Radio communication system for communicating between two stations upon automatic switching to an idle communication channel

• US 4,850,030 A
• Filed: 10/28/1987
• Issued: 07/18/1989
• Est. Priority Date: 06/23/1984
• Status: Expired due to Fees

• Current Assignee: TRIO Kabushiki Kaisha
• Original Assignee: TRIO Kabushiki Kaisha
• Inventors: Hashimoto, Hiroyuki, Suzuki, Akira, Iizuka, Nobuo
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Smith, Ralph E.
• Application Number:
  US07/113,355
• Time in Patent Office: 629 Days
• Field of Search: 455/31-35, 455/38, 455/54, 455/62, 379/63
• US Class Current: 455/516
• CPC Class Codes: H04W 36/06 Reselecting a communication resource in the serving access point
• CPC Class Codes: H04W 4/10 Push-to-Talk [PTT] or Push-On-Call services
• CPC Class Codes: H04W 76/45 for Push-to-Talk [PTT] or Push-to-Talk over cellular [PoC] services

Abstract

In the radio communication system for performing a communication in the idle channel selected from a plurality of frequency channels, the originating call station transmits the station identification code to specify the distant station together with the idle channel data to be actually communicated, and the distant station designated by the station identification code shifts to the designated idle channel, and the communication is executed between two stations. During communication in a certain channel between two stations, in the case where a radio interference occurs in this channel and it is intended to shift to other channel, one station transmits the other channel data in the communication channel and the other station receives it, and the communication is continued each other in the other channel.

Claims

1. A radio communication system including a plurality of stations in which each station includes a radio transceiver including transmitting and receiving sections and a communication is performed between stations on an idle frequency channel which is selected from a plurality of frequency channels, comprising:

an originating call station, said originating call station being one of the plurality of stations, including first means for determining an idle channel, means for transmitting a station identification code and an idle channel code indicative of said idle frequency channel on a special originating call channel which is preliminarily arbitrarily determined between stations, and means for shifting said originating call station to said idle channel after transmission of said station identification code and said code indicative of said idle channel;

a terminating station, said terminating station being one of the plurality of stations, including an apparatus for standing by on said originating call channel, second means for determining when the station identification code in a received signal coincides with a self identification code of said terminating station, and means responsive to said second means for determining shifting of said terminating station to the channel corresponding to said idle channel code in said received signal, thereby performing the communication between at least said two stations on said idle channel; and

means provided in one of said communicating stations for transmitting another idle channel code to the other one of said communicating stations on said communication channel, means provided in said one of said communicating stations for shifting the frequency channel to said another idle channel when said another idle channel is transmitted;

means provided in the other station for responding to said another idle channel code on said communication channel and for shifting to the another idle channel, and means for performing the communication between at least said two stations in said another idle channel.

2. A radio transceiver for use in the radio communicating system according to claim 1, wherein said transceiver further comprises:

frequency signal generating means which determines the communication channel;

a tramsnitting section which uses a frequency signal determined by said frequency signal generating means as a carrier and modulates by said station identification code and said idle channel code and transmits;

a receiving section which receives the signal of the channel of the frequency determined by said frequency signal generating means and demodulates said signal; and

a processor to control said transceiver,

and wherein said processor detects the dile channel by sweeping a communication band in response to an originating call command and allows the channel code corresponding to said detected idle channel and said station identification code to be transmitted in said originating call channel by said transmitting section and thereafter allows said receiving section to stand by so that said receiving section can receive in said detected idle channel,

said processor discriminates to determine whether the station identification code in said received signal received in said receiving section in said originating call channel coincides with the self identification code in response to a reception command, and when said two codes coincide, said processor controls said receiving section such that said receiving section shifts to the idle channel designated in said received signal, and

said processor controlling in a manner such that said other channel code is transmitted in the channel during communication and the frequency channel is shifted to said other channel in response to a command to shift to the other channel and such that the frequency channel is shifted to said other channel in response to the other channel code received in the channel during said communication.

3. A radio transceiver according to claim 2, further comprising a memory to store the channel to be excluded when the idle channel search is swept, and in which when the detected idle channel is the exclusion channel stored in said memory, said processor skips said detected idle channel and searches the next idle channel.

4. A radio transceiver according to claim 2, further comprising a memory to store the channel to be captured when the idle channel search is swept, and in which when the detected idle channel is the capture channel stored in said memory, said processor captures said detected idle channel.

