JPH0439809B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to switching of radio (speech) channels in a radio telephone device using a multi-channel access method.

[Technical background of the invention and its problems]

A multi-channel access type wireless telephone device allows wireless communication between a fixed station connected to a telephone line and a mobile station under the jurisdiction of the fixed station to be carried out over one wireless channel selected from a plurality of assigned wireless channels. This is done using

FIG. 1 is a block diagram of a conventional wireless telephone device.

A call is made from the telephone 1 to the mobile station 20 via an exchange and subscriber line 2 (not shown).
The signal is transmitted to the fixed station 10 that has jurisdiction over the mobile station 20, or vice versa, from the mobile station 20 to the telephone 1.
When the outgoing signal for the call is transmitted to the fixed station 10, the fixed station 10 selects one radio channel (hereinafter referred to as a call channel) from among the plurality of radio channels allocated to the fixed station that can be used for calls. At the same time, the selected communication channel is notified to the mobile station 20, and the telephone 1
and the mobile station 20 are established.

Here, the selection of the communication channel is performed by the control unit 1.
1, a frequency synthesizer 12 constituting a local oscillator sequentially outputs local signals, and a communication channel having a frequency corresponding to the local signals is received by the receiving unit 14 via the receiving antenna 13, for example. If the electric field strength of a communication channel is below a certain value, that communication channel is selected as an empty channel. Further, the selected communication channel is notified to the mobile station 20 from the transmitting unit 15 via the transmitting antenna 16 via a wireless channel for transmitting and receiving control signals (hereinafter referred to as a control channel) among the plurality of wireless channels. This is done by transmitting a signal indicating the selected communication channel.

In this way, a call state is established, and when transmitting a call from the telephone 1 to the mobile station 20, the voice signal applied from the telephone 1 to the transmitter 15 via the subscriber line 2 and the hybrid circuit 17 is transmitted. Frequency modulation is applied to a carrier wave having a frequency corresponding to the selected communication channel, and the modulated wave is transmitted from the transmitting antenna 16. Also, when receiving a call on the telephone 1, the receiver 14 receives the call via the receiving antenna 13.
A voice signal extracted by demodulating the modulated wave from the mobile station 20 received by the mobile station 20 is transmitted to the telephone 1 via the hybrid circuit 17 and the subscriber line 2. Note that, like the fixed station 10, the mobile station 20 includes a control section 21, a frequency synthesizer 22, a receiving antenna 23, a receiving section 24, a transmitting section 25, and a transmitting antenna 26, and receives and transmits calls via a receiver 27. Although each component is similar to that of the fixed station 10, a description thereof will be omitted.

By the way, when the telephone 1 and the mobile station 20 are in a conversation state through a certain communication channel, another mobile station which is in a conversation state with another telephone through the same communication channel enters into the area of the fixed station 10. As a result, interference may occur due to the use of the same communication channel, resulting in crosstalk, deterioration of call quality due to buzzing, and even the inability to make calls. , I had to hang up and then call again, which was inconvenient. Therefore, by detecting the presence or absence of the interference mentioned above,
A wireless telephone device has been proposed that automatically selects an empty channel among communication channels and switches to the empty channel when interference occurs. In this radio telephone device, an interference detection circuit 18 provided in a fixed station 10 converts a modulated wave inputted into a receiving section 14 into an intermediate frequency, and detects the presence or absence of a beat by detection and amplification. I'll let you know on 11. This is because even if two or more stations use the same communication channel, there is a slight difference in the corresponding frequencies, and a beat occurs as a result of interference. This is to detect the presence or absence of. and control section 11
When the interference detection circuit 18 detects that interference has occurred, it disables the call on the previously used call channel, and establishes a new free call in the same manner as the establishment of the call state described above. The communication channel is switched by selecting a channel and notifying the mobile station 20 of the newly selected communication channel via the control channel or the previously used communication channel. However, the interference detection circuit 18 has flat frequency characteristics over a wide band in order to detect slight frequency differences and detect beats for multiple radio telephone devices having various transmission frequency differences. In addition, various performances are required, such as the detection sensitivity not changing due to fluctuations in the level of the desired wave and the interference wave, and the fixed station 10 has to be equipped with a complicated and expensive interference detection circuit 18. It was hot.

