CENTRAL CONTROLLER AND METHODS FOR INTERFERENCE MITIGATION IN TDMA NETWORKS USING RANDOMLY ALLOCATED SERVICE PERIODS

• US 20100165955A1
• Filed: 12/30/2008
• Published: 07/01/2010
• Est. Priority Date: 12/30/2008
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Gong, Xiaohong, Park, Minyoung
• Granted Patent: US 8,514,821 B2
• Time in Patent Office: Days
• US Class Current: 370/337
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 28/16 Central resource management; Negotiation of resources or communication parameters, e.g. negotiating bandwidth or QoS [Quality of Service]
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/541 using the level of interference
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access
• CPC Class Codes: H04W 92/18 between terminal devices

Abstract

Embodiments of a central controller and methods for interference mitigation in TDMA networks are generally described herein. In some embodiments, the central controller mitigates co-channel interference by randomizing locations of channel time allocations within superframes.

Claims

1. A central controller to coordinate operations of a wireless network, the central controller configured to allocate channel time allocations (CTAs) for peer-to-peer communications between pairs of communication stations of the wireless network,

wherein the central controller is configured to randomize locations of the CTAs within superframes to mitigate co-channel interference from neighboring wireless networks.

2. The central controller of claim 1 wherein the central controller is further configured to provide the locations of randomly allocated CTAs within a beacon period for receipt by the communication stations,

wherein the beacon period is an initial time period of a superframe that identifies the locations of the CTAs within a subsequent one or more superframes.

3. The central controller of claim 1 wherein the central controller is further configured to generate a randomization seed,

wherein a starting CTA corresponds to a pseudorandom number calculated based on a value of the randomization seed and a number of CTAs to be allocated in a next superframe,

wherein the CTAs are assigned in a predetermined order within the next superframe beginning with the starting CTA.

4. The central controller of claim 3 wherein the central controller is configured to:

calculate the starting CTA for the next superframe using the value of the randomization seed value and the number of CTAs using a modulo operation; and

provide an indication of the starting CTA to the communication stations in a beacon period,

wherein the communication stations are configured to determine the locations of the CTAs within the next superframe based at least on the indication of the starting CTA provided by the central controller.

5. The central controller of claim 3 wherein the central controller is configured to provide the randomization seed, the number of CTAs to be allocated within the next superframe, and an indication of a length of each of the CTAs within a beacon period, and

wherein the communication stations are each configured to:

calculate the starting CTA for the next superframe using the value of the randomization seed and the number of CTAs using a modulo operation; and

determine the locations of the CTAs within the next superframe based on the starting CTA, the indications of the lengths provided by the central controller, and the predetermined order.

6. The central controller of claim 5 wherein each CTA comprises one or more time-slots, and

wherein the central controller is further configured to provide an indication in the beacon period that the time-slots are to be cyclically rotated between the superframes.

7. The central controller of claim 1 wherein when the central controller is configured to randomize the locations of the CTAs within the superframes, the central controller is further configured to:

refrain from performing interference estimation to detect the co-channel interference with nearby wireless networks; and

instruct the communication stations of the wireless network to refrain from performing the interference estimation.

8. The central controller of claim 1 wherein when the central controller is configured to perform an interference estimation to determine whether detected co-channel interference is static or dynamic,

wherein when the central controller determines that the detected co-channel interference is static, the central controller is configured to:

refrain from randomizing the locations of the CTAs within the superframes; and

assign the CTAs to portions of a next superframe where static co-channel interference is predicted not to be present.

9. The central controller of claim 8 wherein when the central controller determines that the detected co-channel interference is dynamic, the central controller is configured to inform the communication stations that the locations of the CTAs are to be randomized within the superframes.

10. The central controller of claim 9 wherein when the communication stations are configured to perform an interference detection process to detect co-channel interference from one or more neighboring wireless networks, the communication stations are configured to report detected co-channel interference to the central controller,

wherein the central controller is to determine whether the detected co-channel interference reported by the communication stations is static or dynamic.

11. A method for mitigating co-channel interference in a wireless network, the method comprising at least partially randomizing locations of channel time allocations (CTAs) within superframes by a central controller,

wherein pairs of communication stations of the wireless network communicate during the CTAs.

12. The method of claim 11 further comprising transmitting the locations of randomly allocated CTAs within a beacon period for receipt by the communication stations,

wherein the beacon period is an initial time period of a superframe that identifies the locations of the CTAs within a subsequent one or more superframes.

