Method and apparatus for transmitting information for multiple independent users in a communication system

• US 5,627,830 A
• Filed: 03/31/1993
• Issued: 05/06/1997
• Est. Priority Date: 02/27/1990
• Status: Expired due to Term

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Kotzin, Michael D.
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): HOM, SHICK C
• Application Number:
  US08/040,790
• Time in Patent Office: 1,497 Days
• Field of Search: 370/95.1, 370/95.3, 370/85.2, 370/105.1, 370/50.1, 370/94.1, 370/57, 370/104.1, 370/108, 370/18, 375/40, 375/38, 375/200, 375/211, 375/202, 375/203, 455/56.1, 455/59, 455/33.2, 379/60
• US Class Current: 370/336
• CPC Class Codes: H04W 36/30 by measured or perceived connection quality data

Abstract

An RF cellular communication system employing offset frame synchronization between cells, any cell being omni-directional or directional, such that a frame at one cell is offset by an integral number of frames from another cell; the system incorporating multiplexed speech transcoding of traffic channels from multiple cells while supporting stringent delay requirements. Offset frame synchronization for providing rapid mobile assisted handoff.

Claims

1. In a radio frequency communication system supporting a plurality of traffic channels, the traffic channel being framed so as to implement traffic channel frames, a method of transmitting information for multiple independent users comprising:

independently coding information from at least two of said multiple independent users to produce independently coded information for the at least two of said multiple independent users;

placing said independently coded information for the at least two of said multiple independent users into different traffic channel frames; and

transmitting at least two of said traffic channel frames staggered by a time offset related to the traffic channel frame.

2. The radio frequency communication system of claim 1 wherein the traffic channel frames correspond to information inputs which are similarly offset in time.

13. The method of claim 1 wherein the time offset is related to a fraction of the traffic channel frame.

14. The method of claim 1 wherein the information from each of said multiple independent users further comprises speech information from each of said multiple independent users.

15. The method of claim 1 wherein the step of transmitting occurs from a base site to at least two multiple independent users.

16. The method of claim 1 wherein the step of transmitting some of said traffic channel frames staggered by a time offset related to the traffic channel frame further comprises transmitting some of said traffic channel frames staggered, relative to one another, by a time offset related to the traffic channel frame.

17. The method of claim 1 wherein the step of transmitting some of said traffic channel frames staggered by a time offset related to the traffic channel frame further comprises the step of transmitting some of said traffic channel frames staggered, relative to a traffic channel frame having no time offset, by a time offset related to the traffic channel frame.

3. In a radio frequency cellular communication system using carriers, having at least a first and second cell, each cell being assigned at least one carrier, a method of organizing independently coded frames comprising:

providing an independently coded frame for the at least first cell'"'"'s carrier,

providing a corresponding independently coded frame for the at least second cell'"'"'s carrier; and

staggering the independently coded frames for the at least first cell'"'"'s carrier from that of the at least second cell'"'"'s carrier by a predetermined time related to the independently coded frames.

4. The cellular communication system of claim 3 wherein the corresponding independently coded frame, for the at least second cell'"'"'s carrier, comprises information whose content results from a substantially similar algorithmic operation also used to obtain information contained in the independently coded frame for the at least first cell'"'"'s carrier.

5. The cellular communication system of claim 3 wherein the predetermined time related to the coded frames comprises a fraction of the independently coded frames.

6. In an RF communication system using carriers, having at least a first cell and at least one handoff cell, wherein either of the cells may be omni-directional or directional, each cell being assigned at least one carrier, and at least one subscriber unit communicating with the first cell, a system apparatus for synchronization comprising:

at least one base site controller including means for offsetting frame timing between the at least first cell and the at least one handoff cell by a predetermined time, and

the at least one subscriber unit having;

i) means for determining the offset frame timing difference between a frame received from the at least one handoff cell and that of the at least first cell,

ii) means, operably coupled to means for determining, for establishing where information is expected in the frame received from the at least one handoff cell, and

iii) means, operably coupled to means for determining, for transferring from the carrier assigned to the at least first cell, to the carrier assigned to the handoff cell, without synchronizing to a specific frame number of the at least handoff cell thereby facilitating a rapid handoff.

7. The cellular system of claim 6 wherein the predetermined time comprises an integral number of frames.

8. The cellular system of claim 6 wherein the subscriber unit further comprises means for prioritizing a search based upon the frame number received from each of a plurality of neighboring cells to minimize the time to acquire subsequent neighboring cell information.

