1. doc.: IEEE 802.11-05/0247r1 Submission March 2005 Atsushi FujiwaraSlide 1 Advantages of multiple channel usage in 11s WLAN Mesh network Notice: This document has been prepared to assist IEEE 802.11. 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 grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.11. Patent Policy and Procedures: The contributor is familiar with the IEEE 802 Patent Policy and Procedures, including the statement "IEEE standards may include the known use of patent(s), including patent applications, provided the IEEE receives assurance from the patent holder or applicant with respect to patents essential for compliance with both mandatory and optional portions of the standard." Early disclosure to the Working Group of patent information that might be relevant to the standard is essential to reduce the possibility for delays in the development process and increase the likelihood that the draft publication will be approved for publication. Please notify the Chair as early as possible, in written or electronic form, if patented technology (or technology under patent application) might be incorporated into a draft standard being developed within the IEEE 802.11 Working Group. If you have questions, contact the IEEE Patent Committee Administrator at.http:// ieee802.org/guides/bylaws/sb-bylaws.pdfstuart.kerry@philips.compatcom@ieee.org Date: 2005-Mar-17 Authors:

2. doc.: IEEE 802.11-05/0247r1 Submission March 2005 Atsushi FujiwaraSlide 2 Abstract This presentation discusses advantages on usage of multiple channels and requirements of channel setting technology for 11s mesh network

3. doc.: IEEE 802.11-05/0247r1 Submission March 2005 Atsushi FujiwaraSlide 3 Contents Requirements Scenario for Single WLAN interface model Advantage on usage of Multiple channels Required technology for Multi WLAN interface model Suggestions for 11s amendment

4. doc.: IEEE 802.11-05/0247r1 Submission March 2005 Atsushi FujiwaraSlide 4 Requirements Channel unification mechanism shall be defined to ensure the connectivity between Mesh APs –Single WLAN interface case and Single channel Framework to build the optimization technology for Multi WLAN Interface network must be defined –Channel Setting Algorithm itself shall be out of scope –Framework must be defined Measurement in multi hop network TPC/DFS in multi hop network 11h/k extension for WLAN mesh network

5. doc.: IEEE 802.11-05/0247r1 Submission March 2005 Atsushi FujiwaraSlide 5 Single WLAN Interface Case Requirement of channel setting in mesh network All MAPs shall use the same channel to establish mesh network even in such cases: –simultaneous power on –merge of multiple mesh network Channel unification mechanism shall be standardized Power on scan Power on

6. doc.: IEEE 802.11-05/0247r1 Submission March 2005 Atsushi FujiwaraSlide 6 Multiple WLAN Interface Case Requirement of channel setting in mesh network Multiple channel usage will be solutions to some issues on mesh networks –Load balancing –QoS Support –Hidden / Exposed terminal problem Frameworks to support multiple WLAN interfaces shall be standardized –DFS, TPC, Measurement for mesh network –should be extension of 11k and 11h amendment for mesh network

7. doc.: IEEE 802.11-05/0247r1 Submission March 2005 Atsushi FujiwaraSlide 7 TCP Throughput degradation due to exposed terminal problem End-to-end throughput (Mbps) Case 1 Case 2 Case 1 Case 2 Carrier Sense Range TCP Throughput degradation due to exposed terminal problem Using different channel between the first and third hop recovers this degradation How to select channel in more complicated case? 0.5 1.0 1.5

8. doc.: IEEE 802.11-05/0247r1 Submission March 2005 Atsushi FujiwaraSlide 8 Usage of multiple channel for solving exposed terminal problem (1/7) Mesh network example by 6 nodes M1 M2 M3 M4 M6 M5

9. doc.: IEEE 802.11-05/0247r1 Submission March 2005 Atsushi FujiwaraSlide 9 Usage of multiple channel for solving exposed terminal problem (2/7) While nodes 1 and 2 are communicating… M1 M2 M3 M4 M6 M5 L12 – L34 L12 – L45 L12 – L46 Constraints to avoid exposed terminal problem

10. doc.: IEEE 802.11-05/0247r1 Submission March 2005 Atsushi FujiwaraSlide 10 Usage of multiple channel for solving exposed terminal problem (3/7) While nodes 1 and 3 are communicating… M1 M2 M3 M4 M6 M5 Constrains to avoid exposed terminal problem L12 – L34 L12 – L45 L12 – L46 L13 – L26 L13 – L46 L13 – L56

11. doc.: IEEE 802.11-05/0247r1 Submission March 2005 Atsushi FujiwaraSlide 11 Usage of multiple channel for solving exposed terminal problem (4/7) Derivation of chromatic graph M1 M2 M3 M4 M6 M5 L26 L12 L34 L46 L45 L15 L13 L56 L23 L12 – L34 L12 – L45 L12 – L46 L13 – L26 L13 – L46 L13 – L56 L23 – L15 L23 – L45 L23 – L56 L45 – L12 L45 – L23 L45 – L26 L46 – L12 L46 – L13 L46 – L15 L56 – L13 L56 – L23 L56 – L34 Constraints to avoid exposed terminal problem

12. doc.: IEEE 802.11-05/0247r1 Submission March 2005 Atsushi FujiwaraSlide 12 Usage of multiple channel for solving exposed terminal problem (5/7) All possible patterns in 5-MAPs mesh network (21 patterns)

13. doc.: IEEE 802.11-05/0247r1 Submission March 2005 Atsushi FujiwaraSlide 13 Usage of multiple channel for solving exposed terminal problem (6/7) 12345678 11124610142 22 783661599 3 1244688076 451421 tota l 11262111285311117 Channels MAPs Number of required channels for all the possible topology (up to 8 MAPs)

14. doc.: IEEE 802.11-05/0247r1 Submission March 2005 Atsushi FujiwaraSlide 14 Usage of multiple channel for solving exposed terminal problem (7/7) Required number of channels for practical topology (up to 10 MAPs)

15. doc.: IEEE 802.11-05/0247r1 Submission March 2005 Atsushi FujiwaraSlide 15 Suggestions for 11s amendment 11s shall standardize: Channel Unification mechanism to ensure the connectivity Frameworks to support multiple WLAN interfaces –DFS, TPC, Measurement for mesh network –should be extension of 11k and 11h amendment for mesh network