is selected
based on a selected public land mobile network (PLMN).
6. The base station of claim 5, wherein the selected PLMN is
identified based on information included in the reroute message,
and wherein the selected PLMN is identified based on information
included in the reroute message.
7. The base station of claim 5, wherein the controller is further
configured to identify the second mobility management entity, based
on at least one of a mobility management entity group identifier, a
null-network resource identifier (null-NRI)/serving node group
identifier, or an additional globally unique temporary UE identity
(GUTI)/P-temporary mobile subscriber identity (P-TMSI), all of
which are contained in the reroute message.
8. The base station of claim 4, wherein the NAS message includes at
least one of an attach request message, a tracking area update
message, or a routing area update message.
9. A method performed by a first mobility management entity in a
wireless communication system, the method comprising: receiving,
from a base station, a first initial user equipment (UE) message
including a non-access stratum (NAS) message; and transmitting a
reroute message including the first initial UE message, in case
that a reroute is determined by the first MME, wherein in case that
the reroute message is transmitted, a second initial UE message
including the NAS message is transmitted to a second mobility
management entity supporting a dedicated core network for the UE,
wherein the second mobility management entity supporting the
dedicated core network is identified based on the reroute message,
and wherein the second mobility management entity is selected based
on a selected public land mobile network (PLMN).
10. The method of claim 9, wherein the second mobility management
entity is determined, based on at least one of a mobility
management entity group identifier, a null-network resource
identifier (null-NRI)/serving node group identifier, or an
additional globally unique temporary UE identity (GUTI)/P-temporary
mobile subscriber identity (P-TMSI), all of which are contained in
the reroute message.
11. The method of claim 9, wherein the NAS message includes at
least one of an attach request message, a tracking area update
message, or a routing area update message.
12. The method of claim 9, wherein the selected PLMN is stored in
the base station, and wherein the selected PLMN is identified based
on information included in the reroute message.
13. The method of claim 9, wherein the UE usage type information is
received from one of other mobility management entity and a home
subscriber server (HSS).
14. A first mobility management entity in a wireless communication
system, the first mobility management entity comprising: a
transceiver; and a controller coupled with the transceiver and
configured to control the transceiver to: receive, from a base
station, a first initial user equipment (UE) message including a
non-access stratum (NAS) message, and transmit a reroute message
including the first initial UE message, in case that a reroute is
determined by the first MME, wherein in case that the reroute
message is transmitted, a second initial UE message including the
NAS message is transmitted to a second mobility management entity
supporting a dedicated core network for the UE, wherein the second
mobility management entity supporting the dedicated core network is
identified based on the reroute message, and wherein the second
mobility management entity is selected based on a selected public
land mobile network (PLMN).
15. The first mobility management entity of claim 13, wherein the
second MME is determined, based on at least one of a mobility
management entity group identifier, a null-network resource
identifier (null-NRI)/serving node group identifier, or an
additional globally unique temporary UE identity (GUTI)/P-temporary
mobile subscriber identity (P-TMSI), all of which are contained in
the reroute message.
16. The first mobility management entity of claim 13, wherein the
NAS message includes at least one of an attach request message, a
tracking area update message, or a routing area update message.
17. The first mobility management entity of claim 13, wherein the
selected PLMN is stored in the base station, and wherein the
selected PLMN is identified based on information included in the
reroute message.
18. The first mobility management entity of claim 13, wherein the
UE usage type information is received from one of other MME and a
home subscriber server (HSS).
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of prior
application Ser. No. 15/935,727, filed on Mar. 26, 2018, which is a
continuation application of prior application Ser. No. 15/058,794,
filed on Mar. 2, 2016, which has issued as U.S. Pat. No. 9,930,591
on Mar. 27, 2018 and was based on and claimed priority under 35
U.S.C. .sctn. 119(e) of U.S. Provisional application No. 62/126,917
filed on Mar. 2, 2015, 62/202,406 filed on Aug. 7, 2015 and
62/232,100 filed on Sep. 24, 2015 in the U.S. patent and trademark
office, the entire disclosure of each of which is hereby
incorporated by reference.
TECHNICAL FIELD
[0002] The present invention relates to a wireless communication
system and, more particularly, to a method and apparatus for
providing a service to user equipment through a dedicated core
network.
BACKGROUND
[0003] To meet the demand for wireless data traffic having
increased since deployment of 4G communication systems, efforts
have been made to develop an improved 5G or pre-5G communication
system. Therefore, the 5G or pre-5G communication system is also
called a `Beyond 4G Network` or a `Post LTE System`. The 5G
communication system is considered to be implemented in higher
frequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish
higher data rates. To decrease propagation loss of the radio waves
and increase the transmission distance, the beamforming, massive
multiple-input multiple-output (MIMO), Full Dimensional MIMO
(FD-MIMO), array antenna, an analog beam forming, large scale
antenna techniques are discussed in 5G communication systems. In
addition, in 5G communication systems, development for system
network improvement is under way based on advanced small cells,
cloud Radio Access Networks (RANs), ultra-dense networks,
device-to-device (D2D) communication, wireless backhaul, moving
network, cooperative communication, Coordinated Multi-Points
(CoMP), reception-end interference cancellation and the like. In
the 5G system, Hybrid FSK and QAM Modulation (FQAM) and sliding
window superposition coding (SWSC) as an advanced coding modulation
(ACM), and filter bank multi carrier (FBMC), non-orthogonal
multiple access (NOMA), and sparse code multiple access (SCMA) as
an advanced access technology have been developed.
[0004] The Internet, which is a human centered connectivity network
where humans generate and consume information, is now evolving to
the Internet of Things (IoT) where distributed entities, such as
things, exchange and process information without human
intervention. The Internet of Everything (IoE), which is a
combination of the IoT technology and the Big Data processing
technology through connection with a cloud server, has emerged. As
technology elements, such as "sensing technology", "wired/wireless
communication and network infrastructure", "service interface
technology", and "Security technology" have been demanded for IoT
implementation, a sensor network, a Machine-to-Machine (M2M)
communication, Machine Type Communication (MTC), and so forth have
been recently researched. Such an IoT environment may provide
intelligent Internet technology services that create a new value to
human life by collecting and analyzing data generated among
connected things. IoT may be applied to a variety of fields
including smart home, smart building, smart city, smart car or
connected cars, smart grid, health care, smart appliances and
advanced medical services through convergence and combination
between existing Information Technology (IT) and various industrial
applications.
[0005] In line with this, various attempts have been made to apply
5G communication systems to IoT networks. For example, technologies
such as a sensor network, Machine Type Communication (MTC), and
Machine-to-Machine (M2M) communication may be implemented by
beamforming, MIMO, and array antennas. Application of a cloud Radio
Access Network (RAN) as the above-described Big Data processing
technology may also be considered to be as an example of
convergence between the 5G technology and the IoT technology.
[0006] Meanwhile, a terminal (also referred to as user equipment
(UE) or the like) should be offered a service through a suitable
core network (CN) for providing that service. This suitable core
network may be referred to as a dedicated core network (DCN).
Therefore, when a non-access stratum (NAS) message is received from
a terminal, a base station (also referred to as evolved node B
(eNodeB or eNB) or the like) should transmit the NAS message to a
mobility management entity (MME) contained in the DCN so that the
terminal can be offered a service through the DCN. However, if any
MME selected by the base station is not a dedicated MME which is
contained in the DCN, the base station is required to select an MME
again.
SUMMARY
[0007] In order to meet the above-mentioned need or the like, the
present invention provides a method and apparatus for allowing a
base station to transmit an NAS message to a dedicated MME through
rerouting of the NAS message when an MME receiving the NAS message
is not the dedicated MME.
[0008] According to various embodiments of the present invention, a
method implemented at a base station in a wireless communication
system includes steps of receiving a non-access stratum (NAS)
message from user equipment (UE); transmitting a first initial UE
message having the NAS message to a first mobility management
entity (MME); receiving a redirection request message having the
NAS message from the first MME; and transmitting a second initial
UE message having the NAS message to a second MME.
[0009] According to various embodiments of the present invention, a
base station in a wireless communication system includes a
communication unit configured to perform communication with other
network entity; and a control unit configured to control the
communication unit to receive a non-access stratum (NAS) message
from user equipment (UE), to transmit a first initial UE message
having the NAS message to a first mobility management entity (MME),
to receive a redirection request message having the NAS message
from the first MME, and to transmit a second initial UE message
having the NAS message to a second MME.
[0010] According to various embodiments of the present invention, a
method implemented at a mobility management entity (MME) in a
wireless communication system includes steps of receiving a first
initial user equipment (UE) message having a non-access stratum
(NAS) message from a base station; and transmitting a redirection
request message having the NAS message when the MME fails to
support a dedicated core network according to UE usage type
information, wherein if the redirection request message is
transmitted, a second initial UE message having the NAS message is
transmitted to a dedicated MME.
[0011] According to various embodiments of the present invention, a
mobility management entity (MME) in a wireless communication system
includes a communication unit configured to perform communication
with other network entity; and a control unit configured to control
the communication unit to receive a first initial user equipment
(UE) message having a non-access stratum (NAS) message from a base
station, and to transmit a redirection request message having the
NAS message when the MME fails to support a dedicated core network
according to UE usage type information, wherein if the redirection
request message is transmitted, a second initial UE message having
the NAS message is transmitted to a dedicated MME.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a diagram illustrating the structure of a
communication system according to an embodiment of the present
invention.
[0013] FIGS. 2A and 2B are flow diagrams illustrating a procedure
in which UE registers with a network.
[0014] FIG. 3A is a flow diagram illustrating an attach process of
UE according to the first embodiment of the present invention.
[0015] FIG. 3B is a flow diagram illustrating an NAS message
reroute process according to the first embodiment of the present
invention.
[0016] FIG. 3C is a flow diagram illustrating a process of
registering UE in a network through MME/SGSN according to the first
embodiment of the present invention.
[0017] FIG. 4 is a flow diagram illustrating another NAS message
reroute process according to the first embodiment of the present
invention.
[0018] FIG. 5 is a flow diagram illustrating a process in which the
first MME registers UE in a network according to the first
embodiment of the present invention.
[0019] FIG. 6 is a flow diagram illustrating a process in which
eNodeB registers UE in a network according to the first embodiment
of the present invention.
[0020] FIG. 7 is a flow diagram illustrating a process in which
HeNB GW registers UE in a network according to the first embodiment
of the present invention.
[0021] FIG. 8 is a block diagram illustrating a configuration of
the first MME according to the first embodiment of the present
invention.
[0022] FIG. 9 is a block diagram illustrating a configuration of
eNodeB according to the first embodiment of the present
invention.
[0023] FIG. 10 is a block diagram illustrating a configuration of
UE according to the first embodiment of the present invention.
[0024] FIG. 11 is a flow diagram illustrating a process in which UE
applies ACDC in a TAU procedure according to the second embodiment
of the present invention.
[0025] FIG. 12 is a flow diagram illustrating a process of applying
ACDC in a TAU procedure according to the second embodiment of the
present invention.
[0026] FIG. 13 is a flow diagram illustrating another process in
which UE applies ACDC in a TAU procedure according to the second
embodiment of the present invention.
[0027] FIG. 14 is a flow diagram illustrating another process of
applying ACDC in a TAU procedure according to the second embodiment
of the present invention.
[0028] FIG. 15 is a block diagram illustrating a configuration of
UE according to the second embodiment of the present invention.
[0029] FIG. 16A and FIG. 16B are flow diagrams illustrating a
method for providing an MBMS service according to the third
embodiment of the present invention.
[0030] FIG. 17 is another flow diagram illustrating a method for
providing an MBMS service according to the third embodiment of the
present invention.
[0031] FIG. 18 is a block diagram illustrating a configuration of
MME according to the third embodiment of the present invention.
[0032] FIG. 19 is a block diagram illustrating a configuration of
MCE according to the third embodiment of the present invention.
