U.S. patent application number 17/701671 was filed with the patent office on 2022-07-07 for communication apparatus, communication method, and program.
This patent application is currently assigned to Sony Group Corporation. The applicant listed for this patent is Sony Group Corporation. Invention is credited to Hiroaki TAKANO.
Application Number | 20220217700 17/701671 |
Document ID | / |
Family ID | |
Filed Date | 2022-07-07 |
United States Patent
Application |
20220217700 |
Kind Code |
A1 |
TAKANO; Hiroaki |
July 7, 2022 |
COMMUNICATION APPARATUS, COMMUNICATION METHOD, AND PROGRAM
Abstract
[Problem] The delivery of content to a terminal apparatus using
a directional beam is achievable more suitably. [Solution] There is
provided a communication apparatus including a communication unit
configured to perform wireless communication, and a control unit
configured to control in such a way as to deliver content subjected
to multicast from an upper node to a terminal apparatus using at
least a part of a plurality of directional beams allocated to the
terminal apparatus from the directional beams used for the wireless
communication.
Inventors: |
TAKANO; Hiroaki; (Saitama,
JP) |
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Applicant: |
Name |
City |
State |
Country |
Type |
Sony Group Corporation |
Tokyo |
|
JP |
|
|
Assignee: |
Sony Group Corporation
Tokyo
JP
|
Appl. No.: |
17/701671 |
Filed: |
March 23, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16769588 |
Jun 4, 2020 |
11337218 |
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PCT/JP2018/040819 |
Nov 2, 2018 |
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17701671 |
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International
Class: |
H04W 72/04 20060101
H04W072/04; H04W 16/28 20060101 H04W016/28; H04W 72/00 20060101
H04W072/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 14, 2017 |
JP |
2017-239548 |
Claims
1. A communication apparatus comprising: a communication unit
configured to perform wireless communication; and a control unit
configured to control in such a way as to deliver content subjected
to multicast from an upper node to a terminal apparatus using at
least a part of a plurality of directional beams allocated to the
terminal apparatus from the directional beams used for the wireless
communication.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S.
application Ser. No. 10/709,588, filed Jun. 4, 2020, which is based
on PCT filing PCT/JP2018/040819, filed Nov. 2, 2018, which claims
priority to JP 2017-239548, filed Dec. 14, 2017, the entire
contents of each are incorporated herein by reference.
FIELD
[0002] The present disclosure relates to a communication.
apparatus, a communication method, and a program.
BACKGROUND
[0003] Wireless access schemes and wireless networks of cellular
mobile communication (hereinafter also referred to as Long Term
Evolution (LTE), LTE-Advanced (LTE-A), LTE-Advanced Pro (LTE-A
Pro), New Radio (NR), New Radio Access Technology (NRAT), Evolved
Universal Terrestrial Radio Access (EUTRA), or Further EUTRA
(FEUTRA)) are under review in 3rd Generation Partnership Project
(3GPP). Further, in the following description, LTE includes LTE-A,
LTE-A Pro, and EUTRA, and NR includes NRAT and FEUTRA. In LTE and
NR, a base station device (base station) is also referred to as an
evolved Node (eNodeB), a terminal apparatus (a mobile station, a
mobile station device, or a terminal) is also referred to as a user
equipment (UE). LTE and NR are cellular communication systems in
which a plurality of areas covered by a base station device is
arranged in a cell form. A single base station device may manage a
plurality of cells.
[0004] In a fifth-generation (5G) mobile communication system
following LTE/LTE-A, technology using a directional beam for
communication between a base station and a terminal apparatus is
being studied. The use of such technology allows communication
between a base station and a terminal apparatus to achieve spatial
multiplexing in addition to time and frequency multiplexing. In one
example, Patent Document 1 discloses an example of a technique
using a directional beam for communication between a base station
and a terminal apparatus.
[0005] Further, as the technology for delivering content such as
text, music, still images, and moving images to each terminal
apparatus using the above-described wireless network, a technology
called multimedia broadcast and multicast service (MBMS) is
studied. The use of the MBMS technology makes it possible to
efficiently deliver the above-mentioned various types of content
that are broadcast as a program to a plurality of terminal
apparatuses via the wireless network.
CITATION LIST
Patent Literature
[0006] Patent Literature 1: JP 2017-157908 A
SUMMARY
Technical Problem
[0007] On the other hand, in the fifth-generation (5G) mobile
communication system, data is transmitted to each terminal
apparatus while scanning a beam having directivity (also referred
to hereinafter as a "directional beam"), and so the technique of
delivering content to each terminal apparatus within the
communication range is different from the communication using a
non-directional beam. Thus, even in a situation where a directional
beam is used for communication, the technology such as MBMS capable
of efficiently delivering content provided as a so-called Program
(broadcasting program) to each terminal apparatus is desirable to
be applicable more suitably.
[0008] Thus, the present disclosure provides technology enabling
the delivery of content to a terminal apparatus using a directional
beam to be achieved more suitably.
Solution to Problem
[0009] According to the present disclosure, a communication
apparatus is provided that includes: a communication unit that
performs wireless communication; and a control unit that controls
in such a way as to deliver content subjected to multicast from an
upper node to a terminal apparatus using at least a part pf a
plurality of directional bases allocated to the terminal apparatus
from the directional beams used for the wireless communication.
[0010] Moreover, according to the present disclosure, a
communication apparatus is provided that includes: a communication
unit that performs wireless communication; and a control unit that
controls in such a way to receive content subjected to multicast
from an upper node to a base station and delivered from the base
station using at least a part of directional beams allocated from a
plurality of directional beams.
[0011] Moreover, according to the present disclosure, a
communication method executed by a computer, the method is provided
that includes: performing wireless communication; and controlling
in such a way as to deliver content subjected to multicast from an
upper node to a terminal apparatus using at least a part of a
plurality of directional beams allocated to the terminal apparatus
from the directional beams used for the wireless communication.
[0012] Moreover, according to the present disclosure, a
communication method executed by a computer is provided that
includes: performing wireless communication; and controlling in
such a way to receive content subjected to multicast from an upper
node to a base station and delivered from the base station using at
least a part of directional beams allocated from a plurality of
directional beams.
[0013] Moreover, according to the present disclosure, a program
causing a computer to execute: performing wireless communication;
and controlling in such a way as to deliver content subjected to
multicast from an upper node to a terminal apparatus using at least
a part of a plurality of directional beams allocated to the
terminal apparatus from the directional beams used for the wireless
communication.
[0014] Moreover, according to the present disclosure, a program is
provided that causes a computer to execute: performing wireless
communication; and controlling in such a way to receive content
subjected to multicast from an upper node to a base station and
delivered from the base station using at least a part of
directional beams allocated from a plurality of directional
beams.
Advantageous Effects of Invention
[0015] According to the present disclosure as described above, the
technology is provided that enables the delivery of content to the
terminal apparatus using the directional beam more suitably.
[0016] Note that the effects described above are not necessarily
limitative. With or in the place of the above effects, there may be
achieved any one of the effects described in this specification or
other effects that may be grasped from this specification.
BRIEF DESCRIPTION OF DRAWINGS
[0017] FIG. 1 is a diagram illustrated to describe an example of a
schematic configuration of a system according to an embodiment of
the present disclosure.
[0018] FIG. 2 is a block diagram illustrating an example of a
configuration of a base station according to the present
embodiment.
[0019] FIG. 3 is a block diagram illustrating an example of a
configuration of a terminal apparatus according to the present
embodiment.
[0020] FIG. 4 is a diagram illustrated to describe an overview of
MBMS network architecture.
[0021] FIG. 5 is a diagram illustrated to describe an example of a
procedure for performing "counting".
[0022] FIG. 6 is a diagram illustrating an example of a protocol
stack of an M1 interface between an MBMS gateway and a base
station.
[0023] FIG. 7 is a sequence diagram illustrating an example of an
MBMS session start procedure in LTE.
[0024] FIG. 8 shows an example of a frame structure upon using
MBES.
[0025] FIG. 9 is a diagram illustrated to describe an overview of
information associated with an MBMS session.
[0026] FIG. 10 is a schematic sequence diagram illustrating an
example of a procedure for providing a program to each terminal
apparatus using a directional beam in a communication system
according to the present embodiment.
[0027] FIG. 11 is a diagram illustrated to describe an overview of
beam sweeping.
[0028] FIG. 12 is a diagram illustrated to describe an overview of
beam sweeping.
[0029] FIG. 13 is a schematic sequence diagram illustrating an
example of a procedure for providing a program to each terminal
apparatus using a directional beam in a communication system
according to the present embodiment.
[0030] FIG. 14 is a schematic sequence diagram illustrating an
example of a procedure for providing a program to each terminal
apparatus using a directional beam in a communication system
according to a first modification.
[0031] FIG. 15 is a schematic sequence diagram illustrating another
example of a procedure for providing a program to each terminal
apparatus using a directional beam in a communication system
according to the first modification.
[0032] FIG. 16 is a schematic sequence diagram illustrating another
example of a procedure for providing a program to each terminal
apparatus using a directional beam in a communication system
according to the first modification.
[0033] FIG. 17 is a schematic sequence diagram illustrating an
example of a procedure for providing a program to each terminal
apparatus using a directional beam in a communication system
according to a second modification.
[0034] FIG. 18 is a flowchart illustrating an example of a
processing procedure in a base station 100 in the communication
system according to the second modification.
[0035] FIG. 19 is a schematic sequence diagram illustrating an
example of a procedure for providing a program to each terminal
apparatus using a directional beam in a communication system
according to a third modification.
[0036] FIG. 20 is a schematic sequence diagram illustrating another
example of a procedure for providing a program to each terminal
apparatus using a directional beam in a communication system
according to the third modification.
[0037] FIG. 21 is a block diagram illustrating a first example of a
schematic configuration of an eNB.
[0038] FIG. 22 is a block diagram illustrating a second example of
the schematic configuration of the eNB.
[0039] FIG. 23 is a block diagram illustrating an example of a
schematic configuration of a smartphone.
[0040] FIG. 24 is a block diagram illustrating an example of a
schematic configuration of a car navigation apparatus.
DESCRIPTION OF EMBODIMENTS
[0041] Hereinafter, a preferred embodiment of the present
disclosure will be described in detail with reference to the
appended drawings. Note that, in this specification and the
appended drawings, structural elements that have substantially the
same function and structure are denoted with the same reference
numerals, and repeated explanation of these structural elements is
omitted.
[0042] Note. that description will be provided in the following
order. [0043] 1. Configuration example [0044] 1.1. Configuration
example of system [0045] 1.2. Configuration example of base station
[0046] 1.3. Configuration example of terminal apparatus [0047] 2.
MBMS [0048] 3. Technical features [0049] 4.1. Application examples
[0050] 4.1. Application examples for base station device [0051]
4.2. Application examples for terminal apparatus [0052] 5.
Concluding remarks
1. Configuration Example
1.1. Configuration Example of System
[0053] An example of a schematic configuration of a system 1
according to an embodiment of the present disclosure is now
described with reference to FIG. 1. FIG. 1 is a diagram illustrated
to describe an example of a schematic configuration of the system 1
according to an embodiment of the present disclosure. As
illustrated in FIG. 1, the system 1 includes a wireless
communication apparatus 100, a terminal apparatus 200, and an MEC
server 300. The terminal apparatus 200 herein is also called a
user. The user can also be called a UE. In other words, the
above-described UE 200 can correspond to the terminal apparatus 200
illustrated in FIG. 1. The wireless communication apparatus 100C is
also called UE-relay. The UE herein can be a UE defined in LTE or
LTE-A, and the UE-relay can be the Prose-UE-to-Network relay, which
is under development in 3GPP and can refer to more typically
communication equipment.
[0054] (1) Wireless Communication Apparatus 100
[0055] The wireless communication apparatus 100 is an apparatus
that provides a subordinate device with a wireless communication
service. In one example, the wireless communication apparatus 100A
is a base station of a cellular system (or a mobile communication
system). The base station 100A establishes wireless communication
with a device located within a cell 10A (e.g., the terminal
apparatus 200A) of the base station 100A. In one example, the base
station 100A transmits a downlink signal to the terminal apparatus
200A and receives an uplink signal from the terminal apparatus
200A.
[0056] The base station 100A establishes a logical connection with
other base statons over, in one example, the X2 interface, and is
capable of transmitting and receiving control information or the
like. In addition, the base station 100A establishes a logical
connection with a core network 40 over, in one example, the S1
interface, and is capable GT transmitting and receiving control
information or the like. Moreover, communication between these
apparatuses can be relayed through various devices physically.
[0057] In this description, the wireless communication apparatus
100A illustrated in FIG. 1 is a macrocell base station, and the
cell 10 is a macrocell. On the other hand, the wireless
communication apparatuses 100B and 100C are master devices that
operate the small cells 10B and 10C, respectively. As an example,
the master device 100B is a fixedly installed small cell base
station. The small cell base station 100B establishes a wireless
backhaul link with the macrocell base station 100A and establishes
an access link with one or more terminal. apparatuses (e.g., the
terminal apparatus 200B) within the small cell 10B. Moreover, the
wireless communication apparatus 100B can be a relay node defined
by 3GPP. The master device 100C is a dynamic access point (AP). The
dynamic AP 100C is a mobile device that dynamically operates the
small cell 10C. The dynamic AP 100C establishes a wireless backhaul
link with the macrocell base station 100A and establishes an access
link with one or more terminal apparatuses (e.g., the terminal
apparatus 200C) within the small cell 10C. The dynamic AP 100C can
be, in one example, a terminal apparatus equipped with hardware or
software operable as a base station or a wireless access point. In
this case, the small cell 10C is a dynamically configured localized
network (virtual cell).
[0058] The cell 10 can he operated, in one example, in accordance
with any wireless communication scheme such as LTE, LTE-Advanced
(LTE-A), GSM (registered trademark), UMTS, W-CDMA, CDMA200, WiMAX,
WiMAX2, IEEE802.16, and the like.
[0059] Moreover, the small cell is a concept that can include
various types of cells (e.g., such as femtocells, nanocells,
picocells, and microcells) that are smaller than the macrocell and
are arranged to overlap or not to overlap with the macrocell. In
one example, a small cell is operated by a dedicated base station.
In another example, a small cell is operated by a terminal acting
as a master device that temporarily operates as a small cell base
station. It is also possible for a so-called relay node to be
considered as a form of small cell base station. A wireless
communication. apparatus functioning as a master station of a relay
node is also called a donor base station. The donor base station
can mean a DeNB in LTE, and can more generally refer to a master
station of a relay node.
[0060] (2) Terminal Apparatus 200
[0061] The terminal apparatus 200 is capable of performing
communication in a cellular system (or a mobile communication
system). The terminal apparatus 200 performs wireless communication
with a wireless communication apparatus of the cellular system
(e.g., the base station 100A and the master device 100B or 100C).
In one example, the terminal apparatus 200A receives a downlink
signal from the base station 100A and transmits an uplink signal to
the base station 100A.
[0062] (3) Application Server 60
[0063] An application server 60 is a device that provides a user
with a service. The application server 60 is connected to a packet
data network (PDN) 50. On the other hand, the bae station 100 is
connected to the core network 40. The core network 40 is connected
to the PDN 50 via a gateway device (P-GW in FIG. 8). Thus, the
wireless communication apparatus 100 provides the MEC server 300
and the user with the service provided by the application server
60, via the packet. data network 50, the core network 40, and the
wireless on channel.
[0064] (4) NEC Server 300
[0065] The MEC server 300 is a service-providing device that
provides a user with a service (such as application and content).
The MEC server 300 can he provided in the wireless communication
apparatus 100. In this case, the wireless communication apparatus
100 provides the user with the service provided by the MEC server
300 via the wireless communication channel. The MEC server 300 can
be implemented as a logical functional entity or can be configured
integrally with the wireless communication apparatus 100 or the
like as illustrated in FIG. 1.
[0066] In one example, the base station 100A provides the terminal
apparatus 200A connected. to the macrocell 10 with the service
provided by the MEC server 300A. In addition, the base station 100A
provides the terminal apparatus 200B connected to the small cell
10B, via the master device 100B, with the service provided by the
MEC server 300A.
[0067] Further, the master device 100B provides the terminal
apparatus 200B connected to the small 10B with the service provided
by the MEC server 300B. Similarly, the master device 100C provides
the terminal apparatus 200C connected to the small cell 10C with
the service provided by the server 300C.
[0068] (5) Supplement
[0069] Although the schematic configuration of the system 1 is
described above, the present technology is not limited to the
example illustrated in FIG. 1. Examples of the configuration of the
system 1 can employ a configuration with no master device, a
configuration of a small cell enhancement (SCE), a configuration of
a heterogeneous network (HetNet), a configuration of a machine-type
communication (MTC) network, or the like.
1.2. Configuration Example of Base Station
[0070] A configuration of the base station 100 according to an
embodiment of the present disclosure is now described with
reference to FIG. 2. FIG. 2 is a block diagram illustrating an
example of a configuration of the base station 100 according to an
embodiment of the present disclosure. Referring to FIG. 2, the base
station 100 includes an antenna unit 110, a wireless communication
unit 120, a network communication unit 130, a storage unit 140, and
a processing unit 150.
[0071] (1) Antenna Unit 110
[0072] The antenna unit 110 radiates a signal output by the
wireless communication unit 120 into space as a radio wave. In
addition, the antenna unit 110 converts a radio wave in space into
a signal and outputs the signal to the wireless communication unit
120.
[0073] (2) Wireless Communication Unit 120
[0074] The wireless communication unit 120 transmits and receives a
signal. In one example, the wireless communication unit 120
transmits a downlink signal to a terminal apparatus and receives an
uplink signal from a terminal apparatus.
[0075] (3) Network Communication Unit 130
[0076] The network communication unit 130 transmits and receives
information. In one example, the network communication unit 130
transmits and receives information to and from other nodes. In one
example, the above-mentioned other nodes nodes include other base
stations and core network nodes.
[0077] Moreover, as described above, in the system 1 according to
the present embodiment, the terminal apparatus operates as a relay
terminal to relay communication between a remote terminal and a
base station in some cases. In such a case, in one example, the
wireless communication apparatus 100C corresponding to the relay
terminal is not necessarily provided with the network communication
unit 130.
[0078] (4) Storage Unit 140
[0079] The storage unit 140 temporarily or permanently stores
various data and a program necessary for operating the base station
100.
[0080] (5) Processing Unit 150
[0081] The professing unit 150 allows the base station 100 to
perform various functions. The processing unit 150 includes a
communication control unit 151, an information acquisition unit
153, and a notification. unit 155. Moreover, the processing unit
150 can further include other components than these components. In
other words, the processing unit 150 can perform other operations
than the operations of these components.
[0082] The operations of the communication control unit 151, the
information acquisition unit 153, and the notification unit 15.5
will be described later in detail.
1.3. Configuration Example of Terminal Apparatus
[0083] An example of a configuration of the terminal apparatus 200
according to an embodiment of the present disclosure is now
described with reference to FIG. 3. FIG. 3 is a block diagram
illustrating an example of a configuration of the terminal
apparatus 200 according to an embodiment of the present disclosure.
As illustrated in FIG. 3, the terminal apparatus 200 includes an
antenna unit 210, a wireless communication unit 220, a storage unit
230, and a processing unit 240.
[0084] (1) Antenna Unit 210
[0085] The antenna unit 210 radiates a signal output by the
wireless communication unit 220 into space as a radio wave. In
addition, the antenna unit 210 converts a radio wave in space into
a signal and outputs the signal to the wireless communication unit
220.
[0086] (2) Wireless Communication Unit 220
[0087] The wireless communication unit 220 transmits and receives a
signal. In one example, the wireless communication unit 220
receives a downlink signal from a base station and transmits an
uplink signal to a base station.
[0088] Further, as described above, in the system 1 according to
the present embodiment, the terminal apparatus can operate as a
relay terminal to relay communication between a remote terminal and
the base station in some cases. In such a case, in one example, the
wireless communication unit 220 in the terminal apparatus 200C
operating as a remote terminal can transmit and receive a side-link
signal to and from the relay terminal.
[0089] (3) Storage Unit 230
[0090] The storage unit 230 temporarily or permanently stores
various data and a program necessary for operating the terminal
apparatus 200.
[0091] (4) Processing Unit 240
[0092] The processing unit 240 allows the terminal apparatus 200 to
perform various functions. For example, the processing unit 240
includes a communication control unit 241, an information
acquisition unit 243, a measuring unit 245, and a notification unit
247. Moreover, the processing unit 240 can further include other
components than these components. In other words, the processing
unit 240 can perform other operations than the operations of these
components.
[0093] The operations of the communication control unit 241, the
information acquisition unit 243, the measuring unit 245, and the
notification unit 247 will be described later in detail.
2. MBMS
[0094] A description of MBMS is now given. The MBMS is a technique
for delivering content such as text, music, still images, and
moving images to each terminal apparatus using a wireless network
and is officially referred to as "multimedia broadcast multicast
services". Moreover, a description of an overview of broadcast and
multicast is given below to make the characteristics of the
communication system according to an embodiment of the present
disclosure easier to understand.
[0095] The broadcast is a unidirectional point-to-multipoint
downlink transmission. The broadcast is unnecessary to communicate
with a network in providing the service, even in a power-saving
state not connected to the network, such as a so-called "RRC idle"
state, the terminal apparatus is capable of receiving the delivery
of a broadcast service. In other words, the terminal apparatus is
capable of, even in the RRC idle state, receiving content that is
broadcast from the base station and presenting the content to the
user.
[0096] The multicast is similar to the broadcast in that it
provides a plurality of terminal apparatuses with a service.
However, the multicast differs from the broadcast in that the
terminal apparatus, upon receiving a service, is necessary to
indicate to the network that the terminal apparatus attempts to
receive the service. In other words, in the multicast, the terminal
apparatus necessitates communication with the network to receive a
service.
[0097] Moreover, in 5G, a high frequency of 6 GHz or more is
usable, but a high-frequency band has higher propagation loss.
Thus, to compensate for propagation loss, a higher antenna gain is
obtained by giving directivity to radio waves (wireless signals) by
beam forming. For this reason, the directivity is directed to a
particular terminal apparatus by beam forming, so it is desirable
to indicate that the terminal apparatus desires to receive the
service corresponding to MBMS. In other words, in applying MBMS to
the 5G mobile communication system, it is more important to
implement the delivery of content by multicast. Moreover, in the
following description, the service corresponding to MBMS is also
referred to as "MBMS service".
[0098] (MBMS Network Architecture)
[0099] An overview of the MBMS network architecture is now
described with reference to FIG. 4. FIG. 4 is a diagram illustrated
to describe an overview of the MBMS network architecture.
[0100] As illustrated in FIG. 4, the MBMS network architecture
includes a core network (CN) and a radio access network (RAN). In
addition, the CN includes various entities. Examples of the
entities included in the CN include mobility management entity
(MME), home subscriber server (HSS), serving gateway (S-GW), packet
data network gateway (P-GW), MBMS gateway, broadcast multicast
service center (BM-SC), content server, and the like. In addition,
in the MBMS network architecture, an example on the side of the RAN
includes multi-cell/multicast coordination entity (MCE). Moreover,
among these entities, MCE, MBMS gateway, BM-SC, and content server
are entities specific to MBMS, and the other entities are similar
to the entities used for unicast communication in LTE. In addition,
the content to be provided in the MBMS service can be provided from
inside the operator's network or can be provided from the Internet
network. Moreover, an entity in the CN (particularly, an MBMS
gateway or a BM-SC) corresponds to an example of an "upper node" of
the base station. In addition, the MME corresponds to an example of
a "predetermined node that manages a session".
[0101] An overview of each of the entities specific to the MBMS,
that is, the MCE, the MBMS gateway, the BM-SC, and the content
server is now described.
[0102] (MCE)
[0103] A description of MCE is first given. As illustrated in FIG.
4, the MCE is classified as an entity on the side of the PAN. The
MCE can be located in each base station (eModeB) or can be located
outside the base station. Examples of the role of the MCE include
three functions of "allocation of time and frequency resources for
MBMS", "decision of modulation and coding scheme (MOS)", and
"counting function". Moreover, the MCS corresponds to a modulation
scheme or coding rate. In addition, the counting function
corresponds to a function of collecting how much the user is
interested in the service. The counting function makes it possible,
in one example, for the base station to allocate time and frequency
resources for MBMS or stop the allocation depending on the number
of interested users (i.e., the number of terminal apparatuses
desiring to deliver content).
[0104] Moreover, in LTE, an omnidirectional beam is used, so it is
difficult to control the MCS individually for each terminal
apparatus. On the other hand, in 5G, it is possible to allocate a
beam individually to each terminal apparatus, so in one example, it
is also possible to provide content (e.g., content corresponding to
MBMS) using different MCSs for each terminal apparatus.
[0105] In other words, in 5G, in one example, a situation can be
assumed in which an MBMS service is provided to each terminal
apparatus using a UE-specific beam. Even in a case where the
handling between the base station and the terminal apparatus is
used like unicast (strictly speaking, it is multicast because
similar content is delivered to a plurality of terminal
apparatuses), the content is delivered using multicast (multicast
for the IP layer) between the content server and the base station.
Thus, a function called counting is important to specify which base
station to perform multicasting.
[0106] For reference, an example of the existing procedure for
performing the counting is now described with reference to FIG. 5.
FIG. 5 is a diagram illustrated to describe an example of a
procedure for performing counting.
[0107] As illustrated in FIG. 5, at first, an MCE 400 transmits an
MBMS service counting request to the base station 100 (S101). The
base station 100 receives the MBMS service counting request from
the MCE 400 and replies an MBMS service counting response to the
MCE 400 (S103). Then, the base station 100 transmits an MBMS
service counting request to the terminal apparatus 200 (S105). The
terminal apparatus 200 receives the MBMS service counting request
from the base station 100 and replies an MBMS service counting
response to the base station 100 (S107). Then, the base station
100, when receiving the MBMS service counting response from the
terminal apparatus 200, transmits an MBMS service results report to
the MCE 400 (S109). The procedure as described above makes it
possible for the MCE 400 to recognize the number of terminal
apparatuses that desire to provide the MBMS service, in one
example, on the basis of the report (the MBMS service results
report) transmitted from the base station 100.
[0108] (MBMS Gateway)
[0109] Subsequently, a description of the MBMS gateway is given. As
illustrated in FIG. 4, the MBMS gateway is an entity located in the
CN. The MBMS gateway has a function of sending a packet to a
corresponding base station (eNodeB) using Internet protocol (IP)
multicast address as a key. In LTE, MBMS is assumed only to use
broadcast and does not support multicast. This means that the
service does not support multicast. On the other hand, multicast is
used for the IP layer. Specifically, in order for the service to be
broadcast to a plurality of terminal apparatuses, the previous
signaling between the plurality of base stations and the MBMS
gateway allows at least some of the base stations to be specified
and to be transferred only to the specified base station. Thus, a
multicast address is used in the IP layer.
[0110] In one example, FIG. 6 is a diagram illustrating an example
of a protocol stack of the M1 interface between the MBMS gateway
and the base station. Among the protocols illustrated in FIG. 6,
the layers of DASH, HTTP, TPC/UDP, and IP located on the upper side
are not explicitly described in the standard, but it is presumed
that the configuration illustrated in FIG. 6 will be obtained in a
case similar to the ordinary unicast. In addition, the layers of
GTPv1-U, UDP, IP, L2, and L1 located on the lower side are similar
to the S1 interface in the unicast. Moreover, the IP layer used to
transfer a packet to a plurality of base stations on the basis of
the multicast address is an IP layer located on the lower side.
[0111] In LTE, as described above, a packet is multicast from the
MBMS gateway to a plurality of base stations, and the plurality of
base stations transmit packets received in synchronization with
each other to a terminal apparatus through wireless communication.
On the other hand, in 5G, an MBMS service is provided to each
terminal apparatus using a UE-specific beam. Thus, a cache function
is provided for the base station, and the terminal apparatus is
capable of optionally selecting the time for receiving the MBMS
service within a certain fixed period.
[0112] In 5G MBMS, caching of the content corresponding to MBMS
(hereinafter also referred to as "MBMS content") in a base station
makes it possible to provide a terminal apparatus with a service
more flexibly, resulting in expecting an effect of further reducing
the CN traffic. In addition, it is possible to further reduce
resource consumption by MBMS on the side of RAN, by transmitting
content for each terminal apparatus using the UE-specific beam
instead of transmitting content by the existing broadcast or
multicast on the side of RAN.
[0113] (BM-SC)
[0114] Subsequently, a description of BM-SC is given. The BM-SC
corresponds to the entry point of MBMS content. The BM-SC has the
functions as described below. As the first function, the BM-SC
performs MBMS session management. Specifically, the BM-SC manages
the start and end of the MBMS service. As the second function, the
BM-SC allocates an ID called a temporary mobile group identity
(TMGI) to each MBMS session. As the third function, the BM-SC
allocates QoS to an MBMS session. As the fourth function, the BM-SC
provides the terminal apparatus with information regarding
broadcasting such as a program guide at the application level
(TS29.061).
[0115] In LTE, the MBMS traffic and the unicast traffic are
separated into sub frames. Specifically, a radio frame having a
length of 1 ms is divided into ten sub frames having a length of
0.1 ms, and an MBMS service is provided in some of the sub frames.
Thus, MBMS and unicast are separate networks, and even if the
unicast traffic increases, the situation where the MBMS traffic is
affected is extremely limited, in one example, as in the case or
the like where the sub frames allocated to MBMS are semi-statically
changed. In a case where the MBMS service is provided by unicast
using a UE-specific beam, it can be assumed that there is a
possibility that at least one of the ordinary unicast or the
unicast of the MBMS service affects the other.
[0116] (Content Server)
[0117] Subsequently, a description of the content server is given.
The content server is a server that provides content. The content
server can be located both inside and outside the operator's
network.
[0118] (Session Start Procedure)
[0119] Subsequently, an example of an MBMS session start procedure
in LTE is described for reference to make the characteristics of
the communication system according to the present embodiment more
understandable. In one example, FIG. 7 is a sequence diagram
illustrating an example of the MBMS session start procedure in
LTE.
[0120] As illustrated in FIG. 7, the MBMS session start procedure
starts from an MB-SC. Specifically, at first, an MB-SC 460
transmits a request to start (Start Request) an MBMS session to an
MBMS gateway 440 (S121). In this case, in one example, information
such as a service area, QoS, and a mobile group identity (MGI) is
notified through the request. The MBMS gateway 440 replies a
response to the request (Start Response) from the MB-SC 460
(S123).
[0121] Subsequently, the MBMS gateway 440 transmits a request to
start (Start Request) the MBMS session to the MME 420 (S12S). The
MME 420, when receiving the request from the MBMS gateway 440,
transmits a request to start (Start Request) an MBMS session to the
MCE 400 (S127). The MCE 400, when receiving the request from the
MME 420, replies a response (Start Response) to the MME 420 (S129).
The MME 420, when receiving the response from the MCE 400, replies,
to the MBMS gateway 440, a response (Start Response) to the request
from the MBMS gateway 440 (S131).
[0122] Subsequently, the MCE 400 transmits a request to start
(Start Request) the MBMS session to the base station 100 that is
the service area (S133), In addition, the MCE 400 notifies the base
station 100 of information regarding the schedule of the MBMS
session (Scheduling Info) (S135). The base station 100 replies, to
the MCE 400, a response (Start Response) to the request from the
MCE 400 (S137). In addition, the base station 100, when receiving
the notification of the information regarding the schedule of the
MBMS session from the MCE 400, replies a response (Scheduling Info
Response) to the MCE 400 (S139).
[0123] Subsequently, the base station 100, on the basis of the
information notified from the MCE 400, transmits an MCCH change
notification to the terminal apparatus 200 within the communication
range (S141) and then transmits MCCH/MCH/PMCH to the terminal
apparatus 200 (S143). Moreover, the details of MCCH, MCH, and PMCH
will be separately described later.
[0124] Subsequently, the target MBMS content is transferred from
the MB-SC 460 to the MBMS gateway 440, and the MBMS content is IP
multicast from the MBMS gateway 440 to the base station 100 (S145).
The base station 100, when receiving the MBMS content from the MBMS
gateway 440, transmits MCCH/MCH/PMCH to the terminal apparatus 200.
In other words, the base station 100 broadcasts the received MBMS
content (S147).
[0125] The example of the MBMS session start procedure in LTE is
described above with. reference to FIG. 7 On the other hand, there
is a possibility that, in 5G NB, a procedure for starting a session
from the terminal apparatus is added to the existing session start
procedure. This is because it s possible to change the content
delivery time for each terminal apparatus in the MBMS service
provided using the UE-specific beam.
[0126] (Radio Access Network of MBMS)
[0127] Subsequently, the characteristics of the MBMS in the RAN now
described.
[0128] (1) Logical Channel for MBMS
[0129] The multimedia broadcast multicast service (MBMS) is
provided over two logical channels of multicast transport channel
(MTCH) and multicast control channel (MCCH). These two channels are
mapped to PMCH (PHY Multicast Channel) as physical channels. In the
PMCH, both the MCCH and the MTCH are sent, and scheduling
information for mapping between the MBMS session and the PMCH
generated as MAC signaling is also sent. This Mac signaling is sent
in the header of the PMCH.
[0130] (2) Physical Channel for MBMS
[0131] The PMCH uses a cyclic prefix having a relatively long CP
length called extend CP. This is to constitute a single-frequency
network for combining signals from a plurality of base stations. In
LTE, one radio frame has 10 sub frames of which sub frames in which
MBMS single-frequency network (MBSFN) is usable are designated
semi-statically to be used. In one example, FIG. 8 illustrates an
example of a frame structure in a case of using the MBMS. In FIG.
8, the marked sub frames schematically show sub frames in which the
MBSFN is usable. In addition, the marked frames schematically show
a frame including a sub frame in which the MBSFN is usable.
[0132] Some of the sub frames for MBSFN are used for PDCCH and
PDSCH, but the PDCCH is used not for MBMS but for transmission of
uplink scheduling information necessary for ordinary unicast
traffic. Thus, the PDSCH portion in the sub frames for MBSFN is
used for MBMS, and the PMCH is transmitted by the PDSCH.
[0133] (3) MBMS Session
[0134] In the present disclosure, one program is also referred to
as an MBMS session. In this case, the MBMS session is mapped to the
PMCH (PHY Multicast Channel) that is the physical channel. In
addition, the PMCH is mapped to a sub frame allocated for the
MBMS.
[0135] (4) MBMS Service Area
[0136] The MBMS service area corresponds to an area where one MBMS
service is provided. In addition, the MBSFN area corresponds to an
area that constitutes a single-frequency network (SFN). In the
MBSFN area, it is possible, to set up to eight areas for one base
station. In a case where the SFN is configured, a plurality of base
stations cooperates and transmits the same content.
[0137] Moreover, in 5G, it can be assumed that the MBMS session is
provided to each terminal apparatus using the UE-specific beam. In
the existing MBMS, the SFN technology described later is used, so
it is not necessary to consider handover. On the other hand, in 5G,
a mechanism corresponding to the MBMS handover is necessary due to
the above-described characteristics. Thus, in one example, it can
be necessary to notify the number of the MBMS session from the
switching source base station to the switching destination base
station. In this description, in a case where a beam necessary for
beam recovery is provided from another base station (e.g., a base
station in an adjacent cell), it is also possible to reduce the
latency by including the MBMS session in a beam recovery
request.
[0138] (5) SFN
[0139] The single-frequency network (SFN) is the technology in
which the same signal is transmitted simultaneously at the same
time and frequency from a plurality of base stations (eNodeBs) and
the plurality of downlink signals is regarded as a reflected wave
within the range of the cyclic prefix (CP), combined, and received,
resulting in improving the signal strength. In the case of
broadcasting, a wide reception range of the terminal apparatus is
necessary, so the SFN can he used in some cases.
[0140] (6) MBMS Scheduling
[0141] In some cases, it is difficult for a terminal apparatus to
receive a program without knowing where the base station (eNodeB)
transmits the program. In such a case, the terminal apparatus is
necessary to acquire scheduling information (i.e., information
indicating where transmission is being performed).
[0142] The scheduling is performed in accordance with the procedure
described below. The details of each procedure are described below
with reference to FIG. 9. FIG. 9 is a diagram illustrated to
describe an overview of information associated with an MBMS
session. [0143] Specifying radio frame and sub frame [0144] MBSFN
area configuration [0145] Specifying MBMS session
[0146] (Specifying Radio Frame and Sub Frame)
[0147] The location of the MCCH is specified in the SIB 13 of the
system information. Specifically, the location of a radio frame
including the MCCH is specified by a period and an offset.
Furthermore, it is specified which sub frame in each radio frame
includes the MCCH. The location of the MCCH is actually the PMCH,
so the MCCH is transmitted in the PDSCH portion of the MBSFN sub
frame.
[0148] (MBSFN Area Configuration)
[0149] The MCCH includes the MBSFN area configuration. The MBSFN
area configuration specifies which sub frame where the MBSFN is
performed. The specifying of the sub frame is settable by a period
and an offset of a radio frame. In this case, it is possible to set
simultaneously eight types of different periods and offsets for the
specifying of the sub frame. In addition, which sub frame in the
radio frame is used is also set. Such an operation allows a sub
frame usable for MBMS to be determined. In the sub frames for MBMS
determined as described above, how to allocate the PMCH is also
specified. The PMCH can set up to 16 channels
[0150] (Specifying of MBMS Session)
[0151] It is possible to set up to 30 MBMS sessions (i.e.,
programs) for 16 PMCHs determined as described above. As a specific
example, MBMS sessions 0 and 1 can be set for PMCH0, and MBMS
sessions 2, 3, 4, 5, and 6 can be set for PMCH1.
[0152] How to map the MBMS session to the PMCH is specified using
the Mac signaling sent by the PMCH. The Mac signaling is a kind of
RPC signaling in the SIB13, so it is said that the MBMS scheduling
is performed by a combination of RPC signaling and Mac
signaling.
[0153] In 5G, it is conceivable that the MBMS session can be
provided to each terminal using the UE-specific beam. In this case,
the SFN is not necessary to be used, and there is a possibility
that the terminal apparatus is able to receive the delivery of
television broadcast at the desired time. The content that is
broadcast in the MBMS session is transmitted from the EM-SC to each
base station (eNodeB) via the MBMS gateway. This content can be
provided as a broadcast to the terminal apparatus at a time desired
by the terminal apparatus as long as the content is held as a cache
in the base station. In a case where the cache capacity has a
physical limit, the expiration date can be given to the information
of the MBMS session disclosed in the SIB. The location where the
existing MBMS session is provided is disclosed on the PMCH
specified by the information of the radio frame and sub frame and
the location of the PMCH in the sub frame. On the other hand, in
the case where the MBMS service is provided using the beam, it is
also possible to disclose the information of the MBMS session as
follows. [0154] Disclosure is performed as before by system
information embedded in performing beam forming during beam
management. Moreover, beam management is a procedure for
identifying an appropriate beam between a base station and a
terminal apparatus. [0155] In a procedure after determining an
appropriate beam between a base station and a terminal apparatus,
the provision of MBMS information is notified on the downlink
control channel (DCI).
[0156] (7) Entity for Receiving MBMS
[0157] The above-mentioned MBMS service can be provided to both the
terminal apparatus in the RRC idle mode and the terminal apparatus
in the RRC connected mode. Thus, it is also possible for a terminal
in the RRC idle mode to receive the various information described
above.
[0158] (8) MCS (Modulation Scheme) used in MBMS
[0159] As described above in connection with the network
architecture, in the existing MBMS in LTE, the MCS can be changed
by the MCE, but it is the broadcasting, so the frequency to be
changed is small. Thus, in the existing MBMS in LTE, in one
example, a common MCS that is preset for all terminal apparatuses
is used.
[0160] On the other hand, in 5G, it is conceivable that the MBMS
session is provided to each terminal apparatus using a UK-specific
beam. In such a case, it is possible to provide the MBMS service by
changing the MCS between the base station and the terminal
apparatus. Furthermore, in a case where the beam is blocked by an
obstacle such as a person or a car located between the base station
and the terminal apparatus, it is necessary, in some cases, to
switch the beam used for communication into that from another base
station. In such a case, there is a possibility that an MCS
different from the MCS used in the beam before the switching is
used for the beam after the switching, and it can be assumed that
the MCS before and after the switching is discontinuous.
[0161] (9) Feedback Information from Terminal Apparatus
[0162] The feedback information from a terminal apparatus is not
specified in the MBMS in LTE at present. There is the mixed mode in
which both ordinary LTE and MBMS are operated, but even in this
case, feedback regarding the MBMS is not specified as a
standard.
3. Technical Features
[0163] Technical features of the communication system according to
an embodiment of the present disclosure are now described.
[0164] (Basic Configuration)
[0165] A basic configuration of the communication system according
to an embodiment of the present disclosure is first described. In
5G, the beam forming technique that enables the concentration of
radio wave energy in a particular direction is used to compensate
for attenuation of radio wave propagation of a relatively high
frequency in the 6 GHz to 100 GHz range. In a situation where a
beam is emitted in a particular direction by applying the beam
forming technique in this way, the number of terminal apparatuses
existing within the range of the beam is considerably limited. In
addition, among the limited terminal apparatuses that are present,
in the area covered by the beam, the number of terminal apparatuses
desiring to deliver the same program is also considerably
limited.
[0166] Thus, in the 5G MBMS, the broadcasting content is
transmitted to each base station by multicast during transmission
in the core network, and in the subsequent radio access network
(RAN), the broadcasting content (i.e., MBMS service) is provided to
the terminal apparatus by multicast using a UE-specific beam (i.e.,
transmission by specifying a destination).
[0167] The procedure for delivering the MBMS content to the
terminal apparatus by multicast, the MBMS content (i.e., the
broadcasting content) transmitted by multicast to the base station
using a UE-specific beam is, in one example, as follows.
