Methods and apparatus for dynamically assigning time slots in a wireless communication system

• US 6,801,513 B1
• Filed: 06/20/2000
• Issued: 10/05/2004
• Est. Priority Date: 06/23/1999
• Status: Expired due to Fees

• Current Assignee: Clearwire Ip Holdings LLC (Deutsche Telekom AG)
• Original Assignee: AT&T Wireless Services Incorporated (AT&T, Inc.)
• Inventors: Gibbons, David B., Hong, Liang A., Hoole, Elliott, Moinzadeh, Kamyar, Gormley, Eamonn
• Primary Examiner(s): TON, DANG T
• Application Number:
  US09/597,044
• Time in Patent Office: 1,568 Days
• Field of Search: 370/328, 370/329, 370/335, 370/336, 370/337, 370/448, 370/442, 370/468, 370/461, 370/462, 370/470, 370/384, 370/535, 370/537, 370/347, 370/341, 370/401, 370/431, 370/437, 370/443, 370/444, 370/455, 370/456-459
• US Class Current: 370/337
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 74/00 Wireless channel access

Abstract

A wireless communication system having a base unit and a plurality of remote transceiver units utilizes a dynamic time slot assignment scheme for channel access. The base unit receives and processes a channel access request message from a remote transceiver unit and prepares a channel measurement request message in response. If an M^th time slot of a time frame is available, the base unit sends this message in the M^th time slot and receives a message having channel measurement data in the M^th time slot of the next time frame. On the other hand, if the M^th time slot of the time frame is already reserved, the base unit sends the message in an N^th time slot of the time frame and receives a message having the channel measurement data in the N^th time slot of the next time frame. The base unit selects, based on the channel measurement data, an appropriate channel for communication for the remote transceiver unit, Continuing with use of the dynamic slot assignment, the base unit sends a message having a channel identifier associated with the selected channel and receives an acknowledgement from the remote transceiver unit in response.

Claims

1. A method for dynamically assigning time slots between a base unit and a transceiver unit of a wireless communication system defining L time slots per time frame, the method comprising:

receiving a first message;

processing the first message and generating a second message in response;

when an M^th time slot of a time frame is available;

sending the second message that is responsive to the first message in the M^th time slot;

receiving a third message that is responsive to the second message in the M^th time slot of a following time frame;

when the M^th time slot of the time frame is unavailable;

sending the second message that is responsive to the first message in an N^th time slot of the time frame, the N^th time slot following the M^th time slot in the time frame; and

receiving the third message that is responsive to the second message in the N^th time slot of the following time frame.

2. The method according to claim 1, further comprising:

when the M^th and N^th time slots of the time frame are unavailable;

sending the second message that is responsive to the first message in a P^th time slot of the time frame, the P^th time slot following the M^th and N^th time slots in the time frame; and

receiving the third message that is responsive to the second message in the P^th time slot of the following time frame.

3. The method according to claim 1, wherein the first message comprises a channel access request for communication.

4. The method according to claim 1, wherein the first message comprises a channel access request for communication, the second message comprises a channel measurement request, and the third message comprises channel measurement data.

5. The method according to claim 1, further comprising:

when the M^th time slot of the time frame is available;

reserving the M^th time slot of the following time frame prior to receiving the third message; and

when the M^th time slot of the time frame is unavailable;

reserving the N^th time slot of the following time frame prior to receiving the third message.

6. The method according to claim 1, further comprising:

when the M^th time slot of the time frame is available;

reserving the M^th time slot of the following time frame prior to receiving the third message;

unreserving the M^th time slot for after receiving the third message in the M^th time slot of the following time frame;

when the M^th time slot of the time frame is unavailable;

reserving the N^th time slot of the following time frame prior to receiving the third message; and

unreserving the N^th time slot after receiving the third message in the N^th time slot of the following time frame.

7. The method according to claim 1, wherein the first message comprises a Common Access channel (CAC) message and the second message comprises a Common Link Channel (CLC) message.