DETAILED DESCRIPTION
[0033] Hereinafter, embodiments of the present invention will be
described with reference to the accompanying drawings. Through the
drawings, the same or similar reference numerals denote
corresponding features consistently. Additionally, well known
functions and configurations may not be described or illustrated in
detail to avoid obscuring the subject matter of the present
invention.
[0034] Also, embodiments of the present invention will be described
hereinafter by mainly targeting Long-Term Evolution (LTE) and
Evolved Packet Core (EPC), which are a Radio Access Network (RAN)
and a Core Network (CN) defined as standards by the 3rd Generation
Partnership Project (3GPP), the essential concept of this invention
may be favorably applied to any other communication system having a
similar technical background without departing from the scope of
this invention as will be apparent to those skilled in the art.
[0035] The present invention may be embodied in many different
forms without changing technical subject matters and essential
features as will be understood by those skilled in the art.
Therefore, embodiments set forth herein are exemplary only and not
to be construed as a limitation.
[0036] In embodiments, all steps and messages are not a target for
selective implementation or omission. Additionally, in each
embodiment, steps may not be always performed in the order
described and may be changed in order. Similarly, delivery of
messages may not be always performed in the order described and may
be changed in order. Each step and messaging may be performed
independently.
[0037] The whole or parts of exemplary contents in embodiments are
provided to promote understanding by showing a detailed embodiment
of this invention. Therefore, the detailed contents may be regarded
as expressing a part of method and apparatus proposed by this
invention. Namely, with regard to such contents, a syntax-based
approach may be more desirable than a semantics-based approach.
While this disclosure has been particularly shown and described
with reference to an exemplary embodiment thereof, it will be
understood by those skilled in the art that various changes in form
and details may be made therein without departing from the spirit
and scope of this disclosure as defined by the appended claims.
[0038] The present invention may be embodied in many different
forms and should not be construed as limited to the embodiments set
forth herein. Rather, the disclosed embodiments are provided so
that this disclosure will be thorough and complete, and will fully
convey the scope of this invention to those skilled in the art. The
principles and features of the present invention may be employed in
varied and numerous embodiments without departing from the scope of
the invention.
[0039] The terms used in the present disclosure are only used to
describe specific various embodiments, and are not intended to
limit the present disclosure. As used herein, the singular forms
are intended to include the plural forms as well, unless the
context clearly indicates otherwise.
[0040] It will be understood that each block of the flowchart
illustrations, and combinations of blocks in the flowchart
illustrations, can be implemented by computer program instructions.
These computer program instructions can be provided to a processor
of a general purpose computer, special purpose computer, or other
programmable data processing apparatus to produce a machine, such
that the instructions, which are executed via the processor of the
computer or other programmable data processing apparatus, create
means for implementing the functions specified in the flowchart
block or blocks. These computer program instructions may also be
stored in a computer usable or computer-readable memory that can
direct a computer or other programmable data processing apparatus
to function in a particular manner, such that the instructions
stored in the computer usable or computer-readable memory produce
an article of manufacture including instruction means that
implement the function specified in the flowchart block or blocks.
The computer program instructions may also be loaded onto a
computer or other programmable data processing apparatus to cause a
series of operational steps to be performed on the computer or
other programmable apparatus to produce a computer implemented
process such that the instructions that are executed on the
computer or other programmable apparatus provide steps for
implementing the functions specified in the flowchart block or
blocks.
[0041] And each block of the flowchart illustrations may represent
a module, segment, or portion of code, which comprises one or more
executable instructions for implementing the specified logical
function(s). It should also be noted that in some alternative
implementations, the functions noted in the blocks may occur out of
the order. For example, two blocks shown in succession may in fact
be executed substantially concurrently or the blocks may sometimes
be executed in the reverse order, depending upon the functionality
involved.
[0042] The term "unit", as used herein, may refer to a software or
hardware component or device, such as a Field Programmable Gate
Array (FPGA) or Application Specific Integrated Circuit (ASIC),
which performs certain tasks. A unit may be configured to reside on
an addressable storage medium and configured to execute on one or
more processors. Thus, a module or unit may include, by way of
example, components, such as software components, object-oriented
software components, class components and task components,
processes, functions, attributes, procedures, subroutines, segments
of program code, drivers, firmware, microcode, circuitry, data,
databases, data structures, tables, arrays, and variables. The
functionality provided for in the components and modules/units may
be combined into fewer components and modules/units or further
separated into additional components and modules.
First Embodiment
[0043] FIG. 1 is a diagram illustrating the structure of a
communication system according to an embodiment of the present
invention. According to this embodiment, the communication system
may be an LTE-based mobile communication system.
[0044] Referring to FIG. 1, as shown, a wireless access network of
the LTE mobile communication system may be formed of an evolved
Node B (also referred to as eNB, a base station, E-UTRAN, etc.)
130, a mobility management entity (MME) 150, and a serving gateway
(S-GW) 140.
[0045] User equipment (also referred to as UE, a terminal, etc.)
100 may access an external network through the eNB 130, the S-GW
140, and a PDN gateway (P-GW) 160. In order to transmit or receive
data through the P-GW, the UE should create a PDN connection, which
may include at least one EPS bearer.
[0046] An application function (AF) 110 is an apparatus that
exchanges application-related information with a user at the level
of application.
[0047] A policy charging and rules function (PCRF) 120 is an
apparatus that controls a policy associated with user's quality of
service (QoS). A policy and charging control (PCC) rule
corresponding to the above policy is delivered and applied to the
P-GW 160.
[0048] The eNB 130 is a radio access network (RAN) node and
corresponds to RNC of a UTRAN system and to BSC of a GERAN system.
The eNB 130 is connected to the UE 100 in a radio channel and
performs a role similar to that of the existing RNC/BSC.
[0049] Since all user traffics including real-time services such as
a voice over internet protocol (VoIP) are offered through a shared
channel in LTE, an apparatus for collecting status information of
UEs 100 and performing scheduling is needed. The eNB 130 is in
charge of this.
[0050] The S-GW 140 is an apparatus that offers a data bearer, and
creates or removes the data bearer under the control of the MIME
150.
[0051] The MME 150 is an apparatus that performs various control
functions, and a single MME 150 may be connected with a plurality
of eNBs. In this invention, a certain MME newly accessed by the UE
100 is referred to as a new MME 150. Also, an MME accessed before
attachment and a corresponding network entity are referred to as
old MME/SGSN 152. And also, an MME accessed by the UE 100 to access
a dedicated core network is referred to as a dedicated MME 154.
[0052] The PCRF 120 is an entity that controls QoS of traffic and
charging.
[0053] Meanwhile, as mentioned above, the LTE system supports
interworking with any access network other than 3GPP as well as
E-UTRAN. If any non-3GPP access network is interworked, the
non-3GPP access network may be connected to the PGW 160 directly or
through an additional ePDG. For processing subscriber information
or authentication with regard to the non-3GPP access network, a
home subscriber server (HSS) 170 and an authentication,
authorization and accounting (AAA) server may exchange information
with each other and may also be realized as a signal entity. The
term ePDG is exemplarily used for convenience. Even in case the
non-3GPP access network is connected to the PGW directly or
connected through any node, e.g., the S-GW, other than ePDG, an
embodiment disclosed herein may be applied without any considerable
modification.
[0054] FIGS. 2A and 2B are flow diagrams illustrating a procedure
in which UE registers with a network.
[0055] This registration procedure is also referred to as a network
attachment. During this procedure, a default EPS bearer is created
for always-on IP connectivity.
[0056] Referring to FIG. 2A, at step 201, the UE 100 may transmit
an attach request message to the eNB 130. At step 202, the eNB 130
that receives the attach request message may transmit the attach
request message to a new MME 150.
[0057] The new MME 150 that receives the attach request message may
transmit an identification request message for identifying UE to an
old MME or serving GPRS support node (SGSN) 152 at step 203a and
may receive an identification response message from the old
MME/SGSN 152 at step 203b. If the old MME/SGSN 152 and the new MME
150 fail to identify the UE 100, the new MME 150 may transmit an
identity request message to the UE 100 at step 204a and may receive
an identity response message containing an international mobile
subscriber identity (IMSI) from the UE 100 at step 204b.
[0058] If context of the UE 100 does not exist in the network, the
UE 100, the new MME 150 and the HSS 170 may perform an
authentication/security procedure at step 205a.
[0059] After the authentication/security procedure, at step 205b,
the UE 100 may transmit a ciphered identity request message to the
new MME 150 and may receive a ciphered identity response message
from the new MME 150. This step may be performed together with the
authentication/security step 205a.
[0060] Thereafter, if the UE 100 sets a ciphered options transfer
flag in the attach request message, the new MME 150 may transmit a
ciphered options request message to the UE 100 at step 206a and may
receive a ciphered options response message from the UE 100 at step
206b.
[0061] If there is activated bearer context for the UE 100 in the
new MME 150, the new MME 150 may transmit a delete session request
message to the S-GW 140 at step 207a. Then the S-GW 140, the P-GW
160 and the PCRF 120 may terminate a session at step 207b, and the
S-GW 140 may transmit a delete session response message to the new
MME 150 at step 207c.
[0062] If the MME is changed after the final detach, or if there is
no valid subscriber context for the UE in the MME, the new MME 150
may transmit an update location request message to the HSS 170 at
step 208. Then the HSS 170 may transmit a cancel location message
to the old MMS/SGSN 152 at step 209a and may receive a cancel
location ACK message from the old MMS/SGSN 152 at step 209b.
[0063] If there is activated bearer context for the UE 100 in the
old MME/SGSN 152, the old MME/SGSN 152 may transmit a delete
session request message to the S-GW 140 at step 210a. Then the S-GW
140, the P-GW 160 and the PCRF 120 may terminate a session at step
210b, and the S-GW 140 may transmit a delete session response
message to the old MME 150 at step 210c. Thereafter, the HSS 170
may transmit an update location ACK message to the new MME 150 at
step 211.
[0064] FIG. 2B shows steps after the new MME 150 receives the
update location ACK message in FIG. 2A.
[0065] Referring to FIG. 2B, at step 212, the new MME 150 may
transmit a create session request message to the S-GW 140. Then the
S-GW 140 may create a session with the P-GW 160 and the PCRF 120 at
steps 213, 214 and 215, and may transmit a create session response
message to the new MME 150 at step 216.
[0066] Thereafter, the new MME 150 may transmit an initial context
setup request message, by inserting an attach accept message
therein, to the eNB 130 at step 217.
[0067] The eNB 130 that receives this may transmit a radio resource
control (RRC) connection reconfiguration message to the UE 100 at
step 218. If the UE 100 transmits an RRC connection reconfiguration
complete message to the eNB 130 at step 219, the eNB 130 may
transmit an initial context setup response message to the new MME
150 at step 220.
[0068] Thereafter, the UE 100 may transmit a direct transfer
message containing an attach complete message to the eNB 130 at
step 221, and the eNB 130 may deliver the attach complete message
to the new MME 150 at step 222.
[0069] The new MME 150 that receives the initial context response
message and the attach complete message may transmit a modify
bearer request message to the S-GW 140 at step 223a. The S-GW 140
and the P-GW 160 may perform a bearer modification at steps 223b
and 223c, and the S-GW 140 may transmit a modify bearer response
message to the new MME 150 at step 224.
[0070] Thereafter, if a mobile equipment identity of the UE 100 is
changed, the new MME 150 may transmit a notify request message to
the HSS 170 at step 225 and may receive a notify response message
from the HSS 170 at step 226.
[0071] Meanwhile, when the UE 100 transmits the attach request
message to the eNB 130 at step 201, this attach request message may
be contained in an RRC connection setup complete message that is
transmitted from the UE to the eNB. Also, at step 202, the eNB may
transmit an initial UE message, which is an S1-MME control message
containing the attach request message, to the new MME 150.
[0072] At this time, a core network to which the new MME 150
receiving the attach request message from the UE 100 belongs may be
not identical to a dedicated core network (DCN) of the UE. This
dedicated core network may be used for allowing an operator to
offer a particular function or for separating specific UE or
subscriber. For example, the dedicated core network may be used for
separating subscribers for machine-to-machine (M2M) communication
or separating subscribers of a specific company.
