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Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: Acknowledgement Scheme for 4k Fragmentation Date Submitted: Nov . 6, 2011 Source: Betty Zhao, Bin Zhen, Zhihao Xing, Yanping Jiang, Yongjun Liu, Yong Xu, Houcheng Tang

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Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

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  1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title:Acknowledgement Scheme for 4k Fragmentation Date Submitted:Nov. 6, 2011 Source: Betty Zhao, Bin Zhen, Zhihao Xing, Yanping Jiang, Yongjun Liu, Yong Xu, Houcheng Tang Company: Huawei Technologies Co., Ltd. Voice: +86 10 60612971, E-mail: betty.zhao@huawei.com Re: [802.15 TG4k Call for Proposals] Abstract: An acknowledgement scheme for 4k fragmentation Purpose: Response to TG4k Call for Proposals Notice: This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15. Slide 1

  2. Content • This proposal contains - Original proposal 631-01 presented in Okinawa - Updates presented on conference call - TBD Slide 2

  3. Motivation • To increase the efficiency of fragments transmission • Status of received fragments and channel-switching notification are sent in contention-free mode • To increase transmission reliability in the dramatically changing environment and sharing spectrum. • Switch channel in time when the condition goes bad Slide 3

  4. Case 1 • A group of fragments are received correctly. - Collector sends normal ACK to acknowledge that all the fragments are received correctly. Group 1 of fragments Group 2 of fragments FP1 FP2 FP3 FP4 FP5 FP6 FP7 FP8 FP9 FP10 End-point Channel Sensing Channel Sensing ACK Collector All the fragments are received correctly. Slide 4

  5. Case 2 • A group of fragments are received, but there are failed fragments. - Collector sends a sequence of ACKs with Frame Pending subfield = 1, and prepares EACK at the same time. - Collector sends EACK at the end of the ACK sequence whenever it’s ready. - After EACK received, end-point starts to transmit next group of fragments. Group 1 of fragments Group 2 of fragments FP1 FP2 FP3 FP4 FP5 FP2 FP6 FP7 FP8 FP9 End-point Channel Sensing Channel Sensing ACK ACK ACK EACK Collector ACK sequence Contain status of received fragments Slide 5

  6. Case 3 • A group of fragments are received, but the channel condition was not good enough. (On current channel) - Collector measures RSSI or LQI of each received fragment. - If the values are under certain threshold, collector sends the ACK sequence and prepares CSN command at the same time. - Collector sends CSN command at the end of ACK sequence whenever it’s ready. - End-point acknowledges CSN command. (On new channel) - Collector and end-point switch to the new channel together. - Collector sends EACK including the status of received fragments to end-point. - End-point forms the next group of fragments and transmits. Slide 6

  7. Case 3 diagram Collector and end-point switch channel together. FP1 FP2 FP3 FP4 FP5 FP2 FP6 FP7 FP8 FP9 ACK End-point Channel 1 Channel 2 EACK ACK ACK ACK CSN Collector Measure RSSI/LQI ACK sequence Contain status of received fragments Channel condition is not good according to RSSI/LQI values. • CSN (Channel-Switching Notification) • Used for notifying end-point of channel switching • Keep the length of command as short as possible to survive the bad channel condition Slide 7

  8. Case 3 • Assign a main channel of the PAN. Collector: • Always stay on main channel except communication with end-point on the other channel. • Not notifying other end-points of switching channel. End-point: • Always stay on main channel except communication with collector on the other channel. • Perform the handshake with collector before transmitting a normal packet. • Perform the handshake by sending the first fragment to collector (transmit the first fragment and receive ACK) when transmitting a fragmented packet. Slide 8

  9. Summary • Use ACK sequence to guarantee channel • Could adjust parameters (e.g. channel, date rate, number of fragments in next group) when necessary • No new MAC frames added • Compatible with existing MAC mechanism • Fit for Aggregated acknowledgement and Hybrid acknowledgement Slide 9

  10. TBD • Fields of fragment frame • Fields of ACK, EACK or GACK frame • Fragments retransmission method • Whether or not/How to fragment EACK or any other frame contained fragment status bitmap. • What parameters are dependent on individual PHY and what are in common, e.g. retry interval, retry times, fragment size. • … • All above need to be merged with other fragmentation and MAC/PHY proposals Slide 10

  11. Thank you! Questions? Slide 11

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