JPH0736541B2 - Wireless communication system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a wireless communication system by time division multiplexing, and more particularly to an idle channel notification control technique for a call waiting subscriber terminal.

(Prior Art) As shown in FIG. 4, a time division multiplex wireless communication system to which the present invention is applied, a master station 401 connected to a switching line (not shown), and a time division multiplex to the master station 401. It is composed of a plurality of slave stations (402, 402, ...) Connected via a wireless line, and each slave station 402 has a plurality of subscriber lines (404, 404, ...) Connected to a terminal (telephone, facsimile, etc.) 403. It is housed.

In addition, as shown in FIG. 5, the transmission frame in the time division multiplexing is one control channel (CH).
₀ ) and a plurality of communication channels (CH _{1 to} CHn).

Control channel CH ₀ consists of preamble area 501, synchronization area 502, control area 503, etc.
3 is for call control, call control, etc., and is a control area 50 of the downlink control channel CH ₀ from the master station 401 to the slave station 402.
Callable channel information indicating the presence / absence of an empty channel is inserted in the predetermined area of 3. The call channels (CH _{1 to} CHn) are the preamble area 504, synchronization area 505, communication data area 506, and service area.
507, and when one subscriber terminal is in a call state, 1
The call channel is used.

By the way, the conventional slave station is configured as shown in FIG. 6, for example. In FIG. 6, 601 is an antenna duplexer, 602 is a receiver, 603 is a decoder, 604 is a calling channel detection circuit, and 60.
5 is a Busy Tone control circuit, 606 is an OFF-HOOK detection circuit, 607 is a transmission control circuit, and 608
Is an encoder, 609 is a transmitter, and 610 is a subscriber line interface circuit that interfaces with each subscriber line 404 accommodated in the child station 402.

In such a configuration, when a subscriber terminal now makes a call (OFF-HOOK), the off-hook detection circuit 606 detects which subscriber terminal made the call.

At the same time, the calling channel detection circuit 604 detects a calling available channel from the calling available channel information included in the downlink control channel from the master station 401. When there is a callable channel, the transmission control circuit 607 is activated to transmit to the master station 401 on the designated channel.

Next, consider a case where the call volume increases in the system and a subscriber terminal makes a call when all the communication channels are in use. At this time, there is no calling channel signal 611 from the calling channel detection circuit 604 and OF from the off-hook detection circuit 606.
Busy tone control circuit 605 by F-HOOK detection signal 612
Sends a Busy-Tone transmission enable signal 613 to the subscriber line interface circuit 610 to which the calling subscriber terminal belongs to indicate to the subscriber terminal that all channels are in use.

(Means for Solving the Invention) However, in such a conventional notification method by Busy Tone, the subscriber terminal only knows that all channels are in use by Busy Tone, and then an empty channel occurs. It is useless OFF-HOO until it becomes possible to make a call on the subscriber terminal side waiting for a call
There is a problem that K must be repeated.

The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a wireless communication system capable of automatically notifying the generation of an idle channel to a call waiting subscriber terminal side.

(Means for Solving Problems) In order to achieve the above object, the wireless communication system according to the present invention has the following configuration.

That is, the wireless communication system of the present invention is a wireless communication system configured by a master station and a plurality of slave stations that are connected to the master station via a time division multiplex wireless line and accommodate a plurality of subscriber lines. A callable channel detecting means for detecting the presence or absence of a vacant channel from the content of the callable channel area of the downlink control channel; a call for detecting a call of a terminal connected to the subscriber line; A detecting means; a calling disabling signal sending means for sending a calling disabling signal to a terminal that has called when there is no free channel; a subscriber number storage for storing a subscriber number of the terminal to which the calling disabling signal is sent Means for inserting a subscriber number stored in the subscriber number storage means into a call waiting subscriber number area provided in the uplink control channel; and the downlink control channel Subscriber number detection means for detecting a callable subscriber number from the callable subscriber number area; a determination is made as to whether or not the detected subscriber number and the subscriber number stored in the subscriber number storage means match. A subscriber number comparing means; and a vacant channel notifying means for notifying the terminal of the subscriber number of which the judgment result of the subscriber number comparing means is coincident when the vacant channel is generated, And the master station inserts channel information inserting means for inserting the presence / absence information of an empty channel into the callable channel area provided in the downlink control channel; the subscriber number from the call waiting subscriber number area of the uplink control channel. Calling waiting subscriber number detecting means for detecting; calling waiting subscriber number storing means for storing the detected calling waiting subscriber number; When the empty channel generation information is inserted into the No. channel area, the call waiting subscriber number stored in the call waiting subscriber number storage means is inserted into the callable subscriber number area provided in the downlink control channel. And a subscriber number inserting means ;.

