JPH03241998A - Automobile telephone exchange system - Google Patents

Abstract

PURPOSE:To reduce a talking interrupt time of an automobile telephone set by transferring call control to other automobile telephone exchange station when the automobile telephone set is moved beyond a prescribed electric field strength managed by one automobile telephone exchange station. CONSTITUTION:When an automobile telephone set 21 moves to a zone at the outside of an electric field with a prescribed strength managed by an automobile telephone exchange station 15 while in talking with the automobile telephone exchange station 15, a call management data relating to the automobile telephone set 21 is sent at a high speed via a data line to other automobile telephone exchange station 12 managing an electric field zone with a talking available strength with the automobile telephone set 21. Thus, the talking interrupt time is reduced and even when the automobile telephone set 21 moves beyond the electric field zone with a prescribed strength managed by one automobile telephone exchange station 15, the talking is continued.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is applied to call connection means in a mobile telephone switching system. In particular, the present invention relates to means for continuing a call when the electric field strength deteriorates when the mobile telephone moves beyond an electric field area of a certain strength managed by one mobile telephone exchange.

〔overview〕

The present invention provides a method for transferring call control to another mobile telephone exchange when a mobile phone moves beyond a predetermined electric field strength managed by one mobile telephone exchange in a call connection means of a mobile telephone exchange. By doing so, it is possible to shorten the call interruption time of car telephones.

[Conventional technology]

In the past, in order to continue a call when the field strength deteriorates due to the car phone moving beyond the area where the field strength is required to continue the call, it is necessary to communicate between multiple base stations belonging to a single car telephone exchange. The necessary electric field strength was secured only by reselecting the base station.

[Problem to be solved by the invention]

With such conventional means of continuing a call when the electric field strength deteriorates,
The present invention eliminates such a drawback that it is not possible to continue a call when a car telephone moves beyond an electric field area of a certain strength managed by a single car telephone exchange. An object of the present invention is to provide a car telephone switching system which allows a telephone call to be continued even when moving beyond an electric field area of a certain intensity managed by a car telephone exchange.

Means for Solving the Problem: The present invention provides a mobile phone switching center connected by a trunk line to a plurality of base stations that realize communication with a car phone via a communication path formed via radio waves. In a car telephone exchange system equipped with a plurality of car telephone exchanges, the car telephone exchange is provided with a means for sending and receiving control signals via a data line independent of the telephone line, and a predetermined car telephone exchange managed by one car telephone exchange detecting means for detecting that the mobile telephone has moved to an area outside the electric field area with a strength of , and as a result of which it has become impossible to continue a call; transmitting and receiving call management data related to the mobile telephone set to and from other stations via the data line,
The present invention is characterized by comprising a call control transfer means for transferring call control to another mobile telephone exchange that manages an electric field area in which a car phone that has moved to an area outside the electric field area can continue a call. .

[Effect]

If a car phone moves to an area outside the electric field area with a predetermined strength that is managed by this exchange while talking with one car phone exchange, another car phone that manages an electric field area with a certain strength that can communicate with this car phone Call management data related to car telephones is transmitted at high speed via data lines to the switching center.

Thereby, call interruption time can be shortened.

Example:・ Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

The figure is a block diagram showing the configuration of this embodiment. That is, it is equipped with a plurality of base stations 11 that realize a call with the car telephone 2L via a communication path formed through radio waves, and a plurality of car telephone exchanges 15 connected by a trunk line, and further includes a main body. As a feature of the invention, the mobile telephone exchange 15 is provided with a means for transmitting and receiving control signals via a data line independent of the telephone line, and is managed by one mobile telephone exchange 15. As a result of the car phone 21 moving to an area outside the electric field area 9 with a predetermined strength, the call ξ!
Is it impossible to continue? A detecting means for detecting whether the two are the same, and transmitting and receiving call management data related to the car telephone 21 that has moved to an area outside the electric field region 9 in accordance with the detection by the detecting means with another station via the data line. , another mobile telephone exchange 1 that manages an electric field area in which a mobile phone 21 that has moved to an area outside the electric field area 9 can continue to make a call.
2 and a call control transfer means for transferring control of the call.

Next, the operation of this embodiment will be explained.