[0073] The UE needs to access the DCN corresponding to a usage type
thereof and then be offered a suitable service. However, if the eNB
130 fails to select the DCN, it may be required to deliver a
message, transmitted to the MME/SGSN 150, to a dedicated MME/SGSN
154 contained in the DCN such that the UE can be serviced by the
DCN. Therefore, described hereinafter is a method for allowing the
UE to be offered a service from the DCN by rerouting an NAS message
when the eNB fails to select the DCN.
[0074] FIG. 3A is a flow diagram illustrating an attach process of
UE according to the first embodiment of the present invention.
Steps which are not described herein may follow, partially or
totally, a normal EPS attach procedure.
[0075] Referring to FIG. 3A, the new MME/SGSN 150 may receive an
attach request message from the UE 100 through the eNB 130 at steps
201 and 202. Although the attach request message is used
exemplarily herein, an NAS message including a tracking area update
(TAU) message, a routing area update (RAU) message, or the like may
be used alternatively. The attach request message may be delivered
to the eNB 130 from the UE 100 in the form of being contained in an
RRC message and also delivered to the MME/SGSN 150 from the eNB 130
in the form of being contained in an initial UE message (an RAN
message).
[0076] The attach request message may contain a globally unique
temporary UE identity (GUTI)/P-temporary mobile subscriber identity
(P-TMSI) and/or additional GUTI/P-TMSI. In case a GUTI is created
from a P-TMSI and a routing area identifier (RAI) (this GUTI may be
referred to as a mapped GUTI), or in case a P-TMSI is created from
a GUTI (this P-TMSI may be referred to as a mapped P-TMSI), the
attach request message may contain additional GUTI/P-TMSI. If the
DCN is not considered, the additional GUTI/P-TMSI may be used for
checking whether there is context of UE identified using such
additional GUTI/P-TMSI in the new MME/SGSI 150.
[0077] The new MME 150 that receives the attach request message may
transmit an identification request message to the old MME/SGSN 152
at step 203a and may receive an identification response message
having MM context from the old MME/SGSN 152 at step 203b. The
identification response message having MM context may contain UE
usage type information. In embodiments disclosed herein, the UE
usage type information may refer to information about UE.
Specifically, the UE usage type information may be used for
steering the UE to a suitable DCN. Namely, the UE usage type
information may be information that indicates a usage character of
the UE. A mobile communication network operator may deploy a
suitable DCN for such a UE usage character.
[0078] The UE usage type information may be delivered in the form
of being contained in the MM context or as an information element
which is independent of the MM context. As will be described below
in detail, a suitable DCN for serving the UE 100 may be identified
from this UE usage type information, and the MME 150 may transmit
suitable information to the eNB 130 so that the eNB 130 can
retransmit the attach request message to a suitable DCN.
Alternatively, contrary to this, the UE usage type information
and/or any helpful information to select a DCN may be contained in
an RRC message having the attach request message and then sent to
the eNB 130.
[0079] At step 303a, the new MME/SGSN 150 that receives the
identification response message may have already obtained the UE
usage type information of the UE 100, and thus can determine
whether to support a DCN depending on the UE usage type information
of the UE 100.
[0080] As a result, if it is determined that the new MME/SGSN 150
fails to support a DCN of the UE, the new MME/SGSN 150 may reroute
(also referred to as redirect) the attach request message such that
the UE can receive a service from a suitable dedicated MME/SGSN
154.
[0081] As discussed above, the UE usage type information may be
delivered through the identification response message transmitted
from the old MME/SGSN 152 to the new MME 150 at step 203b or
through an update location acknowledgement message transmitted from
the HSS 170 to the new MME 150 at step 211. The update location
acknowledgement message is a message delivered to the new MME 150
from the HSS 170 at step 211, and the HSS 170 may deliver
subscription data to the new MME 150. At this time, the UE usage
type information may be contained in the subscription data or
delivered separately from the subscription data. Therefore, a
redirection process of a non-access stratum (NAS) message to be
described below may be performed after step 203b or after step 211.
Also, the HSS 170 may deliver the UE usage type information to the
MME 150 at step 205a.
[0082] Although an example of rerouting the attach request message
is described above, this is not considered as a limitation of the
present invention. Namely, this invention relates to a process of
rerouting the NAS message, and this rerouting process may be
performed during the attach procedure, the TAU procedure, and the
RAU procedure.
[0083] FIG. 3B is a flow diagram illustrating an NAS message
reroute process according to the first embodiment of the present
invention.
[0084] Referring to FIG. 3B, in case the new MME/SGSN 150 that
becomes aware of the UE usage type applied to the UE 100 through
step 203b, step 205a, and/or step 211 fails to support the DCN of
the UE 100, the new MME/SGSN 150 may deliver, at step 300, a
message for rerouting the NAS message to MME/SGSN corresponding to
characteristics of UE. Herein, the MME/SGSN corresponding to
characteristics of UE may refer to the dedicated MME/SGSN 154
located in the DCN corresponding to the UE usage type information
of UE. In this case, a message (hereinafter, referred to as a
redirection message) for rerouting the NAS message may be defined
as a new RAN message named a reroute command message, reroute
message, or a reroute NAS request message.
[0085] The redirection message (i.e., the RAN message) may contain
at least one of MME UE S1AP ID, eNB UE S1AP ID, (revised) NAS-PDU
(Protocol Data Unit), GUTI, GUMMEI (Globally Unique MME Identity),
MMEGI (MME Group Identifier) or Null NRI (Network Resource
Identifier)/SGSN group ID, GUMMEI type, S-TMSI (SAE Temporary
Mobile Subscriber Identity), TAI (Tracking Area Identity) and RRC
establishment cause, additional GUTI/P-TMSI, and information
delivered to the MME/SGSN 150 by the eNB 130.
[0086] MME UE S1AP ID is an identifier allocated by the new
MME/SGSN 150 to identify the UE 100 on the S1 interface. Also, eNB
UE S1AP ID is an identifier allocated by the eNB 130 to identify
the UE 100 on the S1 interface. Using eNB UE S1AP ID, the eNB 130
may determine which UE needs redirection. This eNB UE S1AP ID
contained in the redirection message by the new MME/SGSN 150 may be
identical to eNB UE S1AP ID contained in an S1 message received
through at least one of steps 202, 204b, 205a, 205b and 206b.
[0087] NAS-PDU contained in the redirection message may be an NAS
message received from the eNB. For example, the NAS message may be
an attach request message. This attach request message may be
identical to the attach request message received by the new
MME/SGSN 150 at step 202 or a slightly revised version thereof. For
example, the EPS mobile identity field of the attach request
message may be revised to GUTI allocated by the new MME/SGSN 150.
In another example, NAS-PDU may not be revised and GUTI may be
delivered as an independent information element. In this case, the
eNB 130 may deliver GUTI, received at step 300, as an independent
information element to the dedicated MME/SGSN 154 when an initial
UE message or uplink NAS transport message is transmitted at step
310.
[0088] GUMMEI, MMEGI or Null-NRI/SGSN group ID, GUMMEI type,
S-TMSI, and additional GUTI/P-TMSI are information that may be used
for the eNB 130 to select the dedicated MME/SGSN 154. The new
MME/SGSN 150 may set at least one of GUMMEI, MMEGI or Null-NRI/SGSN
group ID, GUMMEI type, and S-TMSI as a value associated with the
dedicated MME/SGSN 154 and then transmit it to the eNB 130.
[0089] MMEGI or Null-NRI/SGSN group ID may be used to identify a
DCN in a PLMN (Public Land Mobile Network).
[0090] GUMMEI may directly indicate the dedicated MME 154. GUMMEI
may be formed of a PLMN identifier, MMEGI, and MMEC. The new MME
may set a PLMN identifier as a serving PLMN of the UE 100 (namely,
identical to a PLMN part of TAI), set MMEGI as a value
corresponding to a dedicated MME group, and set MMEC (MME Code) as
a value corresponding to MMEC of the new MME. The eNB 130 may
select a dedicated MME group by using PLMN and MMEGI, and also
select dedicated MME by referring to MMEC. In another example,
GUMMEI may be a GUMMEI part of additional GUTI contained in the
attach request message. MMEGI may be information corresponding to a
dedicated MME group. This may be MMEGI included in MMEI (MME
Identifier) contained in GUMMEI of additional GUTI contained in the
attach request message.
[0091] TAI and RRC establishment cause may be information received
from the eNB 130 together with the attach request message by the
new MME 150.
[0092] Additional GUTI/P-TMSI may be contained in the reroute NAS
message request only in case the attach request message received by
the MME/SGSN 150 contains the additional GUTI/P-TMSI. Namely, if
additional GUTI/P-TMSI is contained in the attach request message
received at step 202, the MME/SGSN 150 may insert the additional
GUTI/P-TMSI into the reroute NAS message request to be transmitted
at step 300.
[0093] The eNB 130 that receives at least one kind of information
mentioned above may insert the TAI and/or RRC establishment cause,
received at step 300, into a message to be transmitted to the
dedicated MME 154 at step 310. The new MME 150 may also transmit
additional GUTI contained in the attach request message. This
additional GUTI may be delivered only when the new MME 150 fails to
find UE context by means of additional GUTI and when old GUTI
denotes that GUTI is mapped with P-TMSI (P-temporary mobile
subscriber identity) and RAI (routing area identifier).
[0094] The information delivered to the new MME/SGSN 150 by the eNB
130, which is contained in a message delivered by the eNB 130 at
step 300, may mean information contained in the first initial UE
message delivered by the eNB 130 at step 202. The information may
include all or part of information delivered at step 202. According
to 3GPP Release 13, the first initial UE message is formed as shown
in Table 1.
TABLE-US-00001 TABLE 1 IE type and Semantics Assigned IE/Group Name
Presence reference description Criticality Criticality Message Type
M YES ignore eNB UE S1AP ID M YES reject NAS-PDU M YES reject TAI M
Indicating the YES reject Tracking Area from which the UE has sent
the NAS message. E-UTRAN CGI M Indicating the E- YES ignore UTRAN
CGI from which the UE has sent the NAS message. RRC M YES Ignore
Establishment Cause S-TMSI O YES reject CSG Id O YES reject GUMMEI
O YES reject Cell Access Mode O YES reject GW Transport O Transport
Indicating GW YES ignore Layer Address Layer Transport Layer
Address Address if the GW is collocated with eNB. Relay Node O
Indicating a relay YES reject Indicator node. GUMMEI Type O
ENUMERATED YES ignore (native, mapped, . . .) Tunnel O Tunnel
Indicating HeNB's YES ignore Information for Information Local IP
Address BBF assigned by the broadband access provider, UDP port
Number. SIPTO L-GW O Transport Indicating SIPTO YES ignore
Transport Layer Layer L-GW Transport Address Address Layer Address
if the SIPTO L-GW is collocated with eNB. LHN ID O YES ignore MME
Group ID O YES ignore
[0095] Among various kinds of information shown in Table 1, certain
information may be known semipermanently to the eNB 130 and certain
information may need to be received again since the eNB 130 has
already received it from the UE 100 and then stores it. For
example, GW Transport Layer Address is inherent information of the
eNB 130 and thus known to the eNB 130. Also, RRC Establishment
Cause is information received from the UE 100 at step 201.
[0096] However, since backhaul is not very congested in general,
the redirection message delivered at step 300 may contain the first
initial UE message completely for simplification of the operation
of the MME/SGSN 150.
[0097] Additionally, the redirection message may contain other S1
message, e.g., an uplink NAS transport message. This is for
encompassing various cases in which the UE delivers the NAS
message. For example, the UE may register a new location in the
MME/SGSN 150 after handover. In this case, since the NAS message
for location registration is not the initial S1 message for the UE,
the NAS message may be delivered through the uplink NAS transport
message rather than through the initial UE message. In this case,
the redirection message delivered at step 300 may contain the
uplink NAS transport message.
