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The present application describes a system and method of managing beacon periods in a distributed wireless network. According to an embodiment, devices move their beacons to earliest available beacon slots in the beacon period and contract their beacon periods to increase data periods for higher dat

The present application describes a system and method of managing beacon periods in a distributed wireless network. According to an embodiment, devices move their beacons to earliest available beacon slots in the beacon period and contract their beacon periods to increase data periods for higher data throughput of the wireless network. According to another embodiment, devices detect and resolve their beacon collision to maintain the integrity of their beacons for effective exchange of medium access and control messages as needed in a distributed wireless network.

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What is claimed is: 1. A method of managing beacon periods in a distributed wireless network, wherein there is not a central controller, comprising: selecting by a distributed device of the distributed wireless network without a central controller a first available beacon slot that is available in

What is claimed is: 1. A method of managing beacon periods in a distributed wireless network, wherein there is not a central controller, comprising: selecting by a distributed device of the distributed wireless network without a central controller a first available beacon slot that is available in a superframe in the distributed wireless network; and transmitting a beacon in the selected available beacon slot, wherein the first beacon slot is available if the first beacon slot is not encoded as occupied in a beacon period occupancy information element (BPOIE) of beacons transmitted or received by the device in a predetermined number of latest superframes. 2. A method according to claim 1, wherein the first beacon slot is unavailable if the first beacon slot is encoded as occupied in a BPOIE of the beacon transmitted by a device in the current superframe and if in the first beacon slot of the last superframe, the device received a beacon frame with valid header check sequence (HCS) and frame check sequence (FCS). 3. A method according to claim 1, wherein the first beacon slot is encoded as occupied in a BPOIE of the beacon transmitted by a device in the current superframe if in the first beacon slot of the last superframe, the device received an indication of medium activity that did not result in reception of a beacon frame with valid HCS and FCS. 4. A method according to claim 2 or claim 3, wherein a device does not transmit non-beacon frames during the largest beacon period of its neighbor devices. 5. A method according to claim 1, wherein the predetermined number is three. 6. A method according to claim 1, wherein a superframe contains a beacon period (BP), the beacon period having a maximum length of mMaxBPLength beacon slots. 7. A method according to claim 6, wherein mMaxBPLength is 96. 8. A method according to claim 6, wherein the beacon period contains predetermined mSignalSlotCount signaling slots, the signaling slots being used to extend the BP length of neighbor devices. 9. A method according to claim 8, wherein mSignalSlotCount is 2. 10. A method according to claim 1, wherein the beacon transmitted by a device contains a beacon period length (BP length) field, the BP length field defining the length of the device's beacon period. 11. A method according to claim 10, wherein the BP length includes the device's own beacon slot and all unavailable beacon slots in the beacon period of the prior superframe. 12. A method according to claim 10, wherein the BP length does not include more than mBPExtension beacon slots after the last unavailable beacon slot in the beacon period of the prior superframe, unless beacon period merging is occurring. 13. A method according to claim 10, wherein the BP length does not exceed mMaxBPLength beacon slots. 14. A method according to claim 10, wherein a device listens for beacons during the BP length it announced in the last superframe. 15. A method of managing beacon periods in a distributed wireless network, wherein there is not a central controller, comprising: selecting by a distributed device of the distributed wireless network without a central controller a first available beacon slot that is available in a superframe in the distributed wireless network; transmitting a beacon in the selected available beacon slot; scanning for beacons in a selected communication channel for at least one superframe before transmitting any frames in that channel; if the device does not receive beacons with a valid HCS but not necessarily a valid FCS after the scan, then selecting the first beacon slot as a beacon slot immediately following the signaling slots; and creating a beacon period by transmitting a beacon in the said first beacon slot before transmitting or receiving any frames. 16. A method according to claim 15, further comprising: if the device receives beacons with a valid HCS during the scan, then selecting the first beacon slot as a beacon slot chosen from up to mBPExtension beacon slots after the highest-numbered unavailable beacon slot it observes in the last superframe and within mMaxBPLength beacon slots after the BPST, and creating no new beacon period by transmitting a beacon in the said first beacon slot prior to communicating with another device. 