JPH0427223A - Mobile communication system - Google Patents

Abstract

PURPOSE:To automatically restart the communication to an interactive person terminal by disconnecting temporarily the communication, when a mobile station goes out to the outside of a service area, calling the mobile station from a radio base station, when it goes into a different area again and connecting it to the interactive person terminal. CONSTITUTION:An out-range detector 34 which detects a fact that a mobile station 30 is being disconnected from a service area 21 due to the drop of a receiving level sends its output to an out-range informing device 35. The device 35 informs a fact that the station 30 is being disconnected from the area 21 to radio base stations 24a - 26a installed in the adjacent service areas 21 - 23, allows them to detect whether the station 30 is moved to the service areas 21 - 23 or not, and informs it to a radio circuit control station 31. The station 31 calls the station 30 by operating the station 26a of, for instance, the moved area 23, connect it to an interactive person terminal 33 through an exchange 32, and restarts automatically the communication. A message in the course of disconnection of the communication is accumulated in a message accumulating device 36 through the station 31. At the time of fetching the message, in the case of an automatic incoming, the message of the device 36 is sent out automatically, and in the case of a manual incoming, the message is fetched by the button operation of the station 30.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a mobile communication system, in which service areas formed by a plurality of wireless base stations are geographically scattered, and a mobile station moves between these service areas. Regarding communication methods.

[Conventional technology]

FIG. 5 is a block diagram of conventional mobile communication.

As shown in FIG. 5, the service areas are configured discretely, and when the mobile station is in the service area 65 or 66, the interlocutor (for example, a telephone subscriber of the telephone network to which this mobile communication system is connected) ), but once service area 65 or service area 6
If it deviates from 6, it will be outside the wireless zone covered by the wireless base station and communication will be interrupted.

In mobile communication systems, where the service area consists of multiple relatively small wireless zones, the service area is limited due to the cost of wireless base station equipment and the time it takes to build wireless base station equipment in the entire area. Areas are often configured discretely, and service areas are often not continuous but sparse.

FIG. 6 shows a configuration diagram of a conventional mobile communication system such as a car phone. In FIG. 6, a service area 1O111 is composed of a plurality of wireless zones IOa and 10b, lla, 11b and lie, respectively, in order to effectively utilize radio frequencies. Adjacent wireless zones within the same service area
For oa, job, lla, llb, llc, the frequency is fan, fax, or fb, , fb, , fb.
, and different communication channels are assigned. The transmitter/receiver devices 12a and 13a of the wireless base stations 12 and 13 of the wireless thin loa and fob are connected to a wireless line control station 14, and this wireless line control station 14 is connected to the interlocutor terminal 16 via a switching center 15. There is.

In such a mobile communication system, when a mobile station 17 having a transmitting/receiving device 17a moves from the wireless zone 10a to 10b during a call within a certain service area 10, the reception level in the wireless zone 10a decreases and When it is detected that the threshold value VtO shown in the figure has been exceeded, based on the command from the radio network control station 14, the level monitoring receiver included in the transmitting/receiving device of each radio base station in the adjacent radio zone is used to The communication radio channel used by the mobile station 17 (
By monitoring the reception level of frequencies fa, ), it is determined that the mobile station has moved to the wireless zone lOb where the highest level was detected. At the wireless base station 13 in the wireless zone 10b to which the mobile station 17 has migrated, the wireless network control station 1
Based on the command from No. 4, the call is switched to an unused channel (frequency fan) among the radio channels for calls allocated in advance in the wireless zone, thereby preventing the call from being interrupted.

[Problem to be solved by the invention]

In the conventional method, when a mobile station is making a call, the service area
If it deviates from O, the call is forcibly disconnected, and there is a problem in that even if important information needs to be exchanged between the mobile station 17 and its interlocutor terminal 16, it is not taken into account. Furthermore, even if you leave the service area IO and re-enter the geographically distant service area 11 or the original service area IO, if you want to make a call again, the mobile station 17 or the interlocutor Terminal! It is necessary to dial again from service area 10.6, and whether or not mobile station 17 exists within service area 10111 can only be confirmed by dialing from interlocutor terminal 16. There is a problem in that even if you want to communicate as soon as possible after entering II, you cannot do so.

In addition, when moving from the service area 65 to the service area 66 in FIG.
During communication, the mobile station leaves the service area 65 and communication is interrupted.When the mobile station then enters the service area 66, the moving mobile station notices that it has entered the service area through a liquid crystal display indicating that it has entered the wireless zone. , it took time and effort to call the interlocutor again if necessary.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a mobile communication system that makes it easy to secure a call between a mobile station moving between service areas and an interlocutor, and to easily transmit messages to the mobile station. purpose.

