1. doc.: IEEE 802.11-07/2901r06 Submission November 2007 Doug Kavner, RaytheonSlide 1 Use of BSSID in WAVE Date: 2007-12-06 Authors:

2. doc.: IEEE 802.11-07/2901r06 Submission November 2007 Doug Kavner, RaytheonSlide 2 Abstract A solution is proposed to permit simultaneous reception of BSS data frames and non-BSS data frames on the same channel by the same STA.

3. doc.: IEEE 802.11-07/2901r06 Submission November 2007 Doug Kavner, RaytheonSlide 3 Desired Functionality WAVE mode permits transmission of data frames without an established WAVE BSS using a wildcard BSSID It may be desirable now or in the future to permit this in conjunction with data frames within an established WAVE BSS from the same STA –802.11p does not explicitly exclude this operation currently –Note: BSSID for a WAVE BSS is the MAC address of the WAVE BSS Initiator

4. doc.: IEEE 802.11-07/2901r06 Submission November 2007 Doug Kavner, RaytheonSlide 4 The Problem There is no way to set the BSSID in a data frame to the wildcard BSSID while joined to a BSS The BSSID in transmitted data frames is the currently joined BSSID –BSSID is not currently specified on a frame-by-frame basis from higher layers –See IEEE Std 802.11-2007, clause 6.2.1.1.2

5. doc.: IEEE 802.11-07/2901r06 Submission November 2007 Doug Kavner, RaytheonSlide 5 Recommended Solution Add an optional parameter to MA-UNITDATA.request to specify a specific BSSID for the frame Add an optional parameter to MA- UNITDATA.indication to report a received BSSID other than the currently joined BSSID Use of the new parameters is not restricted to WAVE mode

6. doc.: IEEE 802.11-07/2901r06 Submission November 2007 Doug Kavner, RaytheonSlide 6 Implications of the Solution Received BSS data frames are still subject to traditional filtering Received non-BSS data frames are filtered on the non- BSSID criteria –802.11p already contains the exception to allow reception of data frames with a wildcard BSSID Higher layers must know when to set a specific BSSID –In WAVE, non-BSS data frames are for WSMP only –WSMP can be enhanced to have knowledge of the new parameter

7. doc.: IEEE 802.11-07/2901r06 Submission November 2007 Doug Kavner, RaytheonSlide 7 Rejected Solutions (1) Using a non-wildcard WAVE BSSID for non-BSS data frames is problematic –Assume two nearby WAVE BSSs with BSSID=3 and BSSID=4 –STAs on BSSID 3 will filter all data frames from BSSID 4 –Non-BSS data frames sent from a STA on BSSID 4 will also be filtered by STAs on BSSID 3 –Running in promiscuous mode would circumvent the primary purpose of multiple BSSIDs, which is to permit filtering of broadcast/multicast data frames See IEEE Std 802.11-2007, p. 78 first sentence

8. doc.: IEEE 802.11-07/2901r06 Submission November 2007 Doug Kavner, RaytheonSlide 8 Rejected Solutions (2) Resetting the MAC to change the BSSID is not feasible –Loss of MAC state and queued packets –Latency Creating a MLME-SET-BSSID.request to change the BSSID without resetting the MAC would require tight coupling and synchronization of management and data planes

9. doc.: IEEE 802.11-07/2901r06 Submission November 2007 Doug Kavner, RaytheonSlide 9 Rejected Solutions (3) Set BSSID in the MAC Header to the wildcard BSSID when: –DA/RA is a locally administered multicast address with the non_bss_multicast_bit = 1 (non_bss_multicast_bit is an arbitrary value to be selected by the editor) –Broadcast MAC address (FF FF FF FF FF FF) qualifies as a locally administered multicast address with non_bss_multicast_bit = 1 Implications to filtering of WAVE BSS Data Frames –Unicast Data Frames: None Filtering is already based on the RA alone –Broadcast Data Frames: Filtering not supported Use a specific multicast address instead –Multicast Data Frames: Filtered if non_bss_multicast_bit = 0 –Case of non_bss_multicast_bit = 0 when not joined to a WAVE BSS is undefined Note that to/from DS data frames are sent unicast While this solution could work, after a long discussion in the November 2007 TGp sessions, the opinion of the group was that it is too clumsy

10. doc.: IEEE 802.11-07/2901r06 Submission November 2007 Doug Kavner, RaytheonSlide 10 Rejected Solutions (4) Add new MA-UNITDATA-NON-BSS.request/confirm/indication primitives to support transmission of data frames outside of a BSS –Parameters same as for MA-UNITDATA.request/confirm/indication –BSSID in MAC Header always set to wildcard BSSID –Permits a non-wildcard BSSID to be used for data frames sent with current MA-UNITDATA.request On receive, MAC would invoke MA-UNITDATA-NON- BSS.indication if the BSSID is the wildcard BSSID Splitting MA-UNITDATA creates confusion in the architecture and is not supportable in the long-term if other parameters need to be added

11. doc.: IEEE 802.11-07/2901r06 Submission November 2007 Doug Kavner, RaytheonSlide 11 Motion Move to accept the recommended solution and instruct the editor to make updates to the draft Moved: Second: For: Against: Abstain: