Timing Measurement Date: 2010-01-17 Authors: Jan 2010 November 2007 doc.: IEEE 802.11-07/2752r1 Jan 2010 Timing Measurement Date: 2010-01-17 Authors: Ganesh Venkatesan Intel, Gabor Bajko Nokia Peter Ecclesine, Cisco Systems

November 2007 doc.: IEEE 802.11-07/2752r1 Jan 2010 Abstract This submission is a proposed resolution to TGv Initial Sponsor Ballot comments CID #100, CID #101 and CID #317. Ganesh Venkatesan Intel, Gabor Bajko Nokia Peter Ecclesine, Cisco Systems

CID #100, 101 and #317 Can the timing procedure be made symmetric ? November 2007 doc.: IEEE 802.11-07/2752r1 Jan 2010 CID #100, 101 and #317 Can the timing procedure be made symmetric ? The Timing Measurement procedure defined in this version of the draft is not on demand, and the originator does not receive the timer values back. It is also not symmetric. The Timing Measurement feature described in 802.11v could be useful in a variety of cases if it is generalized and rendered symmetrical. Ganesh Venkatesan Intel, Gabor Bajko Nokia Peter Ecclesine, Cisco Systems

Timing Measurement – what is missing? Jan 2010 Timing Measurement – what is missing? Exchange of information is in one direction STA-A and/or STA-B has no way of indicating what measurements are expected from the peer and what measurements are performed locally Additional exchanges are required to ensure that both STA-A and STA-B have all required information Ganesh Venkatesan Intel, Gabor Bajko Nokia

Jan 2010 Options Option-A : Add a Control field to the Timing Measurement action frame to exchange information on local capabilities and expectations from the peer (document 09/981r0) The information is passed in every measurement frame exchanged between the peers – this is wasteful The information is exchanged even for default behavior Option-B: Define a new Timing Measurement Capability action frame where information contained in the Control field is exchanged between the peers as needed (this proposal) Information need not be exchanged if the default behavior is in effect. Information is exchanged only when behavior is changed – not in every frame Ganesh Venkatesan Intel, Gabor Bajko Nokia

Timing Measurement Capability action frame Jan 2010 Timing Measurement Capability action frame Category Action Control Dialog Token Octets: 1 A STA sends the Timing Measurement Capability Advertisement action frame with bits in the Control field set appropriately The receiving STA responds with a Timing Measurement Capability Response action frame with the same Dialog Token as the one in the Timing Measurement Advertisement action frame and bits in the Control field set appropriately Ganesh Venkatesan Intel, Gabor Bajko Nokia

Control field in the Timing Measurement action frame Jan 2010 Control field in the Timing Measurement action frame B0 B1 B2 B3 B4 B5 B7 Request t2t3 Response t2t3 Request t1t4 Response t1t4 Measurement Enabled Reserved Bits: 1 3 Default values Request t2t3 Response t2t3 Request t1t4 Response t1t4 Measurement Enabled Advertisement X 1 Response X  Don’t Care or does not apply Ganesh Venkatesan Intel, Gabor Bajko Nokia

Frame Exchanges Jan 2010 Timing Measurement Capability Advertisement and Timing Measurement Capability Response exchange is optional. * If the Advertisement included Request t2t3 set to 1, the responder needs to send a Timing Measurement action frame to the Requester with the values of t2 and t3 in the ToA and ToD fields respectively. Ganesh Venkatesan Intel, Gabor Bajko Nokia

Jan 2010 Frame Exchanges Ganesh Venkatesan Intel, Gabor Bajko Nokia