JP2885695B2 - Mobile communication system - Google Patents

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, and more particularly to a mobile communication system capable of making a call available again for a call temporarily disconnected due to an abnormality in a radio communication channel.

[0002]

2. Description of the Related Art A conventional technique of this kind will be described with reference to the drawings.

FIG. 2 is a system block diagram showing an example of a conventional mobile communication system.

In FIG. 2, this conventional example is disclosed in
The disclosure content of 198839 is disclosed, and the base station control device 6a constantly measures the electric field strength of the communication channel 5a transmitted by the mobile terminal 3a talking through the base station 2a. When the mobile terminal 3a moves to lower the electric field strength below a predetermined value, the base station controller 6a sends out the electric field strength reduction information to the exchange 1 through the communication line 4a. Upon receiving this information, the exchange 1 issues a request for measuring the electric field strength of the radio wave transmitted from the mobile terminal 3a to the base station 2b and the other base stations adjacent to the base station 2a, and the base station controller receiving the request. 6b and the other base station controllers measure the electric field strength and notify the exchange 1 of the measurement result. The exchange 1 counts and compares the measurement results from the base station 2b and another base station, and normally switches the connection of the communication channel 5a with the mobile terminal 3a to the base station having the highest electric field strength. However, the mobile terminal 3a
Is outside the mobile communication service area, or even within the service area, radio waves do not reach due to the terrain, the electric field strength is low even from another base station, and the exchange 1 talks to another base station. If it is determined that the channel cannot be changed, the transmission output of the mobile radio device 8a and the base station radio device 7a is increased while the communication channel 5a of the mobile terminal 3a is connected to the base station 2a, and the communication is continued. Move on. Before increasing the transmission output, the exchange 1 notifies all base stations close to the base station 2a that may use a communication channel of the same frequency as the communication channel 5a that radio waves may interfere. . The notified base station blocks the communication channel of the same frequency as the communication channel 5a. Further, when the corresponding communication channel is busy, the call during the communication is transferred to another communication channel, and the corresponding communication channel is opened and closed. The base station that has blocked the corresponding communication channel returns blocking completion information to the exchange 1.
The exchange 1 outputs a transmission output enhancement signal only when all the block completion information has been returned from all the base stations that have notified the radio interference, and the mobile radio device 8a and the base station 2a of the mobile terminal 3a whose electric field strength has decreased. The transmission output with the base station wireless device 7a is increased, and the communication is continued with the communication channel 5a.

[0005]

In the conventional mobile communication system, when the mobile terminal moves out of the service area and the electric field strength of the radio wave transmitted from the mobile terminal decreases,
Since the communication can be continued by raising the transmission output of both the base station and the mobile terminal that are currently talking, use a communication channel of the same frequency as the communication channel used by the mobile terminal. The switch notifies all potential base stations that radio waves will interfere, and receives blocking completion information from all base stations to continue the call. There is a problem in that complicated processing such as blocking of an existing communication channel, notification of the exchange to each base station, and subsequent processing must be performed.

[0006]

According to the mobile communication system of the present invention, a plurality of radio base stations are connected to one switch, and a service area (cell zone) can be set for each of the plurality of radio base stations. In the mobile communication system capable of repeatedly using a radio communication channel of the same frequency for each of the plurality of radio base stations, the exchange is provided in the service area transmitted from each of the plurality of radio base stations. Upon receiving the code indicating the reason for disconnecting the mobile terminal and the disconnected cell zone number, the mobile terminal holds a communication line connected to the telephone of the other party with whom the mobile terminal is talking, and talks with the mobile terminal during the hold. The voice guidance to the effect that the mobile terminal has been disconnected due to an abnormality in the wireless communication channel and is again calling the wireless terminal. Voice guidance sending means for sending a connection, a disconnection means for starting a hold timer when the communication line is put on hold and disconnecting the held communication line when a preset holding period expires, and Paging signal transmitting means for transmitting a paging signal to the mobile terminal to a radio base station having the disconnected cell zone number; and a response signal in response to the paging signal from the mobile terminal to the radio base station. And connection means for releasing the held communication line when receiving the voice guidance and enabling a call to the telephone set which has transmitted the voice guidance again.

