1. BSS Transition with Bearing
Month Year
doc.: IEEE yy/xxxxr0
Nov 2009
BSS Transition with Bearing
Date:
Authors:
Allan Thomson, Cisco Systems
John Doe, Some Company

2. Abstract This proposal is submitted as a solution to SB CID#7355400023
Month Year
doc.: IEEE yy/xxxxr0
Nov 2009
Abstract
This proposal is submitted as a solution to SB CID#
Today many clients have the capability to determine bearing (direction) to aid with navigation
This proposal leverages that capability to improve client roaming behavior
Allan Thomson, Cisco Systems
John Doe, Some Company

3. Nov 2009
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
Allan Thomson, Cisco Systems

4. Nov 2009
The solution…
Provide a mechanism for the AP network to notify STAs for each AP neighbor the relative bearing 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
Allan Thomson, Cisco Systems

5. Example #1 Associated AP12 reports preferred transition candidates:
Nov 2009
Example #1
Associated AP12 reports preferred transition candidates:
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
Allan Thomson, Cisco Systems

6. Example #2: Client same distance from AP12 but different position
Nov 2009
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
Allan Thomson, Cisco Systems

7. Nov 2009
Solution Details
Add new Bearing sub-element to Neighbor Report
Allan Thomson, Cisco Systems

8. Sub-element Details Single field indicating Bearing
Nov 2009
Sub-element Details
Single field indicating Bearing
Bearing indicates the direction of the neighbor in degrees relative to the reporting BSS and in relation to true north
Allan Thomson, Cisco Systems

9. Nov 2009
Questions ?
Allan Thomson, Cisco Systems

10. Nov 2009
Motion
Move to incorporate the normative text in 09/1129r0 into the TGv draft
Yes:
No:
Don’t care:
Allan Thomson, Cisco Systems