(Operation) Next, the operation of the wireless communication system of the present invention configured as described above will be described.

In the master station, the channel information inserting means inserts the presence / absence information of a vacant channel into the callable channel area provided in the downlink control channel, and transmits the channel information to the slave station.

In the slave station, the call enable detection means detects the presence or absence of an empty channel from the content of the call enable channel area of the downlink control channel transmitted from the master station. On the other hand, the call detection means detects a call from a terminal connected to the subscriber line. When a call is made when there is no available channel, the call prohibition signal transmitting means transmits the call prohibition signal to the terminal.

At the same time, the subscriber number of the terminal to which the call disapproval signal is transmitted is stored in the subscriber number storage means, while the call waiting subscriber number insertion means stores the subscriber number stored in the subscriber number storage means. It is inserted into the calling waiting subscriber number area provided on the uplink control channel.

In the master station that has received such an uplink control channel, the call waiting subscriber number detecting means detects the subscriber number from the call waiting subscriber number area of the uplink control channel. The detected calling waiting subscriber number is stored in the calling waiting subscriber number storage means. Then, when the empty channel generation information is inserted into the callable channel area of the downlink control channel, the callable subscriber number insertion means outputs the call waiting subscriber signal stored in the call waiting input person number storage means. It is inserted in the callable subscriber number area provided in the downlink control channel.

On the other hand, in the slave station, the subscriber number detecting means detects a callable subscriber number from the callable subscriber number area of the downlink control channel, and the subscriber number comparing means compares the detected subscriber number with the detected subscriber number. To the terminal of the subscriber number for which it is determined that the subscriber numbers stored in the subscriber number storage means are unmatched, and when the idle channel notification means determines an idle channel, the result of the subscriber number comparison means determines that the subscriber numbers match. Notify that a free channel has occurred.

As a result, the calling waiting subscriber terminal side automatically knows the occurrence of a vacant channel, and it is not necessary to perform unnecessary operations for re-calling.

At this time, since the master station can specify the subscriber terminal that can make a call, the call channel can be effectively used, and even if there are many call waiting subscriber terminals in the entire system, a subscriber that can make a call at the same time Since only one terminal can be provided, there is an effect that collision between subscriber terminals waiting for a call can be prevented.

(Examples) Examples of the present invention will be described below with reference to the drawings. First
FIG. 2 and FIG. 2 show configuration examples of a slave station and a master station that implement the wireless communication system of the present invention.

FIG. 1 shows the configuration of the slave station. In FIG. 1, 101 is an antenna duplexer, 102 is a receiver, 103 is a decoder, 104 is a callable channel detection circuit, 105 is a callable subscriber detection circuit, 106 is a call disable signal transmission circuit, 107 Is a subscriber number comparison circuit, 108 is a calling subscriber number detection circuit, 109 is a subscriber number storage circuit, 110 is an idle channel notification circuit, 113 is an AND circuit, 114 is an off-hook detection circuit, and 115 is a transmission control circuit 116.
Is an encoder, 117 is a transmitter, and 118 is a subscriber line interface circuit.

FIG. 2 shows the configuration of the master station. In FIG. 2, 201 is an antenna duplexer, 202 is a receiver, 203 is a decoder, 204 is a call waiting subscriber number detection circuit, 205 is a subscriber number storage circuit, and 2
06 is a transmission control circuit, 207 is an empty channel detection circuit, 208 is an encoder, and 209 is a transmitter.

FIG. 3 shows the structure of a control channel according to the present invention. This control channel includes a subscriber number area 301 in addition to the above-mentioned briamble area 501, synchronization area 502 and control area 503. This subscriber number area 301 is an area where a call waiting subscriber number is inserted in the uplink control channel from the child station to the parent station, and the call can be made in the downlink control channel from the parent station to the child station. This is the area where the subscriber number is inserted. As described above, in the downlink control channel, the specific area in the control area 503 is used as the callable channel area into which the information about the presence / absence of an empty channel is inserted.

