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MAC Protocol to Support Dynamic Bandwidth for 802.11aj (60GHz). Date: 2013-07-17. Presenter:. Author List. This document is to propose a channelization for China 60GHz frequency band for 802.11aj (60GHz)
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MAC Protocol to Support Dynamic Bandwidth for 802.11aj (60GHz) Date: 2013-07-17 Presenter: Xiaoming Peng
Author List Xiaoming Peng
This document is to propose a channelization for China 60GHz frequency band for 802.11aj (60GHz) • This document is to propose a MAC protocol amendment to support dynamic bandwidth for 802.11aj (60GHz) • The proposed MAC protocol supports the backward compatibility with 802.11ad legacy device • This contribution has been discussed in CWPAN group Abstract Xiaoming Peng
Add Slide 13-14 • To support network setup and operation in small band (e.g. Channel 5 or Channel 6) only. • Add Slide 15-18 • To support interoperability with 11ad legacy devices. • Add Slide 22-23 • To add two more study cases to support Mixed Mode with 11ad legacy devices. Highlight of The Main Changes Xiaoming Peng
Background: China 60GHz Spectrum • The released 60GHz spectrum in China only has 5GHz bandwidth, corresponding to channel 2 & 3 used in IEEE 802.11ad. USA, Canada, Korea Europe Japan China Unlicensed 60 GHz spectrum bands. Australia Xiaoming Peng
Advantage of the proposed channelization for 60GHz bands in China • China only has 5GHz bandwidth available in 59-64GHz only has two logical channels if only use 2.16 GHz BW • Further divide 2.16GHz band used in 802.11ad channelization into two 1.08GHz sub-bands, then it become 6 logical channels: 2 bands with 2.16GHz bandwidth (Channel 2 & 3), 4 bands with 1.08GHz bandwidth (Channel 5, 6, 7, 8); Proposed Channelization for 60GHz bands for 802.11aj (1/2) Channelization for 60GHz bands in China Xiaoming Peng
Support dynamic bandwidth Capable of supporting wider applications for lower power, e.g. Smart Phone, Tablet etc. • The impact to implementation in RF, Analog baseband is very minimal. It only needs to add to support four more new center frequency in PLL design, a new filter to support 1.08GHz in analog baseband etc; • The support of dynamic bandwidth in the channelization for China 60GHz bands provides the basis of keeping the interoperability with 802.11ad device; Proposed Channelization for 60GHz bands for 802.11aj (2/2) Channelization for 60GHz bands in China Xiaoming Peng
Proposed MAC Protocol amendment for 802.11aj: support dynamic bandwidth and keep interoperability with 802.11ad • When operating in 2.16GHz channel(Channel 2,3),it is capable of keeping interoperability with 802.11ad device; • When operating in 1.08GHz(Channel 5,6,7,8),it sends common beacon over 2.16GHz channel. The common beacon can use 802.11ad beacon as baseline so that 802.11ad device can also recognize the common beacon; • This allows 802.11aj device to keep the interoperability with 802.11ad device while exploring the benefits in channels with 1.08GHz bandwidth. MAC Protocol: Support Dynamic Bandwidth Revised 60GHz Channelization Common Beacon (e.g., 802.11ad DMG Beacon frames) Proposed frame structure for IEEE 802.11aj Xiaoming Peng
Proposed MAC Protocols (1) • Support that PCP/AP 1 operates in Channel 2 with 3 devices (STA 1, STA 2 and STA 3) • STA (to become PCP/AP 2) wants to share Channel 2 • STA (to become PCP/AP 2) may join PCP/AP 1’s network and send aChannel Split Request frame for the split of Channel 2. Channel Split Request frame Action field format Xiaoming Peng
