1. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 1 Date: 2007-1-15 Scalable Station Association Information Handling 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 Authors:

2. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 2 Abstract In this presentation, we investigate how to handle the legacy stations in the WMNs and we propose three schemes to provide a better solution in managing the legacy station information among the MAPs.

3. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 3 Legacy STA impacts 802.11s Mesh WLAN Seamless integration and self-configuration 802.11 stations (legacy STAs) and 802.11s Mesh Access Points (MAPs). Security issue Man-In-The-Middle (MITM) Attack problem and etc. Fully backwards compatible No change to existing legacy STAs is needed. No interruption of a radio signal from legacy STA to MAP is happened. Shortage of 4-to-6 and 6-to-4 address conversion 4-address scheme for legacy STAs and 6-address scheme for MAPs. Shortcomings of multi-radio configuration Single interface for legacy STAs and multi-interface for MAPs. Interoperability Problem Path selection protocol for only MAPs and no routing table for legacy STA.

4. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 4 802.11s Path Selection Protocol Path selection protocol must be implemented on all MPs/MAPs to ensure baseline interoperability for 802.11s MPs/MAPs and 802.11s MPs/MAPs. legacy STAs and legacy STAs. legacy STAs and 802.11s MPs/MAPs. In current 802.11s specification, two path selection protocols are defined. Hybrid Wireless Mesh Protocol (HWMP) – default protocol. Radio-aware OLSR (RA-OLSR) – optional protocol. HWMP: So far, no Station Association Discovery Scheme to handle the legacy STAs. RA-OLSR: LAB/GAB Scheme is applied to handle the legacy STAs. Is this interoperability work???

5. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 5 Motivation By using the RA-OLSR protocol, each MAP broadcasts LABA message periodically. This phenomenon gives a difficulty to handle a huge proxy table of each MAP.

6. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 6 MAP Table MAP STA Table + + + + + A huge proxy table problem for all MAPs +

7. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 7 We propose three schemes to solve the problem of handling the huge proxy table in each MAP when the RA-OLSR protocol is applied. Efficient LAB/GAB Management Scheme Centralized Station Discovery Scheme On-demand Station Discovery Scheme Our Proposed Schemes

8. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 8 Scheme 1: Efficient LAB/GAB Management Scheme

9. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 9 Approach We introduce a Local Association Update Checksum Advertisement (LAUCA) message to shrink down the overhead. We introduce GABI_REQ and GABI messages to obtain the GAB in a shorter time with less overhead for a newly joined MP/MAP. Motivation The periodical broadcasting of LABA/LABCA message will generate a large communication overhead throughout the WMNs.

10. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 10 “Local Association Base Checksum Advertisement (LABCA)” is changed to “Local Association Update Checksum Advertisement (LAUCA)” LAUCA message consists of an updated (associated/disassociated) STA address information; and an updated checksum of the LAB. Advantage: Overhead reduction of the LABA/LABCA method by using LAUCA method. MAP LAB Associated STA Info MAP Original LABA/LABCA Method join Disassociated STA Info LABA Proposed LAUCA Message leave LABCA Proposed LAUCA Method MAP LAB Associated STA Info LAUCA MAP Disassociated STA Info = Checksum join leave

11. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 11 Define a GABI_REQ message to obtain a GAB Information (GABI) message from the nearest neighbor MP/MAP. Upon receiving the GABI_REQ message, the nearest neighbor MP/MAP sends its own GABI message to the new MP/MAP. Advantage: A new MP/MAP can obtain the GAB in a shorter time with less overhead. new MP/MAP Current Method in the 802.11s draft ABBR (Unicast) LABA GAB Proposed GABI_REQ and GABI Messages LABA Wireless Mesh Networks new MP/MAP Proposed Method GABI_REQ (unicast) GAB This MP/MAP is proactively obtaining the GAB. GABI GAB Wireless Mesh Networks

12. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 12 Scheme 2: Centralized Station Discovery Scheme

13. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 13 Approach By assuming the periodical collecting GAB information is configured and the 6-address scheme is applied, we propose a Centralized Station Discovery Scheme, which allows the Root to collect the LABA messages from all MAPs and provide the required entry of the proxy table to MPs/MAPs. Avoiding an expired route: Once a MAP sends the data of active destination STAs to the Root, the Root send the address sets to the MAP. In each address set, it contains the address of active destination STA that is corresponding to the address of the MAP. Motivation The periodical sharing of GAB information by all the MPs/MAPs will generate a large communication overhead in the WMNs.

14. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 14 Root X 5 7 6 2 4 1 0 21 14 8 13 11 10 16 19 17 22 18 15 3 9 20 12 23 S2 S1 Periodically, e.g., MAP-16 generates a LABA message and sends it to the Root. Root constructs the GAB based on the LABA messages from all MAPs. LABA message Unicasting the LABA message to the Root

15. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 15 Root When S1 wants to communicate with S2 When a source station S1 wants to communicate with a destination station S2, S1 sends its data message to MAP-15. Upon receiving the data message from S1, MAP-15 transforms the header of the data message to the header that is containing 6-address format and directs it to the Root. X 5 7 6 2 4 1 0 21 14 8 13 11 10 16 19 17 22 18 15 3 9 20 12 23 S2 S1 Data message

16. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 16 Root Upon receiving the data messages from MAP-15, the Root that is knowing the MAP-16 is associating S2 redirects the data message to the MAP-16. Upon receiving the data message from the Root, the MAP-16 sends the data message to S2. X 5 7 6 2 4 1 0 21 14 8 13 11 10 16 19 17 22 18 15 3 9 20 12 23 S2 S1 When S1 wants to communicate with S2 Data message

17. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 17 Root To perform a centralized station discovery scheme, the Root informs the MAP-15 of address set, which contain the address of S2 that is corresponding to the address of MAP-16. Upon receiving the address set message from the Root, the MAP-15 sends the S1’s data message to MAP-16 along the route, which is maintained by the OLSR’s normal functions. X 5 7 6 2 4 1 0 21 14 8 13 11 10 16 19 17 22 18 15 3 9 20 12 23 S2 S1 When S1 wants to communicate with S2 address set of S2 and MAP-16 Data message

18. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 18 Root The route within the MAPs that is maintained by the OLSR’s normal functions will not expire. In contrast to that, an entry of the route to station inevitably expired unless it is updated periodically. X 5 7 6 2 4 1 0 21 14 8 13 11 10 16 19 17 22 18 15 3 9 20 12 23 S2 S1 When S1 wants to communicate with S2 Data message

19. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 19 Root If the entry of the route to S2 is expired, the MAP-15 directs the data message to Root. X 5 7 6 2 4 1 0 21 14 8 13 11 10 16 19 17 22 18 15 3 9 20 12 23 S2 S1 When S1 wants to communicate with S2 Expired route Data message

20. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 20 Root When the MAP-15 sends the LABA message (with a list of active destination stations) to the Root. X 5 7 6 2 4 1 0 21 14 8 13 11 10 16 19 17 22 18 15 3 9 20 12 23 S2 S1 When S1 wants to communicate with S2 LABA message with active destination STA (e.g., S2)s’ list Data message

21. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 21 Root Upon receiving the LABA message with active destination STAs’ list from the MAP-15, the Root sends a message of the address sets’ list that is corresponding to the active destination STAs’ list to the MAP- 15. In each address set, it contains the address of active destination station that is corresponding to the address of the MAP and the Destination Sequence Number (DSN) of active destination station. With such information, the route to the active destination station is being updated. X 5 7 6 2 4 1 0 21 14 8 13 11 10 16 19 17 22 18 15 3 9 20 12 23 S2 S1 When S1 wants to communicate with S2 Data message a list of address sets

22. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 22 Scheme 3: On-demand Station Discovery Scheme

23. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 23 Approach By assuming the periodical sharing GAB information is not configured, we propose an On-demand Station Discovery Scheme, which allows a MP/MAP to broadcast an Association Base Address Request (ABAR) message to discover a station and also allows a MAP to unicast a LABA message to inform the discovered station information. Upon receiving the LABA message, the MP/MAP treats the LABA message as an entry of discovered station in its proxy table. This proxy table indirectly takes the role of GAB. Motivation The periodical sharing of GAB information by all the MPs/MAPs will generate a large communication overhead in the WMNs.

24. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 24 On-Demand Station Discovery Scheme Octets: 6…6 STA address… FieldValue/Description STA addressA list of source STA address that is requested by a MAP that is associating the destination STA. When the MP/MAP searches for the MAP that is associating the destination STA, the MP/MAP generates an Association Base Address Request (ABAR) message and broadcasts it to the whole network. Upon receiving the ABAR message, the MAP that is associating the destination STA replies a LABA message in unicasting manner to the MP/MAP originator. Fields specific to RA-OLSR ABAR element

25. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 25 S2 5 7 6 2 4 1 0 21 14 8 13 11 10 16 19 17 22 18 15 3 9 20 12 23 When a source station S1 wants to send a data to a destination station S2, first S1 sends it to MAP-15. When the MAP-15 has no entry in its own proxy table, MAP-15 broadcasts an ABAR message to request for the address of S2. S1 When S1 wants to communicate to S2 Flooding ABAR message

26. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 26 S2 5 7 6 2 4 1 0 21 14 8 13 11 10 16 19 17 22 18 15 3 9 20 12 23 Upon receiving the ABAR message, the MAP-16 unicasts a LABA message, which contains a “address set.” In this address set, it contains the address of S2 that is corresponding to the address of the MAP originator. S1 When S1 wants to communicate to S2 LABA message

27. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 27 S2 5 7 6 2 4 1 0 21 14 8 13 11 10 16 19 17 22 18 15 3 9 20 12 23 Upon receiving the LABA message, the MAPs along the route (e.g., MAP-13, MAP-14, MAP-17) and also MAP-15 insert the LABA message as an entry of S2 in its proxy table. This proxy table indirectly takes the role of GAB. At last, the MAP-15 sends the S1’s data to S2 via the route between MAP-15 and MAP-16. S1 When S1 wants to communicate to S2 Data message

28. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 28 Conclusions We addressed the problem of handling the huge proxy table in each MAP when the RA-OLSR is applied. We also proposed three schemes to solve the problem of huge proxy table in each MAP: Efficient LAB/GAB Management Scheme Centralized Station Discovery Scheme On-demand Station Discovery Scheme

29. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 29 Shall we consider the first scheme (Efficient LAB/GAB Management Scheme) and prepare texts based on it for adoption ? –Yes: No: Abstain: Shall we consider the second scheme (Centralized Station Discovery Scheme) and prepare texts based on it for approval ? –Yes: No: Abstain: Shall we consider the third scheme (On-demand Station Discovery Scheme) and prepare texts based on it for approval ? –Yes: No: Abstain: Straw Poll

30. Submission doc.: IEEE 802.11-06/1842r3January 2007 Azman Osman Lim, et.al.Slide 30 References IEEE P802.11s Draft D1.0