U.S. patent application number 11/346116 was filed with the patent office on 2006-06-15 for switching station, subscriber location information registration method, subscriber service information acquisition method, subscriber service information registration method, and subscriber service information transmission method.
Invention is credited to Kayoko Fukasawa, Masahide Ishida, Kenji Kobayashi, Kazuyuki Kozu, Kazuo Sugiyama, Koji Yamamoto.
Application Number | 20060128379 11/346116 |
Document ID | / |
Family ID | 18895547 |
Filed Date | 2006-06-15 |
United States Patent
Application |
20060128379 |
Kind Code |
A1 |
Fukasawa; Kayoko ; et
al. |
June 15, 2006 |
Switching station, subscriber location information registration
method, subscriber service information acquisition method,
subscriber service information registration method, and subscriber
service information transmission method
Abstract
A switching station etc., are provided. When a mobile station
moves from an area of a switching station into an area of another
switching station having a VLR which has accepted the maximum
number of subscribers, the switching station registers subscriber
location information about the mobile station in an HLR even
through it cannot register the subscriber service information in
its VLR. When a call origination signal is transmitted from the
mobile station, the switching station performs call origination
connection processing by acquiring the subscriber service
information about the mobile station from the HLR. When call
termination to the mobile station occurs, the switching station can
perform call termination processing normally since the subscriber
location information is correctly updated in the HLR. The switching
station performs call termination processing by acquiring the
subscriber service information from the HLR.
Inventors: |
Fukasawa; Kayoko; (Kanagawa,
JP) ; Ishida; Masahide; (Aichi, JP) ;
Sugiyama; Kazuo; (Kanagawa, JP) ; Yamamoto; Koji;
(Saitama, JP) ; Kobayashi; Kenji; (Kanagawa,
JP) ; Kozu; Kazuyuki; (Kanagawa, JP) |
Correspondence
Address: |
WORKMAN NYDEGGER;(F/K/A WORKMAN NYDEGGER & SEELEY)
60 EAST SOUTH TEMPLE
1000 EAGLE GATE TOWER
SALT LAKE CITY
UT
84111
US
|
Family ID: |
18895547 |
Appl. No.: |
11/346116 |
Filed: |
February 2, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10071933 |
Feb 7, 2002 |
7016677 |
|
|
11346116 |
Feb 2, 2006 |
|
|
|
Current U.S.
Class: |
455/428 ;
455/433 |
Current CPC
Class: |
H04W 76/20 20180201;
H04W 8/06 20130101; H04W 24/00 20130101; H04W 60/04 20130101; H04W
8/12 20130101; H04W 28/08 20130101; H04W 8/04 20130101; H04W 8/20
20130101; H04W 92/24 20130101 |
Class at
Publication: |
455/428 ;
455/433 |
International
Class: |
H04Q 7/20 20060101
H04Q007/20 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 7, 2001 |
JP |
2001-031467 |
Claims
1. A switching station comprising: means for receiving a call
origination signal from a mobile station; and means for acquiring,
when the call origination signal is received, subscriber service
information about the mobile station that has transmitted the call
origination signal from a second management unit managing
subscriber information in a case where the subscriber service
information about the mobile station that has transmitted the call
origination signal is not registered in a first management unit
provided for use with the switching station and managing subscriber
information.
2. The switching station as claimed in claim 1, wherein said first
management unit is a VLR.
3. The switching station as claimed in claim 1, wherein said second
management unit is an HLR.
4. A switching station comprising: means for receiving a call
origination signal from a mobile station; and means for acquiring,
when the call origination signal is received, subscriber service
information about the mobile station that has transmitted the call
origination signal from a management unit provided for use with
another switching station and managing subscriber information in a
case where the subscriber service information about the mobile
station that has transmitted the call origination signal is not
registered in a management unit provided for use with the switching
station and managing subscriber information.
5. The switching station as claimed in claim 4, wherein said
management unit is a VLR.