5. A radio transceiver according to claim 2, further comprising means for locking the communication channel, and in which when the communication channel is locked, even if a signal to shift to the other channel is received in said communication channel, the shift to said other channel is not performed.

6. A radio transceiver according to claim 2, further comprising a memory to store the channel to be locked, and in which when said communication channel corresponds to said lock channel stored in said memory, said processor inhibits the shift to the other channel in said communication channel.

7. A radio transceiver according to claim 2, further comprising code squelch means which outputs the received signal only when said station identification code in said received signal coincides with the self station identification code upon reception.

8. A radio transceiver according to claim 2, wherein said self station identification code includes a plurality of codes, and a control is performed so as to shift to the channel which is designated by said received signal in response to the received signal including the station identification code corresponding to any of said codes.

9. A radio transceiver according to claim 2, further comprising means which alternately shifts between said originating call channel and the communication idle channel.

10. A radio transceiver according to claim 2, further comprising means for transmitting a call sign in addition to said code and means for inputting alphabets of said call sign by a numeral code of two digits.

11. A method of operating a radio communication system including a plurality of stations, each station having a radio transceiver including transmitting and receiving sections, comminication being performed between stations on an idle frequency channel selected from a plurality of frequency channels, comprising the steps of:

providing an originating call station, said originating call station being one of said plurality of stations;

causing said originating call station to determine an idle channel, to trasmit a station identification code, and to transmit an idle channel code indicative of said channel on a special originating call channel which is preliminarily arbitrarily determined between stations, and to thereafter shift said originating call station to said idle channel,

providing a terminating station, said terminating station being one of said pluality of stations;

causing said terminating station to stand by on said originating call channel, and when the station identification code in a received signal coincides with a self identification code of said terminating station, causing the terminating station to shift to said idle channel corresponding to said idle channel code in said received signal, thereby performing the communication between at least said two stations on said idle channel; and

in either one of said communicating stations, after another idle channel code is transmitted from the one communicating station to the other communicating station on said communication channel, shifting the frequency channel to said another idle channel, causing the other communicating station to respond to said another idle channel code on said communication channel and to shift to said another idle channel, the communication between at least said two stations being performed on said another idle channel.

12. A method of operating a radio transceiver for use in the radio communication system according to claim 11, further comprising the steps of:

determining the communication channel using frequency signal generating means;

causing a transmitting section to transmit, using a frequency signal determined by said frequency signal generating means as a carrier and modulating by said station identification code and said idle channel code;

receiving in a receiving section, the signal of the channel of the frequency determined by said frequency signal generating means and demodulating said signal;

controlling said transceiver via a processor;

wherein said processor detects the idle channel by sweeping a communication band in response to an originating call command and allows the channel code corrsponding to said detected idle channel and said station identification code to be transmitted in said originating call channel by said transmitting section and thereafter allows said receiving section to stand by so that said receiving section can receive in said detected idle channel;

said processor discriminating to determine whether the station identification code in said received signal received in said receiving section in said originating call channel coincides with the self identification code in response to a reception command, and when said two codes coincide, said processor controlling said receiving section such that said receiving section shifts to the idle channel designated in said received signal, and

said processor controlling in a manner such that said other channel code is transmitted in the channel during communication and the frequency channel is shifted to said another channel in response to a command to shift to the other channel and that the frequency channel is shifted to said other channel in response to the other channel code received in the channel during said communication.

13. A radio communication system including at least two stations in which each station includes a radio transceiver including transmitting and receiving sections and a communication is established between the stations on a frequency channel which is selected from a plurality of frequency channels, comprising:

a transceiver of the station transmitting a control signal at a predetermined time during the communication through the frequency channel established between one and the other stations, a predetermined part of the control signal being selectively set as either one of specific code or a shift channel frequency code, the transceiver of one station shifting to the shift channel from the established channel after transmitting the shift channel frequency code through the established channel; and

a transceiver of the other station in response to the received control signal on the established channel, keeping the established channel when the recieved control signal includes the specific code and shifting to the shift channel when the received control signal include the shift channel frequency code.

14. A radio communication system according to claim 13, wherein said transceiver of one station in response to a channel shift instruction conducts a search for an idle channel among the plurality of frequency channels and set the searched idle channel for the control signal.