JP2001078244A - Mobile communication method and mobile communication control station - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mobile communication method by which the number of radio channels occupied by a roaming terminal during communications can be reduced. SOLUTION: In this mobile communication method, when mobile stations A1-A3 belonging to a system A move to a radio service area 4 of a different system D, the mobile stations A1-A3 use a roaming terminal group number A in the system D to make group communications within a roaming terminal group belonging to the same system A. When a radio channel request comes from any of the mobile stations A1-A3, a radio channel number is assigned to the group number A for the roaming terminals to conduct group communications. Mobile stations B1-B3 use a group number B for roaming terminals and mobile stations C1-C3 use a group number C for roaming terminals to conduct group communications.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication system in which a mobile station moves freely within a plurality of radio service areas managed by a plurality of control stations. The present invention relates to a mobile communication method and a mobile communication control station when moving to a wireless service area managed by a control station.

[0002]

2. Description of the Related Art In a conventional mobile communication system, a mobile station in a plurality of radio service areas is controlled by a control station which manages each radio service area. In the wireless service area,
At least one base station is provided, and the control station controls the mobile station via the base station. The base station mainly performs radio management (RT), and performs radio communication with mobile stations or radio relay between mobile stations. On the other hand, the control station mainly performs mobility management (MM) and call control (CC), and may also include connection control between a mobile radio line and a terrestrial line. The base station and the control station may be integrated.

[0003] A mobile station initially registers with one control station. When the mobile station moves out of the wireless service area of the control station with which the mobile station has been initially registered and communicates using a control station in a different wireless service area, a roaming wireless channel is allocated from the destination control station. Receive. The destination control station performs roaming to allocate a roaming radio channel to the mobile station (roaming terminal: roamer).

FIG. 7 is an explanatory diagram of a conventional mobile communication method. In the figure, 1 is a wireless service area of the system A, 4 is a wireless service area of the system D,
It is managed by the control station of the system D. 5 is a wireless channel of the system D. Mobile stations A1 to A4 belonging to system A
However, when moving to a wireless service area 4 of a different system D, the mobile stations A1 to A4 communicate using the wireless channel 5 of the system D as roaming terminals of the system D. In the illustrated example, one roaming wireless channel number is assigned to communication between mobile stations A1 and A2, and another roaming wireless channel number is assigned to communication between mobile stations A3 and A4. Assigned. As described above, the roaming terminal occupies the wireless channel for each individual communication.

[0005] In particular, in the mobile communication system for business use, the ability to accept the support by roaming from a surrounding area or the like in an emergency such as a disaster is important. However, the channel capacity of the commercial mobile communication system is small (1 to 4).
ch) and medium capacity (5 to 8 ch), the number of radio channels that can be occupied by the roaming terminal is small.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and relates to a mobile communication method and a mobile communication control station for reducing the number of radio channels occupied by roaming terminals during communication. Things. Further, the present invention relates to a mobile communication method and a mobile communication control station corresponding to a plurality of types of roaming terminals.

[0007]

According to the present invention, there is provided a mobile communication method for a mobile station moving in a plurality of radio service areas managed by a plurality of mobile communication control stations. The mobile station is assigned a group number by the mobile communication control station at a different destination from the mobile communication control station that initially registered the mobile station, and a radio channel number is assigned corresponding to the group number. , And performs group communication using the wireless channel of the wireless channel number. Therefore, it is possible to allocate a wireless channel corresponding to the group number to a mobile station that has moved from the wireless service area of the mobile communication control station that has been initially registered. The number is reduced.

[0008] According to the second aspect of the present invention, one of a plurality of mobile communication control stations managing a plurality of radio service areas, the location registration including an individual number from the mobile station. A position registering means for receiving a request, assigning a group number when the mobile station is not initially registered in the one mobile communication control station based on the individual number, and notifying the mobile station of the group number; Receiving a wireless channel request including the group number from the mobile station, assigning the same wireless channel number to all the mobile stations to which the group number is assigned, and assigning the wireless channel number to the group number. Wireless channel allocating means for notifying all the received mobile stations. Therefore,
Since a mobile station that has moved from the initially registered mobile communication control station's wireless service area can be assigned a wireless channel that corresponds to the group number, the number of wireless channels that the mobile station occupies when communicating at the destination is reduced. Reduce. Further, even if a plurality of mobile stations move at different times from the wireless service area of the initially registered mobile communication control station, a group number can be easily assigned to the moving mobile station.

According to a third aspect of the present invention, in the mobile communication control station according to the second aspect, the group number is assigned according to the mobile communication control station that initially registered the mobile station. . Therefore, the initially registered control stations can perform group communication in units of the same type of mobile station. As a result, a group of mobile stations can be freely organized by an assignment method of assigning a group number to the initially registered control station. For example, independent group communication can be performed for each unit described above, and independent group communication can be performed for each mobile station of the same business entity.

According to a fourth aspect of the present invention, one of the plurality of mobile communication control stations which manages a plurality of radio service areas, wherein the one mobile communication control station has an initial setting. Monitoring means for detecting a no-communication state of a mobile station to which a certain group number is assigned by the one mobile communication control station without being registered; A group number canceling unit that cancels the assignment of the certain one group number to all mobile stations to which the number is assigned, and notifies all mobile stations to which the certain one group number is assigned of the cancellation. Things. Therefore, a group number is assigned to a mobile station that has moved from the wireless service area of the initially registered mobile communication control station, but when it is estimated that communication is no longer necessary, the group number is released. be able to. As a result, even if the total number of prepared group numbers is small, this can be used repeatedly.

[0011] In the invention described in claim 5, one of the plurality of mobile communication control stations that manages a plurality of radio service areas, wherein the one mobile communication control station has an initial setting. Monitoring means for detecting that all mobile stations which have not been registered and have been assigned one group number by the one mobile communication control station are out of the wireless service area of the one mobile communication control station; In addition, according to the out-of-service detection output of the monitoring means, the assignment of the certain one group number to all the mobile stations to which the certain one group number is assigned is released, and the assignment of the certain one group number is all Group number canceling means for notifying the mobile station of cancellation. Therefore, a group number is assigned to a mobile station that has moved from the wireless service area of the initially registered mobile communication control station, but when it is estimated that communication is no longer necessary, the group number is released. be able to. As a result, even if the total number of prepared group numbers is small, this can be used repeatedly.

[0012]

FIG. 1 is an explanatory diagram of a mobile communication method according to the present invention. FIG. 1A is an explanatory diagram when one type of roaming terminal group is located, and FIG. 1B is an explanatory diagram when a plurality of types of roaming terminal groups are located. In the figure, the same parts as those in FIG. 7 are denoted by the same reference numerals. 2 is a wireless service area of system B, 3 is a wireless service area of system C, and wireless service areas 1 to 4 are managed by control stations of different systems A to D, respectively. The mobile stations A1 to A3 are initially registered in the control station of the system A and belong to the system A. Mobile stations B1 to B3
Are initially registered in the control station of the system B and belong to the system B. The mobile stations C1 to C3 are initially registered in the control station of the system C and belong to the system C. System D
Mobile stations initially registered with the control station are not shown.

In FIG. 1A, when the mobile stations A1 to A3 belonging to the system A have moved to the radio service area 4 of a different system D, the mobile stations A1 to A3 become roaming terminal group numbers A in the system D. Using
One group communication is performed within the roaming terminal group belonging to the same system A. When a radio channel request is received from any one of the mobile stations A1 to A3, the mobile stations A1 to A4 belonging to the system A are assigned to the roaming terminal group number A.
For example, simplex group communication is performed between A3. Therefore, since the number of occupied radio channels is one for each group, the number of occupied radio channels is reduced as compared with the related art.

As shown in FIG. 1B, when the mobile stations B1 to B3 belonging to the system B move to the radio service area 4, the mobile stations B1 to B3 enter the group number for the roaming terminal of the system D. B, the communication within the roaming terminal group belonging to the same system B is performed by one group communication. Further, the mobile stations C1 to C1 belonging to the system C
When the mobile station C3 also moves to the wireless service area 4, the mobile stations C1 to C3 use the roaming terminal group number C of the system D to perform communication in the roaming terminal group belonging to the same system C by one group communication. .

Up to 2 roaming radio channels
In the case of assigning channels, one roaming terminal group number B and C can be assigned one wireless channel number of wireless channel 5, respectively, as shown in the figure.
Group communication can be performed independently of each other between the mobile stations B1 to B3 belonging to the system B and between the mobile stations C1 to C3 belonging to the system C. Each mobile station B1-B3, C1-C3, which is a roaming terminal, has a roaming terminal group number B, C,
The roaming terminals belonging to the respective systems B and C can be called to perform group communication on the respective wireless channels. As a result, it is possible to support roaming terminals of a plurality of systems and reduce the number of radio channels allocated for roaming.

1A and 1B, the roaming terminal group number can be assigned when a roaming mobile station (roaming terminal) requests location registration. The roaming terminal transmits a unique number unique to itself to the control station via the base station at the time of the location registration request. When the control station determines that the individual number belongs to a mobile station that does not belong to its own system, it adds a roaming terminal group number to the roaming terminal when accepting location registration.

Thereafter, when a roaming terminal belonging to the same system as the roaming terminal to which the roaming terminal group number has already been assigned issues a location registration request, the same roaming terminal group number is assigned when accepting the location registration. On the other hand, if a roaming terminal belonging to a different system subsequently requests a location registration,
Assign an unused roaming terminal group number. The assigned roaming terminal group number is released when the roaming terminal group is out of the service area or when communication is not performed for a certain period of time.

The roaming terminal group number is
It is not necessary to prepare for the number of control stations to be initially registered, but it is necessary to prepare for the number of roaming terminals that accept location registration. Limiting the number of roaming terminal groups that accept location registrations reduces the total number of roaming terminal group numbers to be prepared, and the probability that when a roaming terminal requests wireless channel allocation, congestion will prevent it from being allocated. Can be reduced.
It is not necessary to prepare the number of radio channels equal to the total number of roaming terminal group numbers. It is only necessary to assign a wireless channel number corresponding to a roaming terminal group number when a request for wireless channel assignment is made from a roaming terminal group.

The above description has been made on the assumption that a different roaming terminal group number is assigned to each control station to which a mobile station belongs. However, the same roaming terminal group number may be allocated to all roaming terminals by allocating the same roaming terminal group number to all control stations to be initially registered. Alternatively, the control stations to which the mobile stations belong may be divided into groups according to the area of the radio service area, and the same roaming terminal group number may be assigned to the control stations belonging to each group.

The above description is based on the premise that one business entity (industry) has a plurality of control stations having different wireless service areas, and that a mobile station roams in a network where it moves between the wireless service areas. However, with regard to inter-network roaming, which enables a mobile station to connect to control stations of different business entities (for example, police and fire departments), communication protocols and the like are unified between different business entities, and individual numbers of mobile stations are different. To
This is possible if it is unique between different entities. In this case, the wireless service area of each business entity may partially or entirely overlap geographically. Even if the initially registered control stations are different, if these control stations belong to the same business entity, assign the same roaming terminal group number to the mobile stations initially registered to these control stations. Is also good. In this way, mobile stations belonging to the same business entity can perform group communication.

As described above, the roaming terminals can be freely organized by the allocation method of assigning roaming terminal group numbers to a plurality of types of roaming terminals classified according to a predetermined standard. That is, it is possible to perform group communication for each type, or to perform one group communication with the entire roaming terminal.

FIG. 2 is a schematic block diagram of a mobile station which implements the mobile communication method of the present invention. FIG. 3 is a schematic configuration diagram on the control station side for realizing the mobile communication method of the present invention. 2, reference numeral 4 denotes a wireless service area of the system D shown in FIGS. 7 and 1, and 11 denotes a mobile station (A1) belonging to the system A.
It is. In the mobile station 11, reference numeral 12 denotes a location registration unit, 13 denotes a memory, 14 denotes a group communication unit, 15 denotes an individual communication unit, and 16 denotes a transmission / reception unit. Reference numeral 17 denotes a base station of the system D, and reference numeral 21 denotes a control station of the system D.

An example in which the mobile station A1 moves to the radio service area 4 of the system D and communicates as a roaming terminal will be described. The control station 21 of the system D
Of the mobile station in the wireless service area 4. One system D has at least one base station 17;
Each base station 17 manages one wireless zone. If there is one base station 17, the wireless zone is the wireless service area 4.

The location registration unit 12 moves from the wireless service area 1 of the system A in which the mobile station 11 belonging to the system A has made the initial registration, and
To the control station 21 of the system D via the control unit 21. On the other hand, a position registration acceptance signal including the roaming terminal group number is received from the control station 21 of the system D via the base station 17,
The position registration unit 12 receives the assignment of the roaming terminal group number, and stores it in the memory 13. System D
When the location registration rejection signal is received from the control station 21 of
Communication is not possible in the wireless service area 4.

The memory 13 stores its own individual number, the assigned roaming terminal group number, the wireless channel number, and the like. The group communication unit 14 includes a memory 13
Group communication using the roaming terminal group number and the wireless channel number stored in the. Also, in the wireless service area 1 of the system A in which the mobile station 11 belonging to the system A has been initially registered, the same group communication as in the related art is possible. The group communication itself is known, for example, "900 MHz band simple radio station radio equipment (personal radio) standard RCR STD-11" Japan Radio Industry Association, "Public business digital mobile communication system standard"
RCR STD-39B "is known by the Association of Radio Industries and Businesses. In addition to group communication between mobile stations relaying a base station, group selection calling communication for a plurality of mobile stations from a command console or a communication console is also possible.

The individual communication unit 15 performs individual communication between the command console, the communication console and the mobile station, and individual communication between the mobile stations relaying the base station. The wireless service area 1 of the system A initially registered by the mobile station 11 belonging to the system A
Can communicate individually. The transmission / reception unit 16 conceptually shows a high-frequency unit, a baseband unit including a modulation / demodulation unit, a transmission control unit, and the like as one block.

On the other hand, the control station 21 of the system D shown in FIG.
Among them, 22 is a transmitting / receiving unit, 23 is an initial registration unit, 24
Is a home memory (HLR: home location register), 25 is a terminal discriminating unit, 26 is a home memory of another control station, 27 is a group number allocating unit, 28 is a wireless channel number allocating unit, 29 is a notifying unit, and 30 is a wireless unit. Channel number /
A group number release unit, 31 is a memory, 32 is a group communication unit, and 33 is an individual communication unit.

The transmission / reception unit 22 conceptually shows transmission control with the base station 17 as one block. The initial registration unit 23 receives the individual number from the mobile station and registers it in the home memory 24 at the time of the initial registration.
The home memory 24 stores the individual number of the mobile station initially registered in the control station 21 of the system D. Terminal discriminator 2
Reference numeral 5 refers to information registered in the home memory 24 based on the individual number included in the location registration request signal transmitted by the mobile station. If the individual number transmitted from the mobile station is registered in the home memory 24, the mobile station is a mobile station initially registered in the system D.

In the illustrated example, since the mobile station 11 belongs to the system A, this individual number is not registered in the home memory 24. In this case, the terminal discriminating unit 25 accesses another control station via a common channel signal network or the like (not shown) and refers to the home memory 26 of the other control station, so that the transmitted individual number A search is made to see if the data is initially registered in the control station of the system. It can be seen that the individual number of the mobile station 11 belonging to the system A is stored in the home memory of the control station of the system A.
5 obtains the system ID of the control station of the system A. As a method of initial registration of a mobile station and a search for a control station initially registered by the mobile station, for example, “Mobile Personal Intelligence”, edited by Takeshi Hattori and three others (1996.9.
5) Kyoritsu Shuppan Co., Ltd. Known as 34, 35, 39, 40, etc.

When the terminal determining unit 25 determines that the mobile station is the mobile station (roaming terminal) to which the mobile station has temporarily moved from the individual number of the mobile station that has made the location registration request, the above-described search is performed. By doing so, the system ID of this mobile station is obtained. The group number allocating unit 27 allocates a vacant roaming terminal group number to the system ID. The memory 31 has a roaming terminal registration table in which data of the roaming terminal, such as an individual number, a system ID, a roaming terminal group number, and a wireless channel number, are registered. At this time, the individual number of the mobile terminal that has made the location registration request, the system ID of the control station that the mobile terminal has initially registered, and the assigned roaming terminal group number are written.

Thereafter, the system ID of the control station initially registered by this mobile station is also obtained from the individual number of the mobile terminal that has made a new location registration request. If this system ID is already the same system ID registered in any one of the roaming terminals in the above-described roaming terminal registration table in the memory 31, this mobile station includes:
The same roaming terminal group number assigned in accordance with this system ID is assigned, and the individual number of the mobile terminal that has newly requested location registration and the initial registration of this mobile terminal are registered in the roaming terminal registration table described above. The system ID of the control station and the assigned roaming terminal group number are written.

When a radio channel request signal is transmitted from the mobile station stored in the home memory 24 at the time of calling, the radio channel number allocating section 28 allocates an empty radio channel number in the same manner as in the prior art. . on the other hand,
The radio channel number allocating unit 28 transmits
When the wireless channel request signal is transmitted at the time of calling, the roaming terminal group number included in the wireless channel request signal is input, and the roaming terminal registration table is referenced. If the roaming terminal group number has not yet been assigned a wireless channel number, a wireless channel number is assigned corresponding to the roaming terminal group number, and the wireless channel number is added to the roaming terminal registration table described above. Write. At this time, if another roaming terminal has the same roaming terminal group number, the same wireless channel number is written.

When a group number for roaming terminal is allocated by the group number allocating unit 27 at the time of the position registration request, the notifying unit 29 transmits a position registration accepting signal including the roaming terminal group number via the base station 17. , To the mobile station 11 belonging to the system A. At this time, when the control station 21 of the system D does not assign a roaming terminal group number, the location registration rejection signal is transmitted via the base station 17 to the mobile station 11 belonging to the system A.
Send to When a wireless channel number is assigned by the wireless channel number assigning unit 28 at the time of requesting a wireless channel at the time of calling, a wireless channel designation signal including the wireless channel number is transmitted to the base station 17 together with the roaming terminal group number. , To all mobile stations. At this time, when the control station 21 of the system D does not allocate a wireless channel number, the control station 21 transmits a wireless channel rejection signal to the mobile station 11 belonging to the system A via the base station 17.

The radio channel number / group number de-assignment unit 30 receives the disconnection request from the mobile station, the expiration of the communication time limit, or the non-communication state for more than the first predetermined time, for example, the carrier of the mobile station. When there is no radio channel number, the assignment of the wireless channel number is released. When the assignment of the wireless channel number to the roaming terminal is released, the wireless channel number of the released roaming terminal is deleted from the roaming terminal registration table. To resume communication, the mobile station from which the assignment of the wireless channel number has been canceled makes a wireless channel request again.

The radio channel number / group number de-allocation unit 30 also provides a second predetermined time between mobile stations to which roaming terminal group numbers have been assigned, or between a command station or control station and a roaming terminal. If it is presumed that communication is not being performed, such as in the above-mentioned non-communication state, or if all the mobile stations to which the roaming terminal group number has been assigned, the radio service area 4 of the system D
When it is detected that the roaming terminal is out of the service area, the allocation of the roaming terminal group number itself is released. At this time, from the roaming terminal registration table in the memory 31, all data of all roaming terminals to which the roaming terminal group number has been assigned are deleted. The mobile station to which the assignment of the roaming terminal group number has been released needs a position registration request again to resume communication. The group communication unit 32 executes a transmission connection control procedure during group communication and the like. The individual communication unit 33 executes a connection control procedure during individual communication and the like.

Next, the operation of the mobile station and the control station according to the mobile communication method of the present invention will be described. Standard RC mentioned above
It is based on the communication sequence of R STD-39B. The operation is divided into an initial registration phase, a location registration phase, a communication link establishment phase, a communication phase, a communication link release phase, a group communication setting release phase of roaming terminals, and the like. Here, the description will focus on the specific operation related to the group communication of the roaming terminal using the roaming terminal group number.

In the initial registration phase, when a mobile station having an individual number performs initial registration with one control station, the control station registers the individual number of the mobile station in a home memory. The mobile station may receive and store the system ID of the control station. The mobile station moves from the wireless service area of the control station that has performed the initial registration to a wireless communication service area managed by another control station. The mobile station transmits a location registration request including the individual number to the destination control station via the base station.

The mobile station may receive the system ID of the destination control station from the destination control station in advance. In this case, this system ID
Depends on whether the mobile station matches the stored system ID notified and stored by the control station at the time of the initial registration, the current wireless service area in which the mobile station is located is determined by the wireless service of the control station that performed the initial registration. Area (home area)
Or a different roaming area.

When it is determined that the area is the home area, the process proceeds to the normal home area control. When it is determined that the area is the roaming area, it may be determined whether the roaming area can be roamed.
In this case, the system IDs of all control stations and a reference table indicating whether roaming is possible or not in the wireless service area of the control station of the system ID are stored in the memory of the mobile station. If roaming is possible in the roaming area based on this reference table, a location registration request including the individual number of the mobile station is transmitted to the control station via the base station. If roaming is not possible in that area, location registration is abandoned as out of service area.

FIG. 4 is a flowchart for explaining the location registration request phase in the mobile communication method of the present invention. In S41, the mobile station transmits a location registration request signal including the individual number to the control station of the movement destination. The control station receives the position registration request signal in S51 while performing the normal processing, and proceeds to S52. In S52, it is determined whether the mobile station is a home terminal or a roaming terminal based on the individual number of the mobile station included in the location registration request signal. When the individual number has been registered in the home memory of the control station, it is determined that the terminal is a home terminal.
If the mobile station has not been registered, it searches the home memory of another control station based on the individual number, detects the control station with which the mobile station has performed initial registration, and detects the system of the control station with which the initial registration has been performed. Receive the ID.

If the terminal is a home terminal, the process proceeds to S53, and thereafter, shifts to home terminal control. If the terminal is a roaming terminal, the process proceeds to S54 to determine whether a roaming terminal group number can be assigned. If the mobile station restricts the total number of groups permitted to perform roaming terminal group communication, and if the total number has already exceeded the limit, the process proceeds to S60, and the location registration rejection signal is sent to the mobile station that has made the location registration request. And returns to the normal control state. The mobile station that has received the location registration rejection signal discards the location registration request in S43 as out of service.

On the other hand, if the roaming terminal group number can be assigned in S54, the process proceeds to S55, and it is determined whether or not the roaming terminal is of the already assigned type.
Here, the type is determined based on, for example, whether or not the control station with which the mobile station has performed initial registration is the same. The roaming terminal registration table stored in the memory of the control station is referred to, and the roaming terminal that has newly requested the location registration is initially registered in the system ID of the roaming terminal already registered in the roaming terminal registration table. Is determined based on whether or not there is the same system ID.

If it is determined in step S55 that the roaming terminal is not a roaming terminal of an already-assigned type, the process proceeds to step S57, and it is determined whether or not the roaming terminal group number has a free space.
The total number of roaming terminal group numbers is limited. If there is no vacancy, the process proceeds to S60, where a location registration rejection signal is transmitted to the mobile station. If there is room, S5
Then, the process proceeds to step S8, where one of the vacant roaming terminal group numbers is assigned, the roaming terminal is registered in the roaming terminal registration table, and the individual number, system ID, and roaming terminal group number are written. The process proceeds, and a location registration acceptance signal including the roaming terminal group number is transmitted to the mobile station that has made the location registration request. The mobile station
At 42, the location registration acceptance signal is received, the roaming terminal group number is stored in the memory of the mobile station, and the mobile station enters a standby state.

On the other hand, if it is determined in S55 that the roaming terminal is a roaming terminal of the already assigned type, the process proceeds to S56, and the roaming terminal group number already assigned in correspondence with the system ID is registered in this time. It is also assigned to the roaming terminal that made the request. Then, this roaming terminal is registered in the roaming terminal registration table, the individual number, the system ID, and the roaming terminal group number are written, and the process proceeds to S59.
In S59, a location registration acceptance signal including the roaming terminal group number is transmitted to the mobile station that has made the location registration request.

FIG. 5 is a flowchart for explaining a communication link establishment phase in the mobile communication method of the present invention. The mobile station transmits a radio channel request signal including the roaming terminal group number from the standby state in S71 at the time of calling. The control station receives the wireless channel request signal, identifies the roaming terminal group number, and proceeds to S82. In S82, it is determined whether there is a wireless channel number that can be assigned to the roaming terminal. If there is an allocatable wireless channel, the process proceeds to S83, one of the available wireless channel numbers is designated, and the roaming terminal group number and the wireless channel number are included for all the mobile stations. Transmit the radio channel designation signal.

The mobile station that has made the wireless channel request returns to S72.
Receives a wireless channel designation signal, performs frequency switching based on the wireless channel number, and enters an access permitted state. Also, a mobile station that has not made a wireless channel request but has the same roaming terminal group number also
In step 1, a wireless channel designation signal is received in a standby state, frequency switching is performed based on the wireless channel number, and an access permission state is set. If it is determined in S82 that there is no wireless channel that can be assigned to the roaming terminal, the process proceeds to S84, and a wireless channel rejection signal including the group number is transmitted to the mobile station that has made the wireless channel request. In S73, the mobile station that has made the wireless channel request receives the wireless channel rejection signal and enters a standby state.

The communication phase is the same as the conventional one, and the roaming terminal performs group communication with the same type of roaming terminal group using the assigned roaming terminal group number. In the case of simplex communication, in the access permission state, transmission is performed when the press talk switch of one mobile station is turned on, and a transmission right release signal is transmitted to the control station when the press talk switch is turned off. . Other mobile stations in the group perform a receiving operation. Transmission right control when the press talk switches of a plurality of mobile stations are turned on is the same as the conventional one. In the communication link release phase, in addition to the case where the mobile station requests a disconnection, when the communication time limit expires,
In some cases, a non-communication state exceeding a predetermined time is detected, and a non-communication disconnection signal is transmitted from the base station to release the assignment of the wireless channel, as in the related art.

FIG. 6 is a flowchart for explaining the group communication setting release phase of the roaming terminal in the mobile communication method of the present invention. The control station monitors, for each roaming terminal group, whether or not a non-communication state has continued for a predetermined time or more for each roaming terminal group. At the same time, whether or not all the mobile stations belonging to one roaming terminal group number have gone out of the service area is monitored for each roaming terminal group. More specifically, a paging call can be made to the mobile station having the roaming terminal group number, and the mobile station can be monitored by receiving a response from the mobile station having the roaming terminal group number. If there is no response from one of the mobile stations having a certain roaming terminal group number, it is estimated that all the mobile stations belonging to this roaming terminal group number have gone out of the service area.

In S101 during the normal control, when it is determined that the non-communication state has not continued for a predetermined time or more and that all the mobile stations have not gone out of the service area, the control returns to the normal control state. When it is determined that the non-communication state has continued for a predetermined time or more, or that all the mobile stations have gone out of the service area, S1
The process proceeds to 02, the allocation of the roaming terminal group number is released, and the roaming terminal group number is made empty. From the roaming terminal registration table,
The registration of the mobile station to which the roaming terminal group number is assigned is deleted, and a roaming terminal group number assignment release signal is transmitted to the mobile station to which the roaming terminal group number is assigned.

When the mobile station to which the roaming terminal group number has been assigned receives the deallocation signal, it deletes the stored roaming terminal group number. Also,
The mobile station to which the roaming terminal group number has been added, and because it has already moved out of the service area, the mobile station that cannot receive the deassignment signal has moved out of the service area of the previous control station, for example, By receiving the system ID of another control station, when it is recognized, the roaming terminal group number is deleted.

In the above description, the condition for releasing the assignment of the roaming terminal group number satisfies one of the condition that the non-communication state has continued for a predetermined time or more and the determination that all the mobile stations have gone out of the service area. It was a condition. Alternatively, you may have to satisfy both at the same time,
Either one may be the condition. In addition, if there is a condition that allows the roaming terminal to estimate that it is no longer necessary to perform group communication, this condition may be used. Also, if the total number of roaming terminal group numbers is sufficiently large, it is not necessary to frequently release the roaming terminal group number assignment, and the above-described group communication setting release phase is not required.

In the above description, the group communication between the roaming terminals has been described. However, the group communication between the command console and the control console of the base station and the roaming terminal can be performed similarly to the conventional group communication. In the above description, at the time of the location registration request, the destination control station has obtained the system ID of the control station with which the mobile station has initially registered based on the individual number received from the mobile station. Instead, if the system ID of the initially registered control station is used as the system code in the mobile station number, when registering the location with the destination control station, the destination control station can use this system ID. From the code, it is possible to identify whether the mobile station is a home terminal or a roaming terminal. At the same time, the registered control station can be immediately known.

[0053]

According to the present invention, as apparent from the above description, there is an effect of reducing the number of radio channels occupied by the roaming terminal during communication. Although there are roaming terminals having the same business type but different business areas and different business types, the present invention can support a plurality of types of roaming terminals and can be accepted in a system of one wireless service area. A roaming terminal can be freely organized by an allocation method of allocating roaming terminal group numbers to a plurality of types of roaming terminals. In other words, performing group communication for each type,
Group communication can be performed by the entire roaming terminal. In addition, communication suitable for a roaming terminal can be performed by effectively using group communication of an existing mobile communication system.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a mobile communication method of the present invention.

FIG. 2 is a schematic configuration diagram on the mobile station side for realizing the mobile communication method of the present invention.

FIG. 3 is a schematic configuration diagram on the control station side for realizing the mobile communication method of the present invention.

FIG. 4 is a flowchart for explaining a location registration request phase in the mobile communication method of the present invention.

FIG. 5 is a flowchart for explaining a communication link establishment phase in the mobile communication method of the present invention.

FIG. 6 is a flowchart for explaining a group communication setting release phase of a roaming terminal in the mobile communication method of the present invention.

FIG. 7 is an explanatory diagram of a conventional mobile communication method.

[Explanation of symbols]

1 wireless service area of system A, A1 to A4 mobile station belonging to system A, 2 wireless service area of system B, B1 to B3 mobile station belonging to system B, 3
Radio service area of system C, C1 to C3 mobile stations belonging to system C, 5 radio channels, 11 mobile stations belonging to system A, 17 base stations, 21 control station of system D

Claims (5)

[Claims] 1. A mobile communication method for a mobile station moving in a plurality of wireless service areas managed by a plurality of mobile communication control stations, wherein the mobile station initially registers the mobile station. A group number is assigned by the mobile communication control station at a different destination from the group, a wireless channel number is assigned corresponding to the group number, and group communication is performed using a wireless channel of the wireless channel number. Characteristic mobile communication method. 2. A mobile communication control station among a plurality of mobile communication control stations that respectively manage a plurality of wireless service areas, wherein the mobile communication control station receives a location registration request including an individual number from the mobile station, and Location registering means for assigning a group number and notifying the mobile station of the group number when the mobile station is not initially registered in the one mobile communication control station; And assigning the same wireless channel number to all the mobile stations to which the group number is assigned, and notifying the wireless channel number to all mobile stations to which the group number is assigned A mobile communication control station, comprising: 3. The mobile communication control station according to claim 2, wherein the group number is assigned according to the mobile communication control station that initially registered the mobile station. 4. A mobile communication control station that manages a plurality of wireless service areas, wherein the mobile communication control station is not initially registered with the one mobile communication control station and the one mobile communication control station is not registered. Monitoring means for detecting a non-communication state of a mobile station to which a certain group number is assigned by a communication control station; and all mobile stations to which the certain one group number is assigned, based on a no-communication detection output of the monitoring means. Mobile communication, comprising: a group number canceling unit for canceling the assignment of the certain group number to a station and notifying the cancellation to all the mobile stations to which the certain group number is assigned. Control station. 5. A mobile communication control station of a plurality of mobile communication control stations that respectively manage a plurality of wireless service areas, wherein the mobile communication control station is not initially registered with the one mobile communication control station and the one mobile communication control station is not registered. Monitoring means for detecting that all the mobile stations to which a certain group number is assigned by the communication control station are out of the service area of the one mobile communication control station; and detecting out-of-service area of the monitoring means. According to the output, the assignment of the certain group number to all the mobile stations to which the certain group number is assigned is released, and the release to all the mobile stations to which the certain one group number is assigned is released. A mobile communication control station, comprising: a group number release means for notifying.