[0098] For selecting the dedicated MME/SGSN 154, the eNB 130 may
use at least one of MMEGI or Null-NRI/SGSN group ID and additional
GUTI/P-TMSI which are received at step 300. Specifically, the eNB
130 may select MME/SGSN in a DCN indicated by MMEGI or
Null-NRI/SGSN group ID. If additional GUTI/P-TMSI identifies
MME/SGSN in the DCN indicated by MMEGI or Null-NRI/SGSN group ID,
MME/SGSN identified by additional GUTI/P-TMSI may be selected.
[0099] The eNB 130 that selects the dedicated MME/SGSN 154 may
transmit the second initial UE message or uplink NAS transport
message to the dedicated MME/SGSN 154 at step 310. Herein, while an
initial UE message transmitted to the new MME by the eNB at step
202 is referred to as the first initial UE message, an initial UE
message transmitted to the dedicated MME by the eNB at step 310 is
referred to as the second initial UE message. If it is not possible
to find selectable MME/SGSN in a DCN identified by means of MMEGI
or Null-NRI/SGSN group ID, the eNB 130 may select MME/SGSN in the
default DCN or select again the MME/SGSN 150.
[0100] The above discussion may be applied to only a network which
is not shared by several PLMNs. In a network shared by several
PLMNs, a DCN may be selected using the following method.
[0101] The eNB 130 may select the dedicated MME/SGSN 154 by using a
PLMN (CN operator) selected by the UE 100 and at least one of MMEGI
or Null-NRI/SGSN group ID and additional GUTI/P-TMSI which are
received at step 300. Specifically, the eNB 130 may select MME/SGSN
in a DCN indicated by MMEGI or Null-NRI/SGSN group ID within the
PLMN selected by the UE 100. If additional GUTI/P-TMSI identifies
MME/SGSN in the DCN indicated by MMEGI or Null-NRI/SGSN group ID
within the PLMN selected by the UE 100, the eNB 130 may select
MME/SGSN identified by additional GUTI/P-TMSI. In this case, the
PLMN in the additional GUTI/P-TMSI may be ignored.
[0102] Namely, in case the eNB 130 receives additional GUTI/P-TMSI
in the network shared by several PLMNs, the eNB 130 may select (if
possible) a core network indicated by a combination of the
following information:
[0103] PLMN selected by the UE 100;
[0104] MMEGI or Null-NRI/SGSN group ID; and
[0105] Most significant 8 bits of MMEC or NRI in additional
GUTI/P-TMSI.
[0106] In this case, a method for identifying the PLMN selected by
the UE 100 at the eNB 130 may include at least one of the
followings.
[0107] The eNB 130 may store and use information about the PLMN
selected by the UE 100 by receiving it from the UE 100 at step 201.
Also, the eNB 130 may identify the PLMN selected by the UE 100 from
information contained in the redirection message (S1 message)
received at step 300. In the latter case, the eNB 130 may extract a
PLMN ID part of TAI information in the redirection message (S1
message) and thereby identify the PLMN selected by the UE.
[0108] The eNB 130 that selects the dedicated MME/SGSN 154 may
transmit the second initial UE message or uplink NAS transport
message to the dedicated MME/SGSN 154 at step 310. If it is not
possible to find selectable MME/SGSN in a DCN identified by means
of MMEGI or Null-NRI/SGSN group ID, the eNB 130 may select MME/SGSN
in the default DCN or select again the MME/SGSN 150. Herein, the
second initial UE message (S1 message) delivered at step 310 may be
the S1 message contained in the redirection message received at
step 300.
[0109] The second initial UE message of step 310 may include
information contained in the first initial UE message transmitted
at step 202 and further include at least one of MME UE S1AP ID,
NAS-PDU, GUTI, S-TMSI, and additional GUTI. Namely, the second
initial UE message delivered at step 310 may include the NAS
message (e.g., the attach request message) delivered to the
MME/SGSN 150 at step 202. The dedicated MME 154 that receives this
may check, using at least one of additional GUTI and S-TMSI,
whether there is context of the UE therein. If there is context of
the UE, the existing UE context may be reused without obtaining
context from any other node (the new MME 150 and/or the HSS 170).
For example, context of the UE may be used for mobility management
of the UE. At least one of NAS-PDU, GUTI, MME UE S1AP ID, and
S-TMSI delivered at step 300 may be also delivered at step 320
through step 310.
[0110] Thereafter, at step 320, the new MME 150 may receive an MM
context request message from the dedicated MME 154. At this time,
the MM context request message may be an identification request
message. The dedicated MME 154 may transmit the attach request
message received from the new MME 150 through the eNB 130. Then,
the new MME 150 may verify the attach request message and adjust an
uplink NAS count in MME at step 303a in order to prevent errors at
verification step. For example, even in case verification is made,
the uplink NAS count may be not increased. The operation related to
step 303a may be performed after step 205a.
[0111] When the MME that sends the identification request at step
320 is the dedicated MME 154, and/or when the reroute command
message has been already sent for the UE identified by means of
information contained in the identification request message, the
new MME 150 may skip verification through NAS-PDU. In another
example, when an indicator for indicating a verification skip is
delivered at step 320, the new MME 150 may skip the verification
step. As discussed above, verification is performed in case the NAS
count is adjusted at step 303a. The new MME 150 may identify the UE
100 by using at least one of GUTI, MME UE S1AP ID, and S-TMSI
contained in the identification request message for requesting MM
context, and then deliver MM context corresponding to the UE by
using an identification response message at step 340.
[0112] Thereafter, steps 204 to 211 shown in FIG. 2 may be
performed. The difference is that the dedicated MME 154 is involved
instead of the new MME 150.
[0113] FIG. 3C is a flow diagram illustrating a process of
registering UE in a network through MME/SGSN according to the first
embodiment of the present invention.
[0114] Referring to FIG. 3C, steps 312 to 326 shown in FIG. 3C may
be identical to steps 212 to 226 previously discussed in FIG. 2B.
However, contrary to FIG. 2B, the process of FIG. 3C involves the
dedicated MME/SGSN 154 instead of the new MME 150 in the
registration procedure. Details will be omitted herein since the
same is discussed in FIG. 2B. Using the process discussed in FIGS.
3A to 3C, the UE can be offered a service through the DCN. In this
case, the UE 100 may transit a message to a core network through
two or more eNBs rather than through a single eNB only. For
example, this message may be transmitted to the core network
through HeNB, HeNB GW, MME or UE, relay node, donor eNB, and
MME.
[0115] FIG. 4 is a flow diagram illustrating another NAS message
reroute process according to the first embodiment of the present
invention.
[0116] Referring to FIG. 4, the NAS message reroute process in case
HeNB (home eNB)/DeNB (donor eNB) and HeNB GW (HeNB gateway)/RN
(relay node) are included is shown.
[0117] The new MME may transmit the redirection message to the HeNB
GW/DeNB at step 400. The redirection message may mean a message for
rerouting the NAS message and may include a reroute command or a
reroute NAS request message.
[0118] Considering that a UE-associated message is not terminated
at the HeNB GW/DeNB except for unusual circumstance, steps 410 and
420 may be performed in spite of inefficiency in signaling. Also,
in case an initial UE message needs revision, steps 410 and 420 may
be performed.
[0119] Specifically, the HeNB GW/DeNB may transmit a reroute
command to the HeNB/RN at step 410 and receive a response message
(51 (NAS EMM)) at step 420.
[0120] However, if the message delivered at step 400 contains the
entire information of the attach request message delivered at step
202 (e.g., in case the first initial UE message delivered at step
202 is completely contained in the redirection message delivered at
step 400), the HeNB GW and/or DeNB may perform a message
redirection without performing steps 410 and 420 even though not
storing information received from the HeNB and/or relay node.
Therefore, in this case, the HeNB GW/DeNB may not transmit the
reroute command message to the HeNB.
[0121] Additionally, step 400 may correspond to step 300 in FIG. 3.
Specifically, information contained in the redirection message may
be identical to information contained in the redirection message
transmitted at step 300.
[0122] Thereafter, the HeNB GW may select a DCN at step 430. This
step 430 may correspond to a process of selecting a core network
node performed by the eNB 300 after step 300 in FIG. 3.
[0123] The HeNB GW that selects the DCN may transmit the S1 message
to the dedicated MME at step 440. The step 440 (and step 420) may
correspond to step 310 in FIG. 3, and detailed description thereof
will be omitted.
[0124] FIG. 5 is a flow diagram illustrating a process in which the
first MME registers UE in a network according to the first
embodiment of the present invention.
[0125] Referring to FIG. 5, the first MIME may receive an initial
UE message from the eNB at step 510. The initial UE message may
contain an NAS message received from the UE by the eNB. The NAS
message may be transmitted to the eNB from the UE in the form of
being contained in an RRC message, and then transmitted to the
first MME in the form of being contained in the initial UE
message.
[0126] The first MME that receives the first message may transmit
an identification request message to the second MME at step 520.
Also, the first MME may receive an identification response message
for the identification request message at step 530.
[0127] The identification response message may contain UE usage
type information. The UE usage type information is information for
indicating a usage type of UE and may be included in the MM context
contained in the identification response message or may be
transmitted as an information element which is independent of the
MM context.
[0128] Additionally, the UE usage type information may be contained
in an update location ACK message received from the HSS, and the
following steps may be performed after the eNB receives the update
location ACK message. This embodiment will be discussed regarding
an example in which the UE usage type information is contained in
the identification response message.
[0129] At step 540, the first MME that receives the identification
response message may identify a DCN corresponding to the UE usage
type information and then may check whether the first MME can
support the DCN.
[0130] As the result of check, if it is determined that the first
MME can support the DCN, the first MME may perform a subsequent
network registration process of UE at step 550.
[0131] As the result of check, if it is determined that the first
MME cannot support the DCN, the first MME may enable the UE to be
serviced from a suitable dedicated MME through redirection of the
attach request message.
[0132] Therefore, at step 560, the first MME may transmit a
redirection message to the eNB so as to reroute the attach request
message. At this time, the redirection message may include a
reroute command message or a reroute NAS request message.
[0133] The redirection message may have at least one of MME UE S1AP
ID, eNB UE S1AP ID, (revised) NAS-PDU (Protocol Data Unit), GUTI,
GUMMEI (Globally Unique MME Identity), MMEGI (MME Group Identifier)
or Null NRI (Network Resource Identifier)/SGSN group ID, GUMMEI
type, S-TMSI (SAE Temporary Mobile Subscriber Identity), TAI
(Tracking Area Identity) and RRC establishment cause, additional
GUTI/P-TMSI, and information delivered to the MME/SGSN by the
eNB.
[0134] NAS-PDU contained in the redirection message may include an
NAS message. This embodiment uses an attach request message as the
NAS message. Namely, the first MME may insert the received attach
request message in the redirection message and then transmit it to
the eNB. Also, the first MME may insert the attach request message
with partially revised information in the redirection message and
then transmit it to the eNB.
[0135] Additionally, the redirection message may contain totally
the initial UE message received from the eNB.
[0136] Details of information contained in the redirection message
are discussed earlier in FIG. 3B, so the repetition is omitted
herein.
[0137] The first MME that transmits the redirection message may
receive an identification request message from the dedicated MME at
step 570. The identification request message may have the attach
request message.
[0138] The first MME that receives the identification request
message may check or verify the attach request message at step 580
and then adjust an NAS count in the first MME in order to prevent
errors at the check or verification step. For example, even in case
the attach request message is checked or verified, the uplink NAS
count may be not increased.
[0139] Additionally, the first MME may identify the UE by using at
least one of GUTI, MME UE S1AP ID, and S-TMSI which are contained
in the identification request message. Then, at step 590, using an
identification response message, the first MME may transmit MM
context corresponding to the identified UE to the dedicated
MME.
[0140] FIG. 6 is a flow diagram illustrating a process in which
eNodeB registers UE in a network according to the first embodiment
of the present invention.
[0141] Referring to FIG. 6, the eNB may receive an NAS message
contained in an RRC message at step 610. Since the NAS message may
include an attach request message, a TAU message, an RAU message,
etc., this process may be performed during an attach procedure, a
TAU procedure, or an RAU procedure.
