JPH0454028A - Radio communication privacy call control system - Google Patents

Abstract

PURPOSE:To suppress the quantity of signals and to realize the sophisticated privacy call service by providing plural privacy call system circuits on an automobile telephone exchange and a mobile radio terminal equipment and selecting the different kind of the privacy call system circuit every time a mobile radio terminal equipment makes inter-cell hand-off. CONSTITUTION:When a mobile radio terminal equipment 13 in a radio zone cell 1 moves from the cell 1 to a cell 2, while the terminal equipment 13 uses a radio wave 14 designated from an automobile telephone exchange 5 and one system among four kinds of different privacy call systems and makes communication with a telephone set terminal equipment 16 connected to a public telephone network 15 via a radio base station 3 and the exchange 5, the hand-off operation is executed and a central processing unit 12 in the automobile telephone exchange 5 sends the information of a new radio wave and the information of a different system selected among the privacy call systems to radio base stations 3, 4. The radio base station 3 sends the new radio wave information and the new privacy call system information to the mobile radio terminal equipment 13 by using the radio wave 14 used at present and starts the hand-off operation simultaneously. The mobile radio terminal equipment 13 makes tuning to the new radio wave and the switching to the new privacy call system for the hand-off operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a confidential communication control system in wireless communication, and particularly to a highly confidential communication system in a car telephone.

[Conventional technology]

Conventionally, this type of confidential communication control system generally uses a single confidential communication circuit without switching during a call.

There is also a highly confidential communication system that controls the highly confidential communication circuit by switching the key code at predetermined intervals.

[Problem to be solved by the invention]

The conventional confidential communication system described above has the following drawbacks.

■A system that provides a single confidential communication circuit without switching during a call is a simple and economical system, but the quality of the confidential communication service (degree of confidentiality) is low.

■Highly confidential communication systems that change the key code at regular intervals have a high degree of confidentiality, but the control method is complicated, and the amount of signals during calls increases, impacting the signal processing capacity within the system.

[! l! Means to solve the problem]

In order to solve these problems, the present invention includes a mobile telephone exchange having a plurality of confidential communication circuits, a mobile radio terminal having a plurality of confidential communication circuits, and a central control processing unit provided in the automobile telephone exchange. , this central control processing unit selects a different type of privacy system circuit from among a plurality of privacy system circuits and switches the privacy system circuits in the mobile telephone exchange and the mobile radio terminal each time a mobile radio terminal performs an inter-cell handoff. This is how it was done.

[Effect]

In the wireless communication secret control system according to the present invention, the amount of signals between the car telephone exchange and the mobile wireless terminal is suppressed,
A highly confidential service is provided.

〔Example〕

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

FIG. 1 is a block diagram showing an embodiment of a wireless communication secret control system according to the present invention. In FIG. 1, I, 2 is a wireless zone cell, 3.4 is a wireless base station, 3-1.4-1 is an antenna, 3-2.4-2 is a wireless transceiver, 3-3.4
-3 is a wireless base station controller, 5 is a car telephone exchange, 6
is a voice line, 7 is a signal line, 8 is a switch circuit, 9 is a trunk circuit, 10 is a signal transmitter/receiver, 11-1 to 11-4 are confidential communication system circuits, I2 is a central control processing unit, 13 is a mobile radio terminal, 13-1 is an antenna, 13-2 is a wireless transmitter/receiver, 13-3 is a confidential communication circuit, 13-4 is a terminal control circuit, 13
-5 is a hand station, ]4 is a radio wave, 15 is a public telephone network, and 16 is a telephone terminal.

Radio base stations 3 and 4 serving radio zone cells 1 and 2 each include antennas 3-1 and 4-1, radio transceivers 3-2 and 42, and radio base station controllers 3-3 and 4. -3, and these radio base stations 3.4 are connected to a car telephone exchange 5 by a voice line 6 and a signal line 7.

The car telephone exchange 5 includes a switch circuit 8, a trunk circuit 9 accommodating a voice circuit, a signal transmitter/receiver 10 connected via the signal line 7 and the switch circuit 8, and four types of confidential communication circuits 11-1. 11-2, 113, 11-4, and a central control processing unit 12 that controls each circuit of these mobile phone exchanges.

