JPS6348459B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an out-of-service area display method for a selective call receiver.

Conventional selective calling receivers use electric field,
Alternatively, by detecting a load synchronization signal, it is determined whether the vehicle is outside the service area and the result is displayed.

This method is an effective out-of-range display method for general paging systems. But as below,
When used in a car telephone radio system, it has the disadvantage that it cannot be distinguished from the service area of other selective call transmitters.

Here, a method for indicating that a selective call receiver is out of service area in a car telephone radio system will be explained.
In a car telephone radio system, when a general subscriber calls a car phone subscriber (hereinafter referred to as an incoming call), a method is generally used in which a ringing tone is produced by a speaker. However, in consideration of the case where the user is away from the car, methods are used such as sounding the car's horn or flashing the car's lights when a call arrives, or using a selective call receiver.

As shown in FIG. 1, the method using a selective call receiver consists of a selective call transmitter 2 connected to a car telephone radio device 1 and a portable selective call receiver 3, and is used to receive calls to the car telephone radio device. , and when the activation permission switch 4 for selective calling is set to permission, the selective calling transmitter 2 is activated by the incoming call, and the reception display is displayed on the selective calling receiver 3 carried by the mobile telephone subscriber who is away from the car. This is a service that notifies car phone subscribers of an incoming call by making a sound.

Therefore, when this method is adopted, it is important to know to what extent the service will be provided when the subscriber leaves the car.

However, in the conventional method of determining whether the vehicle is out of service area by detecting a word synchronization signal, if there is a car 6 with the same system nearby as shown in FIG. If the same frequency is used, the selective calling receiver 9 of the car telephone radio device 7 is originally only within the service area 10, but when moving to position 9', the service area of the car 6 telephone radio device can be changed to the service area of the car phone radio device 7. It is mistakenly recognized as a service area. This possibility is even higher in large cities where car phone service is heavily used. Although there is a method of using different frequencies for each car phone subscriber to avoid misrecognition of the service area, it is virtually impossible to use different frequencies from the standpoint of effective frequency utilization.

SUMMARY OF THE INVENTION An object of the present invention is to provide an out-of-service display system for a selective call receiver that solves the above-mentioned drawbacks and makes it possible to distinguish the service area of one's own selective call transmitter from other selective call transmitters.

To achieve the above object, the selective call receiver out-of-service area display method according to the present invention is a method for indicating on the selective call receiver when the selective call receiver is out of the service area of the selective call transmitter. , from the selective call transmitter, a word synchronization signal for synchronizing one word of the data string, an individual selection signal for specifying the selective call transmitter, and information indicating an incoming call, an unincoming call, etc. from the base station. On the other hand, the selective call receiver establishes word synchronization using the word synchronization signal and determines whether the individual selection signal is a signal from a corresponding selective call transmitter; The device is configured to display an out-of-service-area message when a predetermined individual selection signal cannot be received for a predetermined period of time or longer.

Hereinafter, the present invention will be explained in more detail with reference to the drawings and the like. FIG. 3 is an example of a data string used in the out-of-service area display method of the selective calling receiver according to the present invention.
When the activation permission switch 4 is turned on, the selective call transmitter 2 (hereinafter referred to as the master station) sends a signal consisting of (bit synchronization + word synchronization + individual number + information) continuously or in bursts to the selective call receiver 3 (hereinafter referred to as the slave station). station)
Send to. A signal for synchronizing the word is inserted into the word synchronization area from the free run state. A number indicating the master station transmitting the data string is inserted into the individual number area. The information area also includes an incoming call code if there is an incoming call, and a missed call code if there is no incoming call.

FIG. 4 is a circuit block diagram showing one embodiment of the master station. The radio section 12 demodulates the signal from the master station 3. The incoming call signal detection unit 13 decodes the information part of the data string and detects whether there is an incoming call. The word synchronization detection section 16 decodes the word synchronization section,
Synchronize Word. The selection signal detection unit 17 decodes the individual number part and checks whether it is a predetermined individual number. The control unit 18 has a counting function,
The outputs of the word synchronization detection section 16 and the selection signal detection section 17 control the incoming call signal detection section 13 and the ringing sound generation section. 15 is a sounding body.

When there is an incoming call to the car telephone and a data string containing an incoming call code is sent, the control unit 18 puts the incoming call signal detecting unit 13 in a receivable state based on the output of the word synchronization detection unit. When the individual selection signal detection section 17 detects a predetermined selection signal, the sound generation section 1
4, a permission signal for generating a ring tone is output. When the incoming call code is detected by the incoming call signal detection unit 13, the sound generator 14 is activated and the sound generator 15
A ring tone is output to notify you of an incoming call. If there is no incoming call and a missed call code is detected, the sound generator 14 is not activated. On the other hand, outputs detected by the selective call signal detection section 17 and matched with a predetermined selection signal are counted by the control section 18. And if it is no longer counted the predetermined number of times within the predetermined time,
That is, when the user is out of the service area of the parent station, the sound generator 14 is activated so as to emit an alarm sound with a tone different from the ringing sound for notifying an incoming call, and the sound generator 15 sounds the alarm sound.

As explained in detail above, according to the present invention, by sending out a synchronization signal and an individual selection signal from a master station, and demodulating and detecting the individual selection signal at a slave station, it is possible to display without error whether or not it is within its own service area. can.

[Brief explanation of the drawing]

Figures 1 and 2 are schematic diagrams for explaining the car telephone radio system. This shows a case where the service areas of two mobile objects overlap. FIG. 3 is a schematic diagram of a data string received by a selective call receiver, and FIG. 4 is a circuit block diagram showing an embodiment of a selective call receiver constructed in accordance with the system of the present invention. 1...Car telephone radio device, 2...Selective call transmitter (master station), 3, 8, 9...Selective call receiver (slave station), 4...Start permission switch, 5...Base station, 6 , 7... Mobile object (car), 10, 11...
...Service area, 12...Radio device, 13...Incoming call signal detection unit, 14...Sound generation unit, 15...Sound generating unit, 16...Word synchronization detection unit, 17...Selection signal detection unit, 18 ...control section.

Claims (1)

[Claims] 1. In a method of displaying this on the selective calling receiver when the selective calling receiver is out of the service area of the selective calling transmitter, the selective calling transmitter sends a message for synchronizing one word of the data string. A signal consisting of a word synchronization signal, an individual selection signal for identifying the selective call transmitter, and an information signal indicating incoming calls, missed calls, etc. from the base station is transmitted, while the selective call receiver transmits the word synchronization signal. The system synchronizes the words by using the system and determines whether the individual selection signal is a signal from a corresponding selective call transmitter, and displays an out-of-service-area indication when a predetermined individual selection signal cannot be received for a certain period of time. An out-of-service-area display method for a selective calling receiver, which is characterized by: