JPS6052131A - Switching system of mobile communication system - Google Patents

Abstract

PURPOSE:To eliminate an outgoing/incoming call reception disabling time of a mobile station by making a channel switching with the transmission of a channel switching signal during talking while systems are in talking. CONSTITUTION:Even when a mobile station 2 transits to a service area Y where systems A and B are overlapped while the mobile station 2 receives a channel for incoming control by the system A, the mobile station 2 conducts no system switching. On the other hand, the talking channel from the system A to the system B is switched by detecting the talking state of the mobile station 2 through the use of the talking channel of the system A by the outgoing or incoming connection in the area Y in the system. Thus, the mobile station 2 eliminates the outgoing/incoming reception disabling time through the level detection of the incoming control channel of the system B.

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention is directed to a mobile communication system such as a car phone,
When there are multiple different systems that use the same frequency band but do not share the frequency, and the service areas of each system are mixed, a mobile station that is within the service area of system A, which is the first system, The present invention relates to a system switching method for switching the communication method in a mobile station from that of system A to that of system B when the mobile station moves into the service area of system B, which is a second system.

[Background of the invention]

Although mobile communication systems such as car telephones are already in practical use, conventional such systems are likely to reach their limits in terms of subscriber capacity.

Therefore, when a new high-capacity mobile communication system is developed, both systems may coexist depending on the region.

In this case, if the two systems are systems A and B, then systems A and B are different mobile communication systems that use the same frequency band and do not share the frequency, and channels can be switched between each system. , and there are mobile stations that can be connected to each system.

FIG. 1 is a schematic explanatory diagram of each service area of systems A and H. In the figure, A indicates a service area of system A, B indicates a service area of system B, Y indicates an area where both service areas overlap, 1 indicates a wireless base station, and 2 indicates a mobile station.

In FIG. 1, mobile station 2 is in the service area,
The incoming call control channel of the system A is received from the radio base station 1 and the call standby state is established.

Note that the radio base station 1 is connected to a radio control station (not shown) and Ii! i
The radio control station is further connected to the general telephone line network via a mobile station switching center (mobile telephone switching center), and allows calls between the mobile station and the general telephone line network. It goes without saying that this is possible when mobile station 2 moves in the direction of the dotted arrow and reaches the overlapping area Y.
If the mobile station 2 is to proceed to service area B via , it is necessary to switch the communication system in mobile station 2 from A to B at the point in time when the mobile station 2 is in the overlapping area Y.

In order to switch the communication system from system A to system B while the mobile station 2 is receiving the incoming call control channel, according to the conventional technology, the mobile station 2 periodically switches the incoming call control channel of system B to system B. Detects the reception level of system A, compares it with the reception level of the incoming call control channel of item A, and when the former exceeds the latter, switching is performed.

In such a method, it takes a lot of time to detect the reception level of the incoming call control channel of system B, and it is not possible to acquire a specific incoming call control channel and enter the standby state within a predetermined time. Since this is not possible, even if a call is received during this time,
Alternatively, even if a call is made, it cannot be accepted, and there is a drawback that there is a large amount of time during which calls cannot be accepted.

Furthermore, assuming that mobile station 2 in area A is in a call state using the communication channel of system A, if mobile station 2 travels in the direction of the dotted line arrow and enters area Y, which overlaps, then The communication channel is switched to the system B communication channel by switching the active channel, and thereafter the communication state is resumed using the system B communication channel. When the mobile station 2 terminates a call in the system B call system, the mobile station 2 does not know the system B call control channel to be received as it is, so the mobile station 2 selects one of the system B call control channels. The next call must be waited for by selecting the incoming call control channel with the highest electric field level and receiving it.

As mentioned earlier, the search time for the incoming call control channel corresponds to the time during which incoming and outgoing calls cannot be accepted and must be reduced as much as possible. Purpose] The present invention has been made in order to eliminate the drawbacks of the prior art as described above. Therefore, an object of the present invention is to provide The purpose of call reception is to provide a switching method for a mobile communication system that makes it possible to minimize downtime.

[Summary of the invention]

The outline of the present invention is as follows.

In Fig. 1, in order to detect as soon as possible that mobile station 2, which is in the standby state by system A, has entered the service area Y where systems A and B overlap, it is necessary to periodically receive calls from system B. The reception level of the control channel must be detected, and this must be based on the fact that it has been detected. In the present invention, while the mobile station 2 is receiving two incoming call control channels from system A, the service area Y where system A and system B overlap is
Even if the mobile station migrates to IC, the mobile station does not detect this and switch systems, and the mobile station can make a call using the communication channel of system A by making or receiving a call within the overlapping service area Y. When the state is entered, the system detects this and performs system switching by switching the busy channel from system A to system B. As a result, the 11IL station 2 can detect the level of the incoming call control channel of the system B, thereby eliminating the unavailable time for accepting incoming and outgoing calls.

Furthermore, in FIG. 1, mobile station 2 is in a talking state using system A, and system A and system B are communicating.
When the mobile station moves to area Y where the mobile station overlaps, the mobile station is switched to the communication method using system B by the above-described channel switching between the systems during a call, and the mobile station maintains the call state. When a call is terminated in a system B call system, the mobile station does not know the system B incoming call control channel to which it should return. In the present invention, the system side informs the mobile station of the incoming call control channel of system B to be returned to by signal transmission using the communication channel. As a result, the mobile station can eliminate the time during which it is unable to accept incoming and outgoing calls by performing level detection in order to search for an incoming call control channel of system B after the call ends.

[Embodiments of the invention]

Next, the present invention will be described in detail with reference to the drawings. FIG. 2 is an explanatory diagram showing the configuration of the base station side of system A and system B in the case of implementing the present invention. In the same figure, 1
a, 3a, 4. are a wireless base station, a focal line control station, and a mobile telephone switching center, respectively, which use the system AKi, and each has a 1 bt
3b-4b are wireless base stations to which system switching belongs, respectively;
Radio line control station, car telephone exchange, 5 is a common signal line,
It is.

Both systems At3B have a hierarchical structure including a base station, a control station, and a switching center, and the car telephone switching center is connected to the toll network. Also, car telephone exchange 4
4b stores the numbers of mobile stations subscribed to system A and their location information.
stores the numbers and location information of mobile stations subscribed to system B. A mobile station that can connect to both systems A and B connects mobile telephone exchanges 4a and 4b. The number and location information are managed between both exchanges via the common signal line 5.

FIG. 3 is a block diagram showing the circuit configuration of a mobile station connectable to both systems A and B. In the figure, 6a is a radio section for system A, 6b is a radio section for system B, 7 is a control section, 8a is a system A box, and OM18b is a system B radio section.
9 is an antenna, and 10 is a switching circuit.

As is clear from FIG. 3, there are separate wireless units for system A and system B, such as 6ap6b. ° Since the control unit 7 is composed of epu, ROM, RAM, Ilo, etc., most of it can be shared, but only the ROM that stores the program is separate for system A and system B as shown in 8a # 8b. established in

Both systems A and B have their own incoming call control channels, and the mobile station shown in FIG. 3 stores the numbers of all the incoming call control channels. Further, it is assumed that this incoming call control channel is allocated in units of radio channel control stations (in units of control zones).

Therefore, when a mobile station crosses a control zone and goes to another control zone, it switches the incoming call control channel and performs a location registration operation to notify the mobile telephone exchange of its location. That is, the base station manages the location of the mobile station in units of control zones.

FIGS. 4 and 5 are flowcharts showing functional operations performed on the base station side (system side) and mobile station side, including signal transmission and reception, according to the present invention.

There is no need to explain Fig. 4 again.

In FIG. 5, the operation (2), that is, whether or not the mobile station has moved and entered system B (overlapping area) can be determined by the location registration operation of the mobile station with the mobile telephone exchange. Further, the channel switching signal of O can be sent by temporarily interrupting the voice signal during a call and inserting it between them.

〔Effect of the invention〕

As explained above, according to the present invention, when switching between a plurality of different mobile communication systems using the same frequency band, channel switching during a call between systems is performed by transmitting a channel switching signal during a call. Therefore, there is an advantage that the time required for the mobile station to detect the reception level of the incoming control channel (the time during which it is impossible to accept incoming and outgoing calls) can be eliminated.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of each service area of two different mobile communication systems, FIG. 2vA is an explanatory diagram showing the configuration of the base station side of both systems when implementing the present invention, and FIG.
The figure is a block diagram showing the circuit configuration of a mobile station in the case of implementing the present invention, and FIGS. 4 and 5 are flowcharts each showing the operation as an embodiment of the present invention. Code explanation 1.1 atlb... Wireless base station, 2...
・Mobile station, 3a e 3b...Radio line control station, 4at4b...Car telephone exchange, 5...
... Common signal line, 6ay6b ... Radio section, 7
...Control unit, 8at8b...System ROM19...Antenna, 10...
Switching circuit agent Akio Namiki Patent attorney Patent attorney Kiyoshi Matsuzaki Continued from page 1 ■ Inventor Naka 1) Tadaaki Yokosuka Minamikaze 1-cho [Communication Research Institute 123561 Nippon Telegraph and Telephone Public Corporation Yokosuka Electric IQ (1)
−

Claims (1)

[Scope of Claims] 1) In a case where the service areas of a plurality of different mobile communication systems coexist, is there a service area within the service area of system A, which is the first mobile communication system? A mobile station that has received the incoming call control channel of system A and is in standby mode moves into an area where the service area of system B, which is a second mobile communication system, and the service area of system A overlap. Then, when a call is made or received, the mobile station enters a call state using the communication channel of system A, and the system side that detects this changes the communication channel of the mobile station from that of system A to B.
A switching method for a mobile communication system characterized by switching to that of a mobile communication system. 2. In the switching system of the mobile communication system as set forth in claim 1, the mobile station to which the communication channel has been switched from that of system A to that of system B returns to system B when the communication ends. A switching method for a mobile communication system, characterized in that the mobile station is notified of an incoming call control channel from the system side by signal transmission using a communication channel.