Dynamic control of a data channel in a TDM wireless communication system

• US 5,598,417 A
• Filed: 05/13/1996
• Issued: 01/28/1997
• Est. Priority Date: 04/28/1995
• Status: Expired due to Term

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Crisler, Kenneth J., Needham, Michael L.
• Primary Examiner(s): Safourek, Benedict V.
• Assistant Examiner(s): PHILLIPS, MATTHEW
• Application Number:
  US08/644,929
• Time in Patent Office: 260 Days
• Field of Search: 370/95.1, 370/95.2, 370/95.3, 370/79, 370/80, 370/110.1, 370/110.4
• US Class Current: 370/348
• CPC Class Codes: H04B 7/2643 using time-division multiple access [TDMA] H04B7/2615, H04B7/2618 take precedence
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 74/04 Scheduled access hybrid access H04W74/02

Abstract

A central controller (101) in the TDM wireless communication system (100) transmits a data channel update message (600), including an allocation profile (603) and an update interval (605) to a second group of communication units (107-109). The allocation profile indicates time slots used to form a data channel and the update interval indicates a period of time until transmission of the next data channel update message. The data channel update message, transmitted via the data channel, is sent in response to a request from a first group of communication units (104-106) or upon expiration of a period of time based on a previous update interval. Repetition of this process allows time slots to be dynamically allocated in response to changing system requirements, while minimizing use of the data channel for data channel update messages.

Claims

1. In a TDM wireless communication system comprising a plurality of communication units and a central controller that allocates a plurality of time slots among the plurality of communication units, wherein the plurality of communication units are logically divided into a first group and a second group, and wherein a data channel allocated to the second group comprises a portion of the plurality of time slots, a method for the central controller to dynamically control the portion of the plurality of time slots, the method comprising steps of:

a) receiving from a communication unit of the first group a request for at least one time slot of the plurality of time slots;

b) transmitting, via the data channel, responsive to the request, a data channel update message to the second group, wherein the data channel update message comprises an allocation profile that indicates the portion of the plurality of time slots; and

c) allocating the at least one time slot to the communication unit of the first group once the data channel update message has been transmitted.

2. The method of claim 1, step (b) further comprising the step of transmitting the data channel update message, the data channel update message comprising an update interval.

3. The method of claim 2, step (b) further comprising the step of transmitting the data channel update message, wherein the update interval is based on an amount of queued data for the second group.

4. The method of claim 2, step (b) further comprising the step of transmitting the data channel update message, wherein the update interval is based on existence of an ongoing inbound transmission by a communication unit of the second group.

5. The method of claim 2, step (b) further comprising the step of transmitting the data channel update message, wherein the update interval is based on utilization of the data channel for the data channel update message.

6. The method of claim 2, step (b) further comprising the step of transmitting the data channel update message, wherein the update interval is based on an average access delay time for the first group.

7. The method of claim 2, further comprising a step of:

d) transmitting, via the data channel, a second data channel update message to the second group when a period of time based on the update interval has elapsed.

8. The method of claim 1, step (b) further comprising the step of transmitting the data channel update message, wherein the allocation profile comprises a bitmap uniquely corresponding to the plurality of time slots.

9. The method of claim 8, step (b) further comprising the step of transmitting the data channel update message, wherein the allocation profile is based on an average access delay time for the first group.

10. The method of claim 8, step (b) further comprising the step of transmitting the data channel update message, wherein the allocation profile is based on existence of at least one reserved time slot of the plurality of time slots.

11. The method of claim 8, step (b) further comprising the step of transmitting the data channel update message, wherein the allocation profile is based on an amount of queued data for the second group.

12. The method of claim 8, step (b) further comprising the step of transmitting the data channel update message, wherein the allocation profile indicates less than a maximum number of time slots.

13. The method of claim 8, step (b) further comprising the step of transmitting the data channel update message, wherein the allocation profile is unchanged during an ongoing inbound transmission by a communication unit of the second group.

14. In a TDM wireless communication system comprising a plurality of communication units and a central controller that allocates a plurality of time slots among the plurality of communication units, wherein the plurality of communication units are logically divided into a first group and a second group, and wherein a data channel allocated to the second group comprises a portion of the plurality of time slots, a method for a communication unit of the second group to transmit at least one message via the data channel, the method comprising the steps of:

a) receiving, via the data channel, a data channel update message comprising an allocation profile;

b) determining, based on the allocation profile, the portion of the plurality of time slots; and

c) transmitting the at least one message via the data channel comprising the portion of the plurality of time slots.

15. The method of claim 14, step (a) further comprising the step of receiving the data channel update message, wherein the data channel update message comprises an update interval.

16. The method of claim 15, further comprising the step of:

d) receiving a second data channel update message when a period of time based on the update interval has elapsed.

17. The method of claim 16, step (d) further comprising the step of receiving the second data channel update message, wherein the update interval is based on existence of an ongoing inbound transmission by a communication unit of the second group.

18. The method of claim 14, step (b) further comprising the step of determining the portion of the plurality of time slots, wherein the allocation profile comprises a bitmap uniquely corresponding to the plurality of time slots.

19. In a TDM wireless communication system comprising a plurality of communication units and a central controller that allocates a plurality of time slots among the plurality of communication units, wherein the plurality of communication units are logically divided into a first group and a second group, and wherein a data channel allocated to the second group comprises a portion of the plurality of time slots, a method for the central controller to dynamically control the portion of the plurality of time slots, the method comprising the steps of:

a) determining an allocation profile and an update interval, wherein the allocation profile indicates the portion of the plurality of time slots;

b) transmitting, via the data channel, the allocation profile and the update interval to the second group;

c) repeatedly determining the allocation profile and the update interval; and

d) repeatedly transmitting, via the data channel, the allocation profile and the update interval to the second group when a period of time based on the update interval has elapsed.

20. The method of claim 19, step (c) further comprising the step of repeatedly determining the update interval based on an amount of queued data for the second group.

21. The method of claim 19, step (c) further comprising the step of repeatedly determining the update interval based on existence of an ongoing inbound transmission by a communication unit of the second group.

22. The method of claim 19, step (c) further comprising the step of repeatedly determining the update interval based on utilization of the data channel for the transmission of the allocation profile and the update interval.

23. The method of claim 19, step (c) further comprising the step of repeatedly determining the update interval based on an average access delay time for the first group.

24. The method of claim 23, step (c) further comprising the step of repeatedly determining the allocation profile based on the average access delay time for the first group.

25. The method of claim 19, step (c) further comprising the step of repeatedly determining the allocation profile, wherein the allocation profile comprises a bitmap uniquely corresponding to the plurality of time slots.

26. The method of claim 25, step (c) further comprising the step of repeatedly determining the allocation profile based on existence of at least one reserved time slot of the plurality of time slots.

27. The method of claim 26, step (c) further comprising the step of repeatedly determining the allocation profile based on an amount of queued data for the second group.

28. The method of claim 25, step (c) further comprising the step of transmitting the data channel update message, wherein the allocation profile is unchanged during an ongoing inbound transmission by a communication unit of the second group.

29. The method of claim 25, step (b) further comprising the step of transmitting the data channel update message, wherein the allocation profile indicates less than a maximum number of time slots.

30. In a TDM wireless communication system comprising a plurality of communication units and a central controller that allocates a plurality of time slots among the plurality of communication units, wherein the plurality of communication units are logically divided into a first group and a second group, and wherein a data channel allocated to the second group comprises a portion of the plurality of time slots, a method for transmitting at least one message via the data channel, the method comprising the steps of:

at the central controller;

a) determining an allocation profile and an update interval, wherein the allocation profile indicates the portion of the plurality of time slots;

b) transmitting, via the data channel, a data channel update message comprising the allocation profile and the update interval to the second group;

at a communication unit of the second group;

c) receiving the data channel update message;

d) determining the portion of the plurality of time slots based on the allocation profile; and

e) transmitting the at least one message via the data channel comprising the portion of the plurality of time slots.

31. The method of claim 30, further comprising the step of:

f) transmitting, by the central controller via the data channel, a second data channel update message when a period of time based on the update interval has elapsed.

32. The method of claim 31, step (f) further comprising the step of transmitting the second data channel update message, wherein the update interval is based on existence of an ongoing inbound transmission by a communication unit of the second group.

33. The method of claim 32, step (f) further comprising the step of transmitting the data channel update message, wherein the allocation profile is unchanged during the ongoing inbound transmission.