In the mobile communication system of the present invention, an exchange accommodating a telephone via a communication line and a mobile telephone service area connected to the exchange via a communication line and moving within one service area (cell zone). A terminal and a radio base station that can be connected by a radio communication channel, wherein the exchange has a line circuit that interfaces with the communication line, a trunk circuit that interfaces with the communication line, a dial signal from the telephone, and the radio base station. A receiving circuit for receiving a code indicating the reason for disconnection of the mobile terminal and the number of the disconnected cell zone, and the telephone when the communication channel of the mobile terminal becomes abnormal while the telephone is communicating with the mobile terminal. Voice guidance transmitting device for transmitting voice guidance to the telephone, dial tone and busy to the telephone Signal and a ring tone to the mobile terminal, a timer for setting a hold period for holding the telephone, a connection state between the telephone and the mobile terminal, and the mobile terminal a memory for storing number of the belonging the cell zone, and a switch unit for forming a communication path, have a CPU for controlling the entire switch, the CPU, the receiving times from the radio base station
A code indicating the reason for the disconnection through the road and the disconnection
When the cell zone number received is received, the cell zone number
Signal in the memory, start the timer,
Activate the voice guidance sending device to call the telephone.
A voice guidance indicating that the
To send a paging signal to the mobile terminal to a base station
Activate the signal generation circuit and control the switch unit
Put the line to the telephone on hold, and
A response signal from the mobile terminal from the radio base station via
Received, the memory is referred to and the line is held.
Is canceled and the timer expires after the hold period has elapsed.
If the response signal is not received, the line
The switch unit is controlled so as to make the switch .

[0008]

Next, the present invention will be described with reference to the drawings.

FIG. 1 is a system block diagram showing an embodiment of the present invention.

In FIG. 1, the present embodiment employs a
Exchange 5 accommodating telephone 7 through the
To a mobile terminal 1 within one service area (cell zone 2) via a wireless communication channel 3 so that a wireless telephone service can be connected through a communication line 6
The exchange 5 comprises a line circuit 51 for interfacing with the communication line 8, a trunk circuit (TRK) 53 for interfacing with the communication line 6, a dial signal from the telephone 7 and a reason for disconnecting the mobile terminal 1 from the radio base station. (REC) 54 for receiving a code indicating the number and the number of the disconnected cell zone 2, and voice guidance to the telephone 7 when the telephone 7 is in communication with the mobile terminal 1 and the communication channel of the mobile terminal 1 becomes abnormal. A voice guidance transmission device (VOIC) 55 for transmitting a call, a signal tone generation circuit (SIG) 56 for generating a dial tone, a busy tone to the telephone 7 and a ringing tone to the mobile terminal 1, and a hold when the telephone 7 is put on hold A timer 58 for which a period is set, a connection state between the telephone 7 and the mobile terminal 1, a cell zone number to which the mobile terminal 1 belongs, and the like. A memory 59 for storing, and a switch unit (SW) 52 to form a speech path, and a CPU57 for controlling the entire switch 5.

Next, the operation of this embodiment will be described with reference to FIG.
This will be described with reference to FIG.

When the mobile terminal 1 is disconnected (squelched) due to rapid deterioration of the wireless communication channel 3, the radio base station 4 informs the exchange 5 that the call is disconnected due to the disconnection of the squelch as a reason for disconnecting the wireless communication channel 3. Notify, and the number “2” of the cell zone 2 in which the squelch break has occurred is notified.

[0013] The CPU 57 of the exchange 5 determines the communication line 6 used by the mobile terminal 1 from the radio base station 4 connected to the TRK 53 via the communication line 6 when the squelch is cut off, and the number of the cell zone 2 in which the squelch break has occurred. REC5 for "2"
4 and is stored in the memory 59. Exchange 5 C
The PU 57 controls the line circuit 51 to hold the communication line 8 with the telephone 7 that was communicating with the mobile terminal 1. VOIC 55 provides guidance that a call is in progress.
Sent from. The CPU 57 activates the timer 58 when the communication line 8 with the telephone 7 is put on hold.

The CPU 57 controls the SIG 56 to transmit a call signal to the mobile terminal 1 to the radio base station 4 controlling the area of the cell zone 2 from the cell zone 2 number “2” stored in the memory 59. Send out. Wireless base station 4
Sends a paging signal to the mobile terminal 1 upon receiving a paging signal from the exchange 5.

When the mobile terminal 1 responds to the call signal,
The CPU 57 of the exchange 5 hunts the communication line 6 between the TRK 53 and the radio base station 4, controls the line circuit 51 to release the hold of the communication line 8 with the telephone 7, and
And the telephone with the telephone 7 are enabled.

When the mobile terminal 1 does not respond to the call signal, the CPU 57 of the exchange 5 controls the line circuit 51 to hold the communication line 8 with the telephone 7 and to release the timer 5.
Upon expiration of the hold period by the communication line 8, the communication line 8 with the telephone 7 is disconnected.

[0017]

As described above, according to the present invention, a plurality of wireless base stations are connected to one switch, a service area (cell zone) is set for each of the plurality of wireless base stations, and a plurality of wireless base stations are connected. In a mobile communication system capable of repeatedly using a radio communication channel of the same frequency for each base station, an exchange includes a code indicating a reason for disconnecting a mobile terminal in a service area transmitted from each of a plurality of radio base stations. Upon receiving the disconnected cell zone number, the mobile terminal holds the communication line to which the other party's telephone with which the mobile terminal is talking is on hold, and the mobile terminal is currently in radio communication with the telephone on which the mobile terminal is talking on the hold. A voice guidance transmitting means for transmitting voice guidance indicating that a call is being made to the wireless terminal again after being disconnected due to an abnormal communication channel; Disconnecting means for activating a hold timer when a call is held and disconnecting a communication line held when a preset hold period has expired, and a mobile terminal for a radio base station having a cell zone number disconnected for the mobile terminal Calling signal sending means for sending a calling signal to the mobile terminal; and releasing voice communication by releasing the communication line held when the mobile terminal receives a response signal responding to the calling signal from the radio base station. Connection means that allows the user to make a call to the telephone again when the mobile terminal is located in a place where the electric field strength is severely deteriorated, such as behind a building, even if the call is disconnected due to squelch disconnection. Since the call line is held and a call is made to the disconnected mobile terminal, the possibility that the call can be rescued even if the call is squelched is greatly increased.

Further, since the cell zone number at which the squelch break occurs is stored in the call memory of the exchange, it is possible to specify a cell zone in which squelch break occurs frequently.

Further, since the present invention can be realized without changing the specifications of the current mobile terminal and the radio base station, there is an effect that the squelch disconnection can be easily relieved.

[Brief description of the drawings]

FIG. 1 is a system block diagram showing an embodiment of the present invention.

FIG. 2 is a system block diagram showing an example of a conventional mobile communication system.

[Explanation of symbols]

 Reference Signs List 1 mobile terminal 2 cell zone 3 wireless communication channel 4 wireless base station 5 exchange 6 communication line 7 telephone 8 communication line 51 line circuit 52 switch unit (SW) 53 trunk circuit (TRK) 54 reception circuit (REC) 55 voice guidance transmission device ( VOIC) 56 Signal sound generation circuit (SIG) 57 CPU 58 Timer 59 Memory

Claims (2)

(57) [Claims] 1. A plurality of radio base stations are connected to one switch, a serviceable area (cell zone) is set for each of the plurality of radio base stations, and the same frequency is used for each of the plurality of radio base stations. In a mobile communication system capable of repeatedly using a radio communication channel, the exchange includes a code indicating a reason for disconnection of a mobile terminal in the service area transmitted from each of the plurality of radio base stations, and a disconnected cell zone. When you receive the number,
Holding means for holding a communication line connected to the telephone of the other party with which the mobile terminal is talking, and the mobile terminal is currently disconnected from the telephone which was talking with the mobile terminal during the hold due to an abnormality in a wireless communication channel Voice guidance sending means for sending voice guidance to the wireless terminal again indicating that a call is being made, and activating a hold timer when the communication line is put on hold, and holding the hold when a preset hold period expires. Disconnecting means for disconnecting the communication line, call signal transmitting means for transmitting a call signal to the mobile terminal to a radio base station having the disconnected cell zone number for the mobile terminal, Releases the held communication line when receiving a response signal responding to the call signal from the wireless base station, and releases the voice guidance. Mobile communication system, characterized in that it comprises a connection means for enabling the call to the telephone which has been sent again. 2. An exchange for accommodating a telephone set via a telephone line, and an area connected to the exchange via a communication line to provide a radio telephone service by using a radio communication channel with a mobile terminal in one service area (cell zone). A wireless base station that can be connected, wherein the exchange has a line circuit that interfaces with the communication line, a trunk circuit that interfaces with the communication line, a dial signal from the telephone, and disconnection of the mobile terminal from the wireless base station. A receiving circuit that receives a code indicating a reason and a number of the disconnected cell zone,
A voice guidance transmitting device for transmitting voice guidance to the telephone when the communication channel of the mobile terminal becomes abnormal while the telephone is in a call with the mobile terminal; and a dial tone, a busy tone to the telephone and the mobile terminal. A signal tone generating circuit that generates a ringing tone, a timer for setting a hold period when the telephone is put on hold, a connection state between the telephone and the mobile terminal, a number of the cell zone to which the mobile terminal belongs, and the like. A memory for storing,
Possess a switch unit for forming a speech path, and a CPU for controlling the entire switch, the CPU including whether the wireless base station
A code indicating the disconnection reason through the receiving circuit from
Upon receiving the number of the disconnected cell zone, the
The zone number is stored in the memory, and the timer is
Activate the voice guidance sending device and activate
Voice guidance is sent to the telephone
A call signal to the mobile terminal to the radio base station.
Start the signal generation circuit to send out the
Control unit to put the line to the telephone on hold,
From the wireless base station to the mobile terminal via a receiving circuit
When these response signals are received, the memory
Release the hold state of the line, and the timer sets the hold period
If the response signal is not received even after elapse, the line
A mobile communication system characterized in that a switch unit is controlled so as to bring a call into a call termination state .