Proposed MAC Protocols (2) • If PCP/AP 1 agrees to split Channel 2 • PCP/AP 1 replies a Channel Split Response frame to the STA (to become PCP/AP 2). • PCP/AP 1 informs other STAs through a Channel Switch Announcement element contained in DMG Beacon/Announce frames . • PCP/AP 1 proceeds to split Channel 2 Channel Split Response frame Action field format Proposed Frame Structure tosupport Dynamic Bandwidth for 802.11aj Xiaoming Peng
Proposed MAC Protocols (3) • After the split of Channel 2 into Channel 5 and Channel 6, • PCP/AP 1 sends out common DMG beacons in Channel 2 during NP1 to announce its operation and shows its channel bandwidth status (using the reserved B45-46 to indicate Channel Bandwidth info) contained in Beacon Interval Control field). • Following which PCP/AP 2 (The STA become PCP/AP 2) sends out common DMG beacon in Channel 2 during NP2 to announce its operation and shows its channel bandwidth status . • PCP/AP 1 and PCP/AP 2 each creates a quiet period (QP) in their respective networks. • PCP/AP 2 synchronizes with PCP/AP 1 by receiving the time stamps in PCP/AP 1’s common DMG beacons in its BTI. • Non-AP/non-PCP STAscontinue their packet transmissions in small band network in Channel 5 after tuning in and receiving the DMG Beacon frames sent out by PCP/AP 1 in its BTI, coupled with the necessary procedures like beamforming, associations and new schedules for service periods (SPs) and contention-based periods (CBAPs). • Non-AP/non-PCP devices STAs that want to join the network in Channel 6 have to tune in and receive DMG Beacon frames sent by PCP/AP 2 in its BTI, coupled with the necessary procedures. Xiaoming Peng
Proposed MAC Protocols (4) • Constant monitoring of Channel 2 common DMG beacons sent out by PCP/APs 1 and 2 in NP1 and NP2, respectively. • Assume Channel 6 ceases its network operation. • Absence is noted by PCP/AP 1 when it detects no common DMG beacon frames sent during NP1. • PCP/AP 1 shall wait for a aMaxExpireDuration duration before making the decision that Channel 6 network has ceased operation. • Case 1: After which, the PCP/AP 1 can proceed to expand its bandwidth from Channel 5 to Channel 2 (see the following figure), or • Case 2: After which, the PCP/AP1 can proceed to remain its operation in Channel 5. Xiaoming Peng
Proposed MAC Protocols (5) • Suppose that PCP/AP 1 starts up or operates in the small band, e.g., Channel 5. To mitigate interference, PCP/AP 1 must periodically send notification signals during notification periods (NPs) on Channel 2. • Each NP contains at least a beacon header interval (BHI) which may include beacon transmission interval (BTI), association beamforming training (A-BFT) and / or announcement transmission interval (ATI) as shown in the following figure. Xiaoming Peng
Proposed MAC Protocols (6) • Later, a new PCP/AP 2 intends to start its network in the adjacent Channel 6. • First, PCP/AP 2 scans the channel to know whether Channel 6 is empty or not. • If Channel 6 is available, PCP/AP 2 will send a Channel Request frame to PCP/AP 1 for NP allocation. • PCP/AP 1 may reject the PCP/AP 2 request if another network has been successfully established in Channel 6. Otherwise, PCP/AP 1 should accept PCP/AP 2 request through a Chanel Responseframe. • PCP/AP 1 shall allocate a pseudo-static SP for the NP of PCP/AP 2 (i.e., BHI 2) on Channel 2 through an Extended Schedule element. Xiaoming Peng
Backward Compatibility of IEEE 802.11aj [3] has described “Backward Compatibility Feature for 802.11aj” • Legacy Mode • Case 1: An IEEE 802.11ad device scans to find an available large band and starts its network as normal 802.11ad device. • Case 2: An IEEE 802.11ad device scans to find an IEEE802.11ad or IEEE 802.11aj network operating in the large band and joins as a non-PCP/non-AP STA. • Mixed Mode • Support the backward compatibility for IEEE 802.11ad devices when IEEE 802.11aj networks are operating in small bands. Xiaoming Peng