6. A subscriber service information acquisition method comprising
the steps of: receiving, at a switching station, a call origination
signal from a mobile station; and acquiring, at the switching
station, when the call origination signal is received, subscriber
service information about the mobile station that has transmitted
the call origination signal from a second management unit managing
subscriber information in a case where the subscriber service
information about the mobile station that has transmitted the call
origination signal is not been registered in a first management
unit provided for use with the switching station and managing
subscriber information.
7. A subscriber service information acquisition method comprising
the steps of: receiving, at a first switching station, a call
origination signal from a mobile station; and acquiring, at the
first switching station, when the call origination signal is
received, subscriber service information about the mobile station
that has transmitted the call origination signal from a management
unit provided for use with a second switching station and managing
subscriber information in a case where the subscriber service
information about the mobile station that has transmitted the call
origination signal is not registered in a management unit provided
for use with the first switching station and managing subscriber
information.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a divisional application of U.S. patent application
Ser. No. 10/071,933 filed Feb. 7, 2002, which is incorporated
herein by reference in its entirety. That application claims
priority under 35 U.S.C. 119 to Patent Application No. 2001-31467
filed Feb. 7, 2001, all filed in Japan, and the contents of all of
which are incorporate hereinto by reference.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates to a switching station, a
subscriber location information registration method, a subscriber
service information acquisition method, a subscriber service
information registration method, and a subscriber service
information transmission method.
[0004] 2. Related Art
[0005] There are two methods for mobility control in mobile
communication: an HLR (Home Location Register) method in which
location information and service information of subscribers (users)
are managed by an apparatus physically separated from a switching
station; and a VLR (Visited Location Register) method in which
subscriber location information and service information are managed
by a VLR in a switching station.
[0006] In the case of the VLR method, if the location of a user
cannot be registered after the maximum number of accommodated users
has been reached, neither of call origination and call termination
by the user is allowed.
[0007] In connection processing of location registration function,
call origination function and call termination function of the VLR
method, when a mobile station moves into an area covered by a
switching station, the mobile station recognizes change of location
area and transmits a location registration signal to the switching
station. The switching station acquires subscriber service
information about the mobile station from the switching station in
whose coverage area the mobile station has been located (from the
HLR at the time of the first location registration). Also,
information on the location of the mobile station used at the time
of call termination is registered in the HLR. When the mobile
station makes a call origination, the switching station performs
call origination processing by using subscriber service information
from the VLR. At the time of call termination, call termination
processing is performed by using the (subscriber) location
information from the HLR.
[0008] FIG. 1 is a diagram showing an example of a conventional
mobile communication system and an example of processing when a
location registration request is made. Referring to FIG. 1,
switching stations 11 and 12 have VLR 21 and 22, respectively.
[0009] When a mobile station 50 moves from an (service) area 32 of
the switching station 12 into an area 31 of the switching station
11 having the VLR 21 which has accepted the maximum number of
subscribers, the switching station 11 receives a location
registration (request) signal from the mobile station 50 (in S11 of
FIG. 1) and acquires (in S12) subscriber service information about
the mobile station 50 from the switching station 12 in whose
coverage area the mobile station 50 has been located. However, no
subscriber service information can be newly registered in the VLR
21 (in S13). Therefore location registration processing ends in
failure (in S14) and updating (registration) of subscriber location
information in an HLR 40 is not performed. If the subscriber makes
call origination in such a situation, call origination processing
is not normally performed since the switching station 11 has no
service information about the subscriber on the VLR 21. Call
termination processing also ends in failure since the subscriber
location information in the HLR 40 has not been updated.
[0010] The number of subscribers (subscriber information items)
possible to be registered in the VLR depends on hardware resources.
Also, because the hardware resources are fixedly assigned, it is
not possible to manage information on dynamically changing
subscribers (users) with flexibility.
BRIEF SUMMARY
[0011] In the first aspect of the present invention, there is
provided a switching station comprising: means for receiving a call
origination signal from a mobile station; and means for acquiring,
when the call origination signal is received, subscriber service
information about the mobile station that has transmitted the call
origination signal from a second management unit managing
subscriber information in a case where the subscriber service
information about the mobile station that has transmitted the call
origination signal is not registered in a first management unit
provided for use with the switching station and managing subscriber
information.
