1. doc.: IEEE 802.15-06-0227-00-0005 Submission May 10, 2006 Yongjun Liu,Na Shan, HuaweiSlide 1 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Dynamic Channel Selection] Date Submitted: [10 May, 2006] Source: [Yongjun Liu, Na Shan] Company [Huawei Technologies Co., Ltd] Address [No.3 Xinxi Road, Shangdi Information Industry Base, Haidian District, Beijing, P.R.China] Voice:[+86 10 82882921], FAX: [+86 10 82882966], E-Mail:[yongjunliu@huawei.com][shanna@huawei.com] Abstract:[This document discuss a dynamic channel selection mechanism for the Mesh Network.] Purpose:[Final Proposal for the IEEE802.15.5 Standard.] 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. doc.: IEEE 802.15-06-0227-00-0005 Submission May 10, 2006 Yongjun Liu,Na Shan, HuaweiSlide 2 Dynamic Channel Selection Yongjun Liu Na Shan Huawei Technologies Co., Ltd.

3. doc.: IEEE 802.15-06-0227-00-0005 Submission May 10, 2006 Yongjun Liu,Na Shan, HuaweiSlide 3 Contents Necessity of dynamic channel selection Overview of the present mechanism Issues of present mechanism Propose a new mechanism Conclusion

4. doc.: IEEE 802.15-06-0227-00-0005 Submission May 10, 2006 Yongjun Liu,Na Shan, HuaweiSlide 4 Necessity of dynamic channel selection PAN 2 WLAN PAN 1

5. doc.: IEEE 802.15-06-0227-00-0005 Submission May 10, 2006 Yongjun Liu,Na Shan, HuaweiSlide 5 Necessity of dynamic channel selection (cont.) Standards Mid Frequency (MHz) Bandwidth (MHz) 802.15.1/Bluetooth 2402+k, k=0,1,…,78 1 (FH) 802.15.3 2412,2428,2437, 2445,2462 15 802.15.4/ZigBee (2.4GHz bands) 2405+5(k-11), k=11,12,…,26 5 802.11b/Wi-Fi 2407+5k, k=1,2,…,13 22

6. doc.: IEEE 802.15-06-0227-00-0005 Submission May 10, 2006 Yongjun Liu,Na Shan, HuaweiSlide 6 Necessity of dynamic channel selection (cont.) Congested ISM bands: Wi-Fi/802.11b, Bluetooth/802.15.1, ZigBee/802.15.4, 802.15.3, RFID… Mechanisms should help to mitigate co- existence interference Improve reliability

7. doc.: IEEE 802.15-06-0227-00-0005 Submission May 10, 2006 Yongjun Liu,Na Shan, HuaweiSlide 7 Present mechanism 802.15.3: PNC should periodically listen in the current channel to detect interference or request other nodes to do so PNC makes analysis of detection results and decides whether to switch to a new channel 802.15.4: none.

8. doc.: IEEE 802.15-06-0227-00-0005 Submission May 10, 2006 Yongjun Liu,Na Shan, HuaweiSlide 8 Issues of present mechanism The PNC listening range is limited (one hop) – PNC can not detect the interference outside its vicinity – PNC doesn’t know which nodes it should inquire of the channel status – PNC doesn’t know when to inquire the channel status Some nodes are unable to hear the information about channel switching; the process isn’t defined in the present standard

9. doc.: IEEE 802.15-06-0227-00-0005 Submission May 10, 2006 Yongjun Liu,Na Shan, HuaweiSlide 9 Propose a new mechanism -outline Nodes decide to detect by themselves PNC (and coordinators) makes analysis of the interference and decisions PNC notifies all nodes to change channel Residual nodes rejoin the PAN by successive more steps

10. doc.: IEEE 802.15-06-0227-00-0005 Submission May 10, 2006 Yongjun Liu,Na Shan, HuaweiSlide 10 Propose a new mechanism -flow chart

11. doc.: IEEE 802.15-06-0227-00-0005 Submission May 10, 2006 Yongjun Liu,Na Shan, HuaweiSlide 11 Propose a new mechanism -interference detection Nodes decide to do interference detection by themselves –Triggered by instances: too many re- transmissions, high packet loss rate… –Detect periodically: a proactive action help to change the channel faster (Both an instance and an period are implementation dependent)

12. doc.: IEEE 802.15-06-0227-00-0005 Submission May 10, 2006 Yongjun Liu,Na Shan, HuaweiSlide 12 Propose a new mechanism - interference detection (cont) do detection for many re-transmissions periodical detection

13. doc.: IEEE 802.15-06-0227-00-0005 Submission May 10, 2006 Yongjun Liu,Na Shan, HuaweiSlide 13 Propose a new mechanism - interference analysis Detection results shall report to PNC Intermediate coordinators pre-process interference reports (optional) Coordinators make analyses and decide whether to report to PNC (optional) PNC makes analyses and decide whether to change operation channel Detail actions of PNC out of scope

