Method to allow a radio transceiver to automatically select from amongst multiple radio systems

• US 5,261,117 A
• Filed: 03/27/1986
• Issued: 11/09/1993
• Est. Priority Date: 12/28/1984
• Status: Expired due to Term

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Olson, Carl B.
• Primary Examiner(s): Ng, Jin F.
• Assistant Examiner(s): SOBUTKA, PHILIP
• Application Number:
  US06/845,161
• Time in Patent Office: 2,784 Days
• Field of Search: 455/32.1, 455/33.1, 455/33.2, 455/33.4, 455/34.1, 455/17, 455/54.1, 455/54.2, 455/56.1, 455/76, 455/77, 455/166.2, 379/58
• US Class Current: 455/510
• CPC Class Codes: H04W 4/10 Push-to-Talk [PTT] or Push-On-Call services
• CPC Class Codes: H04W 48/18 Selecting a network or a communication service
• CPC Class Codes: H04W 76/45 for Push-to-Talk [PTT] or Push-to-Talk over cellular [PoC] services
• CPC Class Codes: H04W 84/08 Trunked mobile radio systems
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A method and means of automatically accessing several types of radio systems is described. The present invention allows a subscriber unit, which is normally operative in a operator selected radio system, to establish communication with an alternate system if a operator selected system cannot be found. The alternate system may be a conventional single channel mobile relay system or trunked radio system in which the subscriber is authorized to operate. Once communications are established with an alternate communication system, the present invention will periodically attempt to establish communication with the operator selected system while simultaneously attempting to be assigned a higher priority channel in the alternate communication systems according to a priority scan list. Further, the present invention will automatically ignore certain channels which are dedicated for car-to-car use.

Claims

1. A method of controlling a portable or mobile transceiver for automatically seeking an available communications system if a operator selected communication system is not available in an area having a plurality of trunked and non-trunked communications systems, said method comprising the steps of:

(a) searching for a communication channel on an operator selected trunked or non-trunked communication system, and remaining on that system if it can be found;

(b) searching for an alternate channel on another trunked or non-trunked communication system according to a prearranged priority scan list, if said operator selected system cannot be found;

(c) locking onto an alternate non-trunked system if the alternate non-trunked system responds with an acknowledgement when interrogated, or locking onto a trunked system upon detecting a trunked system data channel;

(d) periodically attempting to reestablish communications on the operator selected system system on a periodic basis; and

(e) periodically searching for a higher priority trunked or non-trunked system according to said priority scan list if a channel on the operator selected system cannot be found.

2. A method of controlling a portable or mobile transceiver for automatically seeking an available communications system if a operator selected communication system is not available in an area having a plurality of trunked and non-trunked communications systems, said method comprising the steps of:

(a) searching for a communication channel on an operator selected trunked or non-trunked communication system, and remaining on that system if it can be found;

(b) searching for an alternate channel on another trunked or non-trunked communication system according to a prearranged priority scan list, if said operator selected system cannot be found;

(c) locking onto an alternate non-trunked system if the alternate non-trunked system responds with an acknowledgement when interrogated, or locking onto a trunked system upon detecting a trunked system data channel;

(d) periodically attempting to reestablish communications on the operator selected system system on a periodic basis;

(e) returning to the last assigned alternative system is said operator selected system cannot be found; and

(f) periodically searching for a higher priority trunked or non-trunked system according to said priority scan list if a channel on the last assigned alternative system cannot be found.

3. A method of controlling a portable or mobile transceiver for automatically seeking an available communications system if a operator selected communication system is not available in an area having a plurality of trunked and non-trunked communications systems, said method comprising the steps of:

(a) searching for a communication channel on an operator selected trunked or non-trunked communication system, and remaining on that system if it can be found;

(b) searching for an alternate channel on another trunked or non-trunked communication system according to a prearranged priority scan list, if said operator selected system cannot be found;

(c) locking onto an alternate non-trunked system if the alternate non-trunked system responds with an acknowledgement when interrogated, or locking onto a trunked system upon detecting a trunked system data channel;

(d) remaining on an alternate trunked or non-trunked communication system for a predetermined period of time if said portable or mobile transceiver transmits on that system;

(e) periodically attempting to reestablish communications on the operator selected system system on a periodic basis; and

(f) periodically searching for a higher priority trunked or non-trunked system according to said priority scan list if a channel on the operator selected system cannot be found.

4. A method of controlling a portable or mobile transceiver for automatically seeking an available communications system if a operator selected communication system is not available in an area having a plurality of trunked and non-trunked communications systems, said method comprising the steps of:

(a) searching for a communication channel on an operator selected trunked or non-trunked communication system, and remaining on that system if it can be found;

(b) searching for an alternate channel on another trunked or non-trunked communication system according to a prearranged priority scan list, if said operator selected system cannot be found;

(c) locking onto an alternate non-trunked system if the alternate non-trunked system responds with an acknowledgement when interrogated, or locking onto a trunked system upon detecting a trunked system data channel;

(d) remaining on an alternate trunked or non-trunked communication system for a predetermined period of time if said portable or mobile transceiver transmits on that system;

(e) periodically attempting to reestablish communications on the operator selected system on a periodic basis; and

(f) returning to the last assigned alternative system is said operator selected system cannot be found; and

(g) periodically searching for a higher priority trunked or non-trunked system according to said priority scan list if a channel on the last assigned alternative system cannot be found.

5. A transceiver which is compatible with both trunked and non-trunked communication systems, said transceiver comprised of:

(a) means for enabling an operator activated automatic mode in said transceiver wherein said automatic mode provides a means to request trunked or non-trunked service;

(b) means for determining whether trunked or non-trunked service has been requested;

(c) means for searching and detecting available trunked channels assigned to the particular transceiver;

(d) means for locking onto an available data channel, if trunked service has been requested, if data activity is present, and if a valid system I.D. has been detected,

(e) means for interrogating available non-trunked systems according to a prearranged priority scan list;

(f) means for locking onto a non-trunked system if that system responds with an acknowledgement signal when interrogated;

(g) means for periodically searching for channel activity on trunked system data channels;

(h) means for attempting to reestablish communication with the operator selected trunked or non-trunked communication system on a predetermined periodic basis;

(i) means for periodically attempting to reestablish communication on a higher priority system if not operating on an operator requested system, unless the alternate system can be reacquired; and

(j) means to delay the periodic attempt to reestablish communication on the operator selected system or a higher priority system if the radio has recently been transmitting.