Mixed Mode (1/3) Case 1: Suppose that only PCP/AP 1 operates in Channel 5 while Channel 6 is empty. • If an 802.11ad legacy device requests to join, 802.11aj PCP/AP 1 may change its channel to Channel 2 first, and then operate like 802.11ad PCP/AP and accept 802.11ad legacy device as non-PCP/AP STA • PCP/AP 1 may also decide to operate in Channel 5 and allocate SPs or CBAPs to 802.11ad legacy device in Channel 2 through DMG Beacon or Announce frames as show in the following figure. • To distinguish different channel bandwidths, we use the reserved Bit 5 of the Allocation Type field to indicate allocation type, which supports the backward compatibility to IEEE 802.11ad devices. Xiaoming Peng
Mixed Mode (2/3) Case 2 : Both Channel 5 and 6 are occupied by PCP/AP 1 and PCP/AP2, respectively. Suppose that 11ad legacy STA A intends to join in PCP/AP 1’s network. • PCP/AP 1’s allocations for STA A must abide by TWO conditions: • No overlaps with the existing allocations either in large band or in small bands. • PCP/AP 2 shall avoid to schedule the allocations time-overlapping with that of STA A. • The mixed mode works as below: • First, PCP/AP 1 shall hear the latest DMG Beacon or Announce frames or directly request PCP/AP 2 to reply with Extended Schedule elements . • Second, PCP/AP 1 schedules the allocations for STA A and may notify the result to PCP/AP 2 through an Allocation Request frame. • Third, PCP/AP 2 may reply with an Allocation Grant frame to grant this schedule or not. • Lastly, PCP/AP 1 sends the schedule result to STA A (and PCP/AP 2) through Extended Scheduling element transmitted in DMG Beacon or Announce frame. Xiaoming Peng
Mixed Mode (3/3) Case 3: Suppose that only PCP/AP 1 operates in Channel 5 and has scheduled the allocations for 802.11ad legacy devices within Channel 2. • In this case, another PCP/AP 2 that intends to start up will know that Channel 6 is empty. • PCP/AP 2 follows the same procedures in Slide 14 to establish its BSS in Channel 6. • Since PCP/AP 2 has received the Extended Schedule element through the Beacon/Announce frames transmitted by PCP/AP 1, it will avoid to schedule its SPs or CBAPs that would overlap with the allocations for 802.11ad legacy devices in the following medium time. Xiaoming Peng
Case A: Two PCP/APs operate in two adjacent small bands within the same large band. Case Study A: Support Dynamic Bandwidth Xiaoming Peng
Case B: Only one PCP/AP operates in a small band when the adjacent small band is unoccupied. Case Study B: Support Dynamic Bandwidth Xiaoming Peng
Case C: Only one PCP/AP operates in a large band when the large band is available. Case Study C: Support Dynamic Bandwidth This is similar to 802.11ad Xiaoming Peng
Case D: Only one PCP/AP operates in a small band when the adjacent small band is unoccupied. • In this case, IEEE 802.11ad devices join as non-PCP/non-AP STAs. Case Study D: Mixed Mode Xiaoming Peng
Case E: Two PCP/APs operate in two adjacent small bands within the same large band. • In this case, IEEE 802.11ad legacy devices join one of BSSs as non-PCP/non-AP STAs. Case Study E: Mixed Mode Xiaoming Peng
This presentation proposed a channelization for China 60GHz frequency band for 802.11aj (60GHz) This presentation proposed a MAC protocol amendment to support dynamic bandwidth for 802.11aj (60GHz) The proposed MAC protocol supports the backward compatibility with 802.11ad legacy devices Conclusion Xiaoming Peng
[1] 11-12-1197r0 - Physical Channel Consideration for Chinese 60GHz band [2] 11-13-0176r0 - Proposal of Channelization for 802.11aj [3] 11-13-0175r1 - Backward Compatibility Feature for 802.11aj [4] 11-12-0140r9 - IEEE 802.11.aj PAR [5] 11-12-0141r7 - IEEE 802.11.aj 5C Reference Xiaoming Peng
Thank YOU Xiaoming Peng