[0168] The procedure for transmitting the MBMS content to the base
station is similar to the procedure in LTE described with reference
to FIG. 7. In this description, for the MBMS content transmitted
from the MS-SC 460 to the base station 100 via the MBMS gateway
440, the information indicating that the base station 100 is
deliverable is provided from the base station 100 to the terminal
apparatus 200 as system information. Moreover, the information
indicating that the base station 100 is capable of delivering the
MBMS content is provided to the terminal apparatus 200 after or
before transmission of the MBMS content to the base station
100.
[0169] The procedure of the communication system according to the
present disclosure differs from the procedure in LTE described with
reference to FIG. 7 in that the base station 100 may necessarily
not immediately deliver the multicast MBMS content to the terminal
apparatus. An example of a procedure for providing a program to
each terminal apparatus using a directional beam in the
communication system according to an embodiment of the present
disclosure is now described with reference to FIG. 10. FIG. 10 is a
schematic sequence diagram illustrating an example of a procedure
for providing a program to each terminal apparatus using a
directional beam in the communication system according to an
embodiment of the present disclosure. Moreover, in FIG. 10, the
steps denoted by reference numerals S151 to S169 are substantially
similar to the steps denoted by reference numerals S121 to S139 in
FIG. 7, respectively, and so detailed description thereof is
omitted.
[0170] In a case where the target MBMS content is transferred (IP
multicast) from the MB-SC 460 to the MBMS gateway 440, the: MBMS
content is IP multicast from the MBMS gateway 440 to the base
station 100 (S173). The base station 100 (the: notification unit
155) can provide the terminal apparatus 200 with information
regarding the MBMS content using the system information before the
MBMS content is IP multicast from the MBMS gateway 440 (S171). In
addition, as another example, the base station 100 (the
notification unit 155) can provide the terminal apparatus 200 with
information regarding the MBMS content using the system information
after the MBMS content is IP multicast from the MBMS gateway 440
(S175).
[0171] As described above with reference to FIG. 10, the base
station 100 (the notification unit 155) notifies information
indicating what kind of program (i.e., MBMS content) the relevant
base station 100 can provide to the terminal apparatus 200 using
information that is commonly notified to a plurality of terminal
apparatuses 200, such as system information. The system information
is provided as a broadcast signal that all terminal apparatuses are
receivable in the RRC idle state during beam sweeping.
[0172] An overview of beam sweeping is now described with reference
to FIGS. 11 and 12. FIGS. 11 and 12 are diagrams illustrated to
describe the overview of beam sweeping. As illustrated in FIG. 11,
the base station performs beam sweeping using a plurality of beams
every predetermined period (e.g., 10 ms or 20 ms) as if it were a
lighthouse light. Each beam transmitted by the beam sweeping
includes, in one example, synchronization signal that is a signal
for synchronization, system information, and the like, as
illustrated in FIG. 12. Each of a plurality of beams transmitted
from one base station by one time of beam sweeping (i.e., a
plurality of beams belonging to the beam sweeping) includes system
information indicating common contents. This is because it is not
necessary to change the contents of system information for each
beam due to the characteristics of providing information to an
unspecified number of terminal apparatuses. Thus, information
common to each beam is provided as information regarding the MBMS
session provided in association with the system information (MBMS)
session information). Moreover, although an example in which a beam
including synchronization information is used is described above,
in a case where the beam is used to provide common. information to
a plurality of terminal apparatuses such as system information, the
beam may not necessarily include a synchronization signal.
[0173] An example of a procedure for providing a program to each
terminal apparatus using a directional beam in the communication
system according to an embodiment of the present disclosure is now
described in more detail with reference to FIG. 13. FIG. 13 is a
schematic sequence diagram illustrating an example of a procedure
for providing a program to each terminal apparatus using a
directional beam in the communication system according to an
embodiment of the present disclosure. Moreover, in FIG. 13, the
steps denoted by reference numerals S201 to S225 are similar to the
steps denoted by reference numerals S151 to S175 in FIG. 10,
respectively, and so detailed description thereof is omitted.
[0174] As illustrated in FIG. 13, the terminal apparatus 200 (the
notification unit 247) delivers an MBMS session request to the MME
420 on the side of a network for the MBMS content desired to be
delivered, on the basis of the information regarding the MBMS
session associated with the system information (e.g., information
regarding the MBMS session that is capable of being provided by the
base station 100) (S227). The HME 420, when receiving the MBMS
session request from the terminal apparatus 200, replies an MBMS
session confirmation to the terminal apparatus 200 (S229).
Moreover, it is possible for the communication between the terminal
apparatus 200 and the HME 420 to be achieved by, in one example,
the non-access stratum (NAS) signaling.
[0175] Subsequently, the MME 420 transmits an MBMS session start
request for the UE to the base station 100 in which the terminal
apparatus 200 that is the transmission source of the MBMS session
request is placed in the communication range (cell) in response to
the MBMS session request (S231). The base station 100, when
receiving the MBMS session start request for the UE from the MME
420, replies an MBMS session start confirmation for the UE to the
MME 420 (S233). Moreover, the MBMS session start request for the UE
transmitted to the base station 100 corresponds to an example of a
"request for content delivery".
[0176] Further, the base station 100 transmits, to the terminal
apparatus 200, various types of information used to identify a beam
used for delivering the MBMS content to the terminal apparatus 200
(S235). Examples of the information include information regarding
the resource of beam sweeping (hereinafter also referred to as
"MBMS beam sweeping") for delivering the MBMS content (CSI-RS
resource configuration) and information regarding the settings for
terminal apparatus 200 to report an observation result of a beam
transmitted by the beam sweeping (beam report configuration). Then,
the base station 100 performs MBMS beam sweeping (S237).
[0177] The terminal apparatus 200 (measuring unit 245) measures a
predetermined signal (e.g., a reference signal) in the beam
transmitted by the MBMS beam sweeping, and identifies a beam
desired for receiving the MBMS content depending on a result of the
measurement. Then, the terminal apparatus 200 (notification unit
247) reports information corresponding to the result obtained by
identifying the beam to the base station 100 (S239).
[0178] The base station 100 identifies a beam used for delivering
the MBMS content to the terminal apparatus 200 in response to the
report from the terminal apparatus 200 (S241). Then, the base
station 100 (the communication control unit 241) delivers (e.g.,
Multicast) the MBMS content that is previously multicast from the
MBMS gateway 440 to the terminal apparatus 200 using the
UE-specific beam (i.e., the identified beam) (S243).
[0179] Moreover, in the example described above, the MBMS content
is provided using a beam different from the beam used in ordinary
unicast by performing beam sweeping for MBMS and beam reporting for
MBMS. This is because it can be assumed that a beam having a wider
beam width than the above-mentioned unicast beam is used for
providing content (e.g., MBMS content) as a beam for broadcasting.
In other words, this is because, in a case where such a condition
is assumed, it can be more desirable to obtain a beam for MBMS by a
procedure different from a beam used for or unicast.
[0180] It is natural that a case where it is difficult to use a
beam for MBMS separately from a beam for ordinary unicast can be
assumed. In such a situation, in a case where there is a beam for
unicast being previously in use, the beam can be used for another
purpose as a beam for MBMS. In this case, the procedure for newly
identifying a beam can be omitted.
[0181] A description of the difference between a case where unicast
is performed in all of a series of paths through which MBMS content
is transmitted and a case where MBMS content is transmitted through
the series of paths in the communication system according to the
present embodiment is now given. Moreover, the case where unicast
is performed in all of the series of paths corresponds to,
specifically, a case where unicast is used for transmitting MBMS
content in both core network (CN) and radio access network (RAN).
In the communication system according to the present embodiment as
described above, the transmission of MBMS content from the MB-SC to
the base station via the MBMS gateway is performed using multicast.
Thus, this makes it possible to reduce the amount of signaling for
the transmission and reduce an increase in traffic, as compared to
a case where the transmission of the MBMS content on the path is
performed using unicast.
[0182] Moreover, it is expected that a new MBMS session request and
a beam sweeping procedure dedicated to MBMS are necessary to
implement the mechanism as described above. As described above, it
can be assumed that different beam widths are set for the ordinary
unicast beam and the MBMS beam. Thus, it is desirable to manage the
beam for MBMS separately from the beam for ordinary unicast in some
cases. Such management can be necessary, even in the case where the
terminal apparatus to which the beam for MBMS is once allocated
makes a transition to the RRC idle state, so that the beam for MBMS
is receivable in the RRC idle state. Moreover, the details of a
technique for enabling the terminal apparatus to receive the beam
for MBMS in the PRC idle state (i.e., enabling reception of the
MBMS content) will be described separately later as a
modification.
First Modification
[0183] Subsequently, a modification of the communication system
according to an embodiment of the present disclosure is described.
Moreover, the present modification is also referred to as a "first
modification".
[0184] In LTE, it is possible to receive the DL MBMS service
without allowing the terminal apparatus to perform signaling to the
base station. Thus, in LTE, even in the RRC idle state in which the
terminal apparatus is not registered in the base station (i.e., the
communication between the terminal apparatus and the base station
is not established), it is possible for the terminal apparatus to
receive the MBMS content. On the other hand, in the case where the
MBMS content is delivered to the terminal apparatus by multicast
using a UE-specific beam as described above, the terminal apparatus
may be necessary to be in a state registered in the base station,
that is, in the RRC connected state. On the other hand, the
increase in the number of terminal apparatuses in the RRC connected
state may consume the memory area of the base station. In addition,
the UL or DL signaling Is necessary to keep the RRC connected
state, so there is a possibility to increase the signaling
overhead
[0185] In view of the above situation, the present modification
provides the technology enabling the terminal apparatus to keep the
beam for MBMS provided in the RRC connected state, even in the case
of making the state transition to the RRC idle state.
[0186] For example, FIG. 14 is a schematic sequence diagram
illustrating an example of a procedure for providing a program to
each terminal apparatus using a directional beam in a communication
system according to the present modification. Moreover, the
procedure illustrated in FIG. 14 is executed after the provision of
MBMS content using a UE-specific beam to a particular terminal
apparatus is started by the procedure described with reference to
FIG. 13. Specifically, the steps denoted by reference numerals.
S301 and S303 correspond to the steps denoted by reference numerals
S221 and S223 in FIG. 13, respectively. Moreover, the steps denoted
by reference numerals S305 to S321 correspond to the steps denoted
by reference numerals S227 to S243 in FIG. 13, respectively.
Therefore, detailed description of the steps denoted by reference
numerals S301 to S321 is omitted.
[0187] As illustrated in FIG. 14, after the provision of the MBMS
content using the UE-specific beam is started, the terminal
apparatus 200 (the notification unit 247) transmits a detach
request to the MME 420 to make the transition to the RRC idle
state. At this time, in the communication system according to the
present modification, the terminal apparatus 200 can indicate the
intention to continue receiving the provision of the MBMS service
using the beam set at this time (that is, receiving the MBMS
content) in response to the Detach request (S323). The MME 420,
when receiving the Detach request transmitted from the terminal
apparatus 200, notifies the terminal apparatus 200 that the Detach
request is confirmed and the provision of the MBMS service
continues (S325).
[0188] Moreover, a state or mode in which communication used for
notification of information from the terminal apparatus 200 to the
base station 100, such as the RRC idle state, is restricted
corresponds to an example of a "first mode". On the other hand, a
state or mode in which the communication used for notification of
information from the terminal apparatus 200 to the base station
100, such as the RRC connected state, is established corresponds to
an example of a."second mode". Moreover, the communication
restricted in the first mode corresponds to an example of "first
wireless communication". In addition, as described above, in the
communication system according to the present modification, even in
the case of making the state transition to the RRC idle state
(i.e., the, first mode), the communication for providing the MBMS
service is kept in response to the request from the terminal
apparatus. The communication kept in response to the request from
the terminal apparatus even in the case of making the state
transition to the first mode, that is, the communication for
providing the MBMS service corresponds to an example of "second
wireless communication". In other words, in the communication
system according to the present modification, even in a case where
the above-mentioned first wireless communication and second
wireless communication are set and make a transition to the first
mode (e.g., the RRC idle state), the first wireless communication
is restricted. However, the second wireless communication is kept
in response to a request from the terminal apparatus. In addition,
in the example illustrated in FIG. 14, the MME 420 corresponds to
an example of a "device that manages a transition between the first
mode and the second mode".
[0189] Moreover, in the communication system according to the
present modification, in order to continue to provide the MBMS
service, the control can be performed such that the terminal
apparatus 200 makes a transition to the RRC connected state again
within a predetermined period (e.g., every hour) and transmits an
MBMS session request to the MME 420. In this case, in one example,
in a case where the MME 420 receives the detach request indicating
that the terminal apparatus 200 attempts to continue to receive the
provision of the MBMS service, the MME 420 starts timing for a
predetermined period by a timer (S327). Then, if the MBMS session
request is not transmitted from the terminal apparatus 200 before
the expiration of the timer (S329), the MME 420 instructs the base
station 100 to stop providing the corresponding MBMS service
(S331).
[0190] For the above-described control, in one example, the beam
width of the beam used for providing the MBMS service is wider than
the beam used for ordinary unicast, the coverage area is relatively
wide, and the affinity with the situation where the terminal
apparatus 200 moves less (ideally, the terminal apparatus 200 does
not move) is high.
[0191] Moreover, the above description is given focusing on the
case where the terminal apparatus 200 makes a transition to the RRC
idle state. On the other hand, even in a case where the terminal
apparatus 200 makes a transition to the inactive mode, it is also
possible to control in such a way that the provision of the MBMS
service continues during the relevant mode on the basis of a
similar concept to the example described with reference to FIG. 14.
For example, FIG. 15 is a schematic sequence diagram illustrating
another example of a procedure for providing a program to each
terminal apparatus using a directional beam in a communication
system according to the present modification. Specifically, FIG. 15
illustrates an example of a procedure for controlling the provision
of the MBMS service to the terminal apparatus to continue even in
the case where the terminal apparatus 200 makes a transition to the
inactive mode. Moreover, the steps denoted by reference numerals
S351 to S371 correspond to the steps denoted by reference numerals
S301 to S321 in FIG. 14, respectively. Therefore, detailed
description of the steps denoted by reference numerals S351 to S371
is omitted.
