JPH0473814B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention enables smooth sharing of the same radio waves where interference occurs between several distributed multi-channel access radio telephone systems.

(Prior art and its problems) Figure 1 shows a distributed multi-channel access wireless telephone system, where C is the control station for the entire system, and L, L ₂ ...L _o are installed in each district. A multichannel access line is configured between the terminal stations P ₁ , P _{2 .} . . P _n in the master station device of the system.
Therefore, it is possible to select and use an empty radio wave from among a plurality of radio waves. L ₁ , L ₂ ...There is no problem if the radio waves used in _Lo do not interfere with each other, but when the same radio waves are shared by multiple systems, interference between the systems becomes a problem. When a terminal station P _n makes a call, the terminal station cannot know whether the radio wave is being used by another system. At control station C, systems L ₁ , L ₂ ...
...Since it is possible to monitor the radio waves used in _Lo , it is necessary for the terminal station to first try making a call from a channel that is not in use in the same system, check whether that radio wave is in use, and then connect the line. be.

However, if that line is in use, the call signal and number information from the call will interfere with the uplink line in use, causing interference.

(Purpose) In order to eliminate this drawback, the present invention transmits a call signal with only the call type and system identification information when making a call from a terminal station to a shared channel of radio waves. After receiving the call permission signal, the calling station number,
By transmitting the called station number, etc., interference on the line during a call is reduced.

(Example) An example of the present invention will be described below with reference to a time chart shown in FIG.

A, B, and C indicate the status of the terminal station;
E and F indicate the status of the master station line control device. Part A shows the transmission timing of the terminal station. When a call is made from the telephone of the terminal station, it finds its own empty channel, starts up the transmitter as shown in Part A, and receives the signal from the master station. After the necessary time for the machine to start up, the master station sends out a selection signal that can identify the call from its own system, including the call type and system identification information shown in A-2, stops transmission, and Wait for the oscillation permission signal from the station. When the master station receives the selection signal 2 from the terminal station, if there is no busy signal (indicated by a dotted line) sent from the control station shown in (f), it sends out the calling permission signal shown in (d)3. After the terminal station receives this call permission signal 3, it sends out the calling station number information, called station information, etc. shown in A-4. The signal d.5 indicates a verification signal sent from the master station.

If the radio waves of the channel originating from the terminal station are being used by another system, a busy signal will be sent from the control station as shown by the dotted line in F, and the call permission signal 3 shown in D will not be sent. Therefore, the terminal station determines that the line is busy and scans the next empty channel.

(Effects) As explained above, even if a terminal station makes a call from a busy channel according to the present invention, the interference to the busy channel will only last for several hundred milliseconds, so it will not affect the call and will allow the line to be used with less noise. Can be configured.

[Brief explanation of the drawing]

FIG. 1 shows a diagram of a distributed multi-channel access wireless telephone system. C: control station, L ₁ to _{L o} : district control station and master station of the multi-channel access system, P ₁ to _{P n} : terminal station, FIG. 2 shows a time chart in an embodiment of the present invention.

Claims (1)

[Claims] 1. In a system that has a control station that controls multiple multichannel access radiotelephone systems and monitors and controls the availability of radio waves shared among the multichannel access radiotelephone systems, When making a call from a system system terminal station, a calling signal containing only the system identification signal and call type information is sent out in a short period of time, and after receiving a call permission signal from the master station, the terminal station A multichannel access wireless telephone system characterized by reducing interference to busy lines by transmitting a calling station number and a called station number.