Global communication system receiver and method for operating the same

• US 5,129,095 A
• Filed: 09/30/1991
• Issued: 07/07/1992
• Est. Priority Date: 11/03/1989
• Status: Expired due to Term

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Macnak, Philip P., Davis, Walter L.
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): CHAROUEL, LISA
• Application Number:
  US07/767,352
• Time in Patent Office: 281 Days
• Field of Search: 455/12, 455/13, 455/32, 455/33, 455/34, 455/54, 455/56, 379/57, 379/58, 379/59, 379/60, 379/63, 340/825.44, 340/311.1, 342/356, 342/357
• US Class Current: 455/12.1
• CPC Class Codes: H04B 7/18567 Arrangements for providing additional services to the basic mobile satellite telephony service
• CPC Class Codes: H04B 7/18578 Satellite systems for providing broadband data service to individual earth stations for selecting H04W; provisions for broadband connection, H04Q11/0478
• CPC Class Codes: H04W 84/022 One-way selective calling networks, e.g. wide area paging

Abstract

A global communications system is described having terrestrial transmitters for transmitting coded message signals in each of a plurality of geographic areas. The global communication system further includes at least one satellite transmitter for transmitting the coded messages signals in each of a plurality of global geographic areas. The coded message signals transmissions include channel identification codewords identifying the terrestrial channels and the satellite channel. The terretrial channel is selected for operation when the channel identification codeword received matches a first predetermined channel identification codeword. The satellite channel is selected for operation when the channel identification codeword does not match the first predetermined channel identification codeword. When the satellite channel is selected the terrestrial channel is periodically reselected to enable decoding the channel identification codeword received on the terrestrial channel. The terrestrial channel is again selected when the channel identification codeword received on the terrestrial channel matches the first predetermined channel identification codeword.

Claims

1. A global communication system, comprising:

terrestrial transmitter means, for transmitting coded message signals on at least one terrestrial channel in a plurality of local geographic areas, the coded message signals transmitted thereon including a first channel identification codeword identifying the terrestrial channel;

satellite transmitter means, for transmitting the coded message signals on at least one satellite channel in a plurality of global geographic areas, the global geographic areas encompassing in part at least one of the local geographic areas, the coded message signals transmitted thereon including a second channel identification codeword, different from the first, identifying the satellite channel; and

receiver means, capable of receiving the coded message signals transmitted on the terrestrial and the satellite channels and including channel selecting means responsive to the channel identification codewords received thereon,

said channel selecting means selecting the terrestrial channel and maintaining the receiver operation thereon when the channel identification codeword received on the terrestrial channel matches the first channel identification codeword, otherwise said channel selecting means selecting the receiver operation on the satellite channel,

said channel selecting means then being further responsive to the channel identification codeword received on the satellite channel, for maintaining the receiver operation on the satellite channel when the channel identification codeword received thereon matches the second channel identification codeword, and periodically thereafter, said channel selecting means reselecting the receiver operation on the terrestrial channel for a predetermined time interval to enable decoding of the channel identification codeword received thereon.

2. The global communication system according to claim 1 wherein said terrestrial transmitter means transmits different channel identification codewords on the terrestrial channels in each of the plurality of local geographic areas.

3. The global communication system according to claim 1 wherein said satellite transmitter means transmits different channel identification codewords on the satellite channels in each of the plurality of global geographic areas.

4. The global communication system according to claim 1 wherein said channel selecting means selects the satellite channel only when the channel identification codeword received on the terrestrial channel fails to match the first predetermined codeword within the predetermined number of detection time intervals.

