doc.: IEEE /1128r1 Submission Nov 2009 Allan Thomson, Cisco SystemsSlide 1 BSS Transition with Bearing Date: Authors:

doc.: IEEE /1128r1 Submission Nov 2009 Allan Thomson, Cisco SystemsSlide 2 Abstract This proposal is submitted as a solution to SB CID# Today many clients have the capability to determine bearing (direction) and relative height to aid with navigation This proposal leverages that capability to improve client roaming behavior

doc.: IEEE /1128r1 Submission Nov 2009 Allan Thomson, Cisco SystemsSlide 3 The problem… BSS Transition Management provides information to the client to aid client roaming Today the Neighbor Report element included in the BSS Transition Management Request frame includes BSSID, Reg Class, Channel and various additional sub-elements related to the BSSID One such sub-element is BSS Transition Preference This indicates the relative preference from the “network-side” of what APs should be considered by the client for roaming to –This information is not based on what the client is actually doing For clients that are in motion and have bearing information, there is no information available from the network that indicates which APs are in the path of the client Therefore AP provided preferences cannot always help clients while in motion

doc.: IEEE /1128r1 Submission Nov 2009 Allan Thomson, Cisco SystemsSlide 4 The solution… Provide a mechanism for the AP network to notify STAs for each AP neighbor the relative bearing and height of AP neighbors from the AP reporting the information Therefore allowing the STA to choose an appropriate AP transition if that STA knows its direction while in motion

doc.: IEEE /1128r1 Submission Example #1 Associated AP12 reports preferred transition candidates (all candidates same height): –AP7 (0degs) –AP8 (20degs) –AP13 (25degs) –AP6 (340 degs) –AP11 (320degs) –…etc Client knows 0 == North Client knows that it is facing/moving bearing 22degs Client chooses AP8 or AP13 Nov 2009 Allan Thomson, Cisco SystemsSlide 5

doc.: IEEE /1128r1 Submission Example #2: Client same distance from AP12 but different position Client could be anywhere on the grey circle AP12 continues to report same transition information as Example 1 Client still knows that it is moving towards 22degs Client chooses AP neighbors based on direction of travel Nov 2009 Allan Thomson, Cisco SystemsSlide 6

doc.: IEEE /1128r1 Submission Example #3: Client walking up to a building Client walking to building can see APs on 1 st, 2 nd and 3 rd floors AP on 1 st floor reports APs on same floor and 2 nd floor in candidate list Client chooses AP neighbors based on 1 st floor level as reporting BSS Nov 2009 Allan Thomson, Cisco SystemsSlide 7

doc.: IEEE /1128r1 Submission Nov 2009 Allan Thomson, Cisco SystemsSlide 8 Solution Details Add new Bearing sub-element to Neighbor Report Table 7-43b—Optional Subelement IDs for Neighbor Report Subelement IDName Length field (octets) Extensible 0Reserved 1TSF Information4Yes 2Condensed Country String2Yes 3BSS Transition Candidate Preference1 4 BSS Termination Duration 12 5 Bearing Reserved 66Measurement Pilot Transmission Information 1 to 238Subelements 67-69Reserved 70RRM Enabled Capabilities4Yes 71Multiple BSSID1 to 238Subelements Reserved 221Vendor Specific1 to Reserved

doc.: IEEE /1128r1 Submission Nov 2009 Allan Thomson, Cisco SystemsSlide 9 Sub-element Details Single field indicating Bearing and Relative Height Bearing indicates the direction of the neighbor in degrees relative to the reporting BSS and in relation to true north Relative Height indicates the +/- distance in meters between the reporting BSS and the neighbor BSS –0 indicates the reporting BSS does not know the relative height difference or the neighbor is at the same height

doc.: IEEE /1128r1 Submission Nov 2009 Allan Thomson, Cisco SystemsSlide 10 Questions ?

doc.: IEEE /1128r1 Submission Nov 2009 Allan Thomson, Cisco SystemsSlide 11 Motion Move to incorporate the normative text in 09/1129r0 into the TGv draft Yes: No: Don’t care: