1. A mobile communication system comprising: a first gateway device that transmits user data with a base station; and a second gateway device that transmits the user data with the first gateway device and an external network, wherein the first gateway device and the second gateway device transmit a small amount of data autonomously transmitted from a terminal device through the base station by using a communication resource for transmitting a control signal, not a communication resource for transmitting user data, between the first gateway device and the second gateway device.

2. The mobile communication system according to Claim 1, wherein the terminal device is a machine type.

3. The mobile communication system according to Claim 1 or 2, wherein the first gateway device determines whether data transmitted from the terminal device is the small amount of data or not, and when the data is determined to be the small amount of data, the first gateway device transmits the data transmitted from the terminal device to the second gateway device by using the communication resource for transmitting the control signal.

4. The mobile communication system according to any one of Claims 1 to 3, wherein when the data transmitted from the terminal device is determined not to be the small amount of data, the first gateway device sets a communication resource to be used for transmitting the user data between the first gateway device and the second gateway device. 51

5. The mobile communication system according to any one of Claims 1 to 4, wherein the second gateway device determines whether data addressed to the terminal device is the small amount of data or not, and when the data is determined to be the small amount of data, the second gateway device transmits the data addressed to the terminal device to the first gateway device by using the communication resource for transmitting the control signal.

6. The mobile communication system according to any one of Claims 1 to 5, wherein when the data addressed to the terminal device is determined not to be the small amount of data, the second gateway device sets a communication resource to be used for transmitting the user data between the first gateway device and the second gateway device.

7. The mobile communication system according to any one of Claims 1 to 6, wherein the first gateway device and the second gateway device acquire information as to whether the terminal device transmits the small amount of data from a service control device that manages subscriber data.

8. The mobile communication system according to any one of Claims 1 to 7, wherein when an instruction to reserve a communication resource for transmitting the user data is given from a call control device that performs call control in the mobile communication system upon execution of a location registration process of the terminal device, the first gateway device and the second gateway device perform a process of reserving a pseudo communication resource for transmitting the user data that does not actually reserve a communication resource.

9. The mobile communication system according to Claim 8, wherein 52 when the data transmitted from the terminal device is determined not to be the small amount of data, the first gateway device changes the reserved pseudo communication resource for transmitting the user data to a general communication resource to be used for transmitting the data transmitted from the terminal device.

10. The mobile communication system according to Claim 8, wherein when the data addressed to the terminal device is determined not to be the small amount of data, the second gateway device changes the reserved pseudo communication resource for transmitting the user data to a general communication resource to be used for transmitting the data transmitted from the terminal device.

11. The mobile communication system according to Claim 1, wherein the base station and the first gateway device further transmit the small amount of data transmitted from the terminal device by using the communication resource for transmitting and receiving the control signal between the base station and the first gateway device.

12. The mobile communication system according to any one of Claims 1 to 11, wherein the first gateway device is SGW (Serving Gateway) specified in 3GPP, and the second gateway device is PGW (Packet Data Network Gateway) specified in 3GPP.

13. The mobile communication system according to any one of Claims 1 to 11, wherein the first gateway device is SGSN (Serving GPRS Support Node) specified in 3GPP, and the second gateway device is GGSN (Gateway GPRS Support Node) specified in 3GPP.

14. A data communication method between a first gateway device 53 that transmits user data with a base station and a second gateway device that transmits the user data with an external network, comprising: transmitting a small amount of data autonomously transmitted from a terminal device through the base station by using a communication resource for transmitting a control signal, not a communication resource for transmitting user data, between the first gateway device and the second gateway device.

15. A gateway device that transmits user data with a base station and an external network, wherein the gateway device transmits a small amount of data autonomously transmitted from a terminal device through the base station by using a communication resource for transmitting a control signal, not a communication resource for transmitting user data.

16. A base station that transmits user data with a terminal device and a gateway device, wherein the base station transmits a small amount of data autonomously transmitted from the terminal device by using a communication resource for transmitting a control signal, not a communication resource for transmitting user data.

2
DESCRIPTION
MOBILE COMMUNICATION SYSTEM, DATA COMMUNICATION
METHOD, GATEWAY DEVICE AND BASE STATION
5 Technical Field
[0001]
The present invention relates to a mobile communication system, a
data communication method, a gateway device and a base station an d,
particularly, to a mobile communication system that accommodates an
10 MTC device and a data communication method in the mobile
communication system.
Background Art
[0002]
In the current mobile phone system network that is specified in the
15 3GPP (3rd Generation Partnership Project) standardization group or the
like, a protocol called GTP (GPRS Tunnelling Protocol) or PMIP (Proxy
Mobile IP) is applied. Such a protocol reserves resources necessary to
implement communication requested by users and thereby pro vide
transmission channels to the users. The necessar y resources need to be
20 prepared in accordance with the number of users and the number of
connections requested by each user. Such a protocol is composed of a
control signal (Control Plane or C -Plane) for communication control and
a user data signal (User Plane or U -Plane) for transmission of user data.
Further, a plurality of transmission channels (GTP tunnel for GTP, and IP
25 tunnel for PMIP) to be used for user data signal transmission can be
reserved in response to users’ requests.
[0003]
On the other hand, as the latest technological trends,
communication intended not only for general mobile phones but also for
30 devices that do not require human operations (which is referred to
hereinafter as "non -human") such as data terminals, sensors, automatic
vending machines and automobiles using a general mobile phone system
is under review. The communication intended for non -human devices is
generally called MTC (Machine Type Communication). One
3
characteristi c of the MTC is to perform data communication in a
relatively small size. For example, in the case where a temperature
sensor reports the temperature at regular intervals, the amount of data
required for one-time communication is only several bytes. Furt her,
5 another characteristic of a device used for the MTC (which is referred to
hereinafter as "MTC device") is to implement communication during late
night hours where the mobile phone system is not in heavy use, avoiding
busy hours where it is in heavy use. By utilizing such characteristics,
mobile operators envision the mobile phone system to accommodate
10 several hundred times more MTC devices than those in a general mobile
terminal.
[0004]
When an MTC device is connected to a mobile phone system
(ATTACH process is done), a node device in the mobile phone system
15 reserves a user data transmission channel for MTC. The reservation of
the user data transmission channel intends to reserve necessary resources
for the user data transmission channel for the MTC device by the node
device in the mobile phone system.
[0005]
20 Non Patent Literature 1 discloses a procedure to reserve necessary
resources for a user data transmission channel in the network specified in
the 3GPP.
Citation List
Non Patent Literature
25 [0006]
NPL 1: 3GPP TS 23.401 V11.1.0 "GPRS enhancements for EUTRAN
access (Release 11)", clauses 5.3.2 and 5.10.2, 2012-03
Summary of Invention
Technical Problem
30 [0007]
However, as described above, mobile operators envision the
mobile phone system to accommodate several hundred times more MTC
devices than those in a general mobile terminal. Therefore, if necessar y
resources are reserved for the MTC device in the same manner as for a
4
general mobile terminal in the node device in the mobile phone system,
resource load (memory load) in the mobile phone system becomes a major
issue.
[0008]
5 To solve the above problem, an exemplary object of the present
invention is to provide a mobile communication system, a data
communication method, a gatewa y device and a base station that can
reduce resource load in a mobile phone system.
Solution to Problem
10 [0009]
A mobile communication system according to a first aspect of the
invention includes a first gateway device that transmits user data with a
base station, and a sec ond gateway device that transmits the user data
with the first gateway device and an external network, wherein the first
15 gateway device and the second gateway device transmit a small amount of
data autonomously transmitted from a terminal device through th e base
station by using a communication resource for transmitting a control
signal, not a communication resource for transmitting user data, between
the first gateway device and the second gateway device .
20 [0010]
A data communication method according to a second aspect of the
invention is a data communication method between a first gateway device
that transmits user data with a base station and a second gateway device
that transmits the user data with an external network , the method
25 including transmitting a small amount of data autonomously transmitted
from a terminal device through the base station by using a communication
resource for transmitting a control signal, not a communication resource
for transmitting user data, between the first gateway device an d the
second gateway device.
30 Advantageous Effects of Invention
[0011]
According to the exemplary aspects of the present invention, it is
possible to provide a mobile communication system, a data
communication method, a gatewa y device and a base station th at can
5
reduce resource load in a mobile phone system.
Brief Description of Drawings
[0012]
Fig. 1 is a block diagram of a mobile communication system
5 according to a first exemplary embodiment.
Fig. 2 is a block diagram of a mobile communication system
according to the first exemplary embodiment.
Fig. 3 is a block diagram of a mobile communication system
according to the first exemplary embodiment.
10 Fig. 4 is a block diagram of a GTP-C message according to the
first exemplary embodiment .
Fig. 5 is a diagram illustrating a flow of an ATTACH process
according to the first exemplary embodiment.
Fig. 6 is a diagram illustrating a flow of a process when
15 performing TAU according to the first exemplary embodiment.
Fig. 7 is a diagram illustrating a flow of a p rocess when
transmitting a small amount of data from UE according to the first
exemplary embodiment.
Fig. 8 is a diagram illustrating a flow of a handover process
20 according to the first exemplary embodiment.
Fig. 9 is a diagram illustrating a flow of a h andover process
according to the first exemplary embodiment.
Fig. 10 is a diagram illustrating a flow of a process when
receiving a small amount of data by PGW according to the first
25 exemplary embodiment.
Fig. 11 is a diagram illustrating a flow of a pro cess when
transmitting a small amount of data from UE according to the first
exemplary embodiment.
Fig. 12 is a diagram illustrating a flow of a process when
30 transmitting a large amount of data according to the first exemplar y
embodiment.
Fig. 13 is a diagram illustrating a flow of a process when
transmitting a large amount of data according to the first exemplar y
embodiment.
6
Fig. 14 is a diagram illustrating a flow of a process when deleting
a dedicated bearer according to the first exemplary embodiment .
Fig. 15 is a diagram illustrating a flow of a process when deleting
a dedicated bearer according to the first exemplary embodiment .
5 Fig. 16 is a diagram illustrating a flow of an ATTACH process
according to a second exemplary embodiment.
Fig. 17 is a diagram illustrating a flow of an ATTACH process
according to the second exemplary embodiment.
Fig. 18 is a diagram illustrating a flow of a process when
10 performing TAU according to the second exemplary embodiment.
Fig. 19 is a diagram illustrating a flo w of a handover process
according to the second exemplary embodiment.
Fig. 20 is a block diagram of a mobile communication system
according to a third exemplary embodiment .
15 Fig. 21 is a block diagram of a mobile communication system
according to the third exemplary embodiment.
Fig. 22 is a block diagram of a mobile communication system
according to the third exemplary embodiment.
Fig. 23 is a block diagram of a RANAP message according to the
20 third exemplary embodiment.
Fig. 24 is a diagram illustrating a flow of an ATTACH process
according to the third exemplary embodiment.
Fig. 25 is a diagram illustrating a flow of a process when
transmitting a small amount of data from UE according to the third
25 exemplary embodiment.
Fig. 26 is a diagram illustratin g a flow of a process when
performing RAU according to the third exemplary embodiment.
Fig. 27 is a diagram illustrating a flow of a process when RNC and
SGSN are changed according to the third exemplary embodiment.
30 Fig. 28 is a diagram illustrating a fl ow of a process when RNC and
SGSN are changed according to the third exemplary embodiment.
Fig. 29 is a diagram illustrating a flow of a process when
receiving a small amount of data by GGSN according to the third
exemplary embodiment.
7
Fig. 30 is a diagram illustrating a flow of a process when
transmitting a small amount of data from UE according to the third
exemplary embodiment.
Fig. 31 is a diagram illustrating a flow of a process when
5 transmitting and receiving a large amount of data according to the third
exemplary embodiment.
Fig. 32 is a diagram illustrating a flow of a process when
transmitting and receiving a large amount of data according to the third
exemplary embodiment.
10 Fig. 33 is a diagram illustrating a flow of a process when deleting
a dedicated bearer according to the third exemplar y embodiment.
Fig. 34 is a diagram illustrating a flow of a process when deleting
a dedicated bearer according to the third exemplar y embodiment.
Fig. 35 is a diagram illustrating a flow of an ATTACH process
15 according to a fourth exemplary embodiment.
Fig. 36 is a diagram illustrating a flow of a process when
performing RAU according to the fourth exemplary embodiment.
Fig. 37 is a diagram illustrating a flow of a process when
transmitting a small amount of data from UE according to the fourth
20 exemplary embodiment.
Fig. 38 is a diagram illustrating a flow of a handover process
according to the fourth exemplary embodiment.
Fig. 39 is a diagram illustrating a flow of a handover process
according to the fourt h exemplar y em bodiment.
25 Fig. 40 is a diagram illustrating a flow of a process when
receiving a small amount of data by GGSN according to the fourth
exemplary embodiment.
Fig. 41 is a diagram illustrating a flow of a process when
transmitting a small amou nt of data from UE according to the fourth
30 exemplary embodiment.
Fig. 42 is a diagram illustrating a flow of a process when
transmitting and receiving a large amount of data according to the fourth
exemplary embodiment.
Fig. 43 is a diagram illustrating a flow of a process when
8
transmitting and receiving a large amount of data according to the fourth
exemplary embodiment.
Fig. 44 is a diagram illustrating a flow of a process when deleting
a dedicated bearer according to the fourth exemplary embodiment.
5 Fig. 45 is a diagram illustrating a flow of a process when deleting
a dedicated bearer according to the fourth exemplary embodiment.
Description of Exemplary embodiments
[0013]
(First exemplary embodiment)
10 Exemplar y embodiments of the present invention are described
hereinafter with reference to the drawings. Firstly, a configuration
example of a mobile communication system according to a first
exemplary embodiment of the invention is described hereinafter with
reference to Fig 1. The configuration of th e mobile communication
15 system shown in Fig. 1 is an example of using LTE (Long Term
Evolution) specified in the 3GPP for an access network. The mobile
communication system shown in Fig. 1 includes UE (User Equipment) 10,
eNodeB (enhanced Node B) 20, MME (Mobility Management Entity) 30,
SGW (Serving Gateway) 40 and PGW (Packet Data Network Gateway) 50.
20 [0014]
The UE 10 is communication equipment or a mobile station that
performs wireless communication, and it may be a mobile phone or a
smartphone terminal, for example. Further, the UE 10 may be an MTC
device (machine-type-communication device). The eNodeB 20 is a base
25 station that performs wireless communication with a base station. The
UE 10 and the eNodeB 20 perform wireless communication using LTE,
which is the wireless communication standard specified in the 3GPP.
[0015]
The SGW 40 is used as a data relay device that transmits and
30 receives user data between the eNodeB 20 and the PGW 50. The user
data is packet data including voice data or the like t hat is transmitted
from the UE 10.
[0016]
The PGW 50 is used as a gateway device that transmits and
9
receives user data with an external network. The external network is a
network different from the network that includes the eNodeB20, the
MME30, the SGW40 and the PGW50. The external network is a network
that is managed by a mobile operator different from the mobile operator
5 that manages the eNodeB20, the MME30, the SGW40 and the PGW50, for
example. However, the external network is not limited thereto, an d when
the mobile operator is the same, it may be the same network as the
network that includes the eNodeB20, the MME30, the SGW40 and the
PGW50.
10 [0017]
The MME 30 is a device that performs a call control process. For
example, the MME 30 designates SGW which is the destination of user
data transmitted from the eNodeB 20 and notifies the designated SGW to
the eNodeB 20. The MME 30 transmits and receives a control signal to
15 and from the eNodeB 20 and also transmits and receives a control signal
to and from the SGW 40.
[0018]
Protocols that are specified between the respective node devic es
are described hereinbelow. The control signal between t he UE 10 and the
20 eNodeB 20 is transmitted and received using the protocol specified as
RRC (Radio Resource Control). The user data in the UE 10 and the
eNodeB 20 is transmitted and received using Traffic channel.
[0019]
The user data between the eNodeB 20 and the SGW 40 and the user
25 data between the SGW 40 and the PGW 50 are transmitted and received
using the protocol specified as GTP-U.
[0020]
The control signal between the eNodeB 20 and the MME 30 is
transmitted and received using the protocol specified as S 1AP (S1
30 Application Protocol). The control signal between the MME 30 and the
SGW 40 and the control signal between the SGW 40 and the PGW 50 are
transmitted and received using the protocol specified as GTP-C.
[0021]
A configuration of transmitting and receiving a small amount of
10
data between the SGW 40 and the PGW 50 by using communication
resources for transmitting and receiving a control signal is described
hereinafter with reference to Fig. 2. The small amount of data is data that
is transmitted from the MTC device, for example. Specific examples
5 include measurement values of a sensor and a meter, sales of an
automatic vending machine and the like. Further, the small amount of
data may be user data that is autonomously transmitted and received
between communication equipment without user operation. The small
amount of data is specified as Small Data in the 3GPP (3GPP TS 22.368
10 V11.5.0 "Service requirements for Machine-Type Communications
(MTC)", clause 7.2.5, 2012-06 etc.). The communication equipment is an
automatic vending machine, a sensor terminal or the like, for example.
The communication between the communication equipments is specified
as MTC (Machine Type Communication) in the 3GPP. In other words, the
15 small amount of data is data that is transmitted between MTC devices or
between an MTC device and a server device or the like. In general, the
MTC indicates communication that is autonomously performed without
user operation. The communication resource s are parameters that are set
for transmitting and receiving user data or a control signal, resource s
20 necessar y for transmitting and receiving user d ata or a control signal on
a memory that stores parameter s or a communication channel or the like,
for example.
[0022]
Fig. 2 shows transmitting and receiving a small amount of data
25 between the SGW 40 and the PGW 50 by using the protocol specified as
GTP-C. For example, the SGW 40 transmits a small amount of data from
the UE 10 that is transmitted from the eNodeB 20 through GTP-U to the
PGW 50 through GTP-C. On the other hand, when the PGW 50 receives a
small amount of data addressed to the UE 10, the PGW 50 transmits the
30 small amount of data to the SGW 40 through GTP-C. In this manner, by
transmitting and receiving a small amount of data between the SGW 40
and the PGW 50 by using GTP-C, it is not necessary to reserve
communication resources for user data (for example, GTP-U) in the SGW
40 and the PGW 50 and thereby reduce resource load.
11
[0023]
Fig. 3 shows an example of transmitting a small amount of data,
which has been transmitted using GTP -U, between the eNodeB 20 and the
SGW 40 by using the protocol for transmitting and receiving a control
5 signal. The eNodeB 20 transmits a small amount of data that is
transmitted through Traffic channel to the MME 30 through S1AP.
Further, the MME 30 transmits a small amount of data that is transmitted
from the eNodeB 20 to the SGW 40 through GTP-C. On the other hand,
when the SGW 40 receives a small amount of data addressed to the UE 10
10 from the PGW 50, the SGW 40 transmits the small amount of data to the
MME 30 through GTP-C. Further, the MME 30 transmits the received
small amount of data to the eNodeB 20 through S1AP. Transmitting and
receiving between the SGW 40 and the PGW 50 are the same as shown in
Fig. 2 and not redundantly described in detail.
15 [0024]
A configuration example of a GTP-C message is described
hereinafter with reference to Fig. 4. A GTP-C message that is
transmitted through GTP-C includes a GTP-C message header and IE
(Information Element) A to C. Further, in the GTP-C message, UP-PDU
20 (User Plane-Protocol Date Unit) IE is specified in order to transmit a
small amount of data. Further, in a S1AP message that is used between
the eNodeB 20 to the MME 30 also, UP-PDU IE is specified just like in
the GTP-C message.
[0025]
25 In this manner, by transmitting and receiving a small amount of
data between the eNodeB 20 to the SGW 40, in addition to between the
SGW 40 and the PGW 50, using S1AP and GTP-C that are used for
transmitting a control signal, it is not necessary to reserve
communication resources for user data in the eNodeB 20 and thereby
30 reduce resource load.
[0026]
Further, in the configuration of Fig. 2, the processing operation of
the UE 10 and the eNodeB 20 is the same as that of the UE 10 and the
eNodeB 20 shown in Fig. 1. Therefore, it is not necessary to incorporate
12
a novel feature into the UE 10 and the eNodeB 20 in order to implement
the present invention. On the other hand, in the configuration of Fig. 3,
the processing operation of the UE 10 is the same as that of the UE 10
shown in Fig. 1. Therefore, it is not necessary to incorpo rate a novel
5 feature into the UE 10 in order to implement the present invention. The
novel feature is a feature that receives a small amount of data transmitted
through a user data bearer and transmitting the received small amount of
data through a control signal bearer, for example.
[0027]
10 A flow of a process (ATTACH) for UE location registration is
described hereinafter with reference to Fig. 5. ATTACH is performed
when power is supplied to the UE, for example, for registering the
location of the UE in the mobile communication network. Further, in Fig.
5, eNodeB is denoted as eNB. In the following description, eNodeB and
15 eNB are the same device.
[0028]
First, the UE 10 transmits an ATTACH signal to the MME 30 (S1).
Next, authentication and security setting are performed between the UE
10 and HSS (Home Subscriber Server) (S2). Then, the MME 30 transmits
20 an Update Location request signal to the HSS (S 3). Then, the HSS
transmits an Update Location Ack signal to the MME 30. The Update
Location Ack signal contains pseudo-U/Size attribution that is set per
APN. The pseudo-U/Size attribution may be set per IMSI, IMEISV or the
like, other than per APN. The HSS manages pseudo -U/Size attribution as
25 subscriber data that is associated with the UE 10. Thus, the HSS can add
pseudo-U/Size attribution to the Update Location Ack signal, which is an
acknowledgement signal to the Update Location request signal
transmitted from the UE 10.
[0029]
30 The pseudo-U/Size attribution is used for setting a pseudo-U
bearer. The pseudo-U bearer is a GTP -U bearer that is set in a pseudo or
virtual manner. The bearer is a communication channel between devices.
The bearer may be communication resources that is reserved for setting a
communication channel between devices. Becau se the pseudo-U bearer is
13
a bearer that is set in a pseudo or virtual manner, communication
resources is not reserved or a minimum necessary communication
resource is reserved. Specifically, when the UE 10 performs the
ATTACH process, reservation of communication resources is performed
5 generally in order to set a GTP-U bearer. Instead of setting the GTP -U
bearer, b y setting the pseudo -U bearer for which reservation of
communication resources is not actuall y performed, it is possible to
avoid useless reser vation of communication resources without changing
the processing sequence between devices. To be specific, when
10 transmitting a small amount of data through the GTP-C bearer, setting of
the pseudo-U bearer is performed instead of setting of the GTP-U bearer,
which is generally performed. In this manner, it is possible to
accommodate communication equipment that transmits a small amount of
data into a mobile communication system without allocating
15 communication resources for setting a GTP-U bearer to the
communication equipment.
[0030]
Further, in the pseudo-U/Size attribution, information about a size
that is defined as a small amount of data is specified as well. Data that
20 is larger than the defined size is not treated as a small amount of data.
Thus, data that is smaller than the defined size is treated as a small
amount of data.
[0031]
The MME 30 that has received the pseudo -U/Size attribution
25 transmits a Create Session request signal containing PU (pseudo-U) flag
to the SGW 40. Further, the SGW 40 transmits the Create Session
request signal containing PU (pseudo-U) flag to the PGW 50 (S5). The
PU flag is a parameter that notifies setting of a pseudo-U bearer, not a
general GTP-U bearer, between the SGW 40 and the PGW 50. Further,
30 the PU flag may be a parameter that notifies setting of a pseudo -U bearer,
not a general GTP-U bearer, between the eNodeB 20 and the SGW 40.
[0032]
Then, the PGW 50 transmits a Create Session response signal
containing PU status 1 to the SGW 40. Further, the SGW 40 transmits
14
the Create Session response signal containing PU status 1 to the MME 30
(S6). The PU status 1 is a parameter that indicates the status where the
pseudo-U bearer is set between the SGW 40 and the PGW 50. The Create
Session response signal is transmitted from the PGW 50 to the SGW 40
5 and further from the SGW 40 to the MME 30, and then the PU status 1 is
stored in the SGW 40, and thereby setting of the pseudo -U bearer (which
is referred to hereinafter as Pseudo -U treatment (1)) between the SGW 40
and the PGW 50 is done (S7).
[0033]
10 Then, the MME 30 transmits an Initial Context Setup
Request/Attach Accept signal containing PU flag to the eNodeB 20 (S8).
The MME 30 thereby notifies setting of a pseudo-U bearer, not a GTP-U
bearer, between the eNodeB 20 and the SGW 40. Then, the eNodeB 20
transmits a RRC Connection Reconfiguration signal to the UE 10 (S9).
15 The UE 10 then transmits a RRC Connection Reconfiguration Complete
signal to the eNodeB 20 (S 10).
[0034]
Then, the eNodeB 20 transmits an Initial Context Setup Response
signal containing PU status 2 to the MME 30 (S11). The PU status 2 is a
20 parameter that indicates the status where the pseudo-U bearer is set
between the eNodeB 20 and the SGW 40. Setting of the pseudo-U bearer
(which is referred to hereinafter as Pseudo -U treatment (2)) between the
eNodeB 20 and the SGW 40 is thereby done (S12).
[0035]
25 Then, the MME 30 transmits a Modify bearer request signal
containing PU flag and PU status 2 to the SGW 40 (S13). The MME 30
thereby notifies the status of Pseudo-U treatment (2) to the SGW 40. The
SGW 40 then transmits a Modify bearer response signal to the MME 30
(S14).
30 [0036]
The SGW 40 stores PU status 1 and PU status 2. Therefore, the
SGW 40 can determine which bearer the received small amount of data is
to be set to and transmitted. For example, it is assumed that the SGW 40
stores PU status 2 indicating that the pseudo -U bearer is set between the
15
eNodeB 20 and the SGW 40. In this state, when the SGW 40 receives a
small amount of data from the PGW 50, it transmits the small amount of
data to the MME 30 through the GTP-C bearer. For example, in the case
where the SGW 40 does not store PU status 2, the SGW 40 transmits the
5 small amount of data received from the PGW 50 to the eNodeB 20
through the GTP-U bearer. The case where the SGW 40 does not store
PU status 2 occurs when the eNodeB 20 and the SGW 40 do not have the
feature to set the pseudo-U bearer between the eNodeB 20 and the SGW
40, for example.
10 [0037]
In the above description, the exam ple of setting Pseudo-U
treatment (1) and Pseudo-U treatment (2) is described. In other words,
the example of transmitting a small amount of data from the eNodeB 20
to the PGW 50 by using the bearer for transmitting a control signal is
15 described. Note th at, however, the procedure of setting Pseudo -U
treatment (2) may be omitted for the case of transmitting a small amount
of data only between the SGW 40 and the PGW 50 by using the bearer for
transmitting a control signal. This is the same in the following
description as well.
20 [0038]
Hereinafter, a flow of a process in the case where TAU (Tracking
Area Update) is performed is described with reference to Fig. 6.
Tracking Area (TA) is location information of the UE 10 that is managed
on the mobile communication network, such as a core network, for
25 example. Tracking Area (TA) may be an area composed of a plurality of
cells. TAU is processing that is performed when TA where the UE 10 is
located is changed.
[0039]
First, the UE 10 transmits a TAU request signal to the new MME
30 30 (New MME) that is going to manage the UE 10 after TA is changed
(S21). Next, the New MME transmits a Context Request signal to the
MME 30 (Old MME) that has been managing the UE 10 before TA is
changed (S22). Then, the Old MME transmits a Context Response signal
to the New MME (S23). The Context Response signal contains PU flag.
16
Thus, the Old MME notifies the New MME that the pseudo-U bearer,
instead of GTP -U, is to be set for the UE 10. After that, authentication
and security setting are performed between the UE 10 and HSS (Home
Subscriber Server) (S24). The New MME then transmits a Context
5 Request Ack signal to the Old MME (S25).
[0040]
Then, the New MME transmits a Create Session request signal
containing PU flag to the SGW 40 (New SGW) that is newly allocated to
transmit a small amount of data transmitted from the UE 10 after change
10 in TA (S26). Then, the pseudo-U bearer that has been set between the
SGW 40 (Old SGW) that has been allocated before change in TA and the
PGW 50 is to be set between the New SGW and the PGW 50. To make
this setting, the New SGW transmits a Modify bearer request signal
containing PU flag to the PGW 50 (S27). Next, the PGW 50 transmits a
15 Modify bearer response signal containing PU status 1 to the New SGW
(S28). The New SGW then transmits a Create Session response signal
containing PU status 1 to the New MME (S29). Pseudo-U treatment (1)
is thereby set between the New SGW and the PGW 50 (S30).
[0041]
20 Then, the New MME transmits an Update Location request signal
to the HSS (S31). The HSS then transmits an Update Location Ack signal
to the New MME. The Update Location Ack signal contains pseudo -
U/Size attribution that is set per APN (S 32). The pseudo-U/Size
attribution may be set per IMSI, IMEISV or the like, other than per APN.
25 Then, the New MME transmits a TAU accept signal to the UE 10 (S33).
[0042]
A flow of a process in the case of transmitting a small amount of
data from the UE 10 is described hereinafter with reference to Fig. 7.
First, the UE 10 transmits a PDN Connectivity Request (APN) signal to
30 the MME 30 (S41). Next, the MME 30 transmits an Initial Context Setup
Request signal containing PU flag to the eNodeB 20 (S 42). Processing of
Steps S43 to S48 is the same as that of Steps S 9 to S14 in Fig. 5 and thus
not redundantly described in detail.
[0043]
17
A flow of a handover process is described hereinafter with
reference to Figs. 8 and 9. In the handover shown in Figs. 8 and 9, the
case where the eNodeB, the MME and the SGW to which th e UE 10
belongs are changed is described. First, the eNodeB 20 (Old eNB) from
5 which handover is made transmits a Handover required signal to the MME
(Old MME) that manages the Old eNB (S 51). Next, the Old MME
transmits a Forward relocation request signal to the MME (New MME)
that manages the eNodeB 20 (New eNB) to which handover is made (S52).
The Forward relocation request signal contains PU flag. Then, the New
10 MME transmits a Create Session request signal to the New SGW to be
connected to the New eNB (S53). The Create Session request signal
contains PU flag. Then, the New SGW transmits a Create Session
response signal to the New MME (S54).
[0044]
15 Then, the New MME transmits a Handover request signal
containing PU flag to the New eNB (S 55). The New eNB then transmits a
Handover request ack signal containing PU status 2 to the New MME
(S56). Pseudo-U treatment (2) is thereby set between the New eNB and
the New SGW (S57). Then, the New MME transmits a Forward relocation
20 response signal to the Old MME (S58). The Old MME then transmits a
Handover command signal to the Old eNB (S 59). Then, the Old eNB
transmits a Handover command signal to the UE 10 (S60).
[0045]
A handover process after Step S 60 is described hereinafter with
25 reference to Fig. 9. After Step S60, the UE 10 transmits a Handover
confirm signal to the New eNB (S61). Then, the New eNB transmits a
Handover Notify signal to the New MME (S 62). The New MME then
transmits a Forward relocation complete Notification signal to the Old
MME (S63). Then, the Old MME transmits a Forward relocation
30 complete Ack signal to the New MME (S64). Then, the New MME
transmits a Modify bearer request signal to the New SGW (S 65). The
Modify bearer request signal contains PU flag and PU status 2.
[0046]
Then, the New SGW transmits a Modify bearer request signal
18
containing PU flag to the PGW 50 (S66). Next, the PGW 50 transmits a
Modify bearer response signal containing PU status 1 to the New SGW
(S67). Further, the New SGW transmits a Modify bearer response signal
containing PU status 1 to the New MME (S68). Pseudo-U treatment (1)
5 is thereby set between the New SGW and the PGW 50 (S69).
[0047]
A flow of a process in the case where the PGW 50 receives a small
amount of data addressed to the UE 10 is described hereinafter with
reference to Fig. 10. It is assumed that Pseudo -U treatment (1) is set
10 between the SGW 40 and the PGW 50 (S71). When the PGW 50 receives
a small amount of data addressed to the UE 10 that is associated with
Pseudo-U treatment (1), it transmits the received small amount of data to
the SGW 40 through GTP-C (S72). Next, the SGW 40 transmits a
Downlink Data Notification signal to the MME 30 to notify that the small
15 amount of data is received (S 73). The Downlink Data Notification signal
may contain a small amount of data. Then, the MME 30 transmits a Page
signal to the eNodeB 20 (S 74), and further the eNodeB 20 transmits the
Page signal to the UE 10 (S75). Note that, in order to determine whether
the received data is a small amount of dat a or not, the PGW 50 may
20 determine whether the size of the data exceeds the size that is defined as
a small amount of data.
[0048]
A flow of a process in the case of transmitting a small amount of
data from the UE 10 is described hereinafter with referenc e to Fig. 11.
25 Note that the process shown in Fig. 11 is used also as the process which
is executed by the UE 10 that has received the Page signal in Fig. 10.
[0049]
First, the UE 10 transmits a Service Request signal to the MME 30
(S76). Next, authentication and security setting are performed between
30 the UE 10 and HSS (Home Subscriber Server) (S77). Then, the MME 30
transmits a S1-AP:Initial Context Setup Request signal containing PU
flag to the eNodeB 20 (S78). The S1-AP:Initial Context Setup Request
signal may contain a small amount of data. Then, the eNodeB 20 sets a
radio bearer with the UE 10 (S79). The eNodeB 20 may transmit the
19
small amount of data received with the S 1-AP:Initial Context Setup
Request signal to the UE 10 by using the set radio bearer. Then, the
eNodeB 20 transmits a S1-AP:Initial Context Setup Complete signal
containing PU status 2 to the MME 30 (S80). Pseudo-U treatment (2) is
5 thereby set between the eNodeB 20 and the SGW 40 (S81).
[0050]
Then, the MME 30 transmits a Modify bearer request signal
containing PU flag and PU status 2 (S82). The SGW 40 then transmits a
Modify bearer response signal to the MME 30 (S83).
10 [0051]
The case of transmitting and receiving a large amount of data that
is larger than the data size (or the amount of data) defined as a small
amount of data in the environment of transmitting and receiving a small
amount of data using GTP -C is described hereinafter with reference to
15 Fig. 12. For example, in the case where a temperature sensor is used as
communication equipment that is used for the MTC, the temperature
sensor notifies temperature information to a server device or the like at
regular time intervals. The temperature information in this case is
treated as a small amount of data. On the other han d, when a request for
20 software update of the temperature sensor is made, the temperature
sensor transmits data (which is referred to hereinafter as a large amount
of data) that is larger than the small amount of data in some cases. A
method of transmitting the large amount of data in such a case is
described hereinbelow. The large amount of data is data that is larger
25 than the data size defined in pseudo -U/Size attribution.
[0052]
In the case where the GTP-C bearer is set between the SGW 40 and
the PGW 50 in order to transmit a small amount of data, when a large
amount of data addressed to the UE 10 arrives at the PGW 50, the PGW
30 50 newly sets a dedicated bearer for transmitting a large amount of data
with the SGW 40. The dedicated bearer may be a GTP-U bearer, for
example. To make this setting, the PGW 50 transmits a Create Bearer
Request signal to the SGW 40. Further, the SGW 40 transmits the Create
Bearer Request signal to the MME 30 (S91). Then, the MME 30
20
transmits a Bearer Setup Request signal to the eNodeB 20 (S92). The
eNodeB 20 then transmits a Bearer Setup Response signal to the MME 30
(S93). The MME 30 then transmits a Create Bearer Response signal to
the SGW 40. The SGW 40 then transmits the Create Bearer Response
5 signal to the PGW 50 (S94).
[0053]
In this manner, by transmitting the Create Bearer
Request/Response signal, a dedicated bearer for transmitting a large
amount of data is set between the SGW 40 and the PGW 50, and by
10 transmitting the Bearer Setup Request/Response signal, a dedicated
bearer is set also between the eNodeB 20 and the SGW 40.
[0054]
Further, in the case where GTP -C is set between the SGW 40 and
the PGW 50 in order to transmit a small amount of data, when a large
15 amount of data arrives at the PGW 50, the PGW 50 may change the
pseudo-U bearer that is already set between the SGW 40 and the PGW 50
to a general GTP-U bearer or a dedicated bearer. In this case, an Update
Bearer Request/Response signal is used instead of the Create Bearer
Request/Response signal in Steps S91 and S94 in Fig. 12. Further, a
20 Bearer Modify Request/Response is used instead of the Bearer Setup
Request/Response signal in Steps S 92 and S93 in Fig 12.
[0055]
Further, the Bearer Modify Request/Response signal is transmitted
only when Pseudo-U treatment(2) is set between the eNodeB 20 and the
25 SGW 40.
[0056]
The case of transmitting a large amount of data from the UE 10 in
the environment of transmitting and receiving a small amount of data
using GTP-C and S1-AP is described hereinafter with referen ce to Fig. 13.
30 [0057]
In the case where S1-AP is set between the eNodeB 20 and the
MME 30 and GTP-C is set between the MME 30 and the PGW 50 for
transmitting a small amount of data, a dedicated bearer for transmitting a
large amount of data is newly set between the eNodeB 20 and the PGW 50
21
in order to transmit a large amount of data from the UE 10.
[0058]
First, when the eNodeB 20 receives a large amount of data from
the UE 10, the eNodeB 20 transmits a Bearer Resource Command signal
5 to the MME 30 (S111). The MME 30 then transmits the Bearer Resource
Command signal to the SGW 40, and further the SGW 40 transmits the
Bearer Resource Command signal to the PGW 50 (S112). Then, the PGW
50 transmits a Create Bearer Request si gnal to the SGW 40, and further
the SGW 40 transmits the Create Bearer Request signal to the MME 30
10 (S113).
[0059]
Then, the MME 30 transmits a Bearer Setup Request signal to the
eNodeB 20 (S114). The eNodeB 20 then transmits a Bearer Setup
Response to the MME 30 (S115). The MME 30 then transmits a Create
15 Bearer Response signal to the SGW 40 (S116).
[0060]
In this manner, by transmitting the Create Bearer
Request/Response signal between the MME 30 and the PGW 50, a
dedicated bearer for transmitting a large amount of data is set between
20 the SGW 40 and the PGW 50, and by transmitting the Bearer Setup
Request/Response signal between the MME 30 and the eNodeB 20, a
dedicated bearer is set also between the eNodeB 20 and the SGW 40.
[0061]
In the case of transmitting a small amount of data us ing the GTP-C
25 bearer between the SGW 40 and the PGW 50 and transmitting a small
amount of data using the GTP-U bearer between the SGW 40 and the
eNodeB 20, a large amount of data is transmitted through the GTP -U
bearer from the UE 10 to the SGW 40. In such a case, a Bearer Resource
Command signal is transmitted from the SGW 40 to the PGW 50. Further,
30 a Create Bearer Request/Response signal is transmitted between the PGW
50 and the MME 30. A dedicated bearer that is used for transmitting a
large amount of data is thereby set between the SGW 40 and the PGW 50.
Further, in this case, the Bearer Setup Request/Response signal in Fig. 13
is not transmitted.
22
[0062]
Further, in the case where GTP -C is set between the SGW 40 and
the PGW 50 and between the MME 30 and the SGW 40 for transmitting a
small amount of data, and S1AP is set between the eNodeB 20 and the
5 MME 30, when the eNodeB 20 receives a large amount of data from the
UE 10, the pseudo-U bearer that is already set between the eNodeB 20
and the PGW 50 may be changed to a general GTP-U bearer or a
dedicated bearer. In this case, a Modify Bearer Request signal is used
instead of the Create Bearer Request/Response signal in Steps S 113 and
10 S116 in Fig. 13. Further, a Bearer Modif y Request/Response signal i s
used instead of the Bearer Setup Request/Response signal in Steps S 114
and S115 in Fig 13.
[0063]
Further, the Bearer Modify Request/Response signal is transmitted
15 only when Pseudo-U treatment (2) is set between the eNodeB 20 and the
SGW 40.
[0064]
In the case of transmitting a small amount of data using the GTP -C
bearer between the SGW 40 and the PGW 50 and transmitting a small
20 amount of data using the GTP-U bearer between the SGW 40 and the
eNodeB 20, a large amount of data is transmitted through the GTP-U
bearer from the UE 10 to the SGW 40. In such a case, a Bearer Resource
Command signal is transmitted from the SGW 40 to the PGW 50. Further,
a Modify Bearer Request/Response signal is transmitted between the
25 PGW 50 and the MME 30. The pseudo-U bearer that is already set
between the SGW 40 and the PGW 50 can be thereby changed to a
dedicated bearer or a GTP -U bearer that is used for transmitting a large
amount of data. Further, in this case, the Bearer Modify
Request/Response signal in Fig. 13 is not transmitted.
30 [0065]
A flow of a process in the case of deleting a dedicated bearer that
is set for transmitting a large amount of data is described hereinafter
with reference to Fig. 14. The dedicated bearer is deleted when
transmission of a large amount of data ends between the eNodeB 20 and
23
the PGW 50. To be specific, the dedicated bearer may be deleted when
the fact that a large amount of data is not transmitted for a certain period
of time is detected in the eNodeB 20 or the PGW 50.
[0066]
5 First, when the PGW 50 detects the fact that a large amount of
data is not transmitted for a certain period of time , it transmits a Delete
Bearer Request signal to the SGW 40, and further the SGW 40 transmits
the Delete Bearer Request signal to the MME 30 (S131). Then, in order
to delete the dedicated bearer that is set between the eNodeB 20 and the
10 SGW 40, the MME 30 transmits a Deactivate Bearer Request signal to the
eNodeB 20 (S132).
[0067]
Next, the eNodeB 20 transmits a Deactivate Bearer Response
signal to the MME 30 (S133). The MME 30 then transmits a Delete
15 Bearer Response signal to the SGW 40, and further the SGW 40 transmits
the Delete Bearer Response signal to the PGW 50 (S134). The dedicated
bearer that is set between the eNodeB 20 and the PGW 50 is thereby
deleted.
[0068]
20 Further, in the case where the pseudo -U bearer has been changed
to the GTP-U bearer or the dedicated bearer in order to transmit a large
amount of data, a flow of a process of setting the bearer back to the
pseudo-U bearer at th e end of transmission of a large amount of data is
described hereinafter. To be specific, an Update Bearer
25 Request/Response signal is used instead of the Delete Bearer
Request/Response signal in Steps S 131 and S134 in Fig. 14. Further, a
Bearer Modify Request/Response signal is used instead of the Deactivate
Bearer Request/Response signal in Steps S132 and S133 in Fig. 14.
Using those signals, the process of setting the GTP -U bearer or the
30 dedicated bearer back to the pseudo -U bearer is performed.
[0069]
A flow of a process in the case of deleting a dedicated bearer when
the eNodeB 20 detects the fact that a large amount of data is not
transmitted for a certain period of time is described hereinafter with
24
reference to Fig. 15. First, when the eNodeB 20 detects the fact that
transmission of a large amount of data is not performed for a certain
period of time, it transmits a Bearer Resource Command signal to the
MME 30 (S141).
5 [0070]
Then, the MME 30 transmits a Delete Bearer Command signal to
the SGW 40, and further the SGW 40 transmits the Delete Bearer
Command signal to the PGW 50 (S142). Then, the PGW 50 transmits a
Delete Bearer Request signal to the SGW 40, and further the SGW 40
10 transmits the Delete Bearer Request signal to the MME 30 (S143). Then,
the MME 30 transmits a Deactivate Bearer Request signal to the eNodeB
20 (S144). Then, the eNodeB 20 transmits a Deactivate Bearer Response
signal to the MME 30 (S145). The MME 30 then transmits a Delete
Bearer Response signal to the SGW 40, and further the SGW 40 transmits
15 the Delete Bearer Response signal to the PGW 50 (S146).
[0071]
In this manner, by transmitting the Delete Bearer
Request/Response signal, the dedicated bearer for transmitting a large
amount of data between the SGW 40 and the PGW 50 is deleted, and by
20 transmitting the Deactivate Bearer Request/Response signal, the
dedicated bearer between the eNodeB 20 and the SGW 40 is deleted.
[0072]
Further, in the case where the pseudo -U bearer has been changed
to the GTP -U bearer or the dedicat ed bearer in order to transmit a large
25 amount of data, a flow of a process of setting the bearer back to the
pseudo-U bearer at the end of transmission of a large amount of data is
described hereinafter. To be specific, a Modify Bearer Request/Response
si gnal is used instead of the Delete Bearer Request/Response signal in
Steps S143 and S146 in Fig. 15. Further, a Bearer Modify
30 Request/Response signal is used instead of the Deactivate Bearer
Request/Response signal in Steps S144 and S145 in Fig. 15. Using those
signals, the process of setting the GTP -U bearer or the dedicated bearer
back to the pseudo-U bearer is performed.
[0073]
25
In the case of transmitting a small amount of data using the GTP -C
bearer between the SGW 40 and the PGW 50 and transmitting a small
amount of data using the GTP-U bearer between the SGW 40 and the
eNodeB 20, the fact that a large amount of data is not transmitted may be
5 detected in the SGW 40. In this case, a Delete Bearer Command signal is
transmitted from the SGW 40 to the PGW 50. Further, a Delete Bearer
Request/Response signal is transmitted between the PGW 50 and the
MME 30. The dedicated bearer that is set between the SGW 40 and the
PGW 50 to be used for transmitting a large amount of data is thereby
10 deleted. Further, in this case, the Deactivate Bearer Request/Response in
Fig. 15 is not transmitted.
[0074]
As described above, by using the mobile communication system
according to the first exemplar y embodiment of the invention, it is
15 possible to set the pseudo -U bearer that does not require reservation of
communication resources between the eNodeB 20 and the PGW 50. It is
thereby possible to transmit a small amount of data by using
communication resources that are used for transmitting a control signal
such as GTP-C and S1-AP, in the same process flow as in the case of
20 using the GTP-U bearer for transmission of a small amount of data.
[0075]
(Second exemplary embodiment)
An example in which transfer of a control signal and user data
between the SGW 40 and the PGW 50 is performed using a transfer
25 method that is specified as PMIP (Proxy Mobile IP) according to a
second exemplary embodiment of the invention is described hereinbelow.
The control signal between the SGW 40 and the PGW 50 is transmitted
and received by using the protocol that is specified in PMIP (which is
referred to hereinafter as PMIP). The user data between the SGW 40 and
30 the PGW 50 is transferred as a general IP packet.
[0076]
In the case where PMIP is used between the SGW 40 and the PGW
50, a PMIP bearer is used instead of the GTP-C bearer between the SGW
40 and the PGW 50 in Fig. 2 for transmission of a small amount of data.
26
[0077]
Further, in a PMIP message that is transmitted through PMIP , a
PMIP message header is used instead of the GTP -C message header in Fig.
4, and it has IE A to C just like shown in Fig. 4. Further, in the PMIP
5 message, UP -PDU IE is specified to transmit a small amount of data.
[0078]
A flow of an ATTACH process of the UE 10 in the case where
PMIP is used between the SGW 40 and the PGW 50 is described
hereinafter with reference to Figs. 16 and 17. Steps S151 to S154 are the
10 same as Steps S1 to S4 in Fig. 5 and thus not redundantly described in
detail. In Step S154, when the MME 30 receives an Update Location Ack
signal, it transmits a Create Session request signal containing PU flag to
the SGW 40 (S155).
[0079]
15 Next, the SGW 40 transmits a PBU (Proxy Binding Update) signal
to the PGW 50 (S156). The PBU signal contains PU flag. Then, the
PGW 50 transmits a PBA (Proxy Binding Ack) signal (S157). The PBA
signal contains PU status 1. Then, the SGW 40 transmits a Create
Session response signal to the MME 30 (S158). The Create Session
20 response signal contains PU status 1. Pseudo-U treatment (1) is thereby
set between the SGW 40 and the PGW 50 (S159). Steps S160 to S166 in
Fig. 17 are the sam e as Steps S 8 to S14 in Fig. 5 and thus not
redundantly described in detail.
[0080]
25 A flow of a process of TAU (Tracking Area Update) in the case
where PMIP is used between the SGW 40 and the PGW 50 is described
hereinafter with reference to Fig. 18. Steps S171 to S176 are the same as
Steps S21 to S26 in Fig. 6 and thus not redundantly described in detail.
In Step S176, the New SGW that has received a Create Session request
30 signal transmits a PBU signal containing PU flag to the PGW 50 (S177).
Next, the PGW 50 transmits a PBA signal containing PU status 1 to the
New SGW (S178). Steps S179 to S183 are the same as Steps S29 to S33
in Fig. 6 and thus not redundantly described in detail.
[0081]
27
A flow of a handover process after Handover command is
transmitted to the UE 10 is described hereinafter with reference to Fig.
19. Steps S191 to S195 are the same as Steps S61 to S65 in Fig. 9 and
thus not redundantly described in detail. In Step S195, the New SGW
5 that has received a Modify bearer request signal transmits a PBU signal
containing PU flag to the PGW 50 (S196). The PGW 50 then transmits a
PBA signal containing PU status 1 to the New SGW (S197). Steps S198
and S199 are the same as Steps S68 and S69 in Fig. 9 and thus not
redundantly described in detail.
10 [0082]
As described above, by using the mobile communication system
according to the second exemplary embodiment of the invention, it is
possible to set the pseudo -U bearer that does not require reservation of
communication resources between the eNodeB 20 and the PGW 50 also in
15 the case of using the transfer method that is specified as PMIP between
the SGW 40 and the PGW 50. It is thereby possible to transmit a small
amount of data by using communication resources that are used for
transmitting a control signal such as PMIP, in the same process flow as
in the case of using the GTP -U bearer for transmission of a small amount
20 of data.
[0083]
(Third exemplary embodiment)
A configuration example of a mobile communication system
according to a third exemplary embodiment of the invention is described
25 hereinafter with reference to Fig. 20. The configuration of the mobile
communication system shown in Fig. 20 is an example of using GPRS
that is specified as the second generation or the third generation
specified in the 3GPP for a core network. Device s that constitute GPRS
include SGSN 45 and GGSN 55. Further, RNC 25 is used for an access
30 network or RAN (Radio Area Network), and the UE 10 is connected to the
RNC 25.
[0084]
The UE 10 is the same as that in Fig. 1 and not redundantly
described in detail. The RNC 25 is a device that integrates base stations
28
and performs communication with a UE (mobile station) through a base
station. For example, the RNC 25 specifies the SGSN 45 that is a
destination of user data transmitted from the UE 10 and transmits the
user data to the specified SGSN 45.
5 [0085]
The SGSN 45 is used as a data relay device that transmits and
receives user data between the RNC 25 and the GGSN 55. The user data
is packet data containing voice data or the like transmitted from the UE
10.
10 [0086]
The GGSN 55 is used as a gateway device that transmits and
receives user data with an external network. The external network is a
different network from a network that has the RNC 25, the SGSN 45 and
the GGSN 55. In some cases, the external network is a network that is
15 managed b y a mobile operator different from the mobile operator that
manages the RNC 25, the SGSN 45 and the GGSN 55, for example.
[0087]
Protocols that are specified between the respective node d evices
are described hereinafter with reference to Fig. 20. The control signal
20 between the UE 10 and the RNC 25 is transmitted and received using the
protocol defined as RRC. The user data in the UE 10 and the RNC 25 is
transmitted and received using Traffic channel.
[0088]
The user data between the RNC 25 and the SGSN 45 and the user
25 data between the SGSN 45 and the GGSN 55 are transmitted and received
using the protocol specified as GTP -U.
[0089]
The control signal between the RNC 25 and the SGSN 45 is
transmitted and received using the protocol specified as RANAP . The
30 control signal between the SGSN 45 and the GGSN 55 is transmitted and
received using the protocol specif ied as GTP-C.
[0090]
A configuration of transmitting and receiving a small amount of
data between the SGSN 45 and the GGSN 55 by using communication
29
resources for transmitting and receiving a control signal is described
hereinafter with reference to Fig. 21.
[0091]
Fig. 21 shows transmitting and receiving a small amount of data
5 between the SGSN 45 and the GGSN 55 by using the protocol specified as
GTP-C. For example, the SGSN 45 transmits a small amount of data that
is transmitted from the RNC 25 through GTP-U to the GGSN 55 through
GTP-C. Alternatively, when the GGSN 55 receives a small amount of
data addressed to the UE 10, the GGSN 55 transmits the small amount of
10 data to the SGSN 45 through GTP-C. In this manner, by transmitting and
receiving a small amount of data between the SGSN 45 and the GGSN 55
by using GTP -C, it is not necessary to reserve communication resource s
for user data in the SGSN 45 and the GGSN 55 and thereby reduce
resource load.
15 [0092]
Fig. 22 shows an example of transmitting a sm all amount of data,
which has been transmitted using GTP -U, between the RNC 25 and the
SGSN 45 by using the protocol for transmitting and receiving a control
signal. The RNC 25 transmits a small amount of data that is transmitted
20 through Traffic channel to the SGSN 45 through RANAP. Alternatively,
when the SGSN 45 receives a small amount of data addressed to the UE
10 from the GGSN 55, the SGSN 45 transmits the small amount of data to
the RNC 25 through RANAP. Transmitting and receiving between the
SGSN 45 and the GGSN 55 are the same as shown in Fig. 21 and not
25 redundantly described in detail.
[0093]
In this manner, by transmitting and receiving a small amount of
data between the RNC 25 to the SGSN 45, in addition to between the
SGSN 45 and the GGSN 55, by using RANAP that is used for transmitting
30 a control signal, it is not necessar y to reserve communication resource s
for user data in the RNC 25 and thereby reduce resource load.
[0094]
A configuration example of RANAP is described hereinafter with
reference to Fig. 23. A RANAP message that is transmitted through
30
RANAP has a RANAP message header and IE A to C. Further, in the
RANAP message, UP-PDU IE is specified to transmit a small amount of
data.
[0095]
5 Further, in the configuration of Fig. 21, the processing operation
of the UE 10 and the RNC 25 is the same as that of the UE 10 and the
RNC 25 shown in Fig. 20. Therefore, it is not necessar y to incorporate a
novel feature into the UE 10 and the RNC 25 in order to implement the
present invention. On the other hand, in the configuration of Fig. 22, the
10 processing operation of the UE 10 is the same as that of the UE 10 shown
in Fig. 20. Therefore, it is not necessary to incorporate a novel feature
into the UE 10 in order to implement the present inven tion.
[0096]
A flow of an ATTACH process in the network according to the
15 second exemplary embodiment of the invention is described hereinafter
with reference to Fig. 24. First, the UE 10 transmits an ATTACH signal
to the SGSN 45 (S 201). Next, authentication and security setting are
performed between the UE 10 and HSS (Home Subscriber Server) (S 202).
Then, the SGSN 45 transmits an Update Location request signal to the
20 HSS (S203). Then, the HSS transmits an Insert subscriber data signal to
the SGSN 45 (S204). The Insert subscriber data signal contains pseudo -
U/Size attribution that is set per APN. The pseudo -U/Size attribution
may be set per IMSI, IMEISV or the like, other than per APN.
[0097]
25 Then, the SGSN 45 transmits an Insert subscriber data Ac k signal
to the HSS (S205). The HSS then transmits an Update Location ACK
signal to the SGSN 45. The SGSN 45 thereby acquires and manages
pseudo-U attribution information that is set per APN or the like. Then,
the SGSN 45 transmits an ATTACH accept signal to the UE 10 (S207).
30 [0098]
A flow of a PDP Context Activation process is described
hereinafter with reference to Fig. 25. PDP Context is communication
resources that are used for transmitting user data between the SGSN 45
and the GGSN 55. Further, an example in which a small amount of data
31
is transmitted as user data is described in this figure.
[0099]
First, the UE 10 transmits an Activate PDP Context Request (APN)
signal to the SGSN 45 (S211). The SGSN 45 then transmits a Create PDP
5 Context Request signal containing PU flag to the GGSN 55 (S212). Then,
the GGSN 55 transmits a Create PDP Context Response signal containing
PU status 1 to the SGSN 45 (S213). In this manner, b y sharing PU status
1 between the SGSN 45 and the GGSN 55, Pseudo-U treatment (1) is set
between the SGSN 45 and the GGSN 55 (S214).
10 [0100]
Next, in order to set a pseudo-U bearer between the RNC 25 and
the
SGSN 45, the SGSN 45 transmits a RAB assignment Request signal
containing PU flag to the RNC 25 (S215). The RNC 25 then sets a Radio
15 bearer with the UE 10 (S216). Then, the RNC 25 transmits a RAB
assignment Response signal containing PU status 2 to the SGSN 45
(S217). In this manner, by sharing PU status 2 between the RNC 25 and
the SGSN 45, Pseudo-U treatment (2) is set between the RNC 25 and the
SGSN 45 (S218). Then, the SGSN 45 transmits an Activate PDP Context
20 Accept signal to the UE 10 (S219).
[0101]
A flow of a RAU (Routing Area Update) process that accompanies
change in SGSN is described hereinafter with reference to Fig. 26.
Routing Area (RA) is location information of the UE 10 that is managed
25 on a GPRS network. RA may be an area composed of a plurality of cells.
RAU is processing that is performed when RA where the UE 10 is located
is changed.
[0102]
First, the UE 10 transmits a RAU signal to the SGSN (which is
30 referred to hereinafter as New SGSN) that manages RA after change
(S221). Next, the New SGSN transmits a SGSN Context request signal to
the SGSN (which is referred to hereinafter as Old SGSN) that man ages
RA before change (S222). Then, the Old SGSN transmits a SGSN
Context response signal to the New SGSN (S 223). The SGSN Context
32
response signal contains pseudo -U/Size attribution that is associated with
the UE 10. After that, authentication and secur ity setting are performed
between the UE 10 and HSS (Home Subscriber Server) (S 224).
[0103]
5 Then, the New SGSN transmits a SGSN Context Ack signal to the
Old SGSN (S225). The New SGSN then transmits an Update PDP Context
Request signal to the GGSN 55 in order to set a pseudo -U bearer with the
GGSN 55 (S226). The Update PDP Context Request signal contains PU
flag. Then, the GGSN 55 transmits an Update PDP Context Response
10 signal containing PU status 1 to the New SGSN (S227). Pseudo-U
treatment (1) is thereby set between the New SGSN and the GGSN 55
(S228).
[0104]
Steps S229 to S232 are the same as Steps S203 to S206 in Fig. 24
15 and thus not redundantly described in detail. In Step S 232, the New
SGSN that has received an Update Location Ack signal trans mits a RAU
accept signal to the UE 10 (S233).
[0105]
A flow of a process in the case where the RNC and the SGSN to
20 which the UE 10 is connected are changed is described hereinafter with
reference to Figs. 27 and 28.
[0106]
First, the RNC before change ( which is referred to hereinafter Old
RNC) transmits a Relocation Required signal to the SGSN before change
25 (which is referred to hereinafter Old SGSN) (S241). Next, the Old SGSN
transmits a Forward Relocation Request signal containing PU flag to the
SGSN after change (which is referred to hereinafter New SGSN) (S 242).
Then, the New SGSN transmits a Relocation Request signal containing
PU flag to the New RNC (S243). Then, the New RNC transmits a
30 Relocation Request Acknowledge signal containing PU status 2 to the
New SGSN (S244). Pseudo-U treatment (2) is thereby set between the
New RNC and the New SGSN (S245).
[0107]
Then, the New SGSN transmits a Forward Relocation Response
33
signal to the Old SGSN (S246). The Old SGSN then transmits a
Relocation command signal to the Old RNC (S247). The Old RNC then
transmits a RRC message signal to the UE 10 (S248). Then, the Old RNC
transmits a Forward SRNS Context signal to the Old SGSN (S 249). The
5 Old SGSN then transmits a Forward SRNS Context signal to the New
SGSN (S250). The New SGSN transmits a Forward SRNS Context Ack
signal to the Old SGSN (S251) and further transmits a Forward SRNS
Context signal to the New RNC (S252).
[0108]
10 Referring then to Fig. 28, when the UE 10 is detected by the New
RNC (S253), the New RNC transmits a Relocation detect signal to the
New SGSN (S254). The UE 10 then transmits a RRC message signal to
the New RNC (S255). The New RNC then transmits a Relocation
complete signal to the New SGSN (S256). The New SGSN then transmits
15 a Forward relocation complete signal to the Old SGSN (S257). The Old
SGSN then transmits a Forward relocation complete Ack signal to the
New SGSN (S258). The New SGSN then transmits an Update PDP
Context request signal containing PU flag to the GGSN 55 (S259). The
GGSN 55 then transmits an Update PDP Context Response signal
20 containing PU status 1 to the New SGSN (S260). Pseudo-U treatment (1)
is thereby set between the New SGSN and the GGSN 55 (S261).
[0109]
Further, in order to release communication resource s that are
reserved between the Old SGSN and the Old RNC, the Old SGSN
25 transmits an Iu release command signal to the Old RNC (S 262). The Old
RNC then transmits an Iu release command complete signal to the Old
SGSN (S263).
[0110]
A flow of a process in the case where the GGSN 55 receives a
30 small amount of data addressed to the UE 10 is described hereinafter with
reference to Fig. 29.
[0111]
It is assumed that Pseudo -U treatment (1) is set between the SGSN
45 and the GGSN 55 (S271). When the GGSN 55 receives a small amount
34
of data addressed to the UE 10 that is associated with Pseudo -U treatment
(1), it transmits the received small amount of data to the SGSN 45
through GTP-C (S272). Next, the SGSN 45 transmits a Page signal to the
RNC 25 (S273), and further the RNC 25 transmits the Page signal to the
5 UE 10 (S274).
[0112]
A flow of a process in the case of transmitting a small amount of
data from the UE 10 is described hereinafter with reference to Fig. 30.
Note that the process shown in Fig. 30 is used also as the process which
10 is executed by the UE 10 that has received the Page signal in Fig. 29.
[0113]
First, the UE 10 transmits a Service Request signal to the SGSN 45
(S275). Next, the SGSN 45 transmits a RAB assignment Request signal
containing PU flag to the RNC 25 (S276). The RAB assignment Request
15 signal may contain a small amount of data. Then, the RNC 25 sets a
radio bearer with the UE 10 (S277). The RNC 25 may transmit the small
amount of data received with the RAB assignment Request signal to the
UE 10 by using the set radio bearer. Then, the RNC 25 transmits a RAB
assignment Response signal containing PU status 2 to the SGSN 45
20 (S278). Pseudo-U treatment (2) is thereby set between the RNC 25 and
the SGSN 45 (S279).
[0114]
The case of transmitting and receiving a large amount of data
addressed to the UE 10 in the environment of transmitting and receiving
25 a small amount of data using GTP -C is described hereinafter with
reference to Fig. 31.
[0115]
In the case where GTP-C is set between the SGSN 45 and the
GGSN 55 in order to transmit a small amount of data, when a large
30 amount of data addressed to the UE 10 arrives at the GGSN 55, the GGSN
55 newly sets a dedicated bearer (PDP Context) for transmitting a large
amount of data with the SGSN 45. The dedicated bearer may be referred
to as Secondary PDP Context if a pseudo bearer is Primary PDP Context.
To set the dedicated bearer, the GGSN 55 transmits an Initiate PDP
35
Context Activation Request signal to the SGSN 45 (S281). The SGSN 45
then transmits a RAB assignment Request signal to the RNC 25 (S282).
The RNC 25 then transmits a RAB assignment Response signal to the
SGSN 45 (S283). The SGSN 45 then transmits a Create PDP context
5 Request signal to the GGSN 55 (S284). The GGSN 55 then transmits a
Create PDP context Response signal to the SGSN 45 (S285). The SGSN
45 then transmits an Initiate PDP Context Activation Response signal to
the GGSN 55 (S286).
[0116]
10 In this manner, by transmitting the Create PDP Context
Request/Response signal, a dedicated bearer for transmitting a large
amount of data is set between the SGSN 45 and the GGSN 55, and by
transmitting the RAB assignment Request/Response signal, a dedicated
bearer is set also between the RNC 25 and the SGSN 45. After this
15 process, the GGSN 55 can transmit the received large amount of data to
the SGSN 45, and further the SGSN 45 can transmit the received large
amount of data to the RNC 25, both by using the dedicated bearer.
[0117]
Further, in the case where GTP -C is set between the SGSN 45 and
20 the GGSN 55 in order to transmit a small amount of data, when a large
amount of data arrives at the GGSN 55, the GGSN 55 may change the
pseudo-U bearer that is already set between the SGSN 45 and the GGSN
55 to a general GTP-U bearer or a ded icated bearer. In this case, an
Update PDP Context Request/Response signal is used instead of the
25 Initiate PDP Context Activation Request signal in Steps S281 and S286
in Fig. 31. Further, the processing of Steps S 284 and S285 in Fig. 31 is
omitted in this case.
[0118]
Further, the RAB assignment Request/Response signal is
30 transmitted only when Pseudo-U treatment(2) is set between the RNC 25
and the SGSN 45.
[0119]
The case of transmitting a large amount of data from the UE 10 in
the environment of tran smitting and receiving a small amount of data
36
using GTP -C is described hereinafter with reference to Fig. 32. In the
case where RANAP is set between the RNC 25 and the SGSN 45 and GTPC
is set between the SGSN 45 and the GGSN 55 for transmitting a small
amount of data, a dedicated bearer for transmitting a large amount of
5 data is newly set between the eNodeB 20 and the PGW 50 in order to
transmit a large amount of data from the UE 10.
[0120]
First, when the RNC 25 receives a large amount of data from the
UE 10, the RNC 25 transmits a RAB assignment Request signal to the
10 SGSN 45 (S291). The SGSN 45 then transmits the RAB assignment
Request signal to the RNC 25 (S292). Then, the RNC 25 transmits a RAB
assignment Response signal to the SGSN 45 (S293). The SGSN 45 then
transmits a Create PDP Context Request signal to the GGSN 55 (S294).
The GGSN 55 then transmits a Create PDP Context Response signal to the
15 SGSN 45 (S295).
[0121]
In this manner, by transmitting the Create PDP Context
Request/Response signal, a dedicated bearer for transmitting a large
amount of data is set between the SGSN 45 and the GGSN 55, and by
20 transmitting the RAB assignment Request/Response signal, a dedicated
bearer is set also between the RNC 25 and the SGSN 45. After this
process, the RNC 25 can transmit the received large amount of data to the
SGSN 45, and further the SGSN 45 can transmit the received large
amount of data to the GGSN 55, both by using the dedicated bearer.
25 [0122]
In the case of transmitting a small amount of data using the GTP-C
bearer between the SGSN 45 and the GGSN 55 and transmitting a small
amount of data using the GTP-U bearer between the SGSN 45 and the
RNC 25, a large amount of data is transmitted through the GTP -U bearer
30 from the UE 10 to the SGSN 45. In such a case, a Create PDP Context
Request/Response signal is transmitted between the SGSN 45 and the
GGSN 55. A dedicated bearer is thereby set between the SGSN 45 and
the GGSN 55. Further, in this case, the RAB assignment
Request/Response signal in Fig. 32 is not transmitted.
37
[0123]
Further, in the case where RANAP is set between the RNC 25 and
the SGSN 45 for transmitting a small amount of data, and GTP -C is set
between the SGSN 45 and the GGSN 55 for transmitting a small amount
5 of data, when the RNC 25 receives a large amount of data from the UE 10,
the pseudo-U bearer that is already set between the RNC 25 and the
GGSN 55 may be changed to a general GTP-U bearer or a dedicated
bearer. In this case, a RAB modify Request/Response signal is used
instead of the RAB assignment Request signal in Step S291 in Fig. 32.
10 Further, an Update PDP Context Request/Response signal is used instead
of the Create PDP Context Request/Response signal in Steps S294 and
S295 in Fig 32. The pseudo-U bearer that is already set between the RNC
25 and the GGSN 55 can be thereby changed to a general GTP -U bearer
or a dedicated bearer.
15 [0124]
In the case of transmitting a small amount of data using the GTP -C
bearer between the SGSN 45 and the GGSN 55 and transmitting a small
amount of data using the GTP-U bearer between the SGSN 45 and the
RNC 25, a large amount of data is transmitted through the GTP -U bearer
20 from the UE 10 to the SGSN 45. In such a case, an Update PDP Context
Request/Response signal is transmitted from the SGSN 45 to the GGSN
55. The pseudo-U bearer that is already set between the SGSN 45 and the
GGSN 55 can be thereby changed to a dedicated bearer. Further, in this
case, the RAB assignment Request/Response signal in Fig. 32 is not
25 transmitted.
[0125]
A flow of a process in the case of deleting a dedicated bearer that
is set for transmitting a large amount of data is described hereinafter
with reference to Fig. 33. The dedicated bearer is deleted when
30 transmission of a large amount of data ends between the RNC 25 and the
GGSN 55. To be specific, the dedicated bearer may be deleted when the
fact that a large amount of data is not transmitted for a certain period of
time is detected in the RNC 25 or the GGSN 55.
[0126]
38
First, when the GGSN 55 detects the fact that a large amount of
data is not transmitted for a certain period of time, it transmits a Delete
PDP Context Request signal to the SGSN 45 (S301). Then, in order to
delete the dedicated bearer that is set between the RNC 25 and the SGSN
5 45, the RNC 25 transmits a RAB assignment Request signal to the RNC
25 (S302).
[0127]
Next, the RNC 25 transmits a RAB assignment Response signal to
the SGSN 45 (S303). The SGSN 45 then transmits a Delete PDP Context
10 Response signal to the GGSN 55 (S304). The dedicated bearer that is set
between the RNC 25 and the GGSN 55 is thereby deleted.
[0128]
Further, in the case where the pseudo -U bearer has been changed
to the GTP -U bearer or the dedicated bearer in order to transmit a large
15 amount of data, a flow of a proc ess of setting the GTP-U bearer or the
dedicated bearer back to the pseudo-U bearer at the end of transmission
of a large amount of data is described hereinafter. To be specific, an
Update PDP Context Request/Response signal is used instead of the
Delete Bearer Request/Response signal in Steps S301 and S304 in Fig. 33.
20 Using those signals, the process of setting the GTP -U bearer or the
dedicated bearer back to the pseudo -U bearer is performed.
[0129]
A flow of a process in the case of deleting a dedicate d bearer when
the RNC 25 detects the fact that a large amount of data is not transmitted
25 is described hereinafter with reference to Fig. 34. First, when the RNC
25 detects the fact that transmission of a large amount of data is not
performed for a certain period of time, it transmits a RAB Release
Request signal to the SGSN 45 (S311).
[0130]
30 Then, the SGSN 45 transmits a RAB assignment Request signal to
the RNC 25 (S312). Then, the RNC 25 transmits a RAB assignment
Response signal to the SGSN 45 (S313). Then, the SGSN 45 transmits a
Delete PDP Context Request signal to the GGSN 55 (S314). Then, the
GGSN 55 transmits a Delete PDP Context Response signal to the SGSN
39
45 (S315).
[0131]
In this manner, by transmitting the Delete PDP Context
Request/Response signal, the dedicated bearer for transmitting a large
5 amount of data between the SGSN 45 and the GGSN 55 is deleted, and by
transmitting the RAB assignment Request/Response signal , the dedicated
bearer between the RNC 25 and the SGSN 45 is deleted.
[0132]
Further, in the case where the pseudo -U bearer has been changed
10 to the GTP -U bearer or the dedicated bearer in order to transmit a large
amount of data, a flow of a process of setting the bearer back to the
pseudo-U bearer at the end of transmission of a large amount of data is
described hereinafter. To be specific, a RAB modify Request signal is
used instead of the RAB Release Request signal in Steps S311 in Fig. 33.
15 Further, an Update PDP Context Request/Response signal is used instead
of the Delete PDP Context Request/Response signal in Steps S314 and
S315 in Fig. 33. Using those signals, the process of setting the GTP -U
bearer or the dedicated bearer back to the pseudo -U bearer is performed.
[0133]
20 In the case of transmitting a small amount of data using the GTP-C
bearer between the SGSN 45 and the GGSN 55 and transmitting a small
amount of data using the GTP-U bearer between the SGSN 45 and the
RNC 25, the fact that a large amount of data is not transmitted may be
detected in the SGSN 45. In this case, a Delete PDP Context
25 Request/Response signal is transmitted between the SGSN 45 and the
GGSN 55, and thereby the dedicated bearer that is set between the SGSN
45 and the GGSN 55 can be deleted. Further, in this case, the RAB
Release Request signal and the RAB assignment Request/Response signal
in Fig. 34 are not transmitted.
30 [0134]
Further, in the case where the pseudo -U bearer has been changed
to the GTP -U bearer or the dedicated bearer in order to transmit a large
amount of data, a flow of a proce ss of setting the bearer back to the
pseudo-U bearer at the end of transmission of a large amount of data is
40
described hereinafter. The process in the case where the end of
transmission of a large amount of data is detected in the SGSN 45 is
described hereinafter. In this case, by transmitting an Update PDP
Context Request/Response signal between the SGSN 45 and the GGSN 55,
5 the process of setting the GTP -U bearer or the dedicated bearer back to
the pseudo-U bearer is performed.
[0135]
As described above, by using the mobile communication system
according to the third exemplary embodiment of the invention, it is
10 possible to set the pseudo -U bearer that does not require reservation of
communication resources between the RNC 25 and the GGSN 55. It is
thereby possible to transmit a small amount of data by using
communication resources that are used for transmitting a control signal
such as GTP-C and RANAP, in the same process flow as in the case of
15 using the GTP-U bearer for transmission of a small amount of data.
[0136]
(Fourth exemplary embodiment)
A flow of an ATTCH process according to a fourth exemplary
embodiment of the invention is desribed hereinafter with reference to Fig.
20 35. The network described in the fourth exemplary embodiment has RNC
25 that is used as 3G access in an access network and has SGW 40 and
PGW 50 that are used as EPC in a core network. Further, SGSN 45 is
placed between the access network and the core network. The UE 10 that
transmits and receives a small amount of data is conne cted to the RNC 25.
25 Such a network configuration is assumed in the following description as
well.
[0137]
Steps S321 to S327 in Fig. 35 are the same as Steps S 1 to S7 in
Fig. 5 and thus not redundantly described in detail. Note that, however,
30 the SGSN 45 is used in Fig. 35 instead of the MME 30 in Fig. 5. Further,
Steps S328 to S331 in Fig. 35 are the same as Steps S 215 to S218 in Fig.
25 and thus not redundantly described in detail. When Pseudo -U
treatment (2) is set in Step S 331, the SGSN 45 transmits a Modify bearer
request signal to the SGW 40 (S332). The Modify bearer request signal
41
contains PU flag and PU status 2. Then, the SGW 40 transmits a Modify
bearer response signal to the SGSN 45 (S333). The SGSN 45 then
transmits an ATTACH accept signal to the UE 10 (S334).
[0138]
5 Note that Pseudo -U treatment (2) in Fig. 35 may be set between
the RNC 25, the SGSN 45 and the SGW 40, or may be set between the
RNC 25 and the SGSN 45 without through the SGSN 45. This is the same
in the following descripti on as well.
[0139]
10 A flow of a RAU (Routing Area Update) process that accompanies
change in SGSN and SGW is described hereinafter with reference to Fig.
36. Steps S341 to S345 are the same as Steps S221 to S225 in Fig. 26
and thus not redundantly describ ed in detail. Further, Steps S 346 to
S352 are the same as Steps S 26 to S32 in Fig. 6 and thus not redundantly
15 described in detail. Note that, however, the SGSN is used in Fig. 36
instead of the MME in Fig. 6. In Step S352, the New SGSN that has
received an Update Location Ack signal transmits a RAU accept signal to
the UE 10 (S353).
[0140]
20 A flow of a process in the case of transmitting a small amount of
data from the UE 10 is described hereinafter with reference to Fig. 37.
Steps S361 to S365 in Fig. 37 are the same as Steps S 275 to S279 in Fig.
30 and thus not redundantly described in detail. Further, Steps S 366 and
S367 in Fig. 37 are the same as Steps S332 and S333 in Fig. 35 and thus
25 not redundantly described in detail.
[0141]
A flow of a handover process is described hereinafter with
reference to Figs. 38 and 39. In Figs. 38 and 39, Old RNC and New RNC
are used instead of the Old eNB and the New eNB in Figs. 8 and 9, and
30 further Old SGSN and New SGSN are used instead of the Old MME and
the New MME in Figs. 8 and 9. Further, Steps S371 to S389 in Figs. 38
and 39 are the same as Steps S 51 to S69 in Figs. 8 and 9 and thus not
redundantly described in detail.
[0142]
42
A flow of a process in the case where the PGW 50 receives a small
amount of data addressed to the UE 10 is described hereinafter with
reference to Fig. 40. In Fig. 40, SGSN is used instead of the MME in Fig.
10, and RNC is used instead of the eNB in Fig. 10. Steps S391 to S395
5 in Fig. 40 are the same as Steps S 71 to S75 in Fi g. 10 and thus not
redundantly described in detail.
[0143]
A flow of a process in the case of transmitting a small amount of
data from the UE 10 is described hereinafter with reference to Fig. 41.
10 Note that the process shown in Fig. 41 is used also as the process which
is executed by the UE 10 that has received the Page signal in Fig. 40.
[0144]
First, the UE 10 transmits a Service Request signal to the SGSN 45
(S401). Next, authentication and security setting of the UE 10 are
15 performed between the UE 10 and HSS (Home Subscriber Server) (S 402).
Then, the SGSN 45 transmits a RAB assignment Request signal
containing PU flag to the RNC 25 (S403). The RNC 25 then sets a radio
bearer with the UE 10 (S404). Then, the RNC 25 transmits a RAB
assignment Response signal containing PU status 2 to the SGSN 45
20 (S405). Pseudo-U treatment (2) is thereby set between the RNC 25 and
the SGW 40 (S406).
[0145]
The case of transmitting and receiving a large amount of data
addressed to the UE 10 in the environment of transmi tting and receiving
25 a small amount of data using GTP -C is described herei nafter with
reference to Fig. 42.
[0146]
In the case where GTP-C is set between the SGW 40 and the PGW
50 in order to transmit a small amount of data, when a large amount of
30 data arrives at the PGW 50, the PGW 50 newly sets a dedicated bearer for
transmitting a large amount of data with the SGW 40. For this setting,
the PGW 50 transmits a Create Bearer Request signal to the SGW 40.
Further, the SGW 40 transmits the Create Bearer Request to the SGSN 45
(S411). The SGSN 45 then transmits a RAB assignment Request signal to
43
the RNC 25 (S412). The RNC 25 then transmits a RAB assignment
Response signal to the SGSN 45 (S413). The SGSN 45 then transmits a
Create Bearer Response signal to the SGW 40. Further, the SGW 40
transmits the Create Bearer Response signal to the PGW 50 (S414).
5 [0147]
In this manner, by transmitting and receiving the Create Bearer
Request/Response signal, a dedicated bearer for transmitting a large
amount of data is set between the SGW 40 and the PGW 50, and by
transmitting and receiving the RAB assignment Request/Response signal,
10 a dedicated bearer is set also between the RNC 25 and the SGSN 45 and
between the SGSN 45 and the SGW 40. Alternatively, a dedicated bearer
may be set between the RNC 25 and the SGW 40. After this process, the
PGW 50 can transmit the received large amount of data to the SGW 40,
and further the SGW 40 can transmit the received large amount of data to
15 the RNC 25, or to the RNC 25 through the SGSN 45, by using the
dedicated bearer.
[0148]
Further, in the case where GTP -C is set between the SGW 40 and
the PGW 50 in order to transmit a small amount of data, when a large
20 amount of data arrives at the PGW 50, the PGW 50 may change the
pseudo-U bearer that is alread y set to a general GTP -U bearer or a
dedicated bearer. In this case, an Update Bearer Request/Response signal
is used instead of the Create Bearer Request/Response signal in Steps
5411 and S414 in Fig. 42.
25 [0149]
Further, the RAB assignment Request/Response signal in Steps
5412 and S413 in Fig. 42 is transmitted only when Pseudo-U treatment
(2) is set between the RNC 25 and the SGSN 45.
[0150]
30 The case of transmitting a large amount of data from the UE 10 in
the environment of tran smitting and receiving a small amount of data
using GTP-C or RANAP is described hereinafter with reference to Fig. 43 .
[0151]
In the case where RANAP is set between the RNC 25 and the SGSN
44
45 and GTP-C is set between the SGSN 45 and the PGW 50 for
transmitting a small amount of data, a dedicated bearer for transmitting a
large amount of data is newly set between the RNC 25 and the PGW 50 in
order to transmit a large amount of data from the UE 10.
5 [0152]
First, when the RNC 25 receives a large amount of data from the
UE 10, the RNC 25 transmits a RAB assignment Request signal to the
SGSN 45 (S421). The SGSN 45 then transmits a Bearer Resource
Command signal to the SGW 40, and further the SGW 40 transnits the
10 Bearer Resource Command signal to the PGW 50 (S422). Then, the PGW
50 transmits a Create Bearer Request signal to the SGW 40, and further
the SGW 40 transmits the Create Bearer Request signal to the SGSN 45
(S423).
[0153]
15 Then, the SGSN 45 transmits a RAB assignment Request signal to
the RNC 25 (S424). The RNC 25 then transmits a RAB assignment
Response signal to the SGSN 45 (S425). Then, the SGSN 45 transmits a
Create Bearer Response signal to the SGW 40, and further the SGW 40
transmits the Create Bearer Response signal to the PGW 50 (S426).
20 [0154]
In this manner, by transmitting the Create Bearer
Request/Response signal, a dedicated bearer for transmitting a large
amount of data is set between the SGW 40 and the PGW 50, and by
transmitting the Bearer Setup Request/Response signal, a dedicated
25 bearer is set also between the RNC 25 and the SGSN 45 and between the
SGSN 45 and the SGW 40. Alternatively, by transmitting the Bearer
Setup Request/Response signal, a dedicated bearer may be set between
the RNC 25 and the SGW 40. After this process, the RNC 25 can
transmit the received large amount of data to the SGW 40, or to the SGW
30 40 through the SGSN 45, and further the SGW 40 can transmit it to the
PGW 50, by using the dedicated bearer.
[0155]
In the case of transmitting a small amount of data usin g the GTP-C
bearer between the SGSN 45 and the PGW 50 and transmitting a small
45
amount of data using the GTP-U bearer between the SGSN 45 and the
RNC 25, a large amount of data is transmitted through the GTP -U bearer
from the UE 10 to the SGSN 45. In such a case, a Bearer Resource
Command signal is transmitted from the SGSN 45 to the PGW 50.
5 Further, a Create Bearer Request/Response signal is transmitted between
the PGW 50 and the SGSN 45. A dedicated bearer is thereby set between
the SGSN 45 and the PGW 50. Further, in this case, the RAB assignment
Request/Response signal in Fig. 43 is not transmitted.
[0156]
10 Further, in the case where GTP-C and RANAP are set between the
RNC 25 and the PGW 50 for transmitting a small amount of data, when
the RNC 25 receives a large amount of data from the UE 10, the pseudo-
U bearer that is already set between the RNC 25 and the PGW 50 may be
changed to a general GTP -U bearer or a dedicated bearer. In this case, a
15 Modify Bearer Request/Response signal is used instead of the Create
Bearer Request/Response signal in Steps S423 and S426 in Fig. 43.
[0157]
In the case of transmitting a small amount of data using the GTP -C
bearer between the SGW 40 and the PGW 50 and transmitting a small
20 amount of data using the GTP-U bearer between the SGW 40 and the
eNodeB 20, a large amount of data is transmitted through the GTP -U
bearer from the UE 10 to the SGW 40. In such a case, the pseudo-U
bearer that is already set between the SGW 40 and the PGW 50 may be
changed to a general GTP -U or dedicated bearer. In this case, a Bearer
25 Resource Command signal is transmitted from the SGW 40 to the PGW 50.
Further, a Modify Bearer Request/Response signal is transmitted between
the PGW 50 and the MME 30. Further, in this case, a RAB assignment
Request/Response signal in Fig. 43 is not transmitted.
[0158]
30 A flow of a process in the case of deleting a dedicated bearer that
is set for transmitting a large amount of data is described hereinafter
with reference to Fig. 44. The dedicated bearer is d eleted when
transmission of a large amount of data ends between the RNC 25 and the
PGW 50. To be specific, the dedicated bearer may be deleted when the
46
fact that a large amount of data is not transmitted for a certain period of
time is detected in the RNC 25 or the PGW 50.
[0159]
First, when the PGW 50 detects the fact that a large amount of
5 data is not transmitted for a certain period of time, it transmits a Delete
Bearer Request signal to the SGW 40, and further the SGW 40 transmits
the Delete Bearer Request signal to the SGSN 45 (S 431). Then, in order
to delete the dedicated bearer that is set between the RNC 25, the SGSN
45 and the SGW 40 or between the RNC 25 and the SGW 40, the SGSN 45
10 transmits a RAB assignment Request signal to the RNC 25 (S432).
[0160]
Next, the RNC 25 transmits a RAB assignment Response signal to
the SGSN 45 (S433). The SGSN 45 then transmits a Delete Bearer
Response signal to the SGW 40, and further the SGW 40 transmits the
15 Delete Bearer Response signal to the PGW 50 (S434). The dedicated
bearer that is set between the RNC 25 and the PGW 50 is thereby deleted.
[0161]
Further, in the case where the pseudo -U bearer has been changed
to the GTP -U bearer or the dedicated bearer in order to transmit a large
20 amount of data, a flow of a process of setting the GTP-U bearer or the
dedicated bearer back to the pseudo-U bearer at the end of transmission
of a large amount of data is described hereinafter. To be specific, an
Update Bearer Request/Response signal is used instead of the Delete
Bearer Request/Response signal in Steps S 431 and S434 in Fig. 44. In
25 this manner, the process of setting the GTP -U bearer or the dedicated
bearer back to the pseudo -U bearer is performed.
[0162]
A flow of a process in the case of deleting a dedicate d bearer when
the RNC 25 detects the fact that a large amount of data is not transmitted
30 is described hereinafter with reference to Fig. 45. First, when the RNC
25 detects the fact that transmission of a large amount of data is not
performed for a certain period of time, it transmits a RAB Release
Request signal to the SGSN 45 (S441).
[0163]
47
Then, the SGSN 45 transmits a Delete Bearer Command signal to
the SGW 40, and further the SGW 40 transmits the Delete Bearer
Command signal to the PGW 50 (S442). Then, the PGW 50 transmits a
Delete Bearer Request signal to the SGW 40, and further the SGW 40
5 transmits the Delete Bearer Request signal to the SGSN 45 (S443). Then,
the SGSN 45 transmits a RAB assignment Request signal to the RNC 25
(S444). The RNC 25 then transmits a RAB assignment Response signal
to the SGSN 45 (S445). The SGSN 45 then transmits a Delete Bearer
Response signal to the SGW 40, and further the SGW 40 transmits the
10 Delete Bearer Response signal to the PGW 50 (S446).
[0164]
In this manner, by transmitting the Delete Bearer
Request/Response signal, the dedicated bearer for transmitting a large
amount of data between the SGW 40 and the PGW 50 is deleted, and by
15 transmitting the Deactivate Bearer Request/Response signal, the
dedicated bearer between the RNC 25, the SGSN 45 and the SGW 40 or
between the RNC 25 and the SGW 40 is deleted.
[0165]
Further, in the case where the pseudo -U bearer has been changed
20 to the GTP -U bearer or the dedicated bearer in order to transmit a large
amount of data, a flow of a process of setting the bearer back to the
pseudo-U bearer at the end of transmission of a large amount of data is
described hereinafter. To be specific, a Modify Bearer R equest/Response
signal is used instead of the Delete Bearer Request/Respo nse signal in
25 Steps S443 and S446 in Fig. 45. Using those signals, the process of
setting the GTP-U bearer or the dedicated bearer back to the pseudo -U
bearer is performed.
[0166]
In the case of transmitting a small amount of data using the GTP -C
30 bearer between the SGSN 45 and the PGW 50 and transmitting a small
amount of data using the GTP-U bearer between the SGSN 45 and the
RNC 25, the fact that a large amount of data is not transmitted may be
detected in the SGSN 45. In this case, a Delete Bearer Command signal
is transmitted from the SGSN 45 to the PGW 50 in order to delete the
48
dedicated bearer. Further, a Delete Bearer Request/Response signal is
transmitted between the PGW 50 and the SGSN 45. Further, in this case,
the Deactivate Bearer Request/Re sponse signal in Fig. 45 is not
transmitted.
5 [0167]
Further, in the case where the pseudo -U bearer has been changed
to the GTP -U bearer or the dedicated bearer in order to transmit a large
amount of data, a flow of a process of setting the bearer back to the
pseudo-U bearer at the end of transmission of a large amount of data is
10 described hereinafter. The process in the case where the end of
transmission of a large amount of data is detected in the SGSN 45 is
described hereinafter. In this case, by trans mitting a Modify Bearer
Request/Response signal between the SGSN 45 and the GGSN 55, the
process of setting the GTP -U bearer or the dedicated bearer back to the
15 pseudo-U bearer is performed.
[0168]
As described above, by using the mobile communication sys tem
according to the fourth exemplary embodiment of the invention, it is
possible to set the pseudo -U bearer that does not require reservation of
20 communication resources between the RNC 25 and the PGW 50. It is
thereby possible to transmit a small amount of data by using
communication resources that are used for transmitting a control signal
such as GTP-C, S1-AP or RANAP, in the same process flow as in the case
of using the GTP -U bearer for transmission of a small amount of data.
25 [0169]
It should be noted that the present invention is not limited to the
above-described exemplary embodiment and may be varied in many ways
within the scope of the present invention.
[0170]
30 While the invention has been particularly shown and described
with reference to exemplary embodiments thereof, the invention is not
limited to these embodiments. It will be understood by those of ordinar y
skill in the art that various changes in form and details may be made
therein without departing from the spirit and scope of the present
49
invention as defined by the claims.
[0171]
This application is based upon and claims the benefit of priority
from Japanese patent application No. 2012-200731, filed on September 12,
5 2012, the disclosure of which is incorporated herein in its entirety by
reference.
Reference Signs List
[0172]
10 UE
10 20 eNodeB
25 RNC
30 MME
40 SGW
45 SGSN
15 50 PGW
55 GGSN
50
WE CLAIM:
1. A mobile communication system comprising:
a first gateway device that transmits user data with a base station;
and
a second gateway device that transmits the user data with the first
gateway device and an external network, wherein
the first gateway device and the second gateway device transmit a
small amount of data autonomously transmitted from a terminal device
through the base station by using a communication resource for
transmitting a control signal, not a communication resource for
transmitting user data, between the first gateway device and the second
gateway device.
2. The mobile communication system according to Claim 1,
wherein
the terminal device is a machine type.
3. The mobile communication system according to Claim 1 or 2,
wherein
the first gateway device determines whether data transmitted from
the terminal device is the small amount of data or not, and when the data
is determined to be the small amount of data, the first gateway device
transmits the data transmitted from the terminal device to the second
gateway device by using the communication resource for transmitting the
control signal.
4. The mobile communication system according to any one of
Claims 1 to 3, wherein
when the data transmitted from the terminal device is determined
not to be the small amount of data, the first gateway device sets a
communication resource to be used for transmitting the user data between
the first gateway device and the second gateway device.
51
5. The mobile communication system according to any one of
Claims 1 to 4, wherein
the second gateway device determines whether data addressed to
the terminal device is the small amount of data or not, and when the data
is determined to be the small amount of data, the second gateway device
transmits the data addressed to the terminal device to the first gateway
device by using the communication resource for transmitting the control
signal.
6. The mobile communication system according to any one of
Claims 1 to 5, wherein
when the data addressed to the terminal device is determined not
to be the small amount of data, the second gateway device sets a
communication resource to be used for transmitting the user data between
the first gateway device and the second gateway device.
7. The mobile communication system according to any one of
Claims 1 to 6, wherein
the first gateway device and the second gateway device acquire
information as to whether the terminal device transmits the small amount
of data from a service control device that manages subscriber data.
8. The mobile communication system according to any one of
Claims 1 to 7, wherein
when an instruction to reserve a communication resource for
transmitting the user data is given from a call control device that
performs call control in the mobile communication system upon execution
of a location registration process of the terminal device, the first
gateway device and the second gateway device perform a process of
reserving a pseudo communication resource for transmitting the user data
that does not actually reserve a communication resource.
9. The mobile communication system according to Claim 8,
wherein
52
when the data transmitted from the terminal device is determined
not to be the small amount of data, the first gateway device changes the
reserved pseudo communication resource for transmitting the user data to
a general communication resource to be used for transmitting the data
transmitted from the terminal device.
10. The mobile communication system according to Claim 8,
wherein
when the data addressed to the terminal device is determined not
to be the small amount of data, the second gateway device changes the
reserved pseudo communication resource for transmitting the user data to
a general communication resource to be used for transmitting the data
transmitted from the terminal device.
11. The mobile communication system according to Claim 1,
wherein
the base station and the first gateway device further transmit the
small amount of data transmitted from the terminal device by using the
communication resource for transmitting and receiving the control signal
between the base station and the first gateway device.
12. The mobile communication system according to any one of
Claims 1 to 11, wherein
the first gateway device is SGW (Serving Gateway) specified in
3GPP, and the second gateway device is PGW (Packet Data Network
Gateway) specified in 3GPP.
13. The mobile communication system according to any one of
Claims 1 to 11, wherein
the first gateway device is SGSN (Serving GPRS Support Node)
specified in 3GPP, and the second gateway device is GGSN (Gateway
GPRS Support Node) specified in 3GPP.
14. A data communication method between a first gateway device
53
that transmits user data with a base station and a second gateway device
that transmits the user data with an external network, comprising:
transmitting a small amount of data autonomously transmitted from
a terminal device through the base station by using a communication
resource for transmitting a control signal, not a communication resource
for transmitting user data, between the first gateway device and the
second gateway device.
15. A gateway device that transmits user data with a base station
and an external network, wherein
the gateway device transmits a small amount of data autonomously
transmitted from a terminal device through the base station by using a
communication resource for transmitting a control signal, not a
communication resource for transmitting user data.
16. A base station that transmits user data with a terminal device
and a gateway device, wherein
the base station transmits a small amount of data autonomously
transmitted from the terminal device by using a communication resource
for transmitting a control signal, not a communication resource for
transmitting user data.