Collaborative mechanism of enhanced coexistence of collocated wireless networks

• US 7,099,671 B2
• Filed: 10/21/2001
• Issued: 08/29/2006
• Est. Priority Date: 01/16/2001
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Liang, Jie
• Primary Examiner(s): Anderson, Matthew
• Assistant Examiner(s): Dao, Minh
• Application Number:
  US10/011,221
• Publication Number:
  US 20030083095A1
• Time in Patent Office: 1,773 Days
• Field of Search: 455/450, 455/451, 455/452.1, 455/452.2, 455/454, 455/509, 455/512, 455/41.2
• US Class Current: 455/450
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 72/1215 for collaboration of different radio technologies

Abstract

A digital device 310 with a plurality of collocated wireless networks encounters inter-network interference if the collocated wireless networks operate in a common operating frequency. A coordinator unit 510, coupled to the plurality of wireless networks, provides a transmission reservation system wherein a wireless network with a need to transmit can request and receive a reservation for time to transmit. The coordinator unit 510 provides a way to schedule transmissions from the plurality of wireless networks and to reduce the probability of collisions.

Claims

1. A method for controlling access to a wireless communications medium shared by a plurality of collocated wireless networks comprising:

receiving a plurality of reservation requests at a coordinator unit from collocated wireless networks for transmission on the communications medium;

selected a random number, D;

comparing the random number against a threshold, DP;

granting a reservation request from the plurality of reservation requests based on the comparison; and

returning the results of the decision to wireless networks sending the plurality of reservation requests.

2. The method of claim 1, wherein the deciding step further comprises:

determining if a desired time specified in the reservation request is available;

granting the reservation request if the desired time is available; and

rejecting the reservation request if the desired time is not available.

3. The method of claim 2, wherein the determining step further comprises:

generating a start time and a stop time for the reservation request based on information provided in the reservation request; and

comparing the start time and the stop time for the reservation request against a list of granted start and stop times.

4. The method of claim 1, wherein the receiving step comprises receiving a single reservation request from one collocated wireless network.

5. The method of claim 1, wherein the plurality of reservation requests are for an overlapping transmission time.

6. The method of claim 1, further comprises the step of rejecting all remaining reservation requests from the plurality of reservation requests.

7. The method of claim 6, wherein the returning step comprises returning a granted reservation request to a collocated wireless network whose reservation request was granted and returning rejected reservation requests to collocated wireless networks whose reservation requests were rejected.

8. The method of claim 1, wherein there are two collocated wireless networks, and wherein the threshold, DP, is a number between 0 and 1.

9. The method of claim 1, wherein there are three collocated wireless networks, and wherein the threshold, DP, is a set of two numbers between 0 and 1.

10. The method of claim 1, wherein the reservation request comprises a transmit start time and a transmit duration.

11. The method of claim 1, wherein the reservation request comprises a transmit start time and a transmit stop time.

12. A method for sharing a wireless communications medium among a plurality of collocated wireless networks comprising:

(a) determining a need to transmit;

(b) sending a reservation request to a coordinator unit;

(c) transmit if the reservation request was granted; and

(d) deferring transmission if the reservation request was rejected, herein the reservation request is granted by the coordinator unit based on a comparison of a random number and a predetermined threshold.

13. The method of claim 12, wherein the determining step comprises decoding a message addressed to self that requires a response.

14. The method of claim 12, wherein the determining step comprises receiving a message addressed to self that grants permission to transmit.

15. The method of claim 12, wherein the determining step comprises the assertion of a transmit indicator for transmission of a periodic transmission.

16. The method of claim 12, wherein the determining step comprises servicing a request to grant permission to transmit.

17. The method of claim 13, wherein the determining step further comprises:

determining that the wireless communications medium is idle;

waiting a specified time interval;

generating a random backoff time;

loading the random backoff time into a backoff timer;

decrementing the backoff tinier each time an idle network slot expires; and

determining when the backoff timer reaches zero.

18. The method of claim 12, wherein the deferring step further comprises:

waiting until a next available transmission time; and

repeating steps (b)–

(d).

19. The method of claim 12, wherein the deferring step further comprises:

sending a reservation request to the coordinator unit, requesting a next available time; and

repeating steps (c)–

(d).

20. The method of claim 12, wherein the deferring step comprises repeating steps (a)–

(d).