In addition, since the call channel is automatically switched when interference is detected, there is a problem that the call may suddenly be interrupted for a few seconds to 10 seconds regardless of the user's intention, and the call channel cannot be switched. Accompanying loud switching sounds such as data transmission sounds and noise are not desirable.

Furthermore, if exactly the same frequency is used, even though interference is occurring, it cannot be detected, resulting in crosstalk, deterioration of call quality, and even a situation in which calls are impossible.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and provides a wireless telephone device that selects and switches to an empty channel among communication channels only when a mobile station user operates a manual switch when interference occurs. The purpose is to provide.

[Summary of the invention]

Therefore, in the present invention, a manual switch for interference notification is provided in the mobile station of the radio telephone device, and based on the operation of the manual switch, one free radio channel is selected from a plurality of communication channels and automatically switched. I made it.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a wireless telephone device according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 2 is a block configuration diagram of a radio telephone device according to the present invention, and the same reference numerals are used for parts that perform the same functions as in FIG. 1, and the explanation thereof will be omitted.

The mobile station 20 is provided with an automatic contact return type manual switch 29 for interference notification, and a control unit 21
When the manual switch 29 is closed, the fixed station 1
A call channel switching request is issued to 0.
When the fixed station 10 receives a switching request from the mobile station 20, the fixed station 10 newly switches one communication channel from among the plurality of communication channels.
The newly selected communication channel is selected and called back, and the newly selected communication channel is announced via the control channel. Furthermore, fixed station 10 and mobile station 20 are switched to this newly selected communication channel at the same timing.

Note that the manual switch 29 is, for example, the mobile station 20
For outpulse dialer mobile stations, press the number key “#” or “*”
may also be used.

Furthermore, when a call channel switching request is received from the mobile station 20, unnecessary calls due to malfunction of the manual switch 29 can be avoided by detecting whether or not the call channel used before the request is an empty channel. Channel switching may not be performed. Furthermore, when there are no free channels, the call channel that was used before the call channel switching request is returned to, and even if the call quality is poor, the call status is maintained, and the call channel switch request is made again at another time. It may be possible to make it available.

Furthermore, the usage status of the communication channel may be stored in advance in a memory provided in the fixed station 10, so that when the communication channel switching request is received, the communication channel can be immediately switched to an empty channel.

In the above explanation, the fixed station searches for an empty channel, but various modifications are possible, such as searching at the mobile station or checking at both.

Next, the operation of the wireless telephone device according to the present invention will be explained in detail according to the flowchart shown in FIG.

1 Step 100 (Fixed station 10) and Step
200 (Mobile station 20) The fixed station 10 and the mobile station 20 are connected to the mobile station 20 using the number K among the plurality of communication channels assigned to the fixed station 10.
is in a call state via the call channel S _K marked with .

2 Step 201 Determine whether the manual switch 29 is open or closed, and if it is open, proceed to the step 201.
Continue with steps 100 and 200, and if closed, proceed to step 202. Note that steps 100 and 200
Steps 100 and 201 are not performed sequentially; if manual switch 29 is closed at any time during steps 100 and 200, step 202 is immediately followed.

3 Step 202 In order to switch the call channel S _K to another call channel, turn off the transmitter 28 and other audio circuits.

4 Step 203 A call channel switching request is output to the fixed station 10.

5 Step 204 Disable transmission to communication channel S _K.

6. Step 101 If a call channel switching request is received from the mobile station 20 in step 203, the process immediately proceeds to the next step 102. Note that steps 100 and
Similar to steps 200 and 201, steps 100 and 200 and step 101 are not executed sequentially, but proceed to step 102 as soon as a call channel switching request is received from the mobile station 20.