[0142] The eNB that receives the NAS message may transmit the first
initial UE message having the NAS message to the first MME at step
620. In this case, since information contained in the first initial
UE message is discussed earlier in FIG. 3B, the repetition is
omitted herein.
[0143] If the first MME is not MME contained in the DCN, the first
MME may transmit a redirection message for rerouting the NAS
message to the eNB.
[0144] Therefore, at step 630, the eNB may receive the redirection
message for rerouting the NAS message.
[0145] The redirection message may have at least one of MME UE S1AP
ID, eNB UE S1AP ID, (revised) NAS-PDU (Protocol Data Unit), GUTI,
GUMMEI (Globally Unique MME Identity), MMEGI (MME Group Identifier)
or Null NRI (Network Resource Identifier)/SGSN group ID, GUMMEI
type, S-TMSI (SAE Temporary Mobile Subscriber Identity), TAI
(Tracking Area Identity) and RRC establishment cause, additional
GUTI/P-TMSI, and information delivered to the MME/SGSN by the
eNB.
[0146] The eNB that receives the redirection message may select the
second MME by using information contained in the redirection
message at step 640. In this case, the second MME may refer to a
dedicated MME located in the DCN.
[0147] A method for selecting the second MME by using information
contained in the redirection message is as follows.
[0148] The first MME may set, as a value associated with the
dedicated MME/SGSN 154, at least one of GUMMEI, MMEGI or
Null-NRI/SGSN Group ID, GUMMEI Type, and S-TMSI and transmit it to
the eNB. Then the eNB may select the dedicated MME by using
information set as the value associated with the dedicated MME.
MMEGI or Null-NRI/SGSN Group ID may be used to identify a DCN in a
PLMN. GUMMEI may directly indicate the dedicated MME. Specifically,
GUMMEI may be formed of a PLMN identifier, MMEGI, and MMEC. In this
case, a PLMN identifier may be set as a serving PLMN of the UE 100
(namely, identical to a PLMN part of TAI at step 102), MMEGI may be
set as a value corresponding to a dedicated MME group, and MMEC
(MME Code) may be set as a value corresponding to MMEC of the first
MME. Therefore, the eNB may select a dedicated MME group by using a
PLMN identifier and MMEGI, and then select a dedicated MME by
referring to MMEC.
[0149] Additionally, the eNB may select MME/SGSN in the DCN
indicated by MMEGI or Null-NRI/SGSN Group ID. If additional
GUTI/P-TMSI identifies MME/SGSN in the DCN indicated by MMEGI or
Null-NRI/SGSN Group ID, the eNB may select MME/SGSN identified by
additional GUTI/P-TMSI.
[0150] Meanwhile, in a network shared by several PLMNs, a DCN may
be selected using the following method.
[0151] The eNB may select a dedicated MME by using at least one of
PLMN, MMEGI or Null-NRI/SGSN Group ID, and additional GUTI/P-TMSI
which are selected by the UE. The eNB may select MME/SGSN in the
DCN indicated by MMEGI or Null-NRI/SGSN Group ID in PLMN selected
by the UE. If additional GUTI/P-TMSI identifies MME/SGSN in the DCN
indicated by MMEGI or Null-NRI/SGSN Group ID, the eNB may select
MME/SGSN identified by additional GUTI/P-TMSI. Namely, in case the
eNB receives additional GUTI/P-TMSI, the eNB may select a core
network by considering PLMN, MMEGI or Null-NRI/SGSN Group ID, and
most significant 8 bits of MMEC or NRI in additional GUTI/P-TMSI
which are selected by the UE. In this case, PLMN in additional
GUTI/P-TSMI may be ignored.
[0152] A method in which the eNB identifies PLMN selected by the UE
may be a method of storing PLMN selected by and received from the
UE and then using stored information, or a method of using PLMN
contained in the redirection message and selected by the UE.
[0153] In case of using information contained in the redirection
message, the eNB may identify PLMN selected by the UE by extracting
PLMN ID of TAI information contained in the redirection
message.
[0154] Selection of DCN and dedicated MME by the eNB may be similar
to that discussed in FIG. 3B.
[0155] The eNB that selects the dedicated MME may transmit the
second initial UE message containing an NAS message to the
dedicated MME at step 650. In this case, the second initial UE
message may include the entire information contained in the
redirection message. Also, the eNB may transmit an uplink NAS
transport message to the dedicated MME. If it is not possible to
find selectable MME in a DCN, the eNB may select MME in the default
DCN or select again the MME.
[0156] Using the above-discussed process, the eNB may enable the UE
to be offered service through a DCN.
[0157] FIG. 7 is a flow diagram illustrating a process in which
HeNB GW registers UE in a network according to the first embodiment
of the present invention.
[0158] Referring to FIG. 7, the first MME that identifies a UE
usage type may transmit a redirection message to HeNB GW in case of
failing to support a DCN corresponding to the UE usage type.
Details are similar to discussed above, so the repetition is
omitted herein.
[0159] Therefore, the HeNB GW may receive the redirection message
at step 710. The redirection message may include a reroute command
or a reroute NAS request message.
[0160] In this case, the redirection message may include an NAS
message received from the UE and delivered to the first MME.
[0161] Since a UE-associated message is not terminated at the HeNB
GW/DeNB except for unusual circumstance, the HeNB GW may transmit
the redirection message to the HeNB at step 720 in spite of
inefficiency in signaling. Also, the HeNB GW may receive a response
message (an initial UE message) at step 730. Also, in case the
initial UE message needs revision, the HeNB GW may transmit the
redirection message to the HeNB and then receive the response
message.
[0162] However, if the redirection message has the entire
information contained in the attach request message, the HeNB GW
may perform step 740 without performing steps 720 and 730.
[0163] At step 740, the HeNB GW may select the DCN and dedicated
MME. The HeNB GW may select the dedicated MME by using information
contained in the redirection message. Details are similar to those
discussed above, so the repetition is omitted herein.
[0164] The HeNB GW that selects the dedicated MME may transmit the
initial UE message having the redirection message to the dedicated
MME at step 750. Using the above-discussed process, the HeNB GW may
enable the UE to be offered service through a DCN.
[0165] FIG. 8 is a block diagram illustrating a configuration of
the first MME according to the first embodiment of the present
invention.
[0166] Referring to FIG. 8, the first MME may be formed of a
communication unit 810, a control unit 820, and a storage unit
830.
[0167] The communication unit 810 may perform communication with
other network entities such as the eNB, the second MME, or the
like.
[0168] The control unit 820 may control the reception of an initial
UE message from the eNB. The initial UE message may contain an NAS
message transmitted from the UE.
[0169] Additionally, the control unit 820 may control the
transmission and reception of an identification request message and
an identification response message to and from the second MME, and
may check UE usage type information contained in the received
identification response message. Also, the control unit 820 may
control the reception of an update location ACK message from the
HSS, and may check UE usage type information contained in the
update location ACK message. The control unit 820 may determine
whether to support a DCN according to the UE usage type
information.
[0170] In case of failing to support the DCN as the result of
determination, the control unit 820 may create a redirection
message for rerouting the NAS message so as to allow the UE to be
serviced from a dedicated MME, and then may transmit the
redirection message to the eNB. The redirection message may include
all or part of information contained in the NAS message.
Additionally or alternatively, the redirection message may include
all or part of information contained in the initial UE message.
[0171] Namely, the control unit 820 may deliver the received NAS
message, as it is, to the eNB so that the eNB can forward the NAS
message to the dedicated MME. Therefore, the UE can be offered a
service from the DCN.
[0172] Additionally, the control unit 820 may insert, in the
redirection message, at least one of MME UE S1AP ID, eNB UE S1AP
ID, (revised) NAS-PDU (Protocol Data Unit), GUTI, GUMMEI (Globally
Unique MME Identity), MMEGI (MME Group Identifier) or Null NRI
(Network Resource Identifier)/SGSN group ID, GUMMEI type, S-TMSI
(SAE Temporary Mobile Subscriber Identity), TAI (Tracking Area
Identity) and RRC establishment cause, additional GUTI/P-TMSI, and
information delivered to the MME/SGSN by the eNB. Therefore, using
such information, the eNB may determine the dedicated MME.
[0173] Further, the control unit 820 may control the reception of
an identification request message from the dedicated MME. After
this reception, the control unit 820 may check or verify the NAS
message contained in the identification request message.
[0174] Further, the control unit 820 may identify the UE by using
at least one of GUTI, MME UE S1AP ID, and S-TMSI which are
contained in the received identification request message.
Therefore, using an identification response message, the control
unit 820 may transmit MM context corresponding to the identified UE
to the dedicated MME.
[0175] The storage unit 830 may store information contained in the
initial UE message received from the eNB. Also, the storage unit
830 may store information contained in the identification response
message received from the second MME and information contained in
the update location ACK message received from the HSS. Therefore,
information stored in the storage unit 830 may be used when the
control unit 820 checks whether the DCN corresponding to the UE
usage type information can be supported. Also, such information may
be used when the control unit 820 creates the direction
message.
[0176] FIG. 9 is a block diagram illustrating a configuration of
eNodeB according to the first embodiment of the present
invention.
[0177] Referring to FIG. 9, the eNB may be formed of a
communication unit 910, a control unit 920, and a storage unit
930.
[0178] The communication unit 910 may perform communication with
other network entities such as the first MME, the UE, the dedicated
MME, or the like.
[0179] The control unit 920 may control the reception of an NAS
message contained in an RRC message from the UE. The control unit
920 may create the first initial UE message including the received
NAS message and then transmit it to the first MME. Information
contained in the first initial UE message is discussed earlier in
FIG. 3B, so the repetition is omitted herein.
[0180] In case the first MME that receives the first initial UE
message from the eNB is not a dedicated MME, the control unit 920
may receive a direction message from the first MME. The redirection
message may include all or part of information contained in the NAS
message. Additionally or alternatively, the redirection message may
include all or part of information contained in the first initial
UE message.
[0181] When the redirection message having the NAS message or the
first initial UE message is received, the control unit 920 may
forward the received message to the dedicated MME. Alternatively,
the control unit 920 may create the second initial UE message
having the NAS message contained in the redirection message and
then transmit it to the dedicated MME.
[0182] Therefore, the control unit 920 should determine the
dedicated MME. A method for determining the dedicated MME is as
follows.
[0183] The redirection message may contain at least one of MME UE
S1AP ID, eNB UE S1AP ID, (revised) NAS-PDU (Protocol Data Unit),
GUTI, GUMMEI (Globally Unique MME Identity), MMEGI (MME Group
Identifier) or Null NRI (Network Resource Identifier)/SGSN group
ID, GUMMEI type, S-TMSI (SAE Temporary Mobile Subscriber Identity),
TAI (Tracking Area Identity) and RRC establishment cause,
additional GUTI/P-TMSI, and information delivered to the MME/SGSN
by the eNB.
[0184] The first MME may set, as a value associated with the
dedicated MME/SGSN 154, at least one of GUMMEI, MMEGI or
Null-NRI/SGSN Group ID, GUMMEI Type, and S-TMSI and transmit it to
the eNB. Then the control unit 920 may select the dedicated MME by
using information which is set as the value associated with the
dedicated MME.
[0185] MMEGI or Null-NRI/SGSN Group ID may be used to identify a
DCN in a PLMN.
[0186] GUMMEI may directly indicate the dedicated MME.
Specifically, GUMMEI may be formed of a PLMN identifier, MMEGI, and
MMEC. In this case, a PLMN identifier may be set as a serving PLMN
of the UE 100 (namely, identical to a PLMN part of TAI at step
102), MMEGI may be set as a value corresponding to a dedicated MME
group, and MMEC (MME Code) may be set as a value corresponding to
MMEC of the first MME. Therefore, the control unit 920 may select a
dedicated MME group by using a PLMN identifier and MMEGI, and then
select a dedicated MME by referring to MMEC.
[0187] Additionally, the control unit 920 may select MME/SGSN in
the DCN indicated by MMEGI or Null-NRI/SGSN Group ID. If additional
GUTI/P-TMSI identifies MME/SGSN in the DCN indicated by MMEGI or
Null-NRI/SGSN Group ID, MME/SGSN identified by additional
GUTI/P-TMSI may be selected.