[Means to solve the problem]

In a mobile communication system that is composed of a plurality of radio base stations and mobile stations, and in which the plurality of service areas formed by the plurality of radio base stations are geographically scattered, the mobile station is leaving the service area in which it exists. detects that the mobile station is leaving the service area, and notifies the mobile station and, if there is a communication partner terminal of the mobile station, that the mobile station is leaving the service area. When the communication between the mobile station and the interlocutor terminal is temporarily disconnected, and when the mobile station re-enters any service area, the radio base station in that service area calls the mobile station and the interlocutor terminal is called. The mobile station and the interlocutor terminal are connected and communication is restarted.

Furthermore, in a mobile communication system that is composed of a plurality of radio base stations and mobile stations, and in which the plurality of service areas formed by the plurality of radio base stations are geographically scattered, the mobile station may move out of the service area in which it exists. detects that the
If there is a communication partner of the mobile station and the mobile station, the interlocutor's terminal is notified that the mobile station is leaving the service area, and the interlocutor's terminal communicates with the mobile station until it moves to the next service area. Messages to the mobile station are stored in a database, and when the mobile station re-enters any service area, the mobile station calls the mobile station from the wireless base station in that service area, or from the mobile station to the wireless base station. The message stored in the database is transmitted to the mobile station in response to a connection request.

[Effect]

Even if the mobile station leaves the service area and communication with the interlocutor terminal is cut off, communication between the mobile station and the interlocutor terminal is automatically resumed after entering any of the service areas of this mobile station, It becomes easy to secure communication between the mobile station and the interlocutor's terminal.

In addition, messages to be sent to the mobile station at the request of the interlocutor's terminal are stored in the database from when the mobile station is leaving the service area until it re-enters the next service area, and after the mobile station leaves the service area. , after entering any service area, this stored message can be transmitted to the mobile station or retrieved by the mobile station.

〔Example〕

FIG. 1 shows a block diagram of an embodiment of the method of the present invention.

In FIG. 1, service areas 21, 22, and 23 are geographically scattered. The service areas 21122.23 have transmitting and receiving devices 24a and 25a, respectively.

26a and radio base stations 24, 25, and 26 each having transmitting and receiving antennas 24b, 25b, and 26b. However, each service area 21 to 23 may be composed of a plurality of wireless zones.

The mobile station 30 has a transmitting/receiving device 30a and a transmitting/receiving antenna 31b.
When the mobile station 30 is located within the service area 21, the mobile station 30 is connected to the wireless base station 24 through a communication channel, and is further connected to the interlocutor terminal 33 through the wireless network control station 31 and switching center 32 to which the transmitting/receiving device 24a is connected. Make a call. The transmitting/receiving devices 24a to 26a of each of the radio base stations 24 to 26 are connected to a radio network control station 31, and the radio network control station 31 controls calls, such as outgoing call connection, incoming call connection,
It is under control to end the conversation, etc.

It is now assumed that the mobile station 30 is about to move out of the service area 21. At this time, the signal transmitted from the mobile station 30 is transmitted to the transmitting and receiving antenna 24b of the radio base station 24.
After being received by the mobile station 3o, it is input to the out-of-service area detector 34 via the transmitting/receiving device 24a, and the mobile station 3o attempts to leave the service area 21 because the reception level is divided by the threshold level VTH shown in FIG. is detected. In addition to detecting a drop in the reception level described above, methods for detecting that the mobile station 30 leaves the service area 21 at the radio base stations 24 to 26 in each of the service areas 21 to 23 include detection of a specific data pattern. Detection of an increase in the probability or the number of errors may be used, or the mobile station 30 may notify each radio base station.

In this case, in the transmitting/receiving device 30a of the mobile station 30 having the configuration shown in FIG. 3, the signal received by the antenna 30b is supplied to the receiving section 42 through the demultiplexer 41, and when the reception level is below the threshold V TH The transmitter/receiver 43 emits a warning sound, or the control unit 44 displays an out-of-service area indicator 45. Based on this notification, the subscriber of the mobile station 30 operates the out-of-service information input device 46, and the transmitter 47 is sent from the controller 44 to the transmitter 47.
, turnout 41. Information indicating that the vehicle is leaving the service area is transmitted through the antenna 30b.

The out-of-service area detector 3 detects that the mobile station 30 is leaving the service area 21 due to the aforementioned drop in reception level.
4 supplies the output to the out-of-service notification device 35. The out-of-service area notification device 35 notifies that the mobile station 30 is leaving the service area 21 by informing it of nearby service areas 21, 22, 23.
Wireless base stations 24a and 25 installed respectively
a, 26 a, and detects whether the mobile station 30 has moved to each service area 21, 22, or 23 by a method described later.

In addition, in accordance with the information that the mobile station 30 is moving out of the service area 21, the radio network control station 31 notifies the interlocutor terminal 33 by telephone or other information that the mobile station is moving out of the service area. The mobile station 30 notifies the mobile station 30 by means of a display or the like, and also indicates whether there is a request to send a message to be transmitted to the mobile station 30, and if there is a request to send a message, requests input of the message to be sent. The message to be sent may be voice, data, etc.

The interlocutor uses the interlocutor terminal 33 according to the message input request.
Messages sent from the wireless network control station 31 are supplied to the message storage device 36 via the radio network control station 31, and are stored there. If there is no request to send a message to the mobile station 30 or to resume the call upon relocation, the call ends when the mobile station 30 moves out of the service area.

If there is a request to send the message or to resume the call at the time of retransfer, the service area 21 including the wireless base station 24 that has been notified that the mobile station 30 is leaving the service area 21 and its nearby services. Area 21~
In the radio base stations 24 to 26 within 23, the outputs of the transmitting/receiving devices 24a, 25a, 26a, for example, the increase in the reception level of the control channel predetermined for each service area as shown in FIG. Using information such as a decrease in the error probability or number of errors in the data pattern or a match with a specific pattern, the wireless network control station 31 is notified that the mobile station has detected movement into its own service area.

Note that determining which service area the mobile station has moved to can be realized by mutually comparing reception level information etc. from each of the transmitting/receiving devices 24a, 25a, and 26a of each wireless base station. Further, the output of the out-of-service notification device 35 may be directly notified to each of the wireless base stations 24 to 26, or may be notified to each of the wireless base stations 24 to 26 via the wireless network control station 31. Based on this notification, the radio network control station 31 activates the calling device 37.

In addition, at this time, the mobile station 30 exchanges information regarding the location of the mobile station 30, for example, with the wireless base station 25a in the service area 22, which is the migration destination, using a predetermined control channel. Perform registration, etc.

The radio base station 25 calls the mobile station 30 based on the output of the calling device 37. Furthermore, the mobile station 30 that responded to the call receives a wireless signal in the carrier band of the communication channel that is modulated by the message left in the message storage device 36 by the interlocutor who was communicating with the user before moving to the service area. It is transmitted from the base station 25a. The mobile station 30 receives this signal and displays it on the message display 48 shown in FIG. 3 under the control of the control unit 44, or outputs audio from the handset 43, thereby receiving and receiving a message from the interlocutor. After message transmission and reception are completed, the connection between the mobile station 30 and the message storage device 36 is automatically released, the communication channel is disconnected, and the call is terminated.

On the other hand, if a request to resume the call has been received, the mobile station 30 is called, and the interlocutor terminal 33 for which the request was previously made is called, and the two are connected to make the call. In order to carry out these operations, the numbers of the corresponding mobile station 30 and the interlocutor terminal 33 to be called are stored in advance in the switching center 32, the radio network control station 31, or other location.

By the way, the interlocutor terminal may be a mobile station within a mobile communication network, or may be located within a fixed communication network as shown in FIG.

The out-of-range detector 34 and the out-of-range notification device 35 may be provided individually for each service area 21, 22, and 23 (or, one device may be shared by a plurality of service areas as shown in FIG. 1).

Next, a second embodiment will be explained. FIG. 4 is a diagram for explaining a second embodiment of the present invention.

In the wireless channel configuration of this embodiment, a control channel and a communication channel are provided separately, and messages are sent using the communication channel.

When a mobile station using a mobile communication system is moving from the service area 65 to the service area 66, switching to the wireless zone is performed by first changing the communication channel of the base station when it leaves the service area 65 while communicating in the service area 65. By measuring the received field strength, it is known that a mobile station using a mobile communication system is out of the service area. Next, when the mobile station in communication leaves the service area 65, a level degradation signal is sent from the base station to the control device 68. Upon receiving this, the control device 68 sends out a monitoring request signal for the received field strength of the communication channel used by the mobile station to all base stations adjacent to the base station in order to detect the destination wireless zone. At this time, the control device 68 determines the destination wireless zone based on the monitoring results from each base station, notifies the mobile station of the vacant channel in that zone, switches the wireless line, and at the same time switches the communication path of the switching center 71.

In addition, when moving to a zone that is not adjacent but a certain distance apart, the transfer destination wireless zone cannot be determined based on the monitoring results from each adjacent base station. Call channel (wireless line)
Cut by -dan. The wireless base station notifies the interlocutor 69 that the wireless line cannot secure a call between the wireless base station and the mobile station 60 by means of a talkie or the like, and the interlocutor 69 registers a message for the mobile station 60 in accordance with the instructions of the announcement. The message at this time may be either voice or data, and the message may be either voice or data.
A database 67 that is converted into a digital signal by a digital conversion device in 8 and connected to a control device 68.
is stored in At this time, the mobile station 60 determines that the call is complete, and therefore enters a standby state on the control channels from the radio base stations 61 to 64.