7. Step 102 Determine whether or not the speech channel S _K used before receiving the speech channel switching request is an empty channel. If it is not an empty channel, proceed to step 103; if it is an empty channel, proceed to step 109.

8 Step 103 Start a timer that measures a preset time.

9 Step 104 Any number assigned to the multiple communication channels assigned to the fixed station 10 other than K (the number assigned to the communication channel S _K that was used before receiving the communication channel switching request) Set M to the parameter N.

10 Step 105 It is determined whether the communication channel S _N is an empty channel or not. If it is an empty channel, the process proceeds to the next step 106, and if it is not an empty channel, the process proceeds to step 108.

11 Step 106 Notify mobile station 20 of call channel S _N as the newly selected call channel.

12 Step 107 Call channel before receiving call channel switching request
Switch from S _K to speech channel S _N and proceed to steps 100 and 200 above.

13 Step 108 Determine whether or not the time measurement has ended. If the time measurement has ended, proceed to step 109; if the time measurement has not ended, proceed to step 110.

14 Step 109 Call channel before receiving call channel switching request
The number K assigned to S _K is set to the parameter N, and the process proceeds to step 107.

15 Step 110 The number K and the number other than the number assigned to the parameter N in step 104 are newly set as M, and the process proceeds to step 104.

16 Step 205 When the newly selected speech channel S _N is announced from step 106, the speech channel S _K that was used before the speech channel switching request is switched to the speech channel S _N.

17 Step 206 Enable a call to the call channel S _N and proceed to steps 100 and 200.

As described above, the call channel S _K is switched to the call channel S _N so that the call can be continued.

Note that the present invention is not limited to wireless telephone devices, and the line used is not limited to subscriber lines (public telephone lines). For example, it may be used for a dedicated telephone line such as a press talk radio or a personal radio.

〔Effect of the invention〕

As explained above, according to the present invention, the user can request switching of communication channels at any time at his/her discretion in response to interference that occurs when the same communication channel is used. Communication channels can be switched without using a detection circuit.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a conventional radio telephone device, FIG. 2 is a block diagram of a radio telephone device according to the present invention, and FIG. 3 is a flowchart showing the operation of the radio telephone device according to the present invention. DESCRIPTION OF SYMBOLS 1... Telephone, 2... Subscriber line, 10... Fixed station, 11, 21... Control unit, 12, 22... Frequency synthesizer, 13, 23... Receiving antenna, 14, 24... Receiving unit, 15, 25... Transmission unit, 16, 26... Transmission antenna, 17... Hybrid circuit, 18... Interference detection circuit, 20...
Mobile station, 27...Telephone receiver, 28...Telephone transmitter, 29
...Manual switch for interference notification.

Claims (1)

[Claims] 1. Wireless communication between a fixed station and a mobile station connected to a wired line is carried out using one selected from a plurality of wireless channels.
In a wireless telephone device using a multi-channel access method through two wireless channels, the mobile station is provided with a manual switch for notifying interference, and the mobile station or the commercial station is provided with the plurality of access signals based on the operation of the manual switch. 1. A wireless telephone device comprising a switching means for selecting an empty wireless channel from wireless channels and automatically switching to the selected wireless channel. 2. A patent claim characterized in that the switching means selects the wireless channel with the highest priority when detecting the wireless channel that was being used immediately before operating the manual switch and detecting that the wireless channel is an empty channel. The wireless telephone device according to item 1. 3. The wireless telephone device according to claim 1, wherein the switching means selects the wireless channel that was being used immediately before the manual switch was operated when it is detected that there is no free channel. 4. The wireless communication device according to claim 1, wherein the switching means includes a memory that stores in advance the usage status of a plurality of wireless channels, and selects a wireless channel based on the contents stored in the memory. Telephone device.