EGTS Subgroup Report for IEEE 802.15.4e

1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [EGTS Subgroup Report for IEEE 802.15.4e] Date Submitted: [September 21, 2009] Source: [Myung Lee, Gahng-Seop Ahn, Tae Rim Park, Liang Li, Seong-Soon Joo, Betty Zhao, Ghulum Bhatti, Ning Gu, Jie Shen, Wei Hong, Qin Wang, Quan Wang, Ping Wang, Fumihide Kojima] Address [] Voice:[+1-212-650-7260], FAX: [], E-Mail:[lee@ccny.cuny.edu] Re: [IEEE P802.15.4e] Abstract: [This document describes the EGTS subgroup report for IEEE 802.15.4e. Currently, EGTS subgroup document comprises contributions from CUNY, ETRI, Samsung, Huawei, MERL, Vinno, SIMIT, Arch Rock, USTB, Shenyang Inst. of Automation, NICT] Purpose: [Discussion in 802.15.4e Task Group] 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.

2. EGTS Subgroup Report Myung Lee CUNY

3. This EGTS subgroup report Refer to doc. 09/0666r1 -EGTS September 09 subgroup report • Asynchronous channel adaptation (09/308r4) • Provision for Power Saving in Beacon-enabled mode (09/0514r1) • Resolution of internal comments (09/0622r1)

4. Asymmetric Channel Adaptation-Motivation • Densely deployed large scale network in geographically large area • The variance of channel condition is large. • Channel Asymmetry. • Common channel approach is limited • Therefore, multi-channel adaptation is required. Smart Meter Smart Meter Smart Meter Concentration Point Smart Meter Smart Meter Smart Meter Smart Meter Smart Meter

5. Multi-channel Active Scan A device perform active scan for all Cmax channels twice at worst case. For example, Cmax = 4, Coordinator’s designated channel is C4, New device’s good channel is C3. Channel C4 C1 C2 C3 C3 C4 C4 Coordinator T T New Device C1 C2 C3 C3 C4 C1 C2 C3 C4 Channel Beacon Request Beacon Association Request Association Response

6. Multi-channel Hello • A device can send a multi-channel hello message to its one-hop neighbors to inform its designated channel. • The device should send the same hello message on each channel sequentially starting from its designated channel. • Optional: The device can request hello reply by setting a flag in the hello message. Two Neighbor Example: Cmax = 4, Coordinator’s designated channel is C4, New device’s good channel is C3. Channel C4 C3 C4 Neighbor 1 T New Device C3 C4 C1 C2 C3 Channel Hello Hello Reply Neighbor 2 C3 C2 C2 Channel

7. Power Saving Provision for EGTS (1) Data receiving in the inactive period can improve low-power consumption performance • FFD can determine superframe consists of an active period and an inactive period with/without a beacon • Turned-off beacons with active period • Collection stations only send beacon after receiving “scan” request. In other period, the collection stations does not transmit any beacon: • Intermittent hearing only in active period • Active period consists of only CAP • Data frame shall start in active period and end in the beacon interval. If data frame is sensed in CAP, the destination device continues receiving till the frame end Beacon: Could be turned off BI: Beacon interval SD: Superframe duration Active period CAP CAP Data frame Inactive period CAP: Contention access period

8. Power Saving Provision for EGTS (2) • Collection station and meters construct tree-shaped topology where each device determines superframe with turning off beacon. In the figure below, device M1 is handling both incoming superframe by CS and outgoing superframe by M1 itself in order to conduct successful data relaying in such tree topology. • 15.4MAC defines same BI and SD shall be employed in both incoming and outgoing superframe • Assuming cluster -tree topology, different BI and SD might be suitable for incoming and outgoing superframe

9. Modifications for power saving • Superframe • Suppression of beacons to preserve EGTS superframe structure: combination of BO and the status of PIB macLowEnergySuperframeSupported • CAP Period • When the PIB “False” • Data transmission should end one IFS before the end of CAP period because CFP follows immediately after CAP in EGTS superframe • When the PIB “True” • Data transmission continue but should end before the inactive period ends • No CFP shall exist to avoid the interference from CAP

10. Summary of changes • Modified / New MAC primitives (6) • MCPS-DATA, MLME-GTS, MLME-EGTSinfo, MLME-START, MLME-LINKSTATUSPRT, MLME-Scan-Request • New MAC PIB attributes (18) • macMultisuperframeOrder, macConnecDev, macEGTSABT (Allocation Bitmap Table), macEGTSACT (Allocation Counter Table), macChannelDiversityMode,.., macLowEnergySuperframeSupported • Modified / New MAC command frame (10) • Association request, EGTS handshake, EGTS information request, EGTS information reply, Beacon allocation notification, Beacon conflict notification, Link status report, Asymmetric multi-channel beacon request, Multi-channel hello, Channel probe • New fields in Beacon Payload (4) • EGTS superframe descriptor, Beacon bitmap, ChannelHoppingSpecification, Time synchronization specification

11. Thank you!