[0188] Meanwhile, in a network shared by several PLMNs, the control
unit 920 may select a DCN by using the following method.
[0189] The control unit 920 may select a dedicated MME by using at
least one of PLMN, MMEGI or Null-NRI/SGSN Group ID, and additional
GUTI/P-TMSI which are selected by the UE. The control unit 920 may
select MME/SGSN in the DCN indicated by MMEGI or Null-NRI/SGSN
Group ID in PLMN selected by the UE. If additional GUTI/P-TMSI
identifies MME/SGSN in the DCN indicated by MMEGI or Null-NRI/SGSN
Group ID, MME/SGSN identified by additional GUTI/P-TMSI may be
selected. Namely, in case additional GUTI/P-TMSI is received, the
control unit 920 may select a core network by considering PLMN,
MMEGI or Null-NRI/SGSN Group ID, and most significant 8 bits of
MMEC or NRI in additional GUTI/P-TMSI which are selected by the UE.
In this case, PLMN in additional GUTI/P-TSMI may be ignored.
[0190] In this case, the control unit 920 may control the storage
unit 930 to store PLMN selected by and received from the UE, and
may use stored information. Alternatively or additionally, the
control unit 920 may identify PLMN selected by the UE through PLMN
contained in the redirection message.
[0191] If it is not possible to find selectable MME in a DCN, the
eNB may select MME in the default DCN or select again the MME.
[0192] Using the above-discussed process, the control unit 920 may
enable the UE to be offered service through a DCN.
[0193] The storage unit 930 may store information contained in the
RRC message received from the eNB. Also, the storage unit 930 may
store information contained in the identification response message
received from the first MME. Such information stored in the storage
unit 930 may be used for creating the first initial UE message or
the second initial UE message.
[0194] FIG. 10 is a block diagram illustrating a configuration of
UE according to the first embodiment of the present invention.
[0195] Referring to FIG. 10, the UE may be formed of a
communication unit 1010, a control unit 1020, and a storage unit
1030.
[0196] The communication unit 1010 may perform communication with
other network entities such as the eNB, the first MME, or the
like.
[0197] The control unit 1020 may create an RRC message having an
NAS message and transmit the created RRC message to the eNB through
the RRC layer. The NAS message may include at least one of an
attach request message, a TAU message, and an RAU message.
[0198] The NAS message may be contained in the first initial UE
message transmitted to the first MIME by the eNB. Also, the NAS
message may be contained in the redirection message transmitted by
the first MME. The eNB that receives the redirection message having
the NAS message may create the second initial UE message having the
NAS message and then transmit it to the dedicated MME.
[0199] The storage unit 1030 may store the created NAS message.
Also, the storage unit 1030 may store ID information for response
to an ID request. Also, the storage unit 1030 may store
authentication information.
Second Embodiment
[0200] Hereinafter, a congestion control method and apparatus for
an application according to the second embodiment of the present
invention will be described.
[0201] According as the number of transmission packets is increased
in a network, the performance of the network is degraded. A
phenomenon of rapid degradation in network performance is referred
to as congestion.
[0202] Typically, when congestion occurs, ACM, SSAC, EAB, SCM, etc.
are used as access control technique for UE. However, the UE fails
to support an application-specific congestion control for data
communication (ACDC).
[0203] If there is pending uplink data in the UE when the UE sends
a tracking area update (TAU) request message, the UE sets an active
flag of the TAU request message to 1 and performs transmission. As
a result, a user plane connection is established between the UE and
the network.
[0204] Therefore, ACDC may be applied even when an active flag of
the TAU request message is 1. The present invention proposes a
method for applying ACDC in case of TAU.
[0205] Additionally, in case the UE uses a power saving mode (PSM),
the UE inserts an active timer in the TAU request message and
transmits it to the network. In this case as well, since the active
flag may be set to 1 when there is pending uplink data, ACDC should
be applied. Also, the UE that has the active timer and intends to
enter PSM may be allowed to send a service request regardless of
ACDC with regard to the service request sent during the period of
time.
[0206] In this disclosure, ACDC may be determined according to
operator's policy or regional regulations, providing a service in a
disaster state and also controlling congestion for a commercial
service. Additionally, ACDC may be used as a similar concept with
other functions capable of a congestion control for each
application. An embodiment of the present invention may be
similarly used generally in wireless communication such as WLAN,
Bluetooth, Zigbee, and the like in addition to the communication
system discussed herein. Additionally, a mobile communication
operator may provide UE with information for ACDC. This may be
implemented using OMA standard called Management Object (MO) and
thus referred to as ACDC MO. In order to deliver ACDC MO, a network
operator may use other method such as presetting in the UE or SIM
rather than using OMA standard.
[0207] FIG. 11 is a flow diagram illustrating a process in which UE
applies ACDC in a TAU procedure according to the second embodiment
of the present invention.
[0208] Referring to FIG. 11, the UE may decide to initiate the TAU
procedure at step 1110 according as a tracking area is changed.
When initiating TAU, the UE may have uplink data to be transmitted
through a network.
[0209] At step 1120, the UE may determine whether to set the active
flag of the TAU message to 1 by determining whether there is uplink
data in the UE. If there is no uplink data in the UE, the UE may
not set the active flag to 1 and perform a normal TAU procedure at
step 1130. Namely, the UE may transmit a TAU message contained in
an RRC message to the eNB without checking application
information.
[0210] If there is uplink data in the UE, the UE may set the active
flag of the TAU message to 1. Then, at step 1140, the UE may
determine information about an application that generates the
uplink data.
[0211] In this case, the application information may be a criterion
of determination for applying ACDC, depending on an application
from which pending uplink data in the UE is generated. The
application information may include an application category.
[0212] For example, if an application that generates uplink data
belongs to an application category having lower priority, access
may be disallowed (hereinafter, the term barring may be also used)
as the result of applying ACDC and thus data may be not
transmitted.
[0213] If an application that generate uplink data belongs to an
application category having higher priority, a UE access process
may be performed again even in case of barring access by an
application contained in an application category having lower
priority.
[0214] Therefore, the UE may identify an application generating
transmission-ready uplink data and check an application category by
using an identifier of the application and setting information
thereof. Herein, this setting information may be contained in ACDC
MO. Namely, the UE may map the application to an application
category received with ACDC MO. Through this procedure, the UE
finds application information.
[0215] In this case, an application category contained in
application information may be formed of bit information. For
example, in case information is formed of 3 bits, category #1 may
be represented as 001 and category #4 may be represented as 011. A
value from 2 bits to 8 bits may be used.
[0216] The UE that finds application information may determine, at
step 1150, whether to control access. Namely, the UE may determine
whether to perform access barring.
[0217] Specifically, the UE may extracts, from system information
block (SIB) information received from the eNB, a barring factor
corresponding to an application category contained in application
information. The UE may determine, based on a value specified or
created through random number generation using the barring factor,
whether to perform access barring or not (i.e., pass).
[0218] At this time, access barring of UE may mean, for example,
that the TAU procedure of UE is not initiated. Namely, it may mean
that the UE does not transmit the TAU message to the eNB.
[0219] However, as discussed above, even in case of access barring
due to lower priority of a specific application category, the
access procedure may be performed if the UE supports ACDC in case
radio resources of a user plane is requested for an application
category having higher priority.
[0220] If the access of UE is passed, the UE may transmit the RRC
message containing the TAU message to the eNB at step 1260.
[0221] FIG. 12 is a flow diagram illustrating a process of applying
ACDC in a TAU procedure according to the second embodiment of the
present invention.
[0222] Referring to FIG. 12, the first upper layer unit of the UE
may receive a data transmission request from the third upper layer
unit at step 1210. Then the first upper layer unit may decide to
initiate a TAU procedure at step 1220. Although an example in which
the first upper layer unit initiates the TAU procedure after
receiving the data transmission request is shown, the first upper
layer unit may decide to initiate the TAU procedure and then
receive the data transmission request from the third upper layer
unit.
[0223] Herein, the first upper layer unit may mean an apparatus for
controlling operations on an NAS layer. Also, the third upper layer
unit may mean an apparatus for controlling operations on an
application layer.
[0224] Meanwhile, when the UE initiates the TAU procedure, the UE
may have uplink data to be transmitted through a network.
[0225] If the UE supports ACDC, if user plane radio resource
allocation according to uplink data is requested, and if it is
possible to apply ACDC to this request, the UE may set the active
flag of the TAU message to 1 at step 1230. Additionally, at step
1240, the UE may determine information about an application that
generates the uplink data. This application information may contain
an application category, which is discussed for example
hereinafter. However, the application information is not limited to
application category information.
[0226] In this case, an application from which uplink data pending
in the UE is generated may be a criterion for applying ACDC. For
example, if an application that generates uplink data belongs to an
application category having lower priority, access barring is
determined as the result of applying ACDC and thus data may be not
transmitted.
[0227] Therefore, the UE may find an application category by
identifying an application generating transmission-ready uplink
data and by using an identifier of the application and setting
information thereof. Herein, this setting information may include
category determination information for finding the category of an
application, and may be contained in ACDC MO. Namely, the UE may
map the application to an application category received with ACDC
MO. This ACDC MO may be received through the application that
generates transmission-ready uplink data. Through this procedure,
the UE finds application information.
[0228] The UE that finds application information may transmit the
application information to the second upper layer unit of the UE at
step 1250. Herein, the second upper layer unit may mean an
apparatus for controlling operations on a radio resource control
(RRC) layer of the UE.
[0229] At this time, the first upper layer unit of the UE may form
a call type, based on application category information for applying
ACDC, the TAU message, and RRC establishment cause, and then may
deliver this information to the second upper layer unit.
[0230] In this case, application category information for applying
ACDC may be formed of bit information for indicating an application
category. For example, in case information is formed of 3 bits,
category #1 may be represented as 001 and category #4 may be
represented as 011. A value from 2 bits to 8 bits may be used.
[0231] At step 1260, the second upper layer unit that receives the
TAU message, the application category information for applying
ACDC, and the RRC establishment cause from the first upper layer
unit may determine UE access or not. In order to determine
transmission of uplink data, the UE may compare the application
category information for applying ACDC with ACDC information of SIB
information received from the eNB.
[0232] Specifically, the UE may extracts, from SIB information, a
barring factor corresponding to the application category
information received from the first upper layer unit. Then, based
on the barring factor, the UE performs an access control, i.e., UE
access barring or passing, depending on a value specified or
created through random number generation.
[0233] At this time, barring UE access may mean, for example, that
the TAU procedure of UE is not initiated. Namely, it may mean that
the UE does not transmit the TAU message to the eNB.
[0234] However, even in case of access barring due to lower
priority of a specific application category, the access procedure
may be performed if the UE supports ACDC when radio resources of a
user plane is requested for an application category having higher
priority.
[0235] If the access of UE is passed, the UE may transmit the RRC
message to the eNB at step 1270. This RRC message contains the TAU
message received from the first upper layer unit of the UE.
[0236] Meanwhile, if the UE does not set the active flag to 1 at
step 1230, the UE does not perform application category mapping for
ACDC. Instead, the UE sets a call type complying with TAU
initiation conditions, based on the TAU message and the
establishment cause, and then deliver this information to the
second upper layer unit. Thereafter, the second upper layer unit
transmits the TAU message contained in the RRC message to the
eNB.
[0237] FIG. 13 is a flow diagram illustrating another process in
which UE applies ACDC in a TAU procedure according to the second
embodiment of the present invention.
[0238] Referring to FIG. 13, the UE may decide to initiate the TAU
procedure at step 1310 according as a tracking area is changed.
When initiating the TAU procedure, the UE may have uplink data to
be transmitted through a network.
[0239] If there is uplink data in the UE, the UE may set the active
flag of the TAU message to 1 at step 1320.
[0240] In this case, an application from which uplink data pending
in the UE is generated may be a criterion for applying ACDC. For
example, if an application that generates uplink data belongs to an
application category having lower priority, access barring is
determined as the result of applying ACDC and thus data may be not
transmitted.