13. The method of claim 11 further comprising generating a randomization seed,

wherein a starting CTA corresponds to a pseudorandom number calculated based on a value of the randomization seed and a number of CTAs to be allocated in a next superframe,

wherein the CTAs are assigned in a predetermined order within the next superframe beginning with the starting CTA.

14. The method of claim 13 further comprising:

calculating the starting CTA for the next superframe using the value of the randomization seed value and the number of CTAs using a modulo operation; and

providing an indication of the starting CTA to the communication stations in a beacon period,

wherein the communication stations are configured to determine the locations of the CTAs within the next superframe based at least on the indication of the starting CTA provided by the central controller.

15. The method of claim 13 further comprising transmitting the randomization seed, the number of CTAs to be allocated within the next superframe, and an indication of a length of each of the CTAs within a beacon period,

wherein the communication stations are each configured to:

calculate the starting CTA for the next superframe using the value of the randomization seed and the number of CTAs using a modulo operation; and

determine the locations of the CTAs within the next superframe based on the starting CTA, the indications of the lengths provided by the central controller, and the predetermined order.

16. The method of claim 15 wherein each CTA comprises one or more time-slots, and

wherein the method further comprises transmitting an indication in the beacon period that the time-slots are to be cyclically rotated between superframes.

17. The method of claim 11 wherein when the central controller is configured to randomize the locations of the CTAs within the superframes, the method further comprises:

refraining from performing interference estimation to detect co-channel interference with nearby wireless networks; and

instructing the communication stations of the wireless network to refrain from performing interference estimation.

18. The method of claim 11 further comprising performing an interference estimation process to determine whether detected co-channel interference is static or dynamic,

wherein the detected co-channel interference is static, the method comprises:

refraining from randomizing the locations of the CTAs within the superframes; and

assigning the CTAs to portions of a next superframe where static co-channel interference is predicted not to be present.

19. The method of claim 18 wherein when the detected co-channel interference is dynamic, the method comprises informing the communication stations that the locations of the CTAs are to be randomized within the superframes.

20. A wireless communication device to operate within a wireless personal area network (WPAN), the wireless communication device comprising:

a transceiver to receive an indication within a beacon period from a central controller of the WPAN, the indication to indicate randomization of channel time allocations (CTAs) within a next superframe; and

a CTA schedule randomizer to generate a CTA schedule identifying locations of CTAs within the next superframe based on the indication provided in the beacon period,

wherein the transceiver is configured to communicate with another wireless communication device during an assigned CTA in accordance with the CTA schedule.

21. The wireless communication device of claim 20 wherein the transceiver is configured to receive a randomization seed, a number of CTAs to be allocated within the next superframe, and an indication of a length of each of the CTAs within the beacon period, and

wherein the wireless communication device is configured to:

calculate a starting CTA for the next superframe using a value of the randomization seed and the number of CTAs using a modulo operation; and

determine the locations of the CTAs within the next superframe based on the starting CTA, the indications of the lengths provided by the central controller, and a predetermined order.

22. The wireless communication device of claim 21 wherein the transceiver is configured to perform an interference detection process to detect co-channel interference from one or more neighboring WPANs and to report detected co-channel interference to the central controller,

wherein the central controller is to determine whether the detected co-channel interference reported by the wireless communication device is static or dynamic and provide the indication to indicate randomization of CTAs when dynamic co-channel interference is reported.

23. A central controller for a wireless personal area network (WPAN) comprising:

a transceiver to perform interference estimation to determine whether detected co-channel interference is static or dynamic,

wherein when dynamic co-channel interference is detected, the transceiver is configured to inform communication stations of the WPAN that the locations of channel time allocations (CTAs) are to be randomized within superframes.

24. The central controller of claim 23 wherein the central controller is further configured to generate a randomization seed,

wherein a starting CTA for a next superframe corresponds to a pseudorandom number calculated based on a value of the randomization seed and a number of CTAs to be allocated in a next superframe, and

wherein the CTAs are assigned in a predetermined order within the next superframe beginning with the starting CTA.

25. The central controller of claim 24 wherein when the central controller determines that the detected co-channel interference is static, the central controller is configured to:

refrain from randomizing the locations of the CTAs within the superframes; and

assign the CTAs to portions of a next superframe where the static co-channel interference is predicted not to be present.