14. doc.: IEEE 802.15-06-0227-00-0005 Submission May 10, 2006 Yongjun Liu,Na Shan, HuaweiSlide 14 Propose a new mechanism - change channel PNC decides to change channel if it is no more appropriate for operation and another channel is much better than it Find out PS nodes to be wakened, then waken them: The PNC shall announce the system wake beacon in the Next Wake Beacon field in the PS Status IE with PS Set Index field equal to one in the beacon (optional) Beacons or specified frames are broadcast to notify all nodes of channel switching Nodes change channel after receiving the broadcast frames

15. doc.: IEEE 802.15-06-0227-00-0005 Submission May 10, 2006 Yongjun Liu,Na Shan, HuaweiSlide 15 Propose a new mechanism - actions of residual nodes Some nodes is unable to hear the channel switching notification frame because they are sleeping or suffering from severe interference First scan at the previous channel but cannot find the PAN Then scan all possible channel one by one to relocate the PAN (hold the previous PANID)

16. doc.: IEEE 802.15-06-0227-00-0005 Submission May 10, 2006 Yongjun Liu,Na Shan, HuaweiSlide 16 Propose a new mechanism - actions of residual nodes (cont) may scan more than once and more than one channel

17. doc.: IEEE 802.15-06-0227-00-0005 Submission May 10, 2006 Yongjun Liu,Na Shan, HuaweiSlide 17 Propose a new mechanism -some introduced structures (high rate) A node reports the interference status to PNC by the announce command and primitives (MLME-SCAN) PNC enforces to switch the channel by beacons Interference status IE –Channel number list (1 octet, bitmap) –Interference status descriptions list (variable) –Length (1 octet) IE identifier

18. doc.: IEEE 802.15-06-0227-00-0005 Submission May 10, 2006 Yongjun Liu,Na Shan, HuaweiSlide 18 MSC for HR new mechanism

19. doc.: IEEE 802.15-06-0227-00-0005 Submission May 10, 2006 Yongjun Liu,Na Shan, HuaweiSlide 19 Propose a new mechanism -some introduced structures (low rate) Interference report: Src addr – addr of detection node, Dest addr – addr of PNC, payload – interference detection results Channel switching notification: Src addr – addr of PNC, Dest addr – broadcast addr. May reuse coordinator realignment command frame of 15.4b

20. doc.: IEEE 802.15-06-0227-00-0005 Submission May 10, 2006 Yongjun Liu,Na Shan, HuaweiSlide 20 Propose a new mechanism -some introduced commands (low rate) Command namesParametersDescriptionsRemarks Interference Report CommandSrc AddrThe short address of transmitting the Interference report 2octets Dest AddrThe destination short address of the recipient of the Interference report. 2octets lengthSpecifies the length of channel number list and Interference status description list. 1octet Channel number listThe indication bit of the interference channels 2octets, bitmap Interference status description list Specifies the status of the interference channels variable

21. doc.: IEEE 802.15-06-0227-00-0005 Submission May 10, 2006 Yongjun Liu,Na Shan, HuaweiSlide 21 Propose a new mechanism -some introduced primitives (low rate) Primitive namesParametersDescriptionsRemarks MLME-Interference-report.reqDest AddrThe destination short address of the recipient of the Interference report. 2octets lengthSpecifies the length of channel number list and Interference status description list. 1octet Channel number listThe indication bit of the interference channels 2octets, bitmap Interference status description list Specifies the status of the interference channels variable MLME-Interference-report.confirmResultCodeSpecifies the result of transmitting Interference report. 1 octet MLME-Interference-report.indicationSrc AddrThe short address of transmitting the Interference report 2octets lengthSpecifies the length of channel number list and Interference status description list. 1octet Channel number listThe indication bit of the interference channels 2octets, bitmap Interference status description list Specifies the status of the interference channels variable

22. doc.: IEEE 802.15-06-0227-00-0005 Submission May 10, 2006 Yongjun Liu,Na Shan, HuaweiSlide 22 MSC for LR new mechanism

23. doc.: IEEE 802.15-06-0227-00-0005 Submission May 10, 2006 Yongjun Liu,Na Shan, HuaweiSlide 23 Conclusions Necessity of dynamic channel selection Overview of current mechanism -some issues not resolved -lack mechanisms for low-rate mesh networks Proposed a new mechanism for dynamic channel selection -Nodes do detection by time or when they are in difficulty of communicating with other nodes -PNC/Coordinators makes interference analysis, then PNC decides whether to change channel -PNC wakens some PS nodes (optional) -PNC broadcasts a frame to notify all nodes to change channel -Residual nodes may scan more than once to relocate the PAN -Some new frames should be introduced

24. doc.: IEEE 802.15-06-0227-00-0005 Submission May 10, 2006 Yongjun Liu,Na Shan, HuaweiSlide 24 Problems???

25. doc.: IEEE 802.15-06-0227-00-0005 Submission May 10, 2006 Yongjun Liu,Na Shan, HuaweiSlide 25 Thank you for your attention!