Use of BSSID in WAVE Date: 2007-11-15 Authors: November 2007 doc.: IEEE 802.11-07/2901r0 November 2007 Use of BSSID in WAVE Date: 2007-11-15 Authors: Doug Kavner, Raytheon Doug Kavner, Raytheon

November 2007 doc.: IEEE 802.11-07/2901r0 November 2007 Abstract It is proposed to set the BSSID in all data frames transmitted in WAVE mode to the wildcard BSSID. This is to permit simultaneous reception of WAVE BSS data frames and non-BSS data frames on the same channel. Doug Kavner, Raytheon Doug Kavner, Raytheon

Desired Functionality November 2007 doc.: IEEE 802.11-07/2901r0 November 2007 Desired Functionality WAVE mode permits transmission of data frames without an established WAVE BSS Normally with a wildcard BSSID It may be desirable now or in the future to permit this in conjunction with WAVE BSS data frames 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 Doug Kavner, Raytheon Doug Kavner, Raytheon

November 2007 doc.: IEEE 802.11-07/2901r0 November 2007 The Problem (1) BSSID in transmitted data frames is the currently joined BSSID BSSID is not specified on a frame-by-frame basis from higher layers See IEEE Std 802.11-2007, clause 6.2.1.1.2 Adding a frame specific BSSID would require changing MA-UNITDATA.request and may not be supportable on current implementations 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 Doug Kavner, Raytheon Doug Kavner, Raytheon

November 2007 doc.: IEEE 802.11-07/2901r0 November 2007 The Problem (2) 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 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 IEEE Std 802.11-2007, p. 78 first sentence Doug Kavner, Raytheon Doug Kavner, Raytheon

November 2007 doc.: IEEE 802.11-07/2901r0 November 2007 Solution #1 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 Justification: We can partition the locally administered address space however we like 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 Doug Kavner, Raytheon Doug Kavner, Raytheon

Additional changes for Solution #1 November 2007 doc.: IEEE 802.11-07/2901r0 November 2007 Additional changes for Solution #1 Need to footnote Table 7-7 in IEEE Std 802.11-2007 For “From DS” frame, TA ≠ BSSID when the BSSID is wildcarded For “To DS” frame, RA ≠ BSSID when the BSSID is wildcarded Doug Kavner, Raytheon Doug Kavner, Raytheon

November 2007 doc.: IEEE 802.11-07/2901r0 November 2007 Solution #2 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 Implications to filtering of WAVE BSS Data Frames All traditional filtering methods supported Requires higher layers to know which primitive to invoke Non-BSS data frames are WSMP only Enhance WSMP to have knowledge of the new primitive On receive, MAC invokes MA-UNITDATA-NON-BSS.indication if the BSSID is the wildcard BSSID Doug Kavner, Raytheon Doug Kavner, Raytheon

November 2007 doc.: IEEE 802.11-07/2901r0 November 2007 Motion #1 Move to accept solution #1 and instruct the editor to make updates to the draft Moved: Second: For: Against: Abstain: Doug Kavner, Raytheon Doug Kavner, Raytheon

November 2007 doc.: IEEE 802.11-07/2901r0 November 2007 Motion #2 Move to accept solution #2 and instruct the editor to make updates to the draft Moved: Second: For: Against: Abstain: Doug Kavner, Raytheon Doug Kavner, Raytheon