5. A global communication receiver, capable of receiving coded messages signals transmitted on at least two channels, the second channel being transmitted from a satellite, the coded message signals including a first channel identification codeword identifying the first channel, and a second channel identification codeword, different from the first, identifying the second channel, said global communication receiver comprising:

receiver means, for receiving the coded message signals transmitted on the first and second channels;

decoding means, responsive to the received coded message signals, for decoding the channel identification codewords; and

channel selecting means, responsive to said decoding means, for maintaining the receiver operation on the first channel, when the received channel identification codeword received on the first channel matches the first channel identification codeword, otherwise said channel selecting means selecting the receiver operation on the second channel,

said channel selecting means, being further responsive to said decoding means, for maintaining the receiver operation on the second channel when the received channel identification codeword received on the second channel matches the second channel identification codeword, and periodically thereafter said channel selecting means reselecting the receiver operation on the first channel for a predetermined time interval to enable decoding of the channel identification codeword received thereon.

6. The global communication receiver according to claim 5 wherein said channel selecting means includes manual switching means for selecting one channel from the first or second channels.

7. The global communication receiver according to claim 5 further including means for indicating to the user the channel status of the receiver.

8. A method for selecting a channel on which a global communication receiver will operate to receive transmitted coded message signals, the global communication receiver capable of receiving at least two channels selected from a plurality of channels, at least one of the channels being transmitted from a satellite, the coded message signals including a first channel identification codeword identifying the first channel, and a second channel identification codeword, different from the first, identifying the second channel, said method comprising the steps of:

presetting the receiver to the first channel, wherein the receiver can detect and decode the coded message signals including the channel identification codewords;

correlating the channel identification codeword received on the first channel with the first channel identification codeword;

maintaining operation of the receiver on the first channel, in accordance with said first step of correlation, when the channel identification codeword received thereon matches the first channel identification codeword;

selecting the second channel transmitted from the satellite in accordance with said first step of correlating when the received channel identification codeword does not match the first predetermined channel identification codeword;

correlating the channel identification codeword received on the second channel with the second predetermined channel identification codeword;

maintaining operation of the receiver on the second channel, in accordance with said second step of correlation, when the channel identification codeword received thereon matches the second channel identification codeword;

periodically thereafter reselecting the first channel for a predetermined time interval to enable decoding of the received channel identification codeword received thereon, in accordance with said second step of correlation; and

maintaining the operation of the receiver on the first channel when the received channel identification codeword again matches the first channel identification codeword.

9. A global communication system, comprising:

terrestrial transmitter means, for transmitting coded message signals on at least one terrestrial channel in a plurality of local geographic areas, the coded message signals including a first transmission attribute identifying the terrestrial channel;

satellite transmitter means, for transmitting coded message signals on at least one satellite channel in a plurality of global geographic areas, the global geographic areas encompassing in part at least one of the local geographic areas, the coded message signals including a second transmission attribute different from the first transmission attribute, for identifying the satellite channel; and

receiver means, capable of receiving the coded message signals on the terrestrial channel and the satellite channel, said receiver means including channel selecting means, responsive to the first transmission attribute received on the terrestrial channel, for maintaining the receiver operation thereon when the transmission attribute received matches the first transmission attribute, otherwise said channel selecting means selecting the receiver operation on the satellite channel,

said channel selecting means then being further responsive to the second transmission attribute received on the satellite channel, for maintaining the receiver operation on the satellite channel when the transmission attribute received thereon matches the second transmission attribute, and for periodically thereafter reselecting receiver operation on the terrestrial channel for a predetermined time interval to enable decoding of the transmission attribute received thereon.

10. The global communication system according to claim 11 wherein said satellite transmitter means transmits different transmission attributes on the satellite channels in each of the plurality of global geographic areas.

11. The global communication system according to claim 9 wherein the terrestrial transmitter means transmits one or more different transmission attributes on each of the terrestrial channels in each of the plurality of local geographic areas.

12. The global communication system according to claim 9 wherein the transmission attribute detected on the terrestrial channel includes detection of a predetermined channel operating frequency.

13. The global communication system according to claim 9 wherein the transmission attribute detected on the terrestrial channel includes detection of a predetermined signaling protocol.

14. The global communication system according to claim 9 wherein transmission attribute detected on the terrestrial channel includes detection of a predetermined coded synchronization codeword.