A call from a subscriber 1 of the general switched network to a car telephone 21 is sent to a local office 2 of the general switched network, a trunk line 4, a toll relay station 3 of the general switched network, a trunk line 8, a car telephone exchange 15, and a car telephone. It is assumed that a call is in progress via the base station 11 of the mobile telephone exchange 15 and that the mobile telephone 21 is approaching the area of the base station 10 of the mobile telephone exchange 12. The radio waves emitted by the car telephone 21 that reach the base station 11 of the car telephone exchange 15 gradually become weaker, and when the electric field strength deteriorates and it becomes difficult to continue the call, the radio waves emitted from the car phone 21 reach the base station 11 of the car telephone exchange 15. A signal is sent to the telephone exchange 15 requesting all base stations belonging to the mobile telephone exchange 15 to measure electric field strength. Car telephone exchange 15
In response to the signal, the mobile phone 21 issues a field strength measurement request signal to multiple base stations in the vicinity of where the car phone 21 is currently located, receives and receives the measurement result data, and then transmits a field strength measurement request signal to a plurality of base stations in the vicinity of where the car phone 21 is currently located, receives and receives the measurement result data, and then transmits a field strength measurement request signal to a plurality of base stations near where the car phone 21 is currently located. A suitable substitute for the base station 11 of the mobile telephone exchange 15 within the electric field area 9; when it is found that no other base station is found, the mobile telephone relay exchange 20 communicates with the own station via the common signal line 18. sends a signal requesting that another suitable replacement mobile telephone exchange be found. The automobile telephone relay exchange 20 sends a field strength measurement request signal to the automobile telephone exchange 12 and the automobile telephone exchange 16 in the vicinity of the automobile telephone exchange 15 via the common line signal line 17 and the common line signal line 19. The mobile telephone exchange 12 sends out the mobile telephone exchange, receives and receives measurement result data, and finds that there is an appropriate base station 10 of the mobile telephone exchange 12 in place of the base station 11 of the mobile telephone exchange 15 within the area managed by the mobile telephone exchange 12.

Next, the car telephone relay exchange 20 connects the common line signal line 18
The management data regarding the call, such as the calling subscriber number, call start time, call duration, called number, call type, and information on the relay line 8, which is the opposite station of the mobile phone exchange 15, are sent to the car via The call is received from the telephone exchange 15. Furthermore, the mobile telephone relay exchange 20 sends management data regarding the call and information that the appropriate alternative base station is the base station 10 of the mobile telephone exchange 12 to the mobile telephone exchange 12 via the common signal line 17. Also, for the toll relay station 3 of the general exchange network, the trunk 7 and trunk line 8 to the car telephone exchange 15 are sent via the common line signal line 14.
and another trunk 5 bound for the car telephone exchange 12.
and requests selection of trunk line 6. The mobile telephone exchange 12 receives the activation signal for the trunk line 8 and uses the management data regarding the call received via the common line signal line 17 to connect the line to the base station 10 of the mobile telephone exchange 12 and the trunk line 8. Connect.

〔Effect of the invention〕

As explained above, the present invention transmits and receives call-related management data via a common signal line network separately from the call line, thereby enabling a car phone to maintain a certain level of strength managed by a single car telephone exchange. Even when the electric field strength deteriorates due to moving beyond the electric field area, sufficient electric field strength can be ensured.The effect of being able to continue the call by transferring call control to another mobile telephone exchange, and the ability to manage calls at high speed. Sending and receiving data has the effect of shortening call interruption time.

[Brief explanation of drawings]

The figure is a block diagram showing the configuration of an embodiment of the present invention. l...Subscriber, 2...City station, 3...Long distance relay station, 4.6.8...Relay line, 5.7...Trunk,
9... Electric field region, 10.11... Base station, 12.1
5.16...Car telephone exchange, 13...Common line signaling device, 14.17.18.19...Common line signal line, 20...Automatic*telephone relay exchange, 21... Car phone.

Claims (1)

[Scope of Claims] 1. A system comprising a plurality of base stations that realize communication with a car telephone via a communication path formed through radio waves, and a plurality of car telephone exchanges connected by a trunk line. In the car telephone exchange system, the above car telephone exchange is equipped with a means for sending and receiving control signals via a data line independent of the telephone line, and the electric field area of a predetermined strength is managed by one car telephone exchange. Detection means for detecting that it is no longer possible to continue a call as a result of the car phone moving to an outside area; and a car phone that has moved to an area outside the electric field area in response to the detection by the detection means. Transferring call management data to and from other stations via the above data line, and transmitting the call management data to other mobile telephone exchanges that manage the electric field area where a car phone that has moved to an area outside the electric field area can continue to make a call. A car telephone switching system characterized by comprising: a call control transfer means for transferring control of a call.