8. A base unit for use in a wireless communication system having a plurality of remote transceiver units, the base unit comprising:

a wireless transceiver;

one or more processors coupled to the wireless transceiver;

the wireless transceiver and the one or more processors being operative for;

receiving a first message;

processing the first message and generating a second message in response;

when an M^th time slot of a time frame is available;

sending the second message in the M^th time slot;

receiving a third message that is responsive to the second message in the M^th time slot of a following time frame;

when the M^th time slot of the time frame is unavailable;

sending the second message in an N^th time slot of the time frame, the N^th time slot following the M^th time slot in the time frame; and

receiving the third message that is responsive to the second message in the N^th time slot of the following time frame.

9. The base unit according to claim 8, wherein the first message comprises a channel access request for communication.

10. The base unit according to claim 8, wherein the first message comprises a channel access request for communication, the second message comprises a channel measurement request, and the third message comprises channel measurement data.

11. The base unit according to claim 8, wherein the wireless transceiver and the one or more processors are further operative for:

when the M^th time slot of the time frame is available;

reserving the M^th time slot of the following time frame prior to receiving the third message; and

when the M^th time slot of the time frame is unavailable;

reserving the N^th time slot of the following time frame prior to receiving the third message.

12. The base unit according to claim 8, wherein the wireless transceiver and the one or more processors are further operative for:

when the M^thtime slot of the time frame is available;

reserving the M^th time slot of the following time frame prior to receiving the third message;

unreserving the M^th time slot for after receiving the third message in the M^th time slot of the following time frame;

when the M^th time slot of the time frame is unavailable;

reserving the N^th time slot of the following time frame prior to receiving the third message; and

unreserving the N^th time slot after receiving the third message in the N^th time slot of the following time frame.

13. The base unit according to claim 8, wherein the first message comprises a Common Access Channel (CAC) message and the second message comprises a Common Link Channel (CLC) message.

14. A wireless communication system, comprising:

a base unit operative for;

receiving a first message;

processing the first message and generating a second message in response;

when an M^th time slot of a time frame is available;

sending the second message in the M^th time slot;

receiving a third message that is responsive to the second message in the M^th time slot of a following time frame;

when the M^th time slot of the time frame is unavailable;

sending the second message in an N^th time slot of the time frame, the N^th time slot following the M^th time slot in the time frame;

receiving the third message that is responsive to the second message in the N^th time slot of the following time frame; and

a remote transceiver unit operative for sending the first message, receiving the second message, and sending the third message.

15. The wireless communication system according to claim 14, wherein the first message comprises a channel access request for communication.

16. The wireless communication system according to claim 15, wherein the first message comprises a channel access request for communication, the second message comprises a channel measurement request, and the third message comprises channel measurement data.

17. The wireless communication system according to claim 14, further comprising:

the base unit being further operative for;

when the M^th time slot of the time frame is available;

reserving the M^th time slot of the following time frame prior to receiving the third message; and

when the M^th time slot of the time frame is unavailable;

reserving the N^th time slot of the following time frame prior to receiving the third message.

18. The wireless communication system according to claim 15, further comprising:

the base unit being further operative for;

when the M^th time slot of the time frame is available;

reserving the M^th time slot of the following time frame prior to receiving the third message;

unreserving the M^th time slot for after receiving the third message in the M^th time slot of the following time frame;

when the M^th time slot of the time frame is unavailable;

reserving the N^th time slot of the following time frame prior to receiving the third message; and

unreserving the N^th time slot after receiving the third message in the N^th time slot of the following time frame.

19. A method for dynamically assigning time slots in wireless communication system, the method comprising:

identifying a next available time slot M of a time frame having L time slots;

reserving the M^th time slot of the time frame;

sending a first message in the M^th time slot of the time frame;

receiving a second message that is responsive to the first message in an M^th time slot of a following time frame; and

unreserving the M^th time slot for subsequent use.

20. The method according to claim 19, wherein the first and the second message comprise messages for call establishment.