1. A gateway device comprising: a memory that stores information regarding an environment around a radio base station; a controller that generates a message for paging a mobile s t a t i on which camps on the radio base station to execute processing for determining information of a radio base station to which the message is t r a n s m i t t e d based on the stored information; and a transmission unit that transmits the message.

2. The gateway device according to Claim 1, comprising a reception unit that receives a message regarding paging from a core network device; wherein the controller executes the processing when a value of predetermined information included in the received message satisfies a predetermined condition.

3. The gateway device according to Claim 2, wherein the predetermined information element comprises at least one of: information indicating a class of a Quality of Service (QoS) of a call in the paging; information indicating a service type of the call; and information indicating a type of a calling party.

4. The gateway device according to Claim 2 or 3, wherein: the reception unit receives the message from the radio base s t a t i o n , the received message comprises information in which an i d e n t i f i e r of the mobile station is associated with an identifier of the radio base station, and the controller identifies the radio base station on which the mobile station has camped based on the received message.

5. The gateway device according to Claim 4, wherein the controller deletes the associated information after an elapse of a predetermined period of time.

6. The gateway device according to any one of Claims 1 to 5, wherein: a mobile communication system is a mobile communication system of a Long Term Evolution (LTE) defined by a Third Generation Partnership Project (3GPP), the mobile station is a User Equipment (UE), the radio base station is a Home evolved Node B (HeNB), and the gateway device is an HeNB Gateway (HeNB-GW).

7. The gateway device according to any one of Claims 1 to 6, wherein: the information regarding the environment around the radio base station is information regarding a radio environment around the radio base station, and comprises at least one of: information of a cell of an Enhanced Universal Terrestrial Radio Access Network (E-UTRAN); information regarding a cell of a Universal Terrestrial Radio Access Network (UTRAN); information regarding a cell of a Global System for Mobile Communications EDGE Radio Access Network (GERAN); information regarding a base station of a Worldwide I n t e r o p e r a b i l i t y for Microwave Access (WiMAX); information regarding a wireless Internet hotspot; information regarding a TV station; information regarding a radio station; and information regarding a GPS.

8. The gateway device according to any one of Claims 1 to 7, wherein: the information regarding the environment around the radio base 28 station comprises at least one of: an IP address allocated to the radio base station; an address regarding a position in which the radio base station i s installed; a postcode; a telephone number; and i d e n t i f i c a t i o n information of a gateway device most recently connected to the radio base station.

9. A mobile communication system comprising a radio base s t a t i on and a gateway device that communicates with the radio base s t a t i o n , wherein: the radio base station transmits information regarding an environment around the radio base station to the gateway device, and the gateway device comprises: a reception unit that receives the information; a controller that generates a message for paging a mobile s t a t i o n which camps on the radio base station to execute processing for determining a radio base station to which the message is transmitted based on the received information; and a transmission unit that transmits the message.

10. A paging method comprising the steps of: storing information regarding an environment around a radio base station; generating a message for paging a mobile station which camps on the radio base station to execute processing for determining a radio base station to which the message is transmitted based on the stored information; and t r a n s m i t t i n g the message to the radio base station to which the message is transmitted.

DESCRIPTION
GATEWAY DEVICE, MOBILE COMMUNICATION SYSTEM, AND
PAGING METHOD
Technical Field
[0001]
The present invention relates to a gateway device, a mobile
communication system, and a paging method.
Background Art
[0002]
In a mobile communication system, when a call is placed to a
t e r m i n a l , it is necessary to inform the terminal that the call is placed
to the terminal. The network of the mobile communication system
manages the location information of each terminal as the location
r e g i s t r a t i o n area of the terminal. The network informs each of the
terminals in the location r e g i s t r a t i o n area where the terminal is
r e g i s t e r e d that the call is placed to the terminal. This procedure is
called paging (see, for example, Non-Patent Literature 1).
[0003]
In general, paging optimization is required in the mobile
communication system. In a mobile communication syst.em of the Long
Term Evolution (LTE) defined by the Third Generation Partnership
Project (3GPP), for example, a method of staggered paging is
suggested (Non-Patent l i t e r a t u r e 2). In the LTE, a radio base station
(NB: Node B) that executes paging is determined based on a Tracking
Area Identity (TAI) List. Accordingly, when a large number of TAIs
are included in the TAI List, all the radio base stations having the
TAIs need to execute paging. Non-Patent l i t e r a t u r e 2 suggests a
method for determining and paging, by the MME, a specific Tracking
Area (TA) or a radio base station as a subset of a TA group based on
presence information of the terminal (e.g., information of Tracking
Area Update (TAU) which the terminal has recently executed).
[0004]
I n c i d e n t a l l y , in a recent mobile communication system, there is
a case in which a small-sized radio base station called a femto base
station has been newly introduced in addition to the existing radio base
s t a t i o n s to provide services of a femto cell. In the LTE mobile
communication system, the femto base station is called a Home evolved
Node B (HeNB). The area of the cell covered by the femto base station
is t y p i c a l l y about several meters in radius to several tens of meters in
radius. Further, a large number of femto base stations are often
i n s t a l l e d in the system. Further, in the LTE a r c h i t e c t u r e , a Home
evolved Node B Gateway (HeNB-GW) may be optionally installed
between the HeNB and a Mobility Management Entity (MME) which is
a core network node higher than the HeNB. The use of an interface
between the HeNB, and the MME and the HeNB-GW is specified in
Non-Patent l i t e r a t u r e 3 as the SI Application Protocol (S1AP).