Next, the operation of the free channel automatic notification method of the present invention will be described.

In the slave station, the callable channel detection circuit 104 receives the downlink control channel included in the output of the decoder 103, decodes the content of the callable channel area in the control area 503, and when there is no empty channel, it becomes empty. A no-channel signal 122 is sent to each of the call disabling signal sending circuit 106, the subscriber number storage circuit 109 and one input of the AND circuit 113, and when there is a free channel, a free channel present signal 119 is sent to the free channel notification circuit 110. It is designed to be sent to.

If the subscriber terminal connected to the slave station makes a call when there is no available channel, the off-hook detection circuit 114
Generates an OFF-HOOK detection signal 120, the call origination impossible signal transmission circuit 106 receives the OFF-HOOK detection signal 120 and the empty channel absence signal 122, and the subscriber line interface circuit 118.
The subscriber line interface circuit 118 notifies the corresponding subscriber terminal that the call cannot be made.

This notification is made, for example, by an audible signal different from Busy Tone which is normally used.

At the same time, the subscriber line interface circuit 118 outputs the subscriber number of the calling subscriber terminal to the calling subscriber number detection circuit 108.
The calling subscriber number detecting circuit 108 sends the detected calling subscriber number to the subscriber number storage circuit 109 and the other input of the AND circuit 113. As a result, the subscriber number storage circuit 109 receives the no-channel signal 122 and the calling subscriber number and stores the calling subscriber number. Further, since the AND circuit 113 receives the empty channel no signal 122 and the calling subscriber number and sends the calling subscriber number to the transmission control circuit 115, the transmission control circuit 115 outputs the output of the AND circuit 113 (calling subscriber). Number) and the output of the off-hook detection circuit 114 (OFF-
In response to the HOOK detection signal 120), the calling subscriber number waiting for the calling is inserted into the subscriber number field 301 of the uplink control channel. Therefore, the transmission control circuit 115 also functions as a calling waiting subscriber number insertion means.

On the other hand, in the new station, the calling subscriber number detection circuit 204 detects the above-mentioned calling waiting subscriber number sent through the uplink control channel, and stores it in the subscriber number storage circuit 205. .

Then, when the call between the subscriber terminals ends and the idle channel detection circuit 207 detects it, the transmission control circuit 206
An empty channel number is input to. Transmission control circuit 206
Inserts this vacant channel number into the callable channel area of the control area 503 of the downlink control channel, and at the same time, enters the predetermined subscriber number read from the subscriber number storage circuit 205 as a subscriber number that can be called. Insert in area 301. Therefore, the transmission control circuit 206 also functions as the channel information inserting means and the callable subscriber number inserting means.

Next, in the slave station, the callable channel detection circuit 104 detects the callable channel and then
119) is sent to one input of the idle channel notification circuit 110 and is sent to the subscriber number storage circuit 109 as a read command.

The subscriber number storage circuit 109 receives the read command and stores the stored subscriber number waiting for a call to the subscriber number comparison circuit 107.
To one of the inputs.

On the other hand, the callable subscriber detection circuit 105 detects the callable subscriber number and sends it to the other input of the subscriber number comparison circuit 107.

The subscriber number comparison circuit 107 sends a coincidence signal to the other input of the idle channel notification circuit 110 when the subscriber numbers of both inputs match.

As a result, the idle channel notification circuit 110 notifies the subscriber line interface circuit 118 that a callable channel has occurred. In response to this, the interface circuit 118
A ringer signal is sent to the corresponding subscriber line to notify the subscriber terminal waiting to make a call that it is possible to make a call.

At this time, by distinguishing the ringer ringing method from that at the time of an incoming call, the subscriber terminal can be notified of whether the incoming call or the outgoing call is possible.

Since the master station can select a party to notify that it is possible to make a call when it detects a free channel, even if priority is given by adding an identification code to the calling waiting subscriber number. good. As a result, even if there are many call-waiting subscriber terminals in all systems, only one subscriber terminal can call simultaneously in all systems, and there is no collision with other subscriber terminals. Can be prevented.

