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

2. November 2007
doc.: IEEE /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

3. CID #100, 101 and #317 Can the timing procedure be made symmetric ?
November 2007
doc.: IEEE /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 v 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

4. 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

5. 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

6. 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

7. Control field in the Timing Measurement action frame
Jan 2010
Control field in the Timing Measurement action frame B0 B1 B2 B3 B4
B 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

8. 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

9. Jan 2010
Frame Exchanges
Ganesh Venkatesan Intel, Gabor Bajko Nokia