9. A subscriber unit for use in an RF cellular communication system having at least a first cell and handoff cell, wherein either of the cells may be omni-directional or directional, each cell being assigned at least one carrier, the subscriber unit comprising:

means for determining an offset frame timing difference between a frame received from the at least one handoff cell and that of the at least first cell, and

means, operably coupled to means for determing, for establishing where information is expected in the frame received from the at least one handoff cell

means, operably coupled to means for determining, for transferring from the carrier assigned to the at least first cell, to the carrier assigned to the handoff cell, without synchronizing to a specific frame number of the at least one handoff cell thereby facilitating a rapid handoff.

10. In a radio frequency communication system supporting a plurality of traffic channels, the traffic channel being framed so as to implement traffic channel frames, an apparatus for transmitting information for multiple independent users comprising:

means for independently coding information from at least two of said multiple independent users to produce independently coded information for the at least two of said multiple independent users;

means for placing said independently coded information for the at least two of said multiple independent users into different traffic channel frames; and

means for transmitting at least two of said traffic channel frames staggered by a time offset related to the traffic channel frame.

11. The radio frequency communication system of claim 10 wherein the traffic channel frames correspond to information inputs which are similarly offset in time.

18. The apparatus of claim 10 wherein the time offset is related to a fraction of the traffic channel frame.

19. The apparatus of claim 10 wherein the information from each of said multiple independent users further comprises speech information from each of said multiple independent users.

20. The apparatus of claim 10 wherein the means for transmitting is located at a base site.

21. The apparatus of claim 10 wherein the means for transmitting some of said traffic channel frames staggered by a time offset related to the traffic channel frame further comprises means for transmitting some of said traffic channel frames staggered, relative to one another, by a time offset related to the traffic channel frame.

22. The apparatus of claim 10 wherein the step of transmitting some of said traffic channel frames staggered by a time offset related to the traffic channel frame further comprises transmitting some of said traffic channel frames staggered, relative to a traffic channel frame having no time offset, by a time offset related to the traffic channel frame.

12. In a radio frequency cellular communication system using carriers, having at least a first and second cell, each cell being assigned at least one carrier, an apparatus for organizing independently coded frames comprising:

means for providing an independently coded frame for the at least first cell'"'"'s carrier;

means for providing a corresponding independently coded frame for the at least second cell'"'"'s carrier; and

means for staggering the independently coded frames for the at least first cell'"'"'s carrier from that of the at least second cell'"'"'s carrier by a predetermined time related to the independently coded frames.

23. In a radio frequency communication system having an air-interface structure supporting a plurality of traffic channels, the air-interface structure being framed such that the plurality of traffic channels are organized as traffic channel frames, the traffic channel frames containing information in the form of traffic channel packets, a method of transmitting the traffic channel packets to multiple independent users comprising:

staggering the generation of traffic channel packets to be transmitted to the multiple independent users to produce staggered traffic channel packets; and

transmitting the staggered traffic channel packets to the multiple independent users.

24. The method of claim 23 wherein the generation of the traffic channel packets further comprises at least transcoding information from each of said multiple independent users.

25. The method of claim 24 wherein transcoding information from each of said multiple independent users further comprises transcoding speech information from each of said multiple independent users.

26. A method of transmitting information to multiple users in a wireless communication system, the wireless communication system implementing a base site which supports the transmission of traffic channel frames, the method comprising the steps of:

coding information for each of said multiple users to produce coded information for each of said multiple users;

placing a portion of said coded information for each of said multiple users into a traffic channel frame; and

transmitting some of the traffic channel frames staggered by a time offset related to a fraction of the traffic channel frame.

27. The method of claim 26 wherein the information for each of said multiple users further comprises speech information for each of said multiple users.

28. A apparatus for transmitting information to multiple users in a wireless communication system, the wireless communication system implementing a base site which supports the transmission of traffic channel frames, the apparatus comprising:

means for coding information for each of said multiple users to produce coded information for each of said multiple users;

means for placing a portion of said coded information for each of said multiple users into a traffic channel frame; and

means for transmitting some of the traffic channel frames staggered by a time offset related to a fraction of the traffic channel frame.

29. The apparatus of claim 28 wherein the information for each of said multiple users further comprises speech information for each of said multiple users.

30. The apparatus of claim 28 wherein the means for transmitting some of the traffic channel frames staggered by a time offset related to a fraction of the traffic channel frame further comprises means for transmitting some of the traffic channel frames staggered, relative to a frame having no time offset, by a time offset related to a fraction of the traffic channel frames.