There is a mobile radio terminal 13 in cell l, and this mobile radio terminal 13 has an antenna 13-1 and a radio transceiver 13-2.
and a confidential communication circuit 13 that can provide the four types of confidential communication methods described above.
-3, terminal control circuit 134, and hand center 13-5
It consists of

In FIG. 1, a mobile radio terminal 13 is communicating with a telephone terminal 16 via a public telephone network 15 via a radio base station 3 of a cell 1 and a mobile telephone exchange 5 via radio waves 14. Furthermore, the mobile radio terminal 13 is about to perform a handoff operation toward the cell 2, as indicated by the arrow.

FIG. 2 is an explanatory diagram showing four types of confidential communication methods in this embodiment. The original audio signal shown in Fig. 2(a) is divided into three frequencies, f, , f, , f, and subjected to four different types of spectrum scrambling processing.
) to (e) are provided.

Next, the operation will be explained.

The mobile radio terminal 13 in the radio zone cell l uses the radio waves 14 designated by the mobile telephone exchange 5 and one of four different confidential communication methods (Tbl to (e) in FIG. 2). , wireless base station 3, voice line 6, signal line 7
, is communicating with a telephone terminal 16 connected to a public telephone network 15 via a switch circuit 8 and a trunk circuit 9.

When the mobile radio terminal 13 moves from the radio zone cell I to the radio zone cell 2, a so-called handoff operation is executed in which the communication path is switched from the radio base station 3 to the radio base station 4.
The new radio wave information and the information corresponding to the selected one of the different confidential communication methods (FIG. 2(b) to (e)) are transmitted from the signal transmitter/receiver 10 to the switch circuit 8,
The signal is sent to the radio base station controllers 3 - 3 and 4 - 3 of the radio base station 3 and radio base station 4 through the signal line 7 .

In the radio base station 3, the radio transmitter/receiver 3-2 and the antenna 3-1 transmit the new radio wave information and the new standard system information to the mobile radio terminal 13 via the radio waves 14 currently in use, and at the same time perform handoff. Start the operation.

In the mobile radio terminal 13, the radio waves 14 are transmitted through an antenna 13-
1 and the wireless transceiver 13-2, and the terminal control circuit 13-4 receives the new &?
1 radio wave and switching the secret line circuit 13-3 to the new secret line method.

On the other hand, the car telephone exchange 5 also selects the corresponding confidential communication circuit from the four types of confidential communication circuits 11-1. 9 by the switch circuit 8.

The above series of operations are controlled by the central control processing unit 12.

〔Effect of the invention〕

As explained above, the present invention provides a plurality of privacy system circuits in a car telephone exchange and a mobile radio terminal, and a central control processing unit of the car telephone exchange allows a mobile radio terminal to use a different privacy system each time it performs an inter-cell handoff. Select the circuit and
Similarly, the mobile radio terminal is also configured to switch the confidential communication circuit at each handoff, which has the effect of suppressing the amount of signals between the mobile telephone exchange and the mobile radio terminal and providing a highly confidential communication service.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a wireless communication secret control system according to the present invention, and FIG.
FIG. 2 is an explanatory diagram illustrating a type of confidential conversation method. 1.2...Radio zone cell, 3,4...Radio base station, 3-1.4-1...Antenna, 3-2.4-2...
・Radio transceiver, 3-3.4-3... Radio base station control device, 5... Car telephone exchange, 6... Voice line,
7... Signal line, 8... Switch circuit, 9... Trunk circuit, 10... Signal transmitter/receiver, 11-1 to 11-
4... Confidential system circuit, 12... Central control processing unit,
13... Mobile radio terminal, 13-1... Antenna, 1
3-2... Wireless transmitter/receiver, 13-3... Confidential circuit,
13-4...Terminal control circuit, 13-5...Hand sent, 15...Public telephone network, 16...Telephone terminal. figure

Claims (1)

[Claims] A mobile telephone exchange having a plurality of confidential communication circuits and a mobile radio terminal also having a plurality of confidential communication circuits,
The mobile telephone exchange has a central control processing unit, and the central control processing unit selects a different type of confidential communication circuit from among the plurality of confidential communication circuits to connect the mobile radio terminal to the mobile phone exchange. A wireless communication confidential communication control system characterized by switching confidential communication circuits in a telephone exchange and a mobile radio terminal.