[0241] If an application that generate uplink data belongs to an
application category having higher priority, a UE access process
may be performed again even in case of barring access by an
application contained in an application category having lower
priority.
[0242] If the UE desires to use a power saving mode (PSM), the UE
may set an active timer value of the TAU message and, based on
this, determine whether to apply ACDC.
[0243] The term PSM may refer to a mode in which the UE sends data
for a short time and then enters an idle state. Therefore, the UE
that enters PSM may contribute to reduction in network
congestion.
[0244] Therefore, in case the UE sets the active flag of the TAU
message to 1 at step 1320, the UE may determine whether to set the
active timer value of the TAU message for using PSM at step
1330.
[0245] If the active timer value is set, the UE may skip a
congestion control through ACDC at step 1340. Therefore, at step
1350, the UE may transmit the TAU request message to the network
according to a normal TAU procedure.
[0246] Namely, in case both the active flag and the active timer
value are set, the UE may determine a call type corresponding to
RRC establishment cause corresponding to the TAU message, form the
RRC message including this information, and transmit the RRC
message to the eNB.
[0247] In another example, if the TAU procedure is completed in a
state where both the active flag and the active timer value are set
(i.e., in case of transmitting the TAU request message to the eNB
and then receiving the TAU accept message from the eNB), the UE may
skip ACDC for other service request message until entering a PSM
state after the expiration of an active timer.
[0248] Meanwhile, if the UE fails to set the active timer value of
TAU at step 1330, the UE may apply ACDC to uplink data. Namely, the
UE may find application information (e.g., application category)
associated with the generation of uplink data at step 1370 and then
determine access or not of UE according to the application
information at step 1380. Details are discussed above in FIG. 11,
so the repetition is omitted herein.
[0249] Meanwhile, if the UE does not set the active flag to 1 at
step 1320, the UE may perform a normal TAU procedure at step
1390.
[0250] Namely, the UE may select a call type for the TAU message
and RRC establishment cause without application category mapping,
form the RRC message having such information, and transmit the RRC
message to the eNB.
[0251] FIG. 14 is a flow diagram illustrating another process of
applying ACDC in a TAU procedure according to the second embodiment
of the present invention.
[0252] While FIG. 12 shows a case in which an active timer is not
set, FIG. 14 shows a case in which the active timer is set.
[0253] Referring to FIG. 14, the first upper layer unit of the UE
may receive a data transmission request from the third upper layer
unit at step 1410. Then the first upper layer unit may decide to
initiate a TAU procedure at step 1420. Alternatively, the first
upper layer unit may decide to initiate the TAU procedure and then
receive the data transmission request from the third upper layer
unit.
[0254] Herein, the first upper layer unit may mean an apparatus for
controlling operations on an NAS layer. Also, the third upper layer
unit may mean an apparatus for controlling operations on an
application layer.
[0255] When the UE initiates the TAU procedure, the UE may have
uplink data to be transmitted through a network.
[0256] If the UE supports ACDC, if user plane radio resource
allocation according to uplink data is requested, and if it is
possible to apply ACDC to this request, the UE may set the active
flag of the TAU message to 1 at step 1430. Additionally, at step
1440, the UE may set the active timer of the TAU message.
[0257] The case where the UE sets the active timer of the TAU
message may mean a case in which the UE uses PSM. The term PSM may
refer to a mode in which the UE sends data for a short time and
then enters an idle state. Therefore, the UE that enters PSM may
contribute to reduction in network congestion.
[0258] Therefore, if the UE sets the active flag to 1 because of
the presence of uplink data to be transmitted, and if the UE sets
the active timer value for the use of PSM, the UE may not require a
congestion control through ACDC.
[0259] Therefore, at step 1450, the first upper layer unit may
determine a call type corresponding to RRC establishment cause
corresponding to the TAU message, and transmit this information to
the second upper layer unit. At this time, the second upper layer
unit may mean, but not limited to, an apparatus for controlling
operations on the RRC layer.
[0260] Thereafter, the second upper layer unit may form the RRC
message having the above information at step 1460, and transmit the
RRC message to the eNB at step 1470.
[0261] Meanwhile, if the TAU procedure is completed in a state
where both the active flag and the active timer value are set
(i.e., in case of transmitting the TAU request message to the eNB
and then receiving the TAU accept message from the eNB), the UE may
skip ACDC for other service request message until entering a PSM
state after the expiration of an active timer. If the first upper
layer unit of the UE does not set the active flag to 1, the first
upper layer unit may determine a call type corresponding to the TAU
message and RRC establishment cause without application category
mapping for using ACDC according to a normal TAU procedure, and
transmit this to the second upper layer unit. Then the second upper
layer unit may form the RRC message having the above information
and transmit the RRC message to the eNB.
[0262] FIG. 15 is a block diagram illustrating a configuration of
UE according to the second embodiment of the present invention.
[0263] Referring to FIG. 15, the UE according to the second
embodiment includes a transceiver unit 1505, a control unit 1510, a
multiplexing and demultiplexing unit 1520, a control message
processing unit 1545, and various upper layer processing units
1525, 1530 and 1535. Although three upper layer processing units
1525, 1530 and 1535 are shown, this is exemplary only and not to be
considered as a limitation of this invention.
[0264] The transceiver unit 1505 may perform communication with
other network entities. The transceiver unit 1505 may receive data
and control signals through a downlink channel of a serving cell
and also transmit data and control signals through an uplink
channel.
[0265] The multiplexing and demultiplexing unit 1520 may multiplex
data generated at the upper layer processing units 1525, 1530 and
1535 or the control message processing unit 1545. Also, the
multiplexing and demultiplexing unit 1520 may demultiplex data
received from the transceiver unit 1505 and then deliver it to the
upper layer processing units 1525, 1530 and 1535 or the control
message processing unit 1545.
[0266] The control message processing unit 1545 is a kind of RRC
layer apparatus and may process a control message received from the
eNB.
[0267] The upper layer processing units 1525, 1530 and 1535 may be
formed of the first upper layer processing unit 1525, the second
upper layer processing unit 1530, and the third upper layer
processing unit 1535. The UE may further include a plurality of
upper layer processing units.
[0268] The first upper layer processing unit 1525 may control
operations on the NAS layer, and the second upper layer processing
unit 1530 may control operations on the RRC layer. Also, the third
upper layer processing unit 1535 may control operations on the
application layer. Such upper layer processing units may be formed
for each service. The upper layer processing units may process data
created in a user service such as FTP (File Transfer Protocol) or
VoIP (Voice over Internet Protocol) and then deliver it to the
multiplexing and demultiplexing unit 1520, or may process data
delivered from the multiplexing and demultiplexing unit 1520 and
then deliver it to a service application on the upper layer.
[0269] The control unit 1510 may check scheduling commands, e.g.,
reverse grants, received through the transceiver unit 1505 and then
control the transceiver unit 1505 and the multiplexing and
demultiplexing unit 1520 so that reverse transmission can be
performed with suitable transmission resources at a suitable time
point. Also, the control unit 1510 controls all procedures applying
ACDC in the TAU procedure. Namely, the control unit 1510 performs
control operations associated with the operation of UE as shown in
FIGS. 11 to 14.
[0270] Specifically, the control unit 1510 may control the first
upper layer processing unit to determine whether to initiate the
TAU procedure. At this time, if uplink data transmission is
requested through the third upper layer processing unit, the
control unit 1510 may control the first upper layer processing unit
to determine whether to initiate the TAU procedure. Alternatively
or additionally, the control unit 1510 may control the reception of
a data transmission request from the third upper layer processing
unit after the first upper layer processing unit determines the
initiation of the TAU procedure. Also, the control unit 1510 may
control a value of the active flag to be set to 1, depending on
whether there is transmission-ready uplink data. If the value of
the active flag is not set to 1, the control unit 1510 may control
performing a normal TAU procedure. If the value of the active flag
is set to 1, the control unit 1510 may control determining
application information of an application from which
transmission-ready uplink data is generated. This application
information may include an application category. Additionally, the
control unit 1510 may control delivering the application
information from the first upper layer processing unit to the
second upper layer processing unit. Also, the control unit 1510 may
determine whether to allow the access of UE, using the application
information through the second upper layer processing unit. The
control unit 1510 may extract a barring factor corresponding to an
application category from SIB information received from the eNB.
The control unit 1510 may determine UE access barring or passing,
depending on a value specified or created through random number
generation using the barring factor.
[0271] However, even in case of access barring due to lower
priority of a specific application category, the control unit 1510
may perform the access procedure if the UE supports ACDC when radio
resources of a user plane is requested for an application category
having higher priority.
[0272] If the access of UE is passed, the control unit 1510 may
control transmitting the RRC message having the TAU message to the
eNB through the second upper layer processing unit.
[0273] Meanwhile, with regard to UE that uses PSM, the control unit
1510 may control determining whether to apply ACDC. The term PSM
may refer to a mode in which the UE sends data for a short time and
then enters an idle state. Therefore, the UE that enters PSM may
contribute to reduction in network congestion.
[0274] Therefore, in case of setting the active flag to 1 (i.e.,
transmission-ready uplink data exists) and in case of setting the
active timer value so as to operate in PSM, the control unit 1510
may control performing no congestion control through ACDC.
Therefore, the control unit 1510 may control performing a normal
TAU procedure. Specifically, the control unit 1510 may control the
first upper layer processing unit to determine a call type
corresponding to RRC establishment cause corresponding to the TAU
message, and transmit this information to the second upper layer
processing unit. Further, the control unit 1510 may control the
second upper layer processing unit to form the RRC message having
the above information and transmit the RRC message to the eNB.
[0275] Meanwhile, if the TAU procedure is completed in a state
where both the active flag and the active timer value are set
(i.e., in case of transmitting the TAU request message to the eNB
and then receiving the TAU accept message from the eNB), the
control unit 1510 may skip ACDC for other service request message
until entering a PSM state after the expiration of an active
timer.
Third Embodiment
[0276] Hereinafter, a method and apparatus for providing a
multimedia broadcast multicast service (MBMS) according to the
third embodiment of the present invention will be described.
[0277] In case of providing data to UE through MBMS, a group
communication service application server (GCS AS) and/or a
broadcast/multicast service center (BM-SC) may transmit information
associated with MBMS service area, and the UE may receive MBMS data
based on the MBMS service area. However, since the MBMS service
area covers a wide range, MME may change the MBMS service area even
when considerable traffic is generated due to numerous users in a
specific area. Therefore, in case there are many users in a
specific area, the MME may transmit a message for instructing a
setup or modification of MBMS session to a multi cell/multicast
coordination entity (MCE) contained in the MBMS service area so
that the MBMS session can be created or changed and finally MBMS
data can be transmitted to the UE. However, this method for
creating or changing the MBMS session may invite necessary
signaling. Therefore, this invention proposes a method for
transmitting and receiving data in a smaller MBMS area than the
MBMS service area.
[0278] FIGS. 16A and 16B are flow diagrams illustrating a method
for providing an MBMS service according to the third embodiment of
the present invention.
[0279] In this embodiment, an MBMS applicable area may be a smaller
area than the MBMS service area.
[0280] Referring to FIG. 16A, the GCS AS may transmit an activate
MBMS bearer request message to the BM-SC at step 1601.
Alternatively, the GCS AS may transmit a modify MBMS bearer request
message for modifying an activated MBMS bearer to the BM-SC at step
1604. The activate MBMS bearer request message and the modify MBMS
bearer request message may contain information about an MBMS
broadcast area. The GCS AS may determine the MBMS broadcast area
information, based on information (e.g., a UE location which may be
represented as a cell identifier, an MBSFN area identifier, an MBMS
service area, etc.) obtained from the UE through application
signaling and/or setting information. The MBMS broadcast area
information may include an MBMS service area, an MBSFN area
identifier list, and/or a cell list (i.e., an ECGI (E-UTRAN cell
global identifier) list).