Citation List
Non-Patent Literature
[0005]
[Non-Patent l i t e r a t u r e 1] Keiji Tachikawa, "W-CDMA Mobile
Communication Systems", Maruzen Company, Limited, pp. 254-256
[Non-Patent l i t e r a t u r e 2] R3-082983 3GPP TSG-RAN-WG3 Meeting
#62 http://www.3gpp.org/ftp/tsg_ran/WG3_Iu/TSGR3_6 2/docs/R3-
082983.zip
[Non-Patent l i t e r a t u r e 3] Evolved Universal Terrestrial Radio Access
Network (E-UTRAN); SI Application Protocol (S1AP) [3GPP TS36.413
vlO.3.0]
Summary of Invention
Technical Problem
[0006]
The present inventors have found the following problems in the
aforementioned background.
[0007]
In Non-patent l i t e r a t u r e 2, as described above, paging can be
executed on only one radio base station which belongs to a TA in
which UE is registered. When the femto base station is used, however,
the service area is small, and UE may have moved outside the area at
the time that paging is performed. Further, in the case in which all the
radio base stations that belong to one TA need to execute paging, the
effect of the paging optimization may be small. It is therefore
impossible to gradually adjust the number of radio base stations and
the range in which paging is executed.
[0008]
An exemplary object of the present invention is to provide a
gateway device, a mobile communication system, and a paging method
capable of solving the above problems.
Solution to Problem
[0009]
In order to achieve the above object, a gateway device
according to the present invention includes: a memory that stores
information regarding an environment around a radio base station; a
controller that generates a message for paging a mobile station which
camps on the radio base station to execute processing for determining
information of a radio base station to which the message is transmitted
based on the stored information; and a transmission unit that transmits
the message.
[0010]
Further, a mobile communication system according to the
present invention includes a radio base station and a gateway device
that communicates with the radio base station, in which: the radio base
station transmits information regarding an environment around the
radio base station to the gateway device, and the gateway device
includes: a reception unit that receives the information; a controller
that generates a message for paging a mobile station which camps on
the radio base station to execute processing for determining a radio
base station to which the message is transmitted based on the received
information; and a transmission unit that transmits the message.
[0011]
Further, a paging method according to the present invention
includes the steps of: storing information regarding an environment
around a radio base station; generating a message for paging a mobile
station which camps on the radio base station to execute processing for
determining a radio base station to which the message is transmitted
based on the stored information; and t r a n s m i t t i n g the message to the
radio base station to which the message is transmitted.
Advantageous Effects of Invention
[0012]
According to the present invention, it is possible to achieve
paging optimization by reducing the number of radio base stations that
execute paging.
Brief Description of Drawings
[0013]
Fig. 1 is a diagram showing a configuration according to a first
exemplary embodiment;
Fig. 2 is a sequence diagram showing an operation according to
the first exemplary embodiment;
Fig. 3 is a diagram showing a configuration according to a
second exemplary embodiment;
Fig. 4A is a sequence diagram showing an operation according
to the second exemplary embodiment;
Fig. 4B is a sequence diagram showing the operation according
to the second exemplary embodiment;
Fig. 5 is one example of information transmitted by an HeNB to
an FleNB-GW according to the second exemplary embodiment;
Fig. 6 is one example of information transmitted by the HeNB to
the HeNB-GW according to the second exemplary embodiment;
Fig. 7 is one example of information transmitted by the HeNB to
the HeNB-GW according to the second exemplary embodiment;
Fig. 8 is one example of information transmitted by the HeNB to
the HeNB-GW according to the second exemplary embodiment;
Fig. 9A is one example of information transmitted by the HeNB
to the HeNB-GW according to the second exemplary embodiment;
Fig. 9B is one example of information transmitted by the HeNB
to the HeNB-GW according to the second exemplary embodiment;
Fig. 10 is one example of information transmitted by the HeNB
to the HeNB-GW according to the second exemplary embodiment;
Fig. 11A is a sequence diagram showing an operation according
to a third exemplary embodiment;
Fig. 1 IB is a sequence diagram showing the operation according
to the third exemplary embodiment;
Fig. 12 is a sequence diagram showing an operation according
to a fourth exemplary embodiment;
Fig. 13 is one example of information transmitted by an MME to
an HeNB-GW according to the fourth exemplary embodiment;
Fig. 14 is one example of information transmitted by the MME
to the HeNB-GW according to the fourth exemplary embodiment;
Fig. 15 is one example of information transmitted by the MME
to the HeNB-GW according to the fourth exemplary embodiment; and
Fig. 16 is a sequence diagram showing an operation according
to a fifth exemplary embodiment.
Description of Embodiments
[0014]
Hereinafter, with reference to the drawings, exemplary
embodiments of the present invention will be described.
[0015]
(First exemplary embodiment)
[Configuration]
Fig. 1 is a diagram showing one example of the configuration of
a gateway device 10 according to a first exemplary embodiment of the
present invention. As shown in Fig. 1, the gateway device 10 includes
a storage unit 11, a processing unit 12, and a transmission unit 13.
[0016]
The storage unit 1 1 stores information regarding an environment
around radio base stations (not shown). The processing unit 12
determines, based on the information regarding the environment around
the radio base station on which the mobile station has camped, a radio
base station to which a message to page the mobile station is
t r a n s m i t t e d . The transmission unit 13 transmits the paging message to
the radio base station determined in the processing unit 12.
[0017]
[Operations]
Fig. 2 is a diagram showing one example of the sequence
i n d i c a t i n g the operations of the gateway device 10 according to the
first exemplary embodiment.
[0018]
First, the gateway device 10 stores information regarding the
environment around the radio base station in the storage unit 11 ( S l l ).