[0192] As illustrated in FIG. 15, the terminal apparatus 200 (the
notification unit 247), when making at transition to the inactive
mode, transmits an inactive mode request to the base station 200.
At this time, in the communication system according to the present
modification, the terminal apparatus 200 can indicate the intention
to continue receiving the provision of the MBMS service using the
beam set at this time (that is, receiving the MBMS content) in
response to the inactive mode request S373). In other words, the
terminal apparatus 200 requests the base station 100 to make a
transition to a mode in which the operation relating to
transmission and reception other than the operation of receiving
the provision of the MBMS service (i.e., the reception of the MBMS
content) is stopped. The base station 100 (the notification unit
155), when receiving the inactive mode request transmitted from the
terminal apparatus 200, notifies the terminal apparatus 200 that
the inactive mode request is confirmed and the provision of the
MBMS service continues (S375).
[0193] Further, in the example illustrated in FIG. 15, the
provision of the MBMS service .o the terminal apparatus 200 that
makes a transition to the inactive mode can be managed by a timer
on the basis of a similar concept to the example described with
reference to FIG. 14. In other words, in this case, the base
stations 100 (the communication control unit 155), when receiving,
from the terminal apparatus 200, the inactive mode request
indicating that the user intends to continue to receive the MBMS
service, starts timing for a predetermined period using a timer
(S377). Then, if the base station 100 (the communication control
unit 155) does not receive the notification of the MBMS session
request from the terminal apparatus 200 via the MME 420 before the
expiration of the timer (S379), the base station 100 stops
providing the MBMS service to the terminal apparatus 200 (S361).
Moreover, in the example illustrated in FIG. 15, the inactive mode
corresponds to an example of the "first mode". In other words, in
the example illustrated in FIG. 15, the base station 100
corresponds to an example of a "device that manages a transition
between the first mode and the second mode".
[0194] A supplementary description is now given of the case where
the signaling from the terminal apparatus to the base station
occurs again in the communication system according to the present
modification. In one example, even if the terminal apparatus moves
less, in some cases, it is desirable to change the modulation and
coding scheme (MCS) applied when the terminal apparatus 200
receives the content due to the fluctuation of the channel. Thus,
in one example, in a case where the reception quality of the MBMS
content (e.g., reference signal received power (RSRP) or reference
signal received quality (RSRQ)) fluctuates by a certain value or
more, the terminal apparatus can request the base station to change
the MCS for the beam used for delivering the relevant MBMS content.
Moreover, examples of the index of the reception quality of the
MBMS content include the reception power of channel state
information reference signal (CSI-RS) included in the beam used for
delivering the relevant MBMS content, the amount of interference by
other signals, and the like. In addition, the terminal apparatus,
when requesting the base station to change the MCS, makes a
transition to the RRC connected state.
[0195] For example, FIG. 13 is a schematic sequence diagram
illustrating another example of a procedure for providing a program
to each terminal apparatus using a directional beam in a
communication system according to the present modification.
Specifically, FIG. 16 illustrates an example of a procedure for the
terminal apparatus 200 to request the base station 100 to change
the MCS. Moreover, the steps denoted by reference numerals S601 to
S621 correspond to the steps denoted by reference numerals S351 to
S371 in FIG. 15, respectively. Therefore, detailed description of
the steps denoted by reference numerals S601 to S621 is
omitted.
[0196] As illustrated in FIG. 16, the terminal apparatus 200 (the
notification unit 247), when making a transition to the inactive
mode, transmits an inactive mode request to the base station 200.
At this time, the terminal apparatus 200 can indicate the intention
to continue receiving the provision of the MBMS service using the
beam set at this time (that is, receiving the MBMS content) in
response to the inactive mode request (S623). This is similar to
the example described with reference to FIG. 15. Moreover, the
terminal apparatus 200 can determine whether or not to be necessary
to modify a beam used for providing an MBMS service by using a
state that can be determined in response to a wireless signal
transmitted from the base station 100 (e.g., the quality of a
transmitted beam) as a trigger (S625).
[0197] The base station 100 (the notification unit 155), when
receiving the inactive mode request transmitted from the terminal
apparatus 200, notifies the terminal apparatus 200 that the
inactive mode request is confirmed and the provision of the MBMS
service continues (S627). In addition, the base station 100 (the
communication control unit 155), when receiving, from the terminal
apparatus 200, the inactive mode request indicating the intention
to continue to receive the MBMS service, can start timing for a
predetermined period by a timer (S629). These steps are similar to
the steps denoted by reference numerals S375 and S377 in FIG.
15.
[0198] In this stage, it is assumed that the fluctuation (e.g.,
decrease in reception quality) of the reception quality (e.g.,
RSRP/RSPQ) of the MBMS content in the terminal apparatus 200
exceeds a threshold (S631). In this case, the terminal apparatus
200 (the notification unit 247) can request the base station 100 to
change he MCS for the beam used for delivering the MBMS content by
performing beam reporting for a new beam to the base station 100
(S633).
[0199] The control as described above in the present modification
makes it possible for the terminal apparatus to continue to keep
the beam for the MBMS provided in the RPC connected state even in
the case of making a transition to the RPC idle state or the
inactive mode. In other words, the communication system according
to the present modification makes it possible to limit the number
of terminal apparatuses in the RRC connected state among the
terminal apparatuses to which the MBMS content is delivered
depending on the conditions. Thus, the communication system
according to the present modification makes it possible to reduce
the consumption of the memory area of the base station. In
addition, in the communication system according to the present
modification, it is possible to decrease the UL and DL signaling
for keeping the RRC connected state, resulting in expecting an
effect of reducing signaling overhead.
Second Modification
[0200] Subsequently, a modification of the communication system
according to another embodiment of the present disclosure is
described. Moreover, the present modification is also referred to
as a "second modification",
[0201] In 5G, the beam forming technique, that enables the
concentration of radio wave energy in a particular direction is
used to compensate for attenuation of radio wave propagation of a
high frequency from 6 GHz to 100 GHz. The use of the beam forming
technique allows the beam width of a beam emitted in a particular
direction to be limited, so the area covered by the beam is limited
compared to the case where the beam forming technique is not used.
Under such circumstances, the number of terminal apparatuses that
present within the range covered by the beam radiated in a
particular direction may be more limited than the case where the
beam forming technique is not used. In addition, the area covered
by the beam is limited, so there is a possibility that the number
of terminal apparatuses that desire to deliver the same program
among the terminal apparatuses that present in the area can be
further limited. In view of such a situation, in the 5G MBMS, a
case can be assumed in which a delivery scheme capable of more
efficiently delivering the program content (e.g., MBMS content)
differs depending on the conditions at each time. Examples of an
option of the method of delivering the Program content include
broadcast, multicast, unicast, and the like in the past employed in
LTE or the like in addition to the multicast using the UP-specific
beam described above. Moreover, in the following description,
broadcast, multicast, and unicast employed in the past in LTE or
the like can be referred to as "ordinary broadcast", "ordinary
multicast", and "ordinary unicast", respectively.
[0202] To apply selectively delivery means that are more suitable
from among the above-described examples as delivery means of
broadcast content in a radio access network. (RAN), the base
station is important, in one example, to recognize which program
content is delivered using which beam for each terminal apparatus.
For the base station to grasp such a situation, in one example, it
is possible to use the above-described. counting function.
Moreover, in LTE, a function similar to the, counting function is
defined. Specifically in LTE, as described with reference to FIG.
5, the MCE 400 collects information from each terminal apparatus
200 by transmitting a counting request to the terminal apparatus
200 via the base station 100.
[0203] On the other hand, in the 5G MBMS. only by collecting
information regarding a program that each terminal apparatus 200
desires to deliver, it is difficult for the base station to select
the delivery means for delivering the content corresponding to the.
program in a more suitable manner. In other words, as described
above, to apply selectively a more suitable delivery means, in one
example, it is important to recognize which program content is
delivered using which beam for each terminal apparatus.
[0204] Moreover, as described above with reference to FIG. 13, the
base station is capable of recognizing an ID (MBMS session ID) of
the MBMS content that the terminal apparatus desires to deliver on
the basis of a request (the MBMS session start request for the US)
from. the MME in response to the MBMS session request from the
terminal apparatus to the MME. In addition, the base station is
capable of recognizing a beam used for delivering the MBMS content
on the basis of a report (beam report for MBMS beam sweeping) from
the terminal apparatus. In other words, the base station is capable
of determining whether or not it is possible to merge beam
resources used for delivering the MBMS content with, respect to at
least some of two or more terminal apparatuses among the plurality
of terminal apparatuses by using these pieces of information.
[0205] The determination by the base station as described above can
be achieved by the implementation of the base station. Moreover, in
this case, it is important what kind of modulation and coding
scheme is used to deliver the broadcast content (MBMS content). The
terminal apparatus is capable of notifying what type of modulation
and coding scheme is desired to be applied using the channel
quality indication (CQI). Moreover, it can be said that the CQI
indicates the MCS. Thus, in the following description, it is
assumed that the terminal apparatus notifies the base station of
what type of MCS (i.e., the modulation and coding scheme) is
desired to be applied.
[0206] In a case where the MCSs are approximately equal among a
plurality of terminal apparatuses, in one example, the broadcast
content can be provided to each of the plurality of terminal
apparatuses by applying the MCS having lower communication quality.
On the other hand, even in a case where the direction of the beam
allocated to each of the plurality of terminal apparatuses is the
same and the programs that each of the plurality of terminal
apparatuses desires to deliver are the same, if the difference
between the MCSs is large (e.g., the threshold or more), the base
on can make a selection not to merge the beams. Moreover, in this
case, the MCS corresponds to an example of "wireless communication
settings" between the base station and the terminal apparatus.
[0207] An example of a procedure of a series of processing steps of
the communication system according to the present modification is
now be described with reference to FIG. 17. FIG. 17 is a schematic
sequence diagram illustrating an example of a procedure for
providing a program to each terminal apparatus using a directional
beam in the communication system according to the present
modification. Moreover, in the example illustrated in FIG. 17, it
is assumed that each of the terminal apparatuses 200A and 200B
desires to deliver common MBMS content.
[0208] As illustrated in FIG. 17, the base station 100 transmits
various types of information (e.g., such as CSI-RS resource
configuration or beam report configuration) for identifying a beam
used to deliver the MBMS content to the terminal apparatus 200B, to
the terminal apparatus 200B (S401), and performs the MBMS beam
sweeping (S403). The terminal apparatus 200B measures a
predetermined signal (e.g., a reference signal) in the beam
transmitted by the MBMS beam sweeping, and identifies a beam
desired for receiving the MBMS content depending on a result of the
measurement. Then, the terminal apparatus 200B reports information
corresponding to the result obtained by identifying the beam to the
base station 100 (S405). In this case, the terminal apparatus 200B
can associate information regarding the MCS desired to be applied
at the time of delivering the MBMS content with the report
depending on the result of the measurement.
[0209] Similarly, the base station 100 transmits various types of
information for identifying a beam used to deliver the MBMS content
to the terminal apparatus 200A, to the terminal apparatus 200A
(S407), and performs the MBMS beam sweeping (S409). The terminal
apparatus 200A measures a predetermined signal (e.g., a reference
signal) in the beam transmitted by the MBMS beam sweeping, and
identifies a beam desired for receiving the MBMS content depending
on a result of the measurement. Then, the terminal apparatus 200A
reports information corresponding to the result obtained by
identifying the beam to the base station 100 (S411). In this case,
the terminal apparatus 200A can associate information regarding the
MCS desired to be applied at the time of delivering the MBMS
content with the report depending on the result of the
measurement.
[0210] Subsequently, the base station 100 decides whether or not to
merge the beams used for delivering the MBMS content to the
terminal apparatuses 200A and 200B between the terminal apparatuses
200A and 200B depending on the report from the terminal apparatuses
200A and 200B (S413). Moreover, in this stage, it is assumed that
base station 100 decides to merge beams between terminal
apparatuses 200A and 200B. In addition, an example of the procedure
of a series of processing steps relating to the above decision by
the base station 100 will be described later in detail.
[0211] The base station 100, when deciding to merge beams between
the terminal apparatuses 200A and 200B, decides the MCS to be
applied to the delivery of the MBMS content to each of the terminal
apparatuses 200A and 200B (S415). In this case, the base station
100 can decide the MCS to be applied to the delivery of the MBMS
content to each of the terminal apparatuses 200A and 200B, in one
example, depending on the information notified from the terminal
apparatuses 200A and 200B. Then, the base station 100 delivers
common MBMS content to each of the terminal apparatuses 200A and
200B by using the decided common beam (S4I7).
[0212] Subsequently, an example of the procedure of a series of
processing steps for determining whether or not the base station
100 merges beams among the plurality of terminal apparatuses 200 in
the example illustrated in FIG. 17 is described with reference to
FIG. 18. FIG. 18 is a flowchart illustrating an example of the
procedure of processing of the base station 100 in the
communication system according to the present modification and
illustrates an example of the procedure of processing for
determining whether or not the base station 100 merges beams among
a plurality of terminal apparatuses 200.
[0213] As illustrated in FIG. 18, the base station 100 determines
whether or not a plurality of terminal apparatuses 200 desire to
deliver content (i.e., MBMS content) for the same MBMS session
(S451). In addition, the base station 100 determines whether or not
the plurality of terminal apparatuses 200 desire to use the same
beam or a beam having approximately equal direction, as the beam
used for delivering the content corresponding to the MBMS session
(S453). In addition, the base station 100 determines whether or not
the plurality of terminal apparatuses 200 desire to deliver the
content corresponding to the MBMS session in the approximately
equal MCS (S455). In a case where the plurality of terminal
apparatuses 200 use, for the content corresponding to the same MBMS
session (YES in S451), the same beam or beams having approximately
equal direction (YES in S453) and desire the delivery with
approximately equal MCS (YES in S455), the base station 100
delivers (broadcast or multicast) the content to the plurality of
terminal apparatuses 200 using a common beam (S457).
[0214] On the other hand, if each of the plurality of terminal
apparatuses 200 desires to deliver the content corresponding to
different MBMS sessions from each other (NO in S451), the base
station 100 delivers individually to each of the plurality of
terminal apparatuses 200 using the UE-specific beam (S4S8). The
same applies to a case where the plurality of terminal apparatuses
200 desire to use different beams as beams used for delivering
content corresponding to the MBMS session (NO in S453), or a case
where the plurality of terminal apparatuses 200 desire to deliver
content corresponding to the MBMS session in different MCSs (NO in
S455).
[0215] A supplementary description is now given of the difference
between the case where the MBMS service is provided to a plurality
of terminal apparatuses using a common beam (directional beam) as
described above and the case where the MBMS service is provided to
a plurality of terminal apparatuses using a cell-specific beam. In
the case of using the cell-specific beam, the beam does not include
control information for each terminal apparatus 200. On the other
hand, in the case where the MBMS service is provided to a plurality
of terminal apparatuses using a common beam (UE-specific beam), the
beam includes control information for each terminal apparatus 200
individually. In other words, in this case, the settings of the
beam are also performed for each terminal apparatus 200. Moreover,
even in the case where the control, information is included for
each terminal apparatus 200, common information is used for a data
portion (e.g., a portion corresponding to MBMS content data), so it
is desirable that the modulation scheme or the like are set to be
common among the plurality of terminal apparatuses 200.
[0216] As described above, in the present modification, the base
station merges the resources of the beam used for delivering the
MBMS content with respect to at least some of two or more of the
plurality of terminal apparatuses depending on the conditions. Such
control makes it also possible to switch selectively the delivery
schemes of delivering the program content (e.g., the MBMS content)
to each terminal apparatus depending on the conditions at each time
by using the communication system according to the present
modification. Thus, the communication system according to the
present modification enables the efficiency of resource utilization
in the entire system to be improved, resulting in expecting an
effect of improving the throughput in the entire system.
Third Modification
[0217] Subsequently, a modification of the communication system
according to another embodiment of the present disclosure is
described. Moreover, the present modification is also referred to
as a "third modification".
[0218] As described above, the MBMS content is transmitted by
multicast from the content server to the base station in the CN and
is transmitted by multicast using the UE-specific beam from the
base station to the terminal apparatus in the RAN. In the case
where the MBMS session is provided from a base station to each
terminal apparatus using the UE-specific beam (i.e., the case of
delivering the MBMS content), the UE-specific beam corresponding to
each terminal apparatus is transmitted at a different time in some
cases. This is because, in order to provide the MBMS session to
each of a plurality of terminal apparatuses using the same time
resource, in one example, each of the plurality of terminal
apparatuses is necessary to be arranged at a spatially separable
position. In other words, in a case where a plurality of terminal
apparatuses are located in an area where spatial separation is
difficult (e.g., a case where a plurality of terminal apparatuses
are located in the same area), the UE-specific beam corresponding
to each of the plurality of terminal apparatuses uses different
time/frequency resources from each other. Due to such
characteristics, it can be difficult, in some cases, to deliver the
same information to each of a plurality of terminal apparatuses at
the same timing.
[0219] Further, it is demanded to introduce a mechanism that allows
a user holding a terminal apparatus to specify a time for viewing
broadcast content through the terminal apparatus. In such a case,
in one example, in the case where the terminal apparatus receives
the provision of the MBMS session, there is a possibility to be
necessary to introduce a mechanism capable of specifying the time
at which the provision is performed. In other words, in order to
deliver the MBMS content to each of a plurality of terminal
apparatuses at different timings by multicast using the UE-specific
beam, a different response from the ordinary multicast that is
capable of delivering the content to a plurality of terminal
apparatuses at the same time is necessitated.
[0220] In view of such a situation, in the communication system
according to the present modification, a buffer provided in the
base station absorbs a difference) i.e., a time lag) in the
delivery timing of the MBMS content between a plurality of terminal
apparatuses, and the information regarding the allowable time
difference is notified to each of the plurality of terminal
apparatuses. Moreover, the notification can be performed only by
using, in one example, system information or dedicated signaling.
Thus, an example of the procedure of a series of processing steps
of the communication system according to the present modification
is now described with reference to FIG. 19, by particularly
focusing on a mechanism for absorbing the time difference. FIG. 19
is a schematic sequence diagram illustrating an example of a
procedure for providing a program to each terminal apparatus using
a directional beam in the communication system according to the
present modification. Moreover, the steps denoted by reference
numerals S501 to S519 correspond to the steps denoted by reference
numerals S201 to S219 in FIG. 13, respectively. Thus, a detailed
description of the steps denoted by reference numerals S501 to S519
is omitted.
[0221] As illustrated in FIG. 19, in a case where the MBMS content
is transferred (IF multicast) from the MB-SC 460 to the MBMS
gateway 440, the MBMS content is IF multicast from the MBMS gateway
440 to the base station 100 (S521).
[0222] The base station 100 (the communication control unit 151)
holds (buffers) the data of the MBMS content subjected to the IP
multicast from the MBMS gateway 440 in a predetermined storage area
(S523). In this case, the base station 100 calculates a period
during which the acquired data of MBMS content can be held
(buffered) on the basis of, in one example, the communication speed
for providing the MBMS session (i.e., delivering the MBMS content)
and the capacity (buffer amount) of the storage area available to
itself. Then, the base station 100 (the notification unit 155)
notifies the terminal apparatus 200, by using broadcast or
dedicated signaling as system information, of the information
regarding the calculated period, that is, the information regarding
the period in which the MBMS content can be buffered (S525).
[0223] The terminal apparatus 200 receives the notification of the
information regarding the period in which the MBMS content can be
buffered from the base station 100 and performs a procedure for
setting the UE-specific beam for receiving the MBMS content by
specifying a destination (e.g., unicast or multicast) for itself
within the period (S527 to S539). In addition, the base station 100
identifies a beam to be used for delivering the MBMS content to the
terminal apparatus 200 (S541), in response to the report from the
terminal apparatus 200 in the procedure (S539). Then, the base
station 100 (the communication control unit 241) delivers (e.g.,
Multicast) the MBMS content held in the predetermined storage area
to the terminal apparatus 200 using the UE-specific beam (i.e., the
identified beam) (S543). Moreover, the above processing steps
denoted by reference numerals S527 to S543 are substantially
similar to the steps denoted by reference numerals S227 to S243 in
FIG. 13, respectively.
[0224] Further, the base station 100 is capable of adjusting the
timing to start holding (buffering) the data of the MBMS content
depending on the information regarding the timing at which the MBMS
content notified from the terminal apparatus 200 is desired to be
delivered. Moreover, the information regarding the timing at which
the terminal apparatus 200 desires to deliver the MBMS content can
be notified from the terminal apparatus 200 to the base station 100
before the timing. In addition, the terminal apparatus 200 can
notify the base station 100 that the MBMS content is currently
desired to he delivered.
[0225] Moreover, the association of the information regarding the.
timing at which the terminal apparatus 200 desires to deliver the
MBMS content with the information notified from the terminal
apparatus 200 to the base station 100 for counting makes it
possible for the base station 100 to recognize the timing. In other
words, the base station 100 can adjust the timing to start holding
(buffering) the data of the MBMS content depending on the timing
recognized on the basis of the information notified from the
terminal apparatus 200. In one example, FIG. 20. is a schematic
sequence diagram illustrating another example of a procedure for
providing a program to each terminal apparatus using a directional
beam in the communication system according to the present
modification. In other words, FIG. 20 illustrates an example of a
procedure for adjusting the timing at which the base station 100
starts holding (buffering) the data of the MBMS content. Moreover,
the steps denoted by reference numerals S701 to S719 are similar to
the steps denoted by reference numerals S501 to S519 in FIG. 19,
respectively, and so a detailed description thereof will be
omitted.
[0226] As illustrated in FIG. 20, the base station 100 (the
notification unit 155) notifies the terminal apparatus 200 of a
counting request to perform the counting (S721). The terminal
apparatus 200 (the notification unit 247), when receiving the
counting request from the base station 100, replies information to
the base station 100 regarding the desired timing of the providing
for the MBMS session desired to be provided (i.e., the MBMS content
desired to be delivered) (S723).
[0227] The base station 100 (the communication control unit 151)
decides the timing to start providing the corresponding MBMS
session on the basis of the information notified from the terminal
apparatus 200 (S725). Then, the base station 100 (the notification:
unit 155) notifies the MB-SC 460 of a request for starting
delivering the content (i.e., MBMS content) corresponding to the
MBMS session depending on the decided timing (S727). The MB-SC 460,
when receiving the notification, transfers (IP multicast) the
corresponding HEMS content to the MB MS gateway 440. In addition,
the MBMS gateway 440 performs IP multicast of the HEMS content
transferred from the MB-SC 460 to the base station 100 (S727). The
base station 100 (the communication control unit 151) holds
(buffers) the data of the MBMS content subjected to the IP
multicast from the MBMS gateway 440 in a predetermined storage area
(S731).
[0228] Moreover, the subsequent steps, that is, the steps denoted
by reference numerals S733 to S751 are similar to the steps denoted
by reference numerals S525 to S543 in FIG. 19, respectively, and so
a detailed description thereof will be omitted.
[0229] The control as described above makes it possible for the
base station 100 to control the timing at which the terminal
apparatus 200 starts holding (buffering) data of content
corresponding to the MBMS service depending on the timing at which
the terminal apparatus 200 desires to provide the MBMS service.
[0230] A description of the relationship between the technology
according to the present modification and a technology called
mobile edge computing (MEC) is now given. The MEC is a technology
that allows a base station to hold data of an application executed
on the side of a server, thereby reducing the latency between the
application and a terminal apparatus. In view of such
characteristics, in the communication system according to the
present modification, the technology causing the base station to
hold the data of the MBMS content and delivering the MBMS content
from the base station to the terminal apparatus on the basis of the
data can be regarded as a type of the MEC.
[0231] Moreover, the communication system according to the present
modification is a service assuming provision of broadcast content,
and it differs from a typical MEC in that the period in which data
to be delivered (i.e., MBMS content) is held at the side of a base
station is finite. In addition, in the communication system
according to the present modification, there is a high possibility
that strictly speaking a request for improvement in latency or
response is not provided, as compared to the typical MEC. In other
words, in the communication system according to the present
modification, in providing a service as broadcasting, in order to
absorb the reception timing between the terminal apparatuses, the
characteristic point is that the content data is held (buffered) by
the base station.
4. Application Examples
[0232] The technology according to the present disclosure can be
applied to various products. For example, the base station 100 may
be realized as any type of evolved Node B (eNB) such as a macro eNB
or a small eNB. The small eNB may be an eNB that covers a cell,
such as a pico eNB, a micro eNB, or a home (femto) eNB, smaller
than a macrocell. Instead, the base station 100 may be realized as
another type of base station such as a NodeB or a base transceiver
station (BTS). The base station 100 may include a main entity (also
referred to as a base station device) that controls wireless
communication and one or more remote radio heads (RRHs) disposed at
different locations from the main entity. Further, various types of
terminals to be described below may operate as the base station 100
by performing a base station function temporarily or
semi-permanently. Further, at least one of constituent elements of
the base station 100 may be realized in the base station device or
a module for the base station device.
[0233] Further, for example, the terminal apparatus 200 may be
realized as a mobile terminal such as a smartphone, a tablet
personal computer (PC), a notebook PC, a portable game terminal, a
portable/dongle mobile router or a digital camera, or an in-vehicle
terminal such as a car navigation apparatus. Further, the terminal
apparatus 200 may be realized as a terminal that performs machine
to machine (M2M) communication (also referred to as a machine type
communication (MTC) terminal). Further, the terminal apparatus 200
may be realized as a so-called "low cost terminal", such as an MTC
terminal, an eMTC terminal, or an NB-IoT terminal. Moreover, at
least a part of the constituent elements of the terminal apparatus
200 may be realized in a module mounted on the terminal (for
example, an integrated circuit module configured on one die).
4.1. Application Examples for Base Station Device
[0234] (First Application Example)
[0235] FIG. 21 is a block diagram illustrating a first example of a
schematic configuration of an eNB to which the technology according
to the present disclosure may be applied. An eNB 800 includes one
or more antennas 810 and a base station device 820. Each antenna
810 and the base station device 820 may be connected to each other
via an RF cable.
[0236] Each of the antennas 810 includes a single or a plurality of
antenna elements (e.g., a plurality of antenna elements
constituting a MIMO antenna) and is used for the base station
device 820 to transmit, and receive a wireless signal. The eNB 800
may include the plurality of the antennas 810 as illustrated in
FIG. 21, and the plurality of antennas 810 may, for example,
correspond to a plurality of frequency bands used by the eNB 800.
It should be noted that while FIG. 21 illustrates an example in
which the eNB 300 includes the plurality of antennas 810, the eNB
800 may include the single antenna 610.
[0237] The base station device 820 includes a controller 821, a
memory 822, a network interface 823, and a wireless communication
interface 825.
[0238] The controller 821 may be, for example, a CPU or a DSP, and
operates various functions of an upper layer of the base station
device 820. For example, the controller 821 generates a data packet
from data in a signal processed by the wireless communication
interface 325, and transfers the generated packet via the network
interface 823. The controller 321 may generate a bundled packet by
bundling data from a plurality of base band processors to transfer
the generated bundled packet. Further, the controller 821 may also
have a logical function of performing control such as radio
resource control, radio bearer control, mobility management,
admission control, and scheduling. Further, the control may be
performed in cooperation with a surrounding eNB or a core network
node. The memory 822 includes a RAM and a ROM, and stores a program
executed by the controller 821 and a variety of control data (such
as, for example, terminal list, transmission power data, and
scheduling data).
[0239] The network interface 823 is a communication interface for
connecting the base station device 820 to the core network 824. The
controller 821 may communicate with a core network node or another
eNB via the network interface 823. In this case, the eNB 800 may be
connected to a core network node or another eNB through a logical
interface (e.g., S1 interface or X2 interface). The network
interface 823 may be a wired communication interface or a wireless
communication interface for wireless backhaul. In the case where
the network interface 323 is a wireless communication interface,
the network interface 823 may use a higher frequency band for
wireless communication than a frequency band used by the wireless
communication interface 825.
[0240] The wireless communication interface 825 supports a cellular
communication system such as long term evolution (LTE) or
LIE-Advanced, and provides wireless connection to a terminal
located within the cell of the eNB 800 via the antenna 810. The
wireless communication interface 825 may typically include a base
band (SB) processor 826, an RF circuit 827, and the like. The BB
processor 826 may, for example, perform encoding/decoding,
modulation/demodulation, multiplexing/demultiplexing, and the like,
and performs a variety of signal processing on each layer (e.g.,
L1, medium access control (MAC), radio link control (RLC), and
packet data convergence protocol (PDCP)). The BB processor 826 may
have part or all of the logical functions as described above
instead of the controller 821. The BB processor 826 may be a module
including a memory having a communication control program stored
therein, a processor to execute the program, and a related circuit,
and the function of the BB processor 826 may be changeable by
updating the program. Further, the module may be a card or blade to
be inserted into a slot of the base station device 820, or a chip
mounted on the card or the blade. Meanwhile, the RF circuit 827 may
include a mixer, a filter, an amplifier, and the like, and
transmits and receives a wireless signal via the antenna 810.
[0241] The wireless communication interface 825 may include a
plurality of the BB processors 826 as illustrated in FIG. 21, and
the plurality of BB processors 826 may, for example, correspond to
a plurality of frequency bands used by the eNB 300. Further, the
wireless communication interface 825 may also include a plurality
of the RF circuits 827, as illustrated in FIG. 21, and the
plurality of RF circuits 327 may, for example, correspond to a
plurality of antenna elements. Note that FIG. 21 illustrates an
example in which the wireless communication interface 825 includes
the plurality or BB processors 826 and the plurality of RF circuits
827, but the wireless communication interface 825 may include the
single BB processor 826 or the single RF circuit 827.
[0242] In the eNB 800 illustrated in FIG. 21, one or more
constituent elements (for example, at least one of the
communication control unit 151, the information acquisition unit
153, or the notification unit 155) included in the processing unit
150 described with reference to FIG. 2 may be implemented in the
wireless communication interface 325. Alternatively, at least some
of the constituent elements may be implemented in the controller
821. As one example, a module including a part (for example, the BB
processor 826) of or the whole of the wireless communication
interface 825 and/or the controller 821 may be implemented on the
eNB 800. The one or more constituent elements in the module may be
implemented in the module. In this case, the module may store a
program causing a processor to function as the one or more
constituent elements (in ether words, a program causing the
processor to execute operations of the one or more constituent
elements) and execute the program. As another example, a program
causing the processor to function as the one or more constituent
elements may be installed in the eNB 800, and the wireless
communication interface 825 (for example, the BB processor 826)
and/or the controller 821 may execute the program. In this way, the
eNB 800, the base station device 820, or the module may be provided
as a device including the one or more constituent elements and a
program causing the processor to function as the one or more
constituent elements may be provided. In addition, a readable
recording medium on which the program is recorded may be
provided.
[0243] Further, in the eNB 800 illustrated. in FIG. 21, the
wireless communication. unit 120 described with reference to FIG. 2
may be implemented in the wireless communication interface 825 (for
example, the. RF circuit 027). Further, the antenna unit 110 may be
implemented in the antenna 818. In addition, the network
communication unit 130 may be implemented in the controller 821
and/or the network interface 823. Further, the storage unit 140 may
be implemented in the memory 822.
Second Application Example
[0244] FIG. 22 block diagram illustrating a second example of a
schematic configuration o an eNB to which the technology according
to the present disclosure may be applied. An eNB 830 includes one
or more antennas 840, base station device 850, and an RRH 860. Each
of the antennas 840 and the RRH 860 may be connected to each other
via an RE cable. Further, the base: station device 850 and the RRH
860 may be connected to each other by a high speed line such as
optical fiber cables.
[0245] Each of the antennas 840 includes a single or at plurality
of antenna elements (e.g., antenna elements constituting a MIMO
antenna), and is used for the RRH 860 to transmit and receive a
wireless signal. The eNB 830 may include a plurality of the
antennas 840 as illustrated in FIG. 22, and the plurality of
antennas 840 may, for example, correspond to a plurality of
frequency beads used by the eNB 830. Note that FIG. 22 illustrates
an example in which the eNB 830 includes the plurality of antennas
840, but the eNB 830 may include the single antenna 848.
[0246] The base station device 850 includes a controller 851, a
memory 852, a network interface 853, a wireless communication
interface 855, and a connection interface 857. The controller 851,
the memory 852, and the network interface 853 are similar to the
controller 821, the memory 822, and the network interface 823
described with reference to FIG. 21.
[0247] The wireless communication interface 855 supports a.
cellular communication system such as LTE and LTE-Advanced, and
provides wireless connection to a terminal located in a sector
corresponding to the RRH 860 via the RRE 860 and the antenna 840.
The wireless communication interface 855 may typically include a BB
processor 856 or the like. The BB processor 856 is similar to the
BB processor 826 described with reference to FIG. 21 except that
the BB processor 856 is connected to an RF circuit 864 of the RRH
860 via the connection interface 857. The wireless communication
interface 855 may include a plurality of the BB processors 856, as
illustrated in FIG. 21, and the plurality of BB processors 856 may,
for example, correspond to a plurality of frequency bands used by
the eNB 830. Note that FIG. 22 illustrates an example in which the
wireless communication interface 855 includes the plurality of BB
processors 856, but the wireless communication interface 855 may
include the single BB processor 856.
[0248] The connection interface 857 is an interface for connecting
the base station device 850 (wireless communication interface 855)
to the RRH 860. The connection interface 857 may be a communication
module for communication on the high speed line which connects the
base station device 850 (wireless communication interface 855) to
the RRH 860.
[0249] Further, the RRH 860 includes a connection interface 861 and
a wireless communication interface 863.
[0250] The connection interface 861 is an interface for connecting
the RRH 860 (wireless communication interface 863) to the base
station device 850. The connection interface 861 may be a
communication module for communication on the high speed line.
[0251] The wireless communication interface 863 transmits and
receives a wireless signal via the antenna 840. The wireless
communication interface 863 may typically include the RF circuit
864 or the like. The RF circuit 864 may include a mixer, a filter,
an amplifier and the like, and transmits and receives a wireless
signal via the antenna 840. The wireless communication interface
863 may include a plurality of the RF circuits 864 as illustrated
in FIG. 22, and the plurality of RF circuits 864 may, for example,
correspond to a plurality of antenna elements. Note that FIG. 22
illustrates an example in which the wireless communication
interface 863 includes the plurality of RF circuits 864, but the
wireless communication interface 863 may include the single RF
circuit 864.
[0252] In the eNB 830 illustrated in FIG. 22, one or more
constituent elements (at least one of the communication control
unit 153, the information acquisition unit 153, or the notification
unit 155) included in the processing unit 150 described with
reference to FIG. 2 may be implemented in the wireless
communication interface 855 and/or the wireless communication
interface 863. Alternatively, at least some of the constituent
elements may be implemented in the controller 851. As one example,
a module including a part, (for example, the BB processor 356) of
or the whole of the wireless communication interface 855 and/or the
controller 351 may be implemented on the eNB 330. The one or more
constituent elements in the module may be implemented in the
module. In this case, the module may store a program causing a
processor to function as the one or more constituent elements (in
other words, a program causing the processor to execute operations
of the one or more constituent elements) and execute the program.
As another example, a program causing the processor to function as
the one or more constituent elements may be installed in the eNB
830, and the wireless communication interface 855 (for example, the
BB processor 856) and/or the controller 851 may execute the
program. In this way, the eNB 830, the base station device 650, or
the module may be provided as a device including the one or more
constituent elements and a program causing the processor to
function as the one or more constituent elements may be provided.
In addition, a readable recording medium on which the program is
recorded may be provided.
[0253] Further, in the eNB 830 illustrated in FIG. 22, for example,
the wireless communication unit 120 described with reference to
FIG. 2 may be implemented in the wireless communication interface
883 (for example, the RF circuit 864). Further, the antenna unit
110 may be implemented in the antenna 840. In addition, the network
communication unit 130 may be implemented in the controller 851
and/or the network interface 853. Further, the storage unit 140 may
be implemented in the memory 852.
4.2. Application Examples for Terminal Apparatus
[0254] (First Application Example)
[0255] FIG. 23 is a block diagram illustrating an example of a
schematic configuration of a smartphone 900 to which the technology
according to the present disclosure may be applied. The smartphone
900 includes a processor 901, a memory 902, a storage 903, an
external connection interlace 904, a camera 906, a sensor 907, a
microphone 908, an input device 909, a display device 910, a
speaker 911, a wireless communication interface 912, one or more
antenna switches 915, one or more antennas 916, a bus 917, a
battery 918, and an auxiliary controller 919.
[0256] The processor 901 may be, for example, a CPU or a system on
chip (SoC) and controls the functions of an application layer and
other layers of the smartphone 900. The memory 902 includes a RAM
and a ROM, and stores a program executed by the processor 901 and
data. The storage 903 may include a storage medium such as
semiconductor memories and hard disks. The external connection
interface 904 is an interface for connecting the smartphone 500 to
an externally attached. device such as memory cards and universal
serial bus (USB) devices.
[0257] The camera 906 includes, for example, an image sensor such
as charge coupled devices (CCD) and complementary metal oxide
semiconductor (CMOS), and generates a captured image. The sensor
907 may include a sensor group including, for example, a
positioning sensor, a gyro sensor, a geomagnetic sensor, an
acceleration sensor and the like. The microphone 906 converts a
sound that is input into the. smartphone 900 to an audio signal.
The input device 909 includes, for example, a touch sensor which
detects that a screen of the display device 910 is touched, a key
pad, a keyboard, a button, a switch or the like, and accepts an
operation or an information input from a user. The display deice
910 includes a screen such as liquid crystal displays (LCDs) and
organic light emitting diode (OLED) displays, and displays an
output image of the smartphone 900. The speaker 911 converts the
audio signal that is output from the smartphone 900 to a sound.
[0258] The wireless communication interface 912 supports a cellular
communication system such as LTE or LTE-Advanced, and performs
wireless communication. The wireless communication interface 912
may typically include the BB processor 913, the RF circuit 914, and
the like. The, BB processor 913 may, for example, perform
encoding/decoding, modulation/demodulation,
multiplexing/demultiplexing, and the like, and performs a variety
of types of signal processing for wireless communication. On the
other hand, the RF circuit. 914 may include a mixer, a filter, an
amplifier, and the like, and transmits and receives a wireless
signal via the antenna 916. The wireless communication interface
912 may be a one-chip module in which the BB processor 913 and the
RF circuit 914 are integrated. The wireless communication interface
912 may include a plurality of BB processors 913 and a plurality of
RF circuits 914 as illustrated in FIG. 23. Note that FIG. 23
illustrates an example in which the wireless communication
interface 912 includes a plurality of BB processors 913 and a
plurality of RF circuits 914, but the wireless communication
interface 912 may include a single BB processor 913 or a single RF
circuit 914.
[0259] Further, the wireless communication interface 912 may
support other types of wireless communication system such as a
short range wireless communication system, a near field
communication system, and a wireless local area network (LAN)
system in addition to the cellular communication system, and in
this case, the wireless communication interface 912 may include the
BB processor 913 and the RE circuit 914 for each wireless
communication system.
[0260] Each antenna switch 915 switches a connection destination of
the antenna 916 among a plurality of circuits (for example,
circuits for different wireless communication systems) included in
the wireless communication interface 912.
[0261] Each of the antennas 916 includes one or more antenna
elements (for example, a plurality of antenna elements constituting
a MIMO antenna) and is used for transmission and reception of the
wireless signal by the wireless communication interface 912. The
smartphone 900 may include a plurality of antennas 916 as
illustrated in FIG. 23. Note that FIG. 23 illustrates an example in
which the smartphone 900 includes a plurality of antennas 916, but
the smartphone 900 may include a single antenna 916.
[0262] Further, the smartphone 900 may include the antenna 916 for
each wireless communication system. In this case, the antenna
switch 915 may be omitted from a configuration of the smartphone
900.
[0263] The bus 917 connects the processor 901, the memory 902, the
storage 903, the external connection interface 904, the camera 906,
the sensor 907, the microphone 908, the input device 909, the
display device 910 the speaker 911, the wireless communication
interface 912, and the auxiliary controller 919 to each other. The
batter 918 supplies electric power to each block of the smartphone
900 illustrated in FIG. 23 via a feeder line that is partially
illustrated in the figure as a dashed line. The auxiliary
controller 919, for example, operates a minimally necessary
function of the smartphone 900 in a sleep mode.
[0264] In the smartphone 900 illustrated in FIG. 23, one or more
constituent elements included in the processing unit 240 (at least
one of the communication control unit 241, the information
acquisition unit 243, the measuring unit 245, or the notification
unit 247) described with reference to FIG. 3 may be implemented in
the wireless communication interface 912. Alternatively, at least
some of the constituent elements may be implemented in the
processor 901 or the auxiliary controller 919. As one example, a
module including a part (for example, the BB processor 913) of or
the whole of the wireless communication interface 912, the
processor 901, and/or the auxiliary controller 919 may be
implemented on the smartphone 900. The one or more constituent
elements in the module may be implemented in the module. In this
case, the module may store a program causing a processor to
function as the one or more constituent elements (in other words, a
program causing the processor to execute operations of the one or
more constituent elements) and execute the program. As another
example, a program causing the processor to function as the one or
more constituent elements may be installed in the smartphone 900,
and the wireless communication interface 912 (for example, the BB
processor 913), the processor 901, and/or the auxiliary controller
919 may execute the program. In this way, the smartphone 900 or the
module may be provided as a device including the one or more
constituent elements and a program causing the processor to
function as the one or more constituent elements may be provided.
In addition, a readable recording medium on which the program is
recorded may be provided.
[0265] Further, in the smartphone 900 illustrated in FIG. 23, for
example, the wireless communication unit 220 described with
reference to FIG. 3 may be implemented in the wireless
communication interface 912 (for example, the RF circuit 914).
Further, the antenna unit 210 may be implemented in the antenna
916. Further, the storage unit 230 may be implemented in the memory
902.
Second Application Example
[0266] FIG. 24 is a block diagram illustrating an example of a
schematic configuration of a car navigation apparatus 920 to which
the technology according to the present disclosure may be applied.
The car navigation apparatus 220 includes a processor 921, a memory
922, a global positioning system (GPS) module 924, a sensor 925, a
data interface 926, a content player 927, a storage medium
interface 926, an input device 929, a display device 930, a speaker
931, a wireless communication interface 933, one or more antenna
switches 936, one or more antennas 937, and a battery 938.
[0267] The processor 921 may be, for example, a CPU or an SoC, and
controls the navigation function and the other functions of the car
navigation apparatus 920. The memory 922 includes a RAM and a ROM,
and stores a program executed by the processor 921 and data.
[0268] The GPS module 924 uses a GPS signal received from a GPS
satellite to measure the position (e.g., latitude, longitude, and
altitude) of the car navigation apparatus 920. The sensor 925 may
include a sensor group including, for example, a gyro sensor, a
geomagnetic sensor, a barometric sensor and the like. The data
interface 926 is, for example, connected to an in-vehicle network
941 via a terminal that is not illustrated, and acquires data such
as vehicle speed data generated on the vehicle side.
[0269] The content player 927 reproduces content stored in a
storage medium (e.g., CD or DVD) inserted into the storage medium
interface 928. The input device 929 includes, for example, a touch
sensor which detects that a screen of the display device 930 is
touched, a button, a switch or the like, and accepts operation or
information input from a user. The display device 930 includes a
screen such as LCDs and OLED displays, and displays an image of
the: navigation function or the reproduced content. The speaker 931
outputs a sound of the navigation function or the reproduced
content.
[0270] The wireless communication interface 933 supports a cellular
communication system such as LTE or LTE-Advanced, and performs
wireless communication. The wireless communication interface 933
may typically include the BB processor 934, the RE circuit 935, and
the like. The BB processor 934 may, for example, perform
encoding/decoding, modulation/demodulation,
multiplexihg/demultiplexing, and the like, and performs a variety
of types of signal processing for wireless communication. On the
other hand, the RE circuit 935 may include a mixer, a filter, an
amplifier, and the like, and transmits and receives a wireless
signal via the antenna 937. The wireless communication interface
933 may be a one-chip module in which the BB processor 934 and the
RF circuit 935 are integrated. The wireless communication interface
933 may include a plurality of BB processors 934 and a plurality of
RF circuits 935 as illustrated in FIG. 24. Note that FIG. 24
illustrates an example in which the wireless communication
interface 933 includes a plurality of BB processors 934 and a
plurality of RF circuits 935, but the wireless communication
interface 933 may include a single BB processor 934 or a single RF
circuit 935.
[0271] Further, the wireless communication interface 933 may
support other types of wireless communication system such as a
short range wireless communication system, a near field
communication system, and a wireless LAN system in addition to the
cellular communication system, and in this case, the wireless
communication interface 933 may include the BB processor 934 and
the RF circuit 935 for each wireless communication system.
[0272] Each antenna switch 936 switches a connection destination of
the antenna 937 among a plurality of circuits (for example,
circuits for different wireless communication systems) included in
the wireless communication interface 933.
[0273] Each of the antennas 937 includes one or more antenna
elements (for example, a plurality of antenna elements constituting
a MIMO antenna) and is used for transmission and reception of the
wireless signal by the wireless communication interface 933. The
car navigation apparatus 920 may include a plurality of antennas
937 as illustrated in FIG. 24. Note that FIG. 24 illustrates an
example In which the car navigation apparatus 920 includes a
plurality of antennas 937, but the car navigation apparatus 920 may
include a single antenna 937.
[0274] Further, the car navigation apparatus 920 may include the
antenna 937 for each wireless communication system. In this case,
the antenna switch 936 may be omitted from a configuration of the
car navigation apparatus 920.
[0275] The battery 938 supplies electric power to each block of the
car navigation apparatus 920 illustrated in FIG. 24 via a feeder
line that is partially illustrated in the figure as a dashed line.
Further, the battery 938 accumulates the electric power supplied
from the vehicle.
[0276] In the car navigation apparatus 920 illustrated in FIG. 24,
one or more constituent elements included in the processing unit
240 (at least one of the communication control unit 241, the
information acquisition unit 243, the measuring unit 245, or the
notification unit 247) described with reference to FIG. 3 may be
implemented in the wireless communication. interface 933.
Alternatively, at least some of the constituent elements may be
implemented in the processor 921. As one example, a module
including a part of (for example, the BB processor 934) of or the
whole of the wireless communication interface 933 and/or the
processor 921 may be implemented on the car navigation apparatus
920. The one or more constituent elements in the module may be
implemented in the module. In this case, the module may store a
program causing a processor to function as the one or more
constituent elements (in other words, a program causing the
processor to execute operations of the one or more constituent
elements) and execute, the program. As another example, a program
causing the processor to function as the one or more constituent
elements may be installed in the car navigation apparatus 920, and
the wireless communication interface 933 (for example, the BB
processor 934) and/or the processor 921 may execute the program. In
this way, the car navigation apparatus 920 or the module may be
provided as a device including the one or more constituent elements
and a program causing the processor to function as the one or more
constituent elements may be provided. In addition, a readable
recording medium on which the program is recorded may be
provided.
[0277] Further, in the car navigation apparatus 920 illustrated
FIG. 24, for example, the wireless communication unit 220 described
with reference to FIG. 3 may be implemented in the wireless
communication interface 933 (for example, the RF circuit 935).
Further, the antenna unit 210 may be implemented in the antenna
937. Further, the storage unit 230 may be implemented in the memory
922.
[0278] The technology of the present disclosure may also be
realized as an in-vehicle system (or a vehicle) 940 including one
or more blocks of the car navigation apparatus 920, the in-vehicle
network 941, and a vehicle module 942. In other words, the
in-vehicle system (or the vehicle) 940 may be provided as a device
including at least one of the communication control unit 241, the
information acquisition unit 243, the measuring unit 245, or the
notification unit 247. The vehicle module 942 generates vehicle
data such as vehicle speed, engine speed, and trouble information,
and outputs the generated data to the in-vehicle network 941.
5.Concluding Remarks
[0279] As described above, in the communication system according to
an embodiment of the present disclosure, the base station delivers
the MBMS content that is multicast from the upper node (e.g., the
MBMS gateway) to the terminal apparatus using at least a part of
the directional beams (i.e., UE-specific beam) allocated to the
terminal apparatus from the plurality of directional beams. The
configuration as described above makes it possible to deliver
efficiently so-called broadcast content (e.g., MBMS content) to
each terminal apparatus even under such a situation that the
wireless communication between the base station and each terminal
apparatus is spatially separated by using the directional beam. As
described above, according to the communication system according to
an embodiment of the present disclosure, it is possible to
implement the delivery of content to a terminal apparatus using a
directional beam more suitably.
[0280] The preferred embodiment of the present disclosure has been
described above with reference to the accompanying drawings, whilst
the present disclosure is not limited to the above examples. A
person skilled in the art may find various alterations and
modifications within the scope of the appended claims, and it
should be understood that they will naturally come under the
technical scope of the present disclosure.
[0281] Further, the effects described in this specification are
merely illustrative or exemplified effects, and are not limitative.
That is, with or in the place of the above effects, the technology
according to the present disclosure may achieve other effects that
are clear to those skilled in the art from the description of this
specification.
[0282] Additionally, the present disclosure may also be configured
as below.
(1)
[0283] A communication apparatus comprising:
[0284] a communication unit configured to perform wireless
communication; and
[0285] a control unit configured to control in such a way as to
deliver content subjected to multicast from an upper node to a
terminal apparatus using at least a part of a plurality of
directional beams allocated to the terminal apparatus from the
directional beams used for the wireless communication.
(2)
[0286] The communication apparatus according to (1), wherein the
control unit controls in such a way as to deliver the content to
the terminal apparatus by specifying as a destination the terminal
apparatus to which the at least part of the directional beams is
allocated.
(3)
[0287] The communication apparatus according to (2), further
comprising:
[0288] an acquisition unit configured to acquire a request for
delivering the content for each program,
[0289] wherein the control unit controls, depending on a condition
of the request for each of the programs, a delivery scheme of the
content corresponding to the program.
(4)
[0290] The communication apparatus according to (3), wherein the
control unit selects any one of broadcast, multicast, and unicast
as the delivery scheme of the content depending on the number of
terminal apparatuses desiring to deliver the content for each of
the programs.
(5)
[0291] The communication apparatus according to (3), wherein the
control unit controls, depending on settings of wireless
communication with each of a plurality of the terminal apparatuses,
in such a way as to deliver the content used in common by
specifying each of the plurality of terminal apparatuses as a
destination through the directional beam used in common.
(6)
[0292] The communication apparatus according to (5),
[0293] wherein the acquisition unit acquires information regarding
settings of wireless communication with the terminal apparatus from
each of one or more of the terminal apparatuses, and
[0294] the control unit controls in such a way as to deliver the
content used in common by specifying each of a plurality of the
terminal apparatuses as a destination through the directional beam
used in common depending on the acquired information.
(7)
[0295] The communication apparatus according to any one of (3) to
(6), further comprising: a notification unit configured to notify
the terminal apparatus of information regarding a period in which
the content is held.
(8)
[0296] The communication apparatus according to (7),
[0297] wherein the acquisition unit acquires information regarding
a timing at which the terminal apparatus desires to deliver the
content from a predetermined node managing a session, and
[0298] the notification unit transmits a request for delivering the
content to the upper node depending on the timing.
(9)
[0299] The communication apparatus according to any one of (1) to
(8),
[0300] wherein the control unit
[0301] sets, separately from first wireless communication used for
notification of information from the terminal apparatus, second
wireless communication used for delivering the content, and
[0302] restricts the first wireless communication and maintains the
second wireless communication depending on a request for
maintaining the second wireless communication during a first mode
restricting the first wireless communication, the request being
associated with a request, which is notified from the terminal
apparatus and is for making a transition to the first mode.
(10)
[0303] A communication apparatus comprising:
[0304] a communication unit configured to perform wireless
communication; and
[0305] a control unit configured to control in such a way to
receive content subjected to multicast from an upper node to a base
station and delivered from the base station using at least a part
of directional beams allocated from a plurality of directional
beams.
(11)
[0306] The communication apparatus according to (10), further
comprising:
[0307] a notification unit configured to notify a predetermined
node managing a session of a request for delivering the
content,
[0308] wherein the control unit, after notification of the request,
controls in such a way to receive the content to be delivered using
the allocated at least part of the directional beams.
(12)
[0309] The communication apparatus according to (11),
[0310] wherein second wireless communication used for delivering
the content is set separately from first, wireless communication
used for notification of information to the base station, and
[0311] the notification unit notifies a predetermined device
configured to manage a transition between a first mode and a second
mode of a request for making a transition to the first mode
restricting the first wireless communication in association with a
request for maintaining the second wireless communication during
the first mode.
(13)
[0312] The communication apparatus according to (12),
[0313] wherein the second wireless communication uses the allocated
at least, part of the directional beams,
[0314] the control unit controls in such a way to make a transition
from the first mode to the second mode capable of performing the
first wireless communication depending on a condition relating to
the at least part of the directional beams in the first mode,
and
[0315] the notification unit, after the transition to the second
mode, notifies the base station of a request for settings of
communication using the at least part of the directional beams.
(14)
[0316] The communication apparatus according to any one of (11) to
(13), wherein the notification unit notifies the base station of
information regarding a timing at which the content is desired to
be delivered.
(15)
[0317] A communication method executed by a computer, the method
comprising:
[0318] performing wireless communication; and
[0319] controlling in such a way as to deliver content subjected to
multicast from an upper node to a terminal apparatus using at least
a part of a plurality of directional beams allocated to the
terminal apparatus from the directional beams used for the wireless
communication.
(16)
[0320] A communication method executed by a computer, the method
comprising:
[0321] performing wireless communication; and [0322] controlling in
such a way to receive content subjected to multicast from an upper
node to a base station and delivered from the base station using at
least a part of directional beams allocated from a plurality of
directional beams. (17)
[0323] A program causing a computer to execute:
[0324] performing wireless communication; and
[0325] controlling in such a way as to deliver content subjected to
multicast from an upper node to a terminal apparatus using at least
a part of a plurality of directional beams allocated to the
terminal apparatus from the directional beams used for the wireless
communication.
(10)
[0326] A program causing a computer to execute:
[0327] performing wireless communication; and
[0328] controlling in such a way to receive content subjected to
multicast from an upper node to a base station and delivered from
the base station using at least a part of directional beams
allocated from a plurality of directional beams.
REFERENCE SIGNS LIST
[0329] 1 SYSTEM
[0330] 10 CELL
[0331] 40 CORE NETWORK
[0332] 50 PACKET DATA NETWORK
[0333] 60 APPLICATION SERVER
[0334] 100 RASE STATION
[0335] 110 ANTENNA UNIT
[0336] 120 WIRELESS COMMUNICATION UNIT
[0337] 130 NETWORK COMMUNICATION UNIT
[0338] 140 STORAGE UNIT
[0339] 150 PROCESSING UNIT
[0340] 151 COMMUNICATION CONTROL UNIT
[0341] 153 INFORMATION ACQUISITION UNIT
[0342] 155 NOTIFICATION UNIT
[0343] 200 TERMINAL APPARATUS
[0344] 210 ANTENNA UNIT
[0345] 220 WIRELESS COMMUNICATION UNIT
[0346] 230 STORAGE UNIT
[0347] 240 PROCESSING UNIT
[0348] 241 COMMUNICATION CONTROL UNIT
[0349] 243 INFORMATION ACQUISITION UNIT
[0350] 245 MEASURING UNIT
[0351] 247 NOTIFICATION UNIT
[0352] 300 MEC SERVER
* * * * *