Outside the area between service areas 65 and 66, control channel radio waves from radio base stations 61 to 64 do not reach mobile station 60, but enter service area 66 and mobile station 6
When a radio wave of a control channel in which 0 is included as information such as a channel number that can be accessed from the mobile station 60 is received, the radio wave from the mobile station 60 to the service area 6 on the uplink of the control channel is received.
A connection request is issued to wireless base stations 63 and 64 within 6.

When the mobile station 60 enters the service area 66, it enters the wireless zone covered by the wireless base stations 63 and 64 in the service area 66 and can communicate, so it can retrieve the information stored in the pig base 6F. Wireless base station 6
3.64 inquires of the control device 68 whether a message is registered for the mobile station 60. Mobile station 6
Whether a message has been registered for the mobile station 60 can be determined from the liquid crystal display of the mobile station 60 or the like.

Messages can be retrieved by either automatic or manual reception, and in the case of automatic reception,
A communication channel is automatically set between the radio base stations 61 to 64 and the mobile station 6o, and messages registered in the database 67 are sent from the radio base stations 61 to 64 to the mobile station 6o via the communication channel. In the case of manual call termination, the mobile subscriber accesses the control device 68 by operating a button on the mobile station 60 and retrieves information stored in the database 67.

Note that when the mobile station 65 leaves a certain service area 65, there is no conversation with the interlocutor terminal 69, and if a call is received while the mobile station 60 is outside all service areas, , when there is a request to store a message to be transmitted to the mobile station 60, or a call request when moving back into the service area, the same operation as described above can be performed. Further, the database 67 for storing messages may be located within the radio base stations 61, 62, 63, 64 or the radio network control station, or may be installed at another location.

〔Effect of the invention〕

As described above, in the mobile communication system of the present invention, in the structure of claim (1), communication between the mobile station and the interlocutor terminal that is disconnected because the mobile station is out of the service area returns to the mobile station's service area. This is extremely useful in practice, as it is automatically restarted when the mobile station moves between service areas, and it becomes easy to secure communication between the mobile station and the interlocutor's terminal when moving between service areas.

Further, in the structure of claim (2), when the mobile station is leaving the service area, the message requested by the interlocutor terminal is transmitted to the mobile station as the mobile station moves into the service area, or when the mobile station is moving out of the service area. Retrieval of the information by the communication subscriber facilitates the transmission of messages to the mobile station, which is extremely useful in practice.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the first embodiment of the system of the present invention, FIG. 2 is a diagram for explaining the system of the present invention, FIG. 3 is a block diagram of the first embodiment of the mobile station, and FIG. 4 is a block diagram of the first embodiment of the mobile station. FIG. 5 is a diagram for explaining the second embodiment of the method of the present invention, FIG. 5 is a block diagram of an example of the conventional method, and FIG. 6 is a diagram for explaining the conventional method. 21-23...Service area, 24-26...Radio base station, 30...Mobile station, 31...Radio line control station, 32...Switching center, 33...Interlocutor terminal, 34・
...Out-of-range detector, 35...Out-of-range notification device, 36...
Message storage device, 37... Calling device, 41.
... Duplexer, 42 ... Receiver, 43 ... Handset,
44...Control unit, 45...Out of range display unit, 46...
Out-of-service information input device, 47... Transmission/reception unit, 48... Message display device, 60... Mobile station, 61-64... Wireless base station, 65. 66... Service area, 67...
- Database, 68...control device, 69...interlocutor terminal. 1059 diagram of a mobile station Figure 5: Diagram of the conventional system

Claims (2)

[Claims] (1) In a mobile communication system that is composed of a plurality of radio base stations and mobile stations, and in which the plurality of service areas formed by the plurality of radio base stations are geographically scattered, the mobile station detects that the mobile station is leaving the service area, and notifies the mobile station and the interlocutor terminal, if any, that the mobile station is leaving the service area; When the mobile station enters a service area again, communication between the mobile station and the interlocutor's terminal is temporarily disconnected, and when the mobile station re-enters any service area, the radio base station in that service area calls the mobile station and terminates the conversation. A mobile communication system characterized by calling a terminal of a party to the conversation, connecting the mobile station and the terminal of the party to the conversation, and restarting communication. (2) In a mobile communication system that is composed of a plurality of radio base stations and mobile stations, and in which the plurality of service areas formed by the plurality of radio base stations are geographically dispersed, the service area in which the mobile station is located is Detects that the mobile station is leaving the service area, and notifies the mobile station and, if there is a communication partner of the mobile station, that the mobile station is leaving the service area, until moving to the next service area. Messages from the interlocutor terminal to the mobile station are stored in a database, and when the mobile station re-enters any service area, a call is made to the mobile station from a wireless base station in that service area, or when the mobile station A mobile communication system characterized in that a message stored in the database is transmitted to the mobile station in response to a connection request from the station to the wireless base station.