[0012] Here, the first management unit may be a VLR.
[0013] Here, the second management unit may be an HLR.
[0014] In the second aspect of the present invention, there is
provided a switching station comprising: means for receiving a call
origination signal from a mobile station; and means for acquiring,
when the call origination signal is received, subscriber service
information about the mobile station that has transmitted the call
origination signal from a management unit provided for use with
another switching station and managing subscriber information in a
case where the subscriber service information about the mobile
station that has transmitted the call origination signal is not
registered in a management unit provided for use with the switching
station and managing subscriber information.
[0015] Here, the management unit may be a VLR.
[0016] In the third aspect of the present invention, there is
provided a subscriber service information acquisition method
comprising the steps of: receiving, at a switching station, a call
origination signal from a mobile station; and acquiring, at the
switching station, when the call origination signal is received,
subscriber service information about the mobile station that has
transmitted the call origination signal from a second management
unit managing subscriber information in a case where the subscriber
service information about the mobile station that has transmitted
the call origination signal is not been registered in a first
management unit provided for use with the switching station and
managing subscriber information.
[0017] In the fourth aspect of the present invention, there is
provided a subscriber service information acquisition method
comprising the steps of: receiving, at a first switching station, a
call origination signal from a mobile station; and acquiring, at
the first switching station, when the call origination signal is
received, subscriber service information about the mobile station
that has transmitted the call origination signal from a management
unit provided for use with a second switching station and managing
subscriber information in a case where the subscriber service
information about the mobile station that has transmitted the call
origination signal is not registered in a management unit provided
for use with the first switching station and managing subscriber
information.
[0018] According to the above mentioned configurations, a
subscriber can acquire service without dependence on the
accommodation capacity of a management unit which manages
subscriber information.
[0019] The above and other objects, effects, features and
advantages of the present invention will become more apparent from
the following description of embodiments thereof taken in
conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a diagram showing an example of a configuration of
a conventional mobile communication system and an example of
processing when a location registration request is made;
[0021] FIG. 2 is a diagram showing an example of a configuration of
a mobile communication system and an example of processing when a
location registration request is made in the first embodiment of
the present invention;
[0022] FIG. 3 is a diagram showing an example of a configuration of
a switching station;
[0023] FIG. 4 is a diagram showing an example of processing when a
call origination request is made in the first embodiment of the
present invention;
[0024] FIG. 5 is a diagram showing an example of processing when a
call termination request is made in the first embodiment of the
present invention;
[0025] FIG. 6 is a diagram showing an example of processing when a
location registration request is made in the second embodiment of
the present invention;
[0026] FIG. 7 is a diagram showing an example of processing when a
call origination request is made in the second embodiment of the
present invention;
[0027] FIG. 8 is a diagram showing an example of processing when a
call termination request is made in the second embodiment of the
present invention;
[0028] FIG. 9 is a diagram showing an example of processing when a
location registration request is made in the third embodiment of
the present invention;
[0029] FIG. 10 is a diagram showing an example of processing when a
location registration request is made in the third embodiment of
the present invention;
[0030] FIG. 11 is a diagram showing an example of processing when a
call origination request is made in the third embodiment of the
present invention;
[0031] FIG. 12 is a diagram showing an example of processing when a
call termination request is made in the third embodiment of the
present invention;
[0032] FIG. 13 is a diagram for explaining attach state and detach
state;
[0033] FIG. 14 is a diagram for explaining an example of selecting
a mobile station whose subscriber service information is to be
deleted;
[0034] FIG. 15 is a diagram showing an example of inquiring
communication state of a service control unit, when the service
control unit manages the communication state;
[0035] FIG. 16 is a diagram for explaining an example of selecting
a mobile station whose subscriber service information is to be
deleted;
[0036] FIG. 17 is a diagram showing an example of preparing an area
possible to be overwritten and an area impossible to be overwritten
in a subscriber management memory of VLR; and
[0037] FIG. 18 is a diagram showing an example of processing
corresponding to the example of processing shown in FIG. 9 when a
location registration request is made, in a case where subscriber
service information is acquired from an HLR.
DETAILED DESCRIPTION
[0038] Embodiments of the present invention will be described in
detail with reference to the accompanying drawings.
First Embodiment
[0039] FIG. 2 is a diagram showing an example of a configuration of
a mobile communication system and an example of processing when a
location registration request is made in the first embodiment of
the present invention. Referring to FIG. 2, switching stations 111
and 112 have VLRs 121 and 122, respectively. The VLRs 121 and 122
may be provided inside or outside the switching stations 111 and
112. The VLRs 121 and 122, which are management units respectively
used by the switching stations in management of subscriber
information, manage subscriber information such as subscriber
service information and subscriber location information. An HLR 140
is a management unit which is provided independently of switching
stations, and which manages subscriber information.
[0040] FIG. 3 is a diagram showing an example of a configuration of
a switching station. The switching station 111 has a control
portion 191 which performs various kinds of control, a storage
portion 192 which stores various processing procedures, data, etc.,
and a communication portion 193. A VLR 121 may be provided inside
or outside the switching station 111, as are those described above.
The control portion 191 performs communication with other switching
stations, mobile stations, HLRs, VLRs, etc., through the
communication portion 193 and other switching stations, base
stations or the like. The VLR 121 has a subscriber management
memory 180 which stores subscriber information. Other switching
stations (the switching station 112 etc.) can have the same
configuration as the switching station 111.
[0041] Referring again to FIG. 2, when a mobile station 150 moves
from an area 132 of the switching station 112 into an area 131 of
the switching station 111 having the VLR 121 which has accepted the
maximum number of subscribers, the switching station 111 receives a
location registration signal from the mobile station 150 (in S21 of
FIG. 2) and acquires (in S22) subscriber service information about
the mobile station 150 from the switching station 112 in whose
coverage area the mobile station 150 has been located. Here, no
subscriber service information can be newly registered in the VLR
121 (in S23). However, the switching station 111 registers
subscriber location information about the mobile station 150 in the
HLR 140 (in S24), as it stores corresponding information in the VLR
121 in the case where subscriber service information can be
registered in the VLR 121. The switching station 111 normally
completes location registration processing (in S25). The switching
station 111 can store in the storage portion 192 or the VLR 121,
information of the mobile station 150 as a mobile station whose
subscriber service information is not registered in the VLR 121.
Thereby, the switching station 111 can recognize that subscriber
service information of the mobile station 150 is not registered in
the VLR 121, when call origination from the mobile station 150 or
call termination to the mobile station 150 occurs later.
[0042] FIG. 4 is a diagram showing an example of processing when a
call origination request is made in the present embodiment.
Thereafter, when a call origination signal is transmitted from the
mobile station 150 to the switching station 111 (in S31 of FIG. 4),
the switching station 111 acquires subscriber service information
about the mobile station 150 from the HLR 140 (in step S32) since
the VLR 121 has no subscriber service information about the mobile
station 150. Then the switching station 111 normally performs call
origination connection processing (in S33).
[0043] FIG. 5 is a diagram showing an example of processing when a
call termination request is made in the present embodiment. When a
call termination request is made to the mobile station 150, call
termination processing can also be performed normally since the
subscriber location information about the mobile station 150 has
been correctly updated in the HLR 140. When a call termination
signal to the mobile station 150 is transmitted to the switching
station 111 (in S41 of FIG. 5), the switching station 111 acquires
the subscriber service information about the mobile station 150
from the HLR 140 (in S42) and performs call termination processing
(in S43).
Second Embodiment
[0044] The arrangement may alternatively be such that in a case
where a switching station cannot register subscriber service
information in its own VLR, it registers the subscriber service
information in the VLR of another switching station instead of
acquiring the subscriber service information from the HLR 140.
"Another switching station" may be an adjacent switching station, a
switching station in whose coverage area the mobile station has
been located, a switching station having a large capacity VLR, etc.
A first candidate, a second candidate, and so on for "another
switching station" may be determined in advance with respect to
each switching station. When one switching station requests another
switching station to register subscriber service information, the
requested switching station registers the subscriber service
information. Each switching station stores information that in
which VLR the subscriber service information of the mobile station
was stored, if it had subscriber service information registered by
the another switching station in a situation where it could not
register the subscriber service information of the mobile station
in its own VLR. Thereby, the switching station can recognize the
VLR in which the subscriber service information is stored, when
call origination from the mobile station or call termination to the
mobile station occurs later.
[0045] FIG. 6 is a diagram showing an example of processing when a
location registration request is made in the second embodiment of
the present invention. When the mobile station 150 moves from the
area 132 of the switching station 112 into the area 131 of the
switching station 111 having the VLR 121 which has accepted the
maximum number of subscribers, the switching station 111 receives a
location registration signal from the mobile station 150 (in S51 of
FIG. 6) and acquires (in S52) subscriber service information about
the mobile station 150 from the switching station 112 in whose
coverage area the mobile station 150 has been located. Here, no
subscriber service information can be newly registered in the VLR
121 (in S53). However, the switching station 111 registers
subscriber location information about the mobile station 150 in the
HLR 140 (in S54), as it stores corresponding information in the VLR
121 in the case where subscriber service information can be
registered in the VLR 121. Further, the switching station 111
registers subscriber service information about the mobile station
150 in another switching station (in a VLR 123 of a switching
station 113 in this example) (in S55), and normally completes
location registration processing (in S56).
[0046] FIG. 7 is a diagram showing an example of processing when a
call origination request is made in the present embodiment.
[0047] When a call origination signal is transmitted from the
mobile station to the switching station (in S61 of FIG. 7) after
registration in the another VLR, the switching station acquires
subscriber service information about the mobile station from the
another VLR (in step S62) and performs call origination connection
processing (in S63). When the switching station requests the
another switching station to transmit the subscriber service
information, the another switching station transmits the subscriber
service information to the switching station.
[0048] FIG. 8 is a diagram showing an example of processing when a
call termination request is made in the present embodiment.
[0049] When a call termination signal is transmitted to the mobile
station (in S71 of FIG. 8) after registration in the another
switching station, the switching station acquires the subscriber
service information about the mobile station from the another
switching station (in S72) and performs call termination processing
(in S73). When the switching station requests the another switching
station to transmit the subscriber service information, the another
switching station transmits the subscriber service information to
the switching station.
Third Embodiment
[0050] As an alternative to the method of using the method of
acquiring subscriber service information from the HLR 140 or the
method of registering subscriber service information in another
switching station, a method may be used in which a switching
station deletes one of pieces of subscriber service information
presently registered in its own VLR to enable registration of
subscriber service information about a mobile station that has
transmitted a location registration signal in its own VLR.
[0051] FIG. 9 is a diagram showing an example of processing when a
location registration request is made in the third embodiment of
the present invention. When the mobile station 150 moves from the
area 132 of the switching station 112 into the area 131 of the
switching station 111 having the VLR 121 which has accepted the
maximum number of subscribers, the switching station 111 receives a
location registration signal from the mobile station 150 (in S81 of
FIG. 9) and acquires (in S82) subscriber service information about
the mobile station 150 from the switching station 112 in whose
coverage area the mobile station 150 has been located. In this
situation, no subscriber service information can be newly
registered in the VLR 121. However, the switching station 111
deletes one of pieces of subscriber service information presently
registered in the VLR 121 (assumed to be subscriber service
information about a mobile station 151) and registers the
subscriber service information about the mobile station 150 in the
VLR 121 (in S83). The switching station 111 then registers
subscriber location information about the mobile station 150 in the
HLR 140 (in S84), and normally completes location registration
processing (in S85).
[0052] The arrangement may be such that when one piece of
subscriber service information presently registered in the VLR of
the switching station is deleted, deletion from the VLR of the
subscriber location information about the mobile station
corresponding to the subscriber service information to be deleted
is inhibited.
[0053] FIG. 10 is a diagram showing an example of processing when a
location registration request is made in the present
embodiment.
[0054] Thereafter, when a location registration signal is received
from the mobile station whose subscriber service information has
been deleted (in S91 of FIG. 10), the switching station can acquire
the subscriber location information about the mobile station from
its own VLR (in S92), and register it in the HLR 140 (in S93).
Then, the switching station normally completes location
registration processing (in S94).
[0055] FIG. 11 is a diagram showing an example of processing when a
call origination request is made in the present embodiment.
[0056] In a case where the switching station receives a call
origination signal from the mobile station whose subscriber service
information has been deleted (in S101 of FIG. 11), the switching
station acquires the subscriber service information about the
mobile station from the HLR 140 (in S102). If the switching station
cannot newly register the acquired subscriber service information
in its own VLR, it may delete one of pieces of subscriber service
information presently registered in its own VLR and register the
acquired subscriber service information in its own VLR (in S103).
Then the switching station performs call origination connection
processing (in S104).
[0057] FIG. 12 is a diagram showing an example of processing when a
call termination request is made in the present embodiment.
[0058] In a case where the switching station receives a call
termination signal to the mobile station whose subscriber service
information has been deleted (in S121 of FIG. 12), the switching
station acquires the subscriber service information about the
mobile station from the HLR 140 (in S122). If the switching station
cannot newly register the acquired subscriber service information
in its own VLR, it may delete one of pieces of subscriber service
information presently registered in its own VLR and register the
acquired subscriber service information in its own VLR (in S123).
Then the switching station performs call termination processing (in
S124).
[0059] In the steps S83 S103 and S123, the mobile station whose
subscriber service information is to be deleted can be selected in
consideration of call origination, call termination, location
registration, power state, etc. of mobile stations.
[0060] For example, as the mobile station whose subscriber service
information is to be deleted, a mobile station which has made
neither call origination nor call termination during the longest
time period till the present time can be selected.
[0061] Also, for example, as the mobile station whose subscriber
service information is to be deleted, a mobile station in detach
state, i.e., a mobile station which has made neither call
origination, call termination nor location registration for
predetermined period of time, or a mobile station whose power state
is off can be selected.
[0062] The second example will be described in detail.
[0063] FIG. 13 is a diagram for explaining attach state and detach
state. When location registration is performed for a mobile
station, a switching station makes the state of the mobile station
attach state. Thereafter, the switching station finds, using a
timer #2 (mobile not reachable timer), a mobile station which has
made neither call origination, call termination nor location
registration for predetermined period of time in the area of the
switching station, and makes the state of the found mobile station
detach state. The switching station also makes the state of a
mobile station detach state, when it receives from the mobile
station a detach signal indicating that the power has become off.
When a mobile station whose state is detach state makes call
origination, call termination or location registration, the
switching station makes the state of the mobile station attach
state. A mobile station periodically (for example, every three
hours) transmits, using a timer #1 (periodic routing update timer),
a location registration signal to the switching station to request
location registration. Attach state and detach state can be
represented, for example, by using off and on of a (detach)
flag.
[0064] FIG. 14 is a diagram for explaining an example of selecting
a mobile station whose subscriber service information is to be
deleted. In FIG. 14, the timer #2 column shows, for each mobile
station (subscriber), elapsed time since the last time the mobile
station made call origination, call termination or location
registration. The priority of FIG. 14 is priority (rank) for each
mobile station to be selected as the mobile station whose
subscriber service information is to be deleted. In the example of
FIG. 14, since the state of mobile stations A and B is attach state
and the state of mobile stations C and D is detach state, the
mobile stations C and D have higher priority than the mobile
stations A and B. Between mobile stations having the same state, a
mobile station having longer elapsed time has higher priority.
Therefore, the mobile station D has higher priority than the mobile
station C, and the mobile station B has higher priority than the
mobile station A.
[0065] The mobile station whose subscriber service information is
to be deleted can be selected in consideration of communication
state of mobile stations. In general, when subscriber service
information is deleted, and if the mobile station corresponding to
the deleted subscriber service information is in communication, the
communication is disconnected unconditionally. Therefore, as the
mobile station whose subscriber service information is to be
deleted, a mobile station which is not in communication can be
selected. That is, when a switching station intends to select a
mobile station as the mobile station whose subscriber service
information is to be deleted, and if the mobile station is in
communication, the switching station can select another mobile
station as the mobile station whose subscriber service information
is to be deleted. Communication state of each mobile station can be
managed, for example, at VLR or a service control unit performing
control regarding call processing and service to subscriber, by
having management table of communication state.
[0066] FIG. 15 is a diagram showing an example of inquiring
communication state of a service control unit, when the service
control unit manages the communication state. In this embodiment, a
service control unit is provided for each switching station. The
switching station 111 inquires communication state of each mobile
station of a service control unit 161, receives its response from
the service control unit 161, and selects in consideration of the
response, the mobile station whose subscriber service information
is to be deleted.
[0067] FIG. 16 is a diagram for explaining an example of selecting
a mobile station whose subscriber service information is to be
deleted. In the example of FIG. 16, since the communication state
of mobile stations A and D is not in communication and the state of
mobile stations B and C is in communication, the mobile stations A
and D have higher priority than the mobile stations B and C. That
is, one of the mobile stations A and D is selected as the mobile
station whose subscriber service information is to be deleted.
[0068] The switching station-registers, when it resisters
subscriber service information, the subscriber service information
as subscriber service information possible to be overwritten
(subscriber service information possible to be deleted when the
maximum number of accommodated users has been reached in VLR) or as
subscriber service information impossible to be overwritten, and
selects the subscriber service information to be overwritten from
(pieces of) subscriber service information possible to be
overwritten. For example, it is possible to register subscriber
service information of a subscriber who frequently uses
communication as subscriber service information impossible to be
overwritten, and register subscriber service information of a
subscriber who rarely uses communication as subscriber service
information possible to be overwritten.
[0069] FIG. 17 is a diagram showing an example of preparing an area
possible to be overwritten and an area impossible to be overwritten
in a subscriber management memory of VLR. The switching station 111
registers subscriber service information possible to be overwritten
in an area 181 possible to be overwritten, and registers subscriber
service information impossible to be overwritten in an area 182
impossible to be overwritten.
Others
[0070] In the foregoing description, a case where subscriber
service information about a mobile station is acquired from a
switching station in whose coverage area the mobile station has
been located is described. However, the subscriber service
information can be acquired from HLR when location registration
other than the first location registration is made as well as when
the first location registration is made.
[0071] FIG. 18 is a diagram showing an example of processing
corresponding to the example of processing shown in FIG. 9 when a
location registration request is made, in a case where subscriber
service information is acquired from an HLR. When the switching
station 111 having the VLR 121 which has accepted the maximum
number of subscribers receives a location registration signal from
the mobile station 150 (in S111 of FIG. 18), the switching station
111 registers subscriber location information about the mobile
station 150 in the HLR 140, and receives subscriber service
information about the mobile station 150 from the HLR 140 (in
S112). Then, the switching station 111 deletes one of pieces of
subscriber service information presently registered in the VLR 121
and registers the subscriber service information about the mobile
station 150 in the VLR 121 (in S113). In this way, location
registration processing is normally completed (in S114).
[0072] According to the present invention, as described above, a
subscriber can acquire service without dependence on the
accommodation capacity of a management unit which manages
subscriber information. That is, the system allows location
registration, call origination and call termination processing for
subscribers as an excess over the maximum number of accommodated
subscribers, and more comfortable communication environment can be
provided to subscribers by effectively using VLR memories.
[0073] The present invention has been described in detail with
respect to preferred embodiments, and it will now be apparent from
the foregoing to those skilled in the art that changes and
modifications may be made without departing from the invention in
its broader aspects, and it is the intention, therefore, in the
appended claims to cover all such changes and modifications as fall
within the true spirit of the invention.
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