[0281] At step 1602, the BM-SC that receives the activate MBMS
bearer request message may allocate resources in an MBMS system so
as to support a data flow. Alternatively, at step 1605, the BM-SC
that receives the modify MBMS bearer request message may determine
whether to modify the MBMS bearer.
[0282] If a cell list is contained in the MBMS broadcast area
information received by the BM-SC, the BM-SC may induce the MBMS
service area from the cell list information. For this, the BM-SC
may have mapping information between the cell list information and
the MBMS service area. In this case, if the MBMS service area is
received from the GCS AS, the BM-SC may overwrite the received MBMS
service area with the induced MBMS service area. Thereafter, the
BM-SC may insert mapped MBMS service area and/or cell list in a
message sent to MBMS GW for requesting MBMS bearer activation
and/or MBMS bearer modification. Of course, even though a cell list
is contained in the MBMS broadcast area information received by the
BM-SC, the MBMS service area information received from the GCS AS
may be used as it is. In case the GCS AS sends the cell list and
the MBMS service area, whether the BM-SC will use them as received
or use a new MBMS service area induced from the cell list may
depend on an operator's policy and/or setting.
[0283] If the BM-SC induces the MBMS service area from the cell
list, the BM-SC may deliver, to the GCS AS, the induced MBMS
service area (i.e., the MBMS service area contained in a message
sent to the MBMS GW for requesting MBMS bearer activation and/or
MBMS bearer modification) through a response message for the
request of MBMS bearer activation and/or MBMS bearer modification
at step 1603 or 1606. If the BM-SC does not induce the MBMS service
area from the cell list, or if the received MBMS broadcast area
information does not contain the cell list, the BM-SC may not
insert the MBMS service area in the response message for the
request of MBMS bearer activation and/or MBMS bearer
modification.
[0284] The GCS AS may transmit, to the UE, the MBMS service area
received at step 1603 or 1606. If the GCS AS fails to receive the
MBMS service area at step 1603 or 1606, the GCS AS may transmit, to
the UE, the MBMS service area transmitted to the BM-SC at step 1601
or 1604. Although any cell is located in the MBMS service area,
MBMS may not be applied if the MBMS bearer is activated using the
cell list. Therefore, in case the MBMS service area received from
the GCS AS is not contained in the MBMS service area information
broadcasted by the cell, the UE can know that MBMS is not applied
to a service in that cell. However, in case the MBMS service area
received from the GCS AS is contained in the MBMS service area
information broadcasted by the cell, the UE may not know whether
MBMS is applied or not to a service in that cell.
[0285] Referring to FIG. 16B, the MME may receive, from MBMS-GW, a
message that contains the MBMS service area and the cell list
(i.e., the ECGI list). Also, a message transmitted to the MCE by
the MME may contain parameters received through the BM-SC by the
MBMS-GW. In this case, these parameters may include a temporary
mobile group identity (TMGI), FlowID, QoS, MBMS broadcast area
information, a start time, and the like. The MBMS broadcasts area
information may include the MBMS service area or the cell list
information. If the cell list information is contained in the MBMS
broadcast area information, this information may be mapped to the
MBMS service area by the BM-SC. The BM-SC may deliver, to the GCS
AS, information (MBMS service area) created from the cell list
information.
[0286] The MME that receives the message including the MBMS service
area and the cell list from the MBMS GW may transmit a message
(hereinafter, referred to as an MBMS session setup or modify
message) for a setup or modification of MBMS session to the MCE. At
this time, the MME may send the MBMS session setup or modify
message to only the MCE that controls the received cell list.
[0287] For this, at step 1610 for M3 setup with the MME, the MCE
may deliver, to the MME, an M3 setup request message having a cell
identifier list and/or an identifier list of the eNB connected to
the MCE.
[0288] The M3 setup request message may be defined as shown in
Table 2 and Table 3.
TABLE-US-00002 TABLE 2 IE/Group IE type and Semantics Assigned Name
Presence Range reference description Criticality Criticality
Message Type M 9.2.1.1 YES reject Global M 9.2.1.10 YES reject MCE
ID MCE Name O PrintableString YES ignore (1 . . . 150, . . . ) MBMS
Service 1 YES reject Area List >MBMS 1 to Supported GLOBAL
reject Service Area <maxnoofMBMSServiceAreaIdentitiesPerMCE>
MBMS List Item Service Area Identities in the MCE >>MBMS M
OCTET MBMS Service Area 1 STRING(2) Service Area Identities as
defined in TS 23.003 [13]. eNB list or cell 1 to n list > Global
eNB ID or ECGI
TABLE-US-00003 TABLE 3 Range bound Explanation
maxnoofMBMSServiceAreaIdentitiesPerMCE Maximum no. of Service Area
Identities per MCE. The value for maxnoofMBMSServiceAreaIdentities
is 65536.
[0289] At step 1620, the MME that receives the above-message may
transmit an M3 setup response message for the setup request
message.
[0290] At this time, the MME may identify the eNB by using a global
eNB ID part of the cell list information (ECGI) and also check
serving MCE information for each eNB contained in the setup request
message. Therefore, the MME can determine the MCE to which the MBMS
session setup or modify message will be transmitted. In this
manner, the MME may send the MBMS session setup or modify message
to a few of MCEs, thus effecting a reduction in signaling.
[0291] Meanwhile, the MME may receive, from the eNB, an S1 setup
request message or eNB configuration update request message which
contains an identifier of MCE connected to the eNB or a cell in the
eNB. Therefore, in similar manner using similar information as
discussed above, the MME may determine the MCE to which the MBMS
configuration message will be transmitted.
[0292] FIG. 17 is another flow diagram illustrating a method for
providing an MBMS service according to the third embodiment of the
present invention.
[0293] Referring to FIG. 17, the MME may receive, from MBMS-GW, a
message that contains the MBMS service area and the cell list
(i.e., the ECGI list). Details are discussed earlier in FIG. 16B,
so the repetition is omitted herein.
[0294] The MME that receives the message including the MBMS service
area and the cell list from the MBMS GW may transmit the MBMS
session setup or modify message to the MCE. At this time, the MME
may send the MBMS session setup or modify message to only the MCE
that controls the received cell list.
[0295] For this, at step 1710, the MCE may deliver, to the MME, an
MCE configuration update message having a cell identifier list
and/or an identifier list of the eNB connected to the MCE.
[0296] The MCE configuration update message may be defined as shown
in Table 4 and Table 5.
TABLE-US-00004 TABLE 4 IE/Group IE type and Semantics Assigned Name
Presence Range reference description Criticality Criticality
Message Type M 9.2.1.1 YES reject Global O 9.2.1.10 YES reject MCE
ID MCE Name O PrintableString YES ignore (1 . . . 150, . . . ) MBMS
Service 0 . . . 1 YES reject Area List >MBMS 1 to Supported
GLOBAL reject Service Area
<maxnoofMBMSServiceAreaIdentitiesPerMCE> MBMS List Item
Service Area Identities in the MCE >>MBMS M OCTET MBMS
Service Area STRING(2) Service 1 Area Identities as defined in TS
23.003 [13]. eNB list or cell 1 to n list > Global eNB ID or
ECGI
TABLE-US-00005 TABLE 5 Range bound Explanation
maxnoofMBMSServiceAreaIdentitiesPerMCE Maximum no. of Service Area
Identities per MCE. The value for maxnoofMBMSServiceAreaIdentities
is 65536.
[0297] At step 1720, the MME that receives the above-message may
transmit an MCE configuration update acknowledge message.
[0298] At this time, the MME may identify the eNB by using a global
eNB ID part of the cell list information (ECGI) and also check
serving MCE information for each eNB contained in the MCE
configuration update message. In this manner, the MME may send the
MBMS session setup or modify message to a few of MCEs, thus
effecting a reduction in signaling.
[0299] FIG. 18 is a block diagram illustrating a configuration of
MME according to the third embodiment of the present invention.
[0300] Referring to FIG. 18, the MME may be formed of a
communication unit 1810, a control unit 1820, and a storage unit
1830.
[0301] The communication unit 1810 may perform communication with
other network entities such as the MBMS GW, the MCE, the eNB, or
the like.
[0302] The control unit 1820 may control the reception of a message
having the MBMS service area and the cell list from the MBMS GW.
This message may contain parameters received through the BM-SC by
the MBMS-GW. In this case, these parameters may include TMGI,
FlowID, QoS, MBMS broadcast area information, a start time, and the
like. Details are discussed earlier in FIG. 16, so the repetition
is omitted herein.
[0303] The control unit 1820 may control the reception of an M3
setup request message from the MCE at M3 setup with the MCE. The M3
setup request message may have a cell identifier list and/or an
identifier list of the eNB connected to the MCE. The control unit
1820 may control the transmission of a setup response message for
the setup request message.
[0304] Additionally, the control unit 1820 may identify the eNB by
using a global eNB ID part of the cell list information (ECGI) and
also check serving MCE information for each eNB contained in the
setup request message. Therefore, the control unit 1820 can
determine the MCE to which the MBMS session setup or modify message
will be transmitted.
[0305] Meanwhile, a cell identifier list and/or an identifier list
of the eNB may be contained in the MCE configuration update message
and transmitted to the MME from the MCE.
[0306] Additionally, the control unit 1820 may control the
reception, from the eNB, of the S1 setup request message or eNB
configuration update request message having an identifier of MCE
connected to the eNB or a cell in the eNB. Using the above
information, the control unit 1820 may determine the MCE to which
the MBMS session setup or modify message will be transmitted. This
method is discussed above.
[0307] The storage unit 1830 may store information received from
the MBMS GW. Also, the storage unit 1830 may store information
received from the MCE or the eNB. Therefore, such information
stored in the storage unit 1830 may be used for determining the MCE
to which the MBMS session setup or modify message will be
transmitted.
[0308] Further, the storage unit 1830 may store a list of MCE
determined to transmit the MBMS session setup or modify
message.
[0309] FIG. 19 is a block diagram illustrating a configuration of
MCE according to the third embodiment of the present invention.
[0310] Referring to FIG. 19, the MCE may be formed of a
communication unit 1910, a control unit 1920, and a storage unit
1930.
[0311] The communication unit 1910 may perform communication with
other network entities such as the MME, the eNB, or the like.
[0312] The control unit 1920 may control the transmission of the M3
setup request message to the MME for M3 setup with the MME. The
control unit 1920 may insert, in the M3 setup request message, a
cell identifier list and/or an identifier list of the eNB connected
to the MCE. Also, the control unit 1930 may control the reception
of the setup response message for the setup request message.
[0313] Additionally, the control unit 1920 may control the
transmission, to the MME, of the M3 setup request message having a
cell identifier list and/or an identifier list of the eNB connected
to the MCE, and also control the reception of the MCE configuration
update acknowledge message.
[0314] Further, the control unit 1920 may control the reception of
the MBMS session setup or modify message from the MME in case the
MCE is selected by the MME.
[0315] The storage unit 1930 may store a cell identifier list
and/or an identifier list of the eNB connected to the MCE.
Therefore, such information stored in the storage unit 1930 may be
used for creating the M3 setup request message or the MCE
configuration update message.
[0316] The present invention may be embodied in many different
forms without changing technical subject matters and essential
features as will be understood by those skilled in the art.
Therefore, embodiments set forth herein are exemplary only and not
to be construed as a limitation.
[0317] In embodiments, all steps and messages are not a target for
selective implementation or omission. Additionally, in each
embodiment, steps may not be always performed in the order
described and may be changed in order. Similarly, delivery of
messages may not be always performed in the order described and may
be changed in order. Each step and messaging may be performed
independently.
[0318] The whole or parts of exemplary contents in embodiments are
provided to promote understanding by showing a detailed embodiment
of this invention. Therefore, the detailed contents may be regarded
as expressing a part of method and apparatus proposed by this
invention. Namely, with regard to such contents, a syntax-based
approach may be more desirable than a semantics-based approach.
[0319] While the present invention has been particularly shown and
described with reference to an exemplary embodiment thereof, it
will be understood by those skilled in the art that various changes
in form and details may be made therein without departing from the
spirit and scope of the invention as defined by the appended
claims.
* * * * *