(Effects of the Invention) As described in detail above, according to the wireless communication system of the present invention,
When a call is made at the slave station when all call channels are used, the call disable signal is sent to the subscriber terminal, while the subscriber number of the subscriber terminal is stored and the subscriber number is increased. It is transmitted to the master station on the control channel,
The master station stores it as a calling waiting subscriber number.

When an empty channel occurs, the parent station transmits the occurrence of an empty channel on the downlink control channel and the callable subscriber number to the child station, and the child station stores the transmitted callable subscriber number first. The subscriber terminal that waits for the call can automatically know that an idle channel has occurred because the subscriber terminal that matches the received subscriber number is notified of the idle channel connection. Therefore, the calling waiting subscriber terminal does not need to repeat useless calling operations, the number of calling is reduced, and the idle channel is used for immediate communication, so that the radio waves are effectively used.

Also, since the callable subscriber number is sent through the downlink control channel, even if there are many call waiting subscriber terminals in the entire system, only one subscriber terminal can call at the same time. Therefore, it is possible to prevent the situation where the calls of the subscriber terminals collide with each other, which is an excellent effect.

[Brief description of drawings]

FIG. 1 is a block diagram of a slave station according to an embodiment of the present invention, FIG. 2 is a block diagram of a master station according to an embodiment of the present invention, and FIG. 3 is a configuration of a control channel according to the present invention. FIG. 4 is a block diagram showing the configuration of a time division multiplex wireless communication system, FIG. 5 is a diagram showing the configuration of a conventional transmission frame, and FIG. 6 is a block diagram of the configuration of a conventional slave station. 101-antenna duplexer, 102-receiver, 103-decoder, 104-callable channel detection circuit, 105-callable subscriber detection circuit, 106-call-disabled signal transmission circuit, 107
...... Subscriber number comparison circuit, 108 ...... Calling subscriber number detection circuit, 109 …… Subscriber number storage circuit, 110 …… Vacation channel notification circuit, 113 …… And circuit, 114 …… Off-hook detection circuit, 115 ...... Transmission control circuit, 116 …… Encoder, 117…
… Transmitter, 118 …… Subscriber interface circuit, 201…
… Antenna duplexer, 202 …… Receiver, 203 …… Decoder, 20
4 …… Calling waiting subscriber number detection circuit, 205 …… Subscriber number storage circuit, 206 …… Transmission control circuit, 207 …… Free channel detection circuit, 208 …… Encoder, 209 …… Transmitter, 401… ... Parent station, 402 ... Slave station, 403 ... Subscriber terminal connected to the slave station, 404 ... Subscriber line.

Claims (1)

[Claims] 1. A wireless communication system comprising a master station and a plurality of slave stations connected to the master station via a time division multiplex wireless line and accommodating a plurality of subscriber lines; A callable channel detecting means for detecting the presence / absence of an empty channel from the content of the callable channel area of the downlink control channel; a call detecting means for detecting a call from a terminal connected to the subscriber line; Calling disabling signal sending means for sending a calling disabling signal to a terminal that made a call when there is no channel; subscriber number storage means for storing a subscriber number of the terminal to which the calling disabling signal is sent; Caller waiting subscriber number inserting means for inserting the subscriber number stored in the caller number storage means into the call waiting subscriber number area provided in the uplink control channel; and the callable subscriber number of the downlink control channel. A subscriber number detecting means for detecting a subscriber number that can be called from the area; and a subscriber number comparing means for judging whether the detected subscriber number and the subscriber number stored in the subscriber number storage means match or not. A vacant channel notifying means for notifying the terminal of the subscriber number of which the judgment result of the subscriber number comparing means is coincident when the vacant channel is generated; and the master station, Channel information insertion means for inserting information about presence / absence of a vacant channel into the callable channel area provided in the downlink control channel; call waiting subscription for detecting a subscriber number from the call waiting subscriber number area of the uplink control channel Caller number detecting means; caller waiting subscriber number storage means for storing the detected caller waiting subscriber number; callable channel area When the idle channel generation information is inserted, the call waiting subscriber number stored by the call waiting subscriber number storage means is inserted into the callable subscriber number area provided in the downlink control channel. A wireless communication system comprising means and;