Next, the gateway device 10 determines by the processing unit 12 the
radio base station to which the paging message is transmitted based on
the information regarding the environment around the radio base
s t a t i on on which the mobile station has camped (S12). Lastly, the
gateway device 10 transmits by the transmission unit 13 the paging
message to the radio base station that is determined in S12.
[0019]
[Effects]
As described above, the gateway device 10 determines the radio
base station to which the paging message is transmitted based on
environment information around the radio base station on which the
mobile station has camped. It is therefore possible to reduce the
number of radio base stations that execute paging and to achieve
paging optimization.
[0020]
(Second exemplary embodiment)
[Configuration]
Fig. 3 is a diagram showing one example of the configuration of
a mobile communication system according to a second exemplary
embodiment of the present invention. As shown in Fig. 3, the mobile
communication system includes an HeNB-GW 100, an MME 200, an
HeNB 300, an FleNB 310, an HeNB 320, an HeNB 330, and a UE 400.
[0021]
The HeNB-GW 100 includes a t r a n s m i s s i o n / r e c e p t i o n unit 101, a
processing unit 102, and a storage unit 103. The HeNB-GW 100 is able
to communicate with the HeNB 300, the HeNB 310, and the HeNB 320,
and transmits or receives messages using S1AP to or from the HeNB
300, the HeNB 310, and the HeNB 320. The HeNB-GW 100 also
transmits or receives messages using S1AP to or from the MME 200 as
well. In the HeNB-GW 100, the t r a n s m i s s i o n / r e c e p t i o n unit 101
performs processing for t r a n s m i t t i n g or receiving information, the
processing unit 102 performs processing for generating and analyzing
information to be transmitted or received, and the storage unit 103
performs processing for storing information to be transmitted or
received.
[0022]
The MME 200 includes a t r a n s m i s s i o n / r e c e p t i o n unit 201, a
processing unit 202, and a storage unit 203. The MME 200 transmits
or receives messages using S1AP to or from the HeNB-GW 100
described above, and is able to communicate with the HeNB 330 using
S1AP without the intervention of the HeNB-GW 100. In the MME 200,
the t r a n s m i s s i o n / r e c e p t i o n unit 201 performs processing for
t r a n s m i t t i n g or receiving information, the processing unit 202 performs
processing for generating and analyzing information to be transmitted
or received, and the storage unit 203 performs processing for storing
information to be transmitted or received.
[0023]
The HeNB 300 includes a t r a n s m i s s i o n / r e c e p t i o n unit 301, a
processing unit 302, and a storage unit 303. The same is true for the
HeNB 310, the HeNB 320, and the HeNB 330. Some HeNBs such as the
HeNB 330 communicate with the MME 200 as an upper node and other
HeNBs such as the HeNB 300, the HeNB 310, and the HeNB 320
communicate with the HeNB-GW 100 as an upper node. The HeNBs
transmit or receive messages using S1AP to or from the upper nodes.
The HeNB 300 is further able to communicate with the UE 400 by radio,
and the interface between them is defined as Uu. In the HeNB 300, the
t r a n s m i s s i o n / r e c e p t i o n unit 301 performs processing for transmitting or
receiving information, the processing unit 302 performs processing for
generating and analyzing information to be transmitted or received,
and the storage unit 303 performs processing for storing information to
be transmitted or received. The same is true for the HeNB 310, the
HeNB 320, and the HeNB 330.
[0024]
The UE 400 includes a t r a n s m i s s i o n / r e c e p t i o n unit 401, a
processing unit 402, and a storage unit 403. The UE 400 performs
radio communication with the HeNB 300, as described above. In the
UE 400, the t r a n s m i s s i o n / r e c e p t i o n unit 401 performs processing for
t r a n s m i t t i n g or receiving information, the processing unit 402 performs
processing for generating and analyzing information to be transmitted
or received, and the storage unit 403 performs processing for storing
information to be transmitted or received.
[0025]
[Operations]
Figs. 4A and 4B are diagrams showing an example of the
sequence of the operation according to the second exemplary
embodiment of the present invention. Hereinafter, with reference to
the drawings, the operations of the HeNB 300, the HeNB-GW 100, and
the MME 200 will be described.
[0026]
First, with reference to Fig. 4A, an operation flow when the SI
connection between the HeNB 300 and the HeNB-GW 100 has not been
e s t a b l i s h e d will be described (SI 10). The HeNB 300 transmits an SI
SETUP REQUEST message to the HeNB-GW 100 ( S i l l ) . The HeNB
310 and the HeNB 320 operate in a way similar to that of the HeNB
300. This message is a message that is transmitted to the HeNB-GW
by the FleNB for the first time after the connection of a transport
network layer (TNL) becomes available to establish the SI connection,
and the details of the message are disclosed in Non-patent literature 3.
The HeNB 300 n o t i f i e s , by the message, the HeNB-GW 100 of eNB
Identify which is i d e n t i f i c a t i o n information of the radio base station
and eNB Environment Information which is the information regarding
the environment around the radio base station. The details of these
information will be described later. Next, the HeNB-GW 100 which
has received the message stores eNB Environment Information of each
HeNB (SI 12). The HeNB-GW 100 then transmits the received message
to the MME 200 (SI 13).
[0027]
Meanwhile, the operation flow when the SI connection between
the HeNB 300 and the HeNB-GW 100 has already been established will
be described (S120). The HeNB 300 transmits an ENB
CONFIGURATION UPDATE message to the HeNB-GW 100 (S121).
The HeNB 310 and the HeNB 320 operate in a way similar to that of
the HeNB 300. The details of the ENB CONFIGURATION UPDATE
message is disclosed in Non-patent l i t e r a t u r e 3. The HeNB 300
n o t i f i e s , by the message, the HeNB-GW 100 of eNB Identify which is
the i d e n t i f i c a t i o n information of the radio base station and eNB
Environment Information which is the information regarding the
environment around the radio base station. The details of these
information will be described later. The following operations of S122
and S123 are similar to those of SI 12 and SI 13 described above, and
thus the description thereof will be omitted.
[0028]
With reference to Figs. 5 to 10, the eNB Identity and the eNB
Environment Information described above will be described.
[0029]
Fig. 5 is a diagram showing one example of the information
elements (IEs) of the SI SETUP REQUEST message. Fig. 6 is a
diagram showing one example of the IEs of ENB CONFIGURATION
UPDATE. The eNB Identity and the eNB Environment Information
included in the both messages will be described below in detail.
[0030]
Fig. 7 is a diagram showing one example of the details of the
IEs included in the eNB Identity. The eNB Identity is an IE for
identifying the radio base station.
[0031]
Fig. 8 is a diagram showing one example of the details of the
eNB Environment Information. The eNB Environment Information
includes Radio Information which is information regarding a radio
environment and Non Radio Information which is information
regarding information other than the radio environment.
[0032]
Figs. 9A and 9B are diagrams showing one example of the
details of the IEs included in the Radio Information. The IE of EUTRAN
Cell ID Information includes various types of information
regarding a cell of an Enhanced Universal Terrestrial Radio Access
Network (E-UTRAN). The IE of UTRAN Cell ID Information includes
various types of information regarding a cell of a Universal Terrestrial
Radio Access Network (UTRAN). The IE of GERAN Cell ID
Information includes various types of information regarding a cell of a
Global System for Mobile Communications EDGE Radio Access
Network (GERAN). The IE of WiMAX base stations Information
includes various types of information regarding the base station of a
Worldwide I n t e r o p e r a b i l i t y for Microwave Access (WiMAX). The IE
of Wireless Internet hotspots Information includes various types of
information regarding a wireless Internet hotspot. The IE of
Television stations Information includes various types of information
regarding TV s t a t i o n s . The IE of Radio Stations Information includes
various types of information regarding radio stations. The IE of GPS
Information includes various types of information regarding a Global
P o s i t i o n i n g System (GPS). The information regarding the GPS
i n c l u d e s , as shown in Fig. 9B, positional information (e.g., latitude,
longitude, and a l t i t u d e ) . However, these information are not
n e c e s s a r i l y limited to information acquired using the GPS mounted on
the radio base station. They may be set by an Operation and
Maintenance (O&M) apparatus of the radio base station or may be set
by a maintenance engineer of the radio base station manually.
[0033]
Fig. 10 is a diagram showing one example of the details of the
IEs included in Non Radio Information. The CHOICE IP Address is an
IE indicating the Internet Protocol (IP) address allocated to the radio
base station. Phone number, Address, and Postcode are the IEs
r e s p e c t i v e l y indicating the telephone number, the address, and the
postcode regarding the position in which the radio base station is
i n s t a l l e d . The HeNB-GW ID is an IE indicating identification
information of HeNB-GW to which the HeNB has most recently been
connected when the radio base station is HeNB.
[0034]
With reference to Fig. 4B, the operation flow will be
continuously described. The HeNB-GW 100 recognizes which HeNB
cell the UE 400 camps on and stores which of the HeNB 300, the HeNB
310, and the HeNB 320 the UE 400 camps on (S201).
[0035]
Next, the operation flow when paging is executed will be
described. The HeNB-GW 100 first receives a PAGING message to
page the UE 400 from the MME 200 (S211). The details of the
PAGING message are disclosed in Non-patent l i t e r a t u r e 3.
[0036]
Subsequently, the HeNB-GW 100 determines the HeNB to which
the PAGING message is transmitted based on the eNB Environment
Information stored in SI 12 or S122 regarding HeNB stored in S201
(S212). Consider, for example, a case in which the HeNB on which the
UE 400 last camped is the HeNB 300. When the HeNB 310 includes
the eNB Environment Information that is similar to that included in the
HeNB 300, the HeNB-GW 100 determines the HeNB to which the
PAGING message is transmitted as the HeNB 300 and the HeNB 310.
[0037]
To be more specific, regarding the latitude and the longitude in
GPS Information of eNB Environment Information, for example, when
only the HeNB 310 has values close to those of the HeNB 300, the
HeNB to which the PAGING message is transmitted is determined to be
the HeNB 3 10 and the HeNB 300. Alternatively, the HeNB to which
the PAGING message is transmitted may be determined using values of
a postcode, a telephone number, or an address in a similar way that the
information of l a t i t u d e and longitude is used. Alternatively, the
HeNBs having similar IP address values may be determined as the
HeNBs to which the PAGING message is transmitted. Whether the
HeNBs have similar IP address values may be determined based on
whether the HeNBs have similar IP address values in the address space.
Further, when a provider that allocates the IP addresses determines the
values of the IP addresses on the basis of regional features, these
values may be used. Further, the IP address of each HeNB allocated
when a Security A r c h i t e c t u r e for Internet Protocol (IPsec) tunnel has
been established may be stored, and the HeNB to which the PAGING
message is transmitted may be determined based on the IP address of
the HeNB on which the UE last camped. As described above, the
HeNB-GW 100 may determine the HeNB to which the PAGING message
is transmitted based on any information element shown in Figs. 8 to 10
or may determine the HeNB to which the PAGING message is
t r a n s m i t t e d from a result of a conditional judgment using a
combination of a p l u r a l i t y of information elements.
[0038]
Next, the HeNB-GW 100 transmits the PAGING message to the
HeNB that is determined in S212 (S213).
[0039]
[Effects]
As described above, the HeNB-GW according to the first
exemplary embodiment transmits the paging message to the HeNB that
includes information regarding a surrounding environment close to the
information regarding the environment around the HeNB on which the
UE which is the paging target last camped. Accordingly, even when
UE has already moved from the area of the HeNB on which the UE last
camped, peripheral HeNBs perform paging. Therefore, it is highly
likely that the paging succeeds. In addition, compared to the case in
which the HeNB-GW transmits the paging message to all the HeNBs
having TAI based on the TAI List, the number of messages can be
reduced, and it is possible to achieve paging optimization.
[0040]
By appropriately changing the range of the values of eNB
Environment Information, which is a determination criterion when the
HeNB is determined in S212, it is possible to gradually adjust the
number and the range of the HeNBs that execute paging.
[0041]
(Third exemplary embodiment)
[Configuration]
Since the configuration of a mobile communication system
according to a third exemplary embodiment is similar to that in the
second exemplary embodiment, the description thereof will be omitted.
[0042]
[Operations]
Figs. 11A and 1 1 B are diagrams showing an example of the
sequence of the operation according to the third exemplary embodiment
of the present invention. In the following description, with reference
to the drawings, the operations of the HeNB 300, the HeNB-GW 100,
and the MME 200 will be described.
[0043]
First, in Fig. 11A, the HeNB-GW 100 stores information for
a s s o c i a t i n g a predetermined value of at least one of eNB Identity and
eNB Environment Information with a predetermined value of a
replacement ECGI in the HeNB-GW 100 (S301). The ECGI (E-UTRAN
Cell Global Identifier) is an identifier of the cell having different
values for the respective HeNBs. The replacement ECGI is an
i d e n t i f i e r which serves as a replacement of the ECGI, and the ECGIs of
the p l u r a l i t y of HeNBs and one replacement ECGI may be associated
with each other. Note that the HeNB-GW 100 may acquire the
information regarding the correspondence from another device via a
network or may acquire the information regarding the correspondence
by setting by the maintenance engineer. Any desired method may be
used. Further, regarding the correspondence, for example, a value Al
or A2 of eNB Identity and a value XI of the replacement ECGI may be
associated with each other. Alternatively, values Bl to B5 of the
predetermined information element of eNB Environment Information
and a value X2 of the replacement ECGI may be associated with each
other. Further a l t e r n a t i v e l y , a value A3 of eNB Identitiy and a value
B6 of the predetermined information element of eNB Environment
Information may be associated with a value X3 of the replacement
ECGI. The value of eNB Identity and the value of the predetermined
information element of eNB Environment Information may be combined
to associate the combined value with the replacement ECGI.
[0044]
The following operation is different between the case in which
the SI connection between the HeNB 300 and the HeNB-GW 100 has
been established (S310) and the case in which the SI connection has
not been established (S320). These two cases will be separately
described.
[0045]
When the SI connection has not been established (S3 10), the
HeNB 300 transmits the SI SETUP REQUEST message to the HeNBGW
100 (S311). Since this operation is similar to that in the second
exemplary embodiment, the detailed description will be omitted. Next,
the HeNB-GW 100 determines, for each HeNB that has transmitted the
message, the corresponding ECGI based on the SI SETUP REQUEST
message that the HeNB-GW 100 received (S312). When, for example,
the value of eNB Identity included in the message is A2, the value of
the replacement ECGI in the above example is determined to be XI. In
a similar way, when the value of the predetermined information
element of eNB Environment Information is B l , the replacement ECGI
is determined to be X2. Further, when the value of eNB Identity is A3
and the value of the predetermined information element of eNB
Environment Information is B6, the replacement ECGI is determined to
be X3. The HeNB-GW 100 may use both of eNB Identity and eNB
Environment Information or may use only one of eNB Identity and eNB
Environment Information to determine the replacement ECGI. Next,
the HeNB 300 transmits the received message to the MME 200 (S313).
[0046]
Next, the operation flow when the SI connection has already
been established between the HeNB 300 and the HeNB-GW 100 will be
described (S320). The HeNB 300 transmits an ENB CONFIGURATION
UPDATE message to the HeNB-GW 100 (S321). Since this operation is
similar to that in the second exemplary embodiment, the detailed
description will be omitted. Next, the HeNB-GW 100 determines, for
each HeNB that has transmitted the message, the corresponding ECGI
based on the ENB CONFIGURATION UPDATE message that the HeNBGW
100 receives (S322). Since this operation is similar to that in
S312, the description thereof will be omitted. Next, the HeNB 300
transmits the received message to the MME 200 (S333).
[0047]
With reference next to Fig. 11B, the operation flow will be
described. The HeNB-GW 100 recognizes which HeNB cell the UE 400
camps on, and stores which of the HeNB 300, the HeNB 310, and the
FleNB 320 the UE 400 camps on (S401). This operation is similar to
that in the second exemplary embodiment.
[0048]
Next, the operation flow when the paging is executed will be
described. First, the HeNB-GW 100 receives from the MME 200 the
PAGING message to page the UE 400 (S411).
[0049]
Next, the HeNB-GW 100 determines the HeNB to which the
PAGING message is transmitted based on the replacement ECGI
determined in S312 or S322 regarding the HeNB stored in S401 (S412).
Consider, for example, a case in which the HeNB 300 is the HeNB that
the UE 400 last camped on. When the value of the replacement ECGI
of the HeNB 300 is the same as that of the replacement ECGI of the
HeNB 310 and is different from that of the replacement ECGI of the
HeNB 320, the HeNB-GW 100 determines the HeNB to which the
PAGING message is transmitted as the HeNB 310 and the HeNB 300.
[0050]
Next, the HeNB-GW 100 transmits the PAGING message to the
HeNB that is determined in S412 (S413).
[0051]
[Effects]
As described above, the HeNB-GW according to the third
exemplary embodiment transmits the paging message to the HeNB
having the value of the replacement ECGI which is equal to the value
of the replacement ECGI of the HeNB on which the UE which is the
paging target last camped. Further, the HeNBs having similar
information regarding the environment around the HeNBs have the
same replacement ECGI. Accordingly, the invention according to the
third exemplary embodiment achieves the effects similar to those of
the invention according to the second exemplary embodiment.
[0052]
Further, it is required in the second exemplary embodiment that
the HeNB-GW performs processing for determining the HeNB to which
the PAGING message is t r a n s m i t t e d based on the environment
information around the HeNB on which the UE last camped when the
paging message is received from the MME. In the third exemplary
embodiment, however, before the HeNB-GW receives the paging
message from the MME, the HeNB-GW has already created and stored
another identifier based on the information regarding the environment
around the HeNBs, whereby it is possible to determine the HeNB to
which the PAGING message is transmitted using this identifier.
[0053]
(Fourth exemplary embodiment)
The invention according to a fourth exemplary embodiment
executes the operation for optimizing paging in the second and third
exemplary embodiments only when a predetermined condition is
satisfied. While it is required to reduce the number of paging
messages as stated above, another problem occurs if a large number of
paging messages are deleted. When paging in the deleted paging
message does not succeed since the UE moves away from the radio base
station on which the UE last camped on, for example, normal paging
based on the TAI List is executed again, which causes a problem of
service delay. In some cases like voice communication, re-execution
of the paging is detrimental to user's experiences. In other cases like
mail reception or Machine-to-Machine (M2M) communication, the reexecution
of the paging is less detrimental to user's experiences. The
present invention according to this exemplary embodiment solves the
above problem.
[0054]
[Configuration]
Since the configuration of the mobile communication system
according to the fourth exemplary embodiment is similar to that of the
second exemplary embodiment, the description thereof will be omitted.
[0055]
[Operations]
Fig. 12 is a diagram showing one example of the sequence of
the operation according to the fourth exemplary embodiment of the
present invention. In the following description, with reference to the
drawings, the operations of the HeNB 300, the HeNB-GW 100, and the
MME 200 will be described.
[0056]
In this exemplary embodiment, the operation of Fig. 4A or Fig.
11A is executed before the operation of Fig. 12 is executed. Since
these operations are similar to those in the second exemplary
embodiment or the third exemplary embodiment, the description
thereof will be omitted.
[0057]
First, the HeNB-GW 100 recognizes which HeNB cell the UE
400 camps on, and stores which of the HeNB 300, the HeNB 310, and
the HeNB 320 the UE 400 camps on (S501). This operation is similar
to that in the second exemplary embodiment.
[0058]
Next, the operation flow when the paging is executed will be
described. First, the HeNB-GW 100 receives the PAGING message to
page the UE 400 from the MME 200 (S511).
[0059]
Figs. 13 to 15 are diagrams showing examples of the
information element of the PAGING message. Fig. 14 defines the
details of Service Type Info which is the information element of Fig.
13, and Fig. 15 defines the details of Calling Party Type Info, as is
similar to Fig. 14. The details of the information element will be
described later.
[0060]
Next, the HeNB-GW 100 determines whether the value of the
predetermined information element included in the PAGING message
s a t i s f i e s a predetermined condition (S512). When the value of the
predetermined information element satisfies the predetermined
condition, paging is optimized (S520). When the value of the
predetermined information element does not satisfy the predetermined
condition, the normal paging operation is performed (S530).
[0061]
The information element used for the determination in S512 may
be, for example, QCI Info (QoS Class I d e n t i f i e r ) , which is the
information indicating the class of the Quality of Service (QoS). In
this case, when the value of the QCI Info indicates Transmission
Control Protocol (TCP)-based, for example, it is determined in S512
that the condition is satisfied in order to reduce the system load by the
paging optimization. The "TCP-based" means, for example, World
Wide Web (WWW), e-mail, chat, File Transfer Protocol (ftp), Peer to
Peer (p2p) file sharing, progressive video. Meanwhile, when the value
of QCI Info indicates Conversational Voice, which is a voice call, it is
determined that the condition in S512 is not satisfied in order to avoid
the service delay due the re-execution of the paging.
[0062]
Further, the information element used for the determination in
S512 may be Service Type Info, which is the information indicating the
service type of the call. In this case, when the value of Service Type
Info indicates an e-mail, for example, the service delay due to the reexecution
of the paging does not cause a big problem. In such a case,
p r i o r i ty is given to the reduction in system load by the paging
optimization, and it is determined in S512 that the condition is
satisfied. Meanwhile, when the value of Service Type Info indicates
Voice over Internet Protocol (VoIP), it is determined in S512 that the
condition is not satisfied to avoid the service delay due the reexecution
of the paging.
[0063]
Furthermore, the information element used for the determination
in S512 may be Calling Party Type Info, which is information
i n d i c a t i n g the type of a calling party. In this case, when the value of
Calling Party Type Info indicates Machine, for example, the service
delay does not cause a big problem even when paging is executed again.
In such a case, p r i o r i t y is given to the reduction in system load by the
paging optimization, and it is determined in S512 that the condition is
satisfied. Meanwhile, when the value of Service Type Info indicates
Voice over Internet Protocol (VoIP), it is determined in S512 that the
condition is not satisfied to avoid the service delay due to the reexecution
of the paging.
[0064]
Further, a conditional judgment may be carried out in S512
based on Paging P r i o r i t y , which is the information element indicating
the priority of the paging. Further, the information element illustrated
above may be used alone for the conditional judgment, or a plurality of
information elements may be used in combination with each other for
the conditional judgment.
[0065]
Next, the operation in the case in which it is determined in
S512 that the condition is satisfied will be described (S520). The
HeNB-GW 100 determines the HeNB to which the PAGING message is
transmitted based on processing for optimizing the paging (S521) and
transmits the message to the HeNB that is determined (S522). More
s p e c i f i c a l l y , the processing for optimizing the paging is similar to the
operation of S212 in Fig. 4B in the second exemplary embodiment or
the processing of S412 in Fig. 11B in the third exemplary embodiment,
and thus the description thereof will be omitted.
[0066]
Meanwhile, the operation in the case in which it is determined
in S512 that the condition is not satisfied will be described (S530).
The HeNB-GW 100 determines the HeNB to which the PAGING
message is transmitted based on normal paging processing (S531) and
transmits the message to the HeNB that is determined (S532). More
s p e c i f i c a l l y , the normal paging processing is processing for
determining all the HeNBs having TAI specified by the TAI List which
i s the information element included in the PAGING message as the
HeNBs to which the PAGING message is transmitted.
[0067]
[Effects]
As described above, the HeNB-GW according to the fourth
exemplary embodiment determines, based on the value of the
information element included in the paging message received from the
MME, whether to execute the processing for optimizing the paging or
the normal paging processing. Accordingly, it is possible to avoid
occurrence of the service delay due to the re-execution of the paging
as a result of the failure in paging by optimization processing
according to the type of the paging that is to be executed.
[0068]
(Fifth exemplary embodiment)
The invention according to a fifth exemplary embodiment
further specifies and improves the operation for storing the HeNB on
which the UE 400 last camped in the HeNB-GW 100 ( i . e . , S201 in Fig.
4B, S401 in Fig. 1 I B , and S501 in Fig. 12) in the second to fourth
exemplary embodiments. If the HeNB-GW 100 cannot frequently
acquire information of the HeNB on which the UE 400 camps, the
operation for optimizing paging is carried out based on old information.
In such a case, it is highly likely that the UE 400 has already moved
from the area of the HeNB-GW cell on which the UE 400 last camped
and paging is failed. The invention according to this exemplary
embodiment solves such a problem.
[0069]
[Configuration]
Since the configuration of the mobile communication system
according to the fifth exemplary embodiment is similar to that of the
second exemplary embodiment, the description thereof will be omitted.
[0070]
[Operations]
Fig. 16 is a diagram showing one example of the sequence of
the operation according to the fifth exemplary embodiment of the
present invention. Hereinafter, with reference to the drawing, the
operations of the HeNB 300, the HeNB-GW 100, and the MME 200 will
be described.
[0071]
In this exemplary embodiment, the operation of Fig. 4A or Fig.
11A is executed before the operation of Fig. 16 is executed. Since
these operations are similar to those in the second exemplary
embodiment or the third exemplary embodiment, the description
thereof will be omitted.
[0072]
First, a Radio Resource Control (RRC) connection is established
between the UE 400 and the HeNB 300 (S601). Since the details are
well-known to one of ordinary skilled in the art and are not directly
related to the present invention, the description thereof will be omitted.
[0073]
Next, the HeNB 300 transmits a message of INITIAL UE
MESSAGE to the HeNB-GW 100 (S602). The details of the message of
INITIAL UE MESSAGE is disclosed in Non-patent l i t e r a t u r e 3. This
message includes ECGI with which the HeNB 300 can be identified and
SAE Temporary Mobile Subscriber Identity (S-TMSI) with which the
UE 400 can be identified.
[0074]
Next, the HeNB-GW 100 stores information in'which ECGI and
S-TMSI are associated with each other based on the received message
(S603). The HeNB-GW 100 is therefore able to recognize the UE 400
and the HeNB 300 on which the UE 400 has camped in association with
each other.
[0075]
Further, the HeNB-GW 100 starts a timer, and clears
information of correspondence information stored in S603 when the
timer expires (S604).
[0076]
Next, operations when the paging is executed will be described.
First, the HeNB-GW 100 receives a PAGING message from the MME
200 (S611). This message includes S-TMSI of the UE 400 which is the
target of the paging.
[0077]
Next, the HeNB-GW 100 determines whether there is
information of ECGI associated with S-TMSI included in the received
message (S612). The correspondence information stored in S603 is
present before the timer started in S604 expires. Meanwhile, when the
timer is cleared due to the expiration of the timer, the correspondence
information is absent.
[0078]
Next, when it is determined in S612 that the correspondence
information is present, the operation for optimizing paging is executed
(S620). Since the operation of S620 is similar to that of S520 in Fig.
12, the description thereof will be omitted. On the other hand, when it
is determined in S612 that the correspondence information is absent,
the normal paging operation is performed (S630). Since the operation
of S630 is similar to that of S530 in Fig. 12, the description thereof
will be omitted.
[0079]
[Effects]
As described above, the HeNB-GW according to the fifth
exemplary embodiment specifies the HeNB on which the UE camps
based on INITIAL UE MESSAGE in the operation sequence when the
RRC connection is established. Further, by the use of the timer, the
operation of the paging optimization is executed based on the HeNB
only when the information of the HeNB on which the UE camps is new.
Accordingly, when information of the HeNB on which the UE camps is
old, the operation for optimizing the paging is performed based on the
information, whereby it is possible to avoid the failure of the paging.
In summary, it is possible to avoid occurrence of the service delay
which is due to the r e - e x e c u t i o n of the paging. Further, the fifth
exemplary embodiment may be executed in combination with the
second to fourth exemplary embodiments, thereby achieving the effects
according to the second to fourth exemplary embodiments.
[0080]
While the present invention has been described in detail based
on the preferred exemplary embodiments, the present invention is not
limited to the above embodiments and may be changed in various ways
without departing from the spirit of the present invention.
[0081]
For example, while S-TMSI is used as information for
identifying the UE 400 in the fifth exemplary embodiment,
I n t e r n a t i o n a l Mobile Subscriber Identity (IMSI) may be used instead.
S-TMSI may be other types of information as long as it can identify
the UE. In a similar way, ECGI may be other types of information as
long as it can identify the HeNB.
[0082]
Furthermore, in the mobile communication system defined by
the 3GPP, the HeNB-GW is not necessarily present. In such a case, in
the second exemplary embodiment, the HeNB 300 may transmit or
receive messages using S1AP to or from the MME 200 and the MME
200 may perform the operation of the HeNB-GW 100. In summary, the
higher-level device with which the HeNB 300 according to the present
invention communicates may be either the HeNB-GW 100 or the MME
200. When the higher-level device is the MME, the present invention
may be applied using an eNB instead of using the HeNB.
[0083]
Further, while the present invention is applied to the mobile
communication system of the LTE including the UE, the HeNB, the
FleNB-GW, and the MME in the second exemplary embodiment, the
present invention may be applied to a 3rd Generation (3G) mobile
communication system including UE, a Home Node B (HNB), an HNB
Gateway (HNB-GW), and a Mobile Switching Center (MSC)/ serving
GPRS support node (SGSN). Further a l t e r n a t i v e l y , the present
invention may be applied to a mobile communication system including
a macro base station such as a Node B (NB) or an evolved Node B
(eNB) in place of the femto base station such as the HNB or the HeNB.
[0084]
This application is based upon and claims the benefit of p r i o r i ty
from Japanese Patent Application No. 2012-210767, filed on September
25, 2012, the disclosure of which is incorporated herein in its entirety
by reference.
Reference Signs List
[0085]
10 GATEWAY DEVICE
11 STORAGE UNIT
12 PROCESSING UNIT
13 TRANSMISSION UNIT
100 HeNB-GW
200 MME
300, 310, 320, 330 HeNB
400 UE
101, 201, 301, 311, 321, 331, 401 TRANSMISSION/RECEPTION UNIT
102, 202, 302, 312, 322, 332, 402 PROCESSING UNIT
103, 203, 303, 313, 323, 333, 403 STORAGE UNIT
WE CLAIM:
1. A gateway device comprising:
a memory that stores information regarding an environment
around a radio base station;
a controller that generates a message for paging a mobile
s t a t i on which camps on the radio base station to execute processing for
determining information of a radio base station to which the message is
t r a n s m i t t e d based on the stored information; and
a transmission unit that transmits the message.
2. The gateway device according to Claim 1, comprising a
reception unit that receives a message regarding paging from a core
network device;
wherein the controller executes the processing when a value of
predetermined information included in the received message satisfies a
predetermined condition.
3. The gateway device according to Claim 2, wherein the
predetermined information element comprises at least one of:
information indicating a class of a Quality of Service (QoS) of
a call in the paging;
information indicating a service type of the call; and
information indicating a type of a calling party.
4. The gateway device according to Claim 2 or 3, wherein:
the reception unit receives the message from the radio base
s t a t i o n ,
the received message comprises information in which an
i d e n t i f i e r of the mobile station is associated with an identifier of the
radio base station, and
the controller identifies the radio base station on which the
mobile station has camped based on the received message.
5. The gateway device according to Claim 4, wherein the
controller deletes the associated information after an elapse of a
predetermined period of time.
6. The gateway device according to any one of Claims 1 to 5,
wherein:
a mobile communication system is a mobile communication
system of a Long Term Evolution (LTE) defined by a Third Generation
Partnership Project (3GPP),
the mobile station is a User Equipment (UE),
the radio base station is a Home evolved Node B (HeNB), and
the gateway device is an HeNB Gateway (HeNB-GW).
7. The gateway device according to any one of Claims 1 to 6,
wherein:
the information regarding the environment around the radio base
station is information regarding a radio environment around the radio
base station, and comprises at least one of:
information of a cell of an Enhanced Universal Terrestrial
Radio Access Network (E-UTRAN);
information regarding a cell of a Universal Terrestrial Radio
Access Network (UTRAN);
information regarding a cell of a Global System for Mobile
Communications EDGE Radio Access Network (GERAN);
information regarding a base station of a Worldwide
I n t e r o p e r a b i l i t y for Microwave Access (WiMAX);
information regarding a wireless Internet hotspot;
information regarding a TV station;
information regarding a radio station; and
information regarding a GPS.
8. The gateway device according to any one of Claims 1 to 7,
wherein:
the information regarding the environment around the radio base
28
station comprises at least one of:
an IP address allocated to the radio base station;
an address regarding a position in which the radio base station
i s installed;
a postcode;
a telephone number; and
i d e n t i f i c a t i o n information of a gateway device most recently
connected to the radio base station.
9. A mobile communication system comprising a radio base
s t a t i on and a gateway device that communicates with the radio base
s t a t i o n , wherein:
the radio base station transmits information regarding an
environment around the radio base station to the gateway device, and
the gateway device comprises:
a reception unit that receives the information;
a controller that generates a message for paging a mobile
s t a t i o n which camps on the radio base station to execute processing for
determining a radio base station to which the message is transmitted
based on the received information; and
a transmission unit that transmits the message.
10. A paging method comprising the steps of:
storing information regarding an environment around a radio
base station;
generating a message for paging a mobile station which camps
on the radio base station to execute processing for determining a radio
base station to which the message is transmitted based on the stored
information; and
t r a n s m i t t i n g the message to the radio base station to which the
message is transmitted.