17. A method according to claim 16, wherein mBPExtension is 8. 18. A method of managing beacon periods in a distributed wireless network, wherein there is not a central controller, comprising: selecting by a distributed device of the distributed wireless network without a central controller a first available beacon slot that is available in a superframe in the distributed wireless network: if the device detects a beacon collision, selecting a second available beacon slot and transmitting a beacon in the second available beacon slot in subsequent superframes if the selected first beacon slot or second beacon slot is located beyond the BP length of any of its neighbor devices, then transmitting a beacon in a randomly chosen signaling beacon slot in the beacon period in the current superframe, and in up to mMaxLostBeacons subsequent superframes, until its neighbor devices extend their BP lengths to include the said first beacon slot or second beacon slot. 19. A method according to claim 18, further comprising: if the device received a beacon correctly from a signaling beacon slot in the previous superframe, then setting its BP length to include the regular beacon slot indicated in the beacon received in the signaling slot; and if the device received a frame with incorrect FCS, or detected a medium activity that did not result in reception of a frame with a valid HCS, in a signaling slot in the previous superframe, then listening for an additional mBPExtension beacon slots after its last announced BP length, but not more than mMaxBPLength beacon slots after the BPST. 20. A method according to claim 18, wherein the second available beacon slot is chosen from up to mBPExtension beacon slots after the highest-numbered unavailable beacon slot it observes in the last superframe and within mMaxBPLength beacon slots after the BPST. 21. A method according to claim 18, wherein a device detects a beacon collision if its beacon slot is reported as occupied in the BPOIE of any beacon it receives correctly in the current superframe, but the corresponding Device Address (DevAddr) for the beacon slot is neither its own nor broadcast DevAddr. 22. A method according to claim 18, wherein a device detects a beacon collision if its beacon slot has been reported as occupied, but the corresponding DevAddr has been the broadcast DevAddr, in the BPOIE of a beacon it received correctly in the same beacon slot in each of the latest mMaxLostBeacons superframes. 23. A method according to claim 18, wherein a device detects a beacon collision if its beacon slot is reported as occupied in the BPOIE of any beacon it receives in the current superframe, but it skipped beacon transmission in the last superframe. 24. A method according to claim 18, wherein a device detects a beacon collision if it receives in the beacon slot it skips for beacon transmission a beacon frame MAC header or a PHY indication of medium activity that does not result in correct reception of a MAC header. 25. A method according to claim 24, wherein a device skips beacon transmission at least every mMaxNeighborDetectionInterval. 26. A method according to claim 25, wherein mMaxNeighborDetectionInterval is 128 superframes. 27. A method of managing beacon periods in a distributed wireless network, wherein there is not a central controller, comprising: selecting by a distributed device of the distributed wireless network without a central controller a first available beacon slot that is available in a superframe in the distributed wireless network; and transmitting a beacon in the selected available beacon slot, further comprising: if the device does not detect a beacon collision, selecting a third available beacon slot, the third available beacon slot being located after the signaling slots but before the current beacon slot in the beacon period; and transmitting a beacon in the said third available beacon slot rather than in the current beacon slot. 28. A method according to claim 27, wherein the said third available beacon slot is the earliest beacon slot after the signaling slots that is available to the device. 29. A method according to claim 27, wherein the said third available beacon slot is the latest beacon slot after the signaling slots but before the device's current beacon slot that is available to the device. 30. A method according to claim 27, wherein the device transmits a beacon in the said third available beacon slot rather than in the current beacon slot, if and only if in the latest mMaxLostBeacons+1 superframes, its beacon has been movable and all the beacon slots after the device's own and within the device's BP length have been encoded as non-movable in the BPOIE of the beacons transmitted or received by the device. 31. A method according to claim 30, further comprising: if the devices finds the third available beacon slot, announcing in its beacon that its beacon is movable by setting a predetermined bit or using a predetermined encoding in its beacon; and propagating the said setting or encoding by the device's neighbors in the BPOIEs of their beacons transmitted in the next superframe.