1 / 9

Measurement Start Time

Measurement Start Time. Tim Olson, David Skellern Cisco Systems Inc tolson@cisco.com, skellern@cisco.com. Start Time change proposed by 03/372. Attempt to be compatible with TGh Addition of an absolute start time to each measurement request specified as a TSF

spicerc
Télécharger la présentation

Measurement Start Time

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Measurement Start Time Tim Olson, David Skellern Cisco Systems Inc tolson@cisco.com, skellern@cisco.com Olson & Skellern, Cisco Systems

  2. Start Time change proposed by 03/372 • Attempt to be compatible with TGh • Addition of an absolute start time to each measurement request specified as a TSF • Removal of “parallel” measurement mode bit Olson & Skellern, Cisco Systems

  3. Issues with 03/372 related to TGh • Start time changes don’t match latest TGh draft D3.11 – TGh allows +/- 32usecs • TGh has a very specific scope of detecting radars • Measurement definitions and timing are tailored for that purpose • Synchronization of measurement start times within the Quiet Periods specified by TGh creates a need for absolute start times • TGk should remain compatible with TGh when it makes sense to do so • TGk Requirements do not call for absolute time Olson & Skellern, Cisco Systems

  4. Issues with 03/372 related absolute start time complexity • Demanding an absolute measurement start time requires either • that measurements have priority over data (note an 11k requirement), or • that the AP predict in the future when a measurement may be made; it is a very non-trivial problem (and probably impractical) when measurements may be made • Cisco and several of its partners investigated the implementation of specific measurement start times and found it was not practical • Start times can be unpredictable by as much as 100’s of ms Olson & Skellern, Cisco Systems

  5. Start Time Complexities • Predicting future channel availability • Calculating delays due to other traffic • Factoring in a client in power save for unicast measurement requests • If a client is in power save the broadcast measurement request start times would have to account for DTIM interval and the current amount of other broadcast and multicast traffic. • Factoring in channel switch times (which vary by manufacturer) for non-serving channel measurements Olson & Skellern, Cisco Systems

  6. Why have a specific start time? • Currently in the TGk Issues and Requirements document there is no need for absolute start times • Are best effort measurements sufficient? • What radio measurement features cannot be satisfied with best effort measurements? • The entity best suited for determining when to take a measurement is the STA that received the measurement request Olson & Skellern, Cisco Systems

  7. Proposal • Update the current draft to eliminate the requirement of a specific start time • Two options for doing this…. • Eliminate start time from the draft • Update language to make the current start time merely a recommendation • This proposal recommends removing the start time altogether • Leaving in a start time that does not need to be adhered to seems to be extraneous and of little use • Measurement start times may be delayed if required by sending out the measurement request when needed Olson & Skellern, Cisco Systems

  8. Draft Updates Proposed • Remove Measurement Start Time field from each measurement request messages (sections 7.3.2.19.1, 7.3.2.19.2, 7.3.2.19.3, 7.3.2.19.4, 7.3.2.19.5, 7.3.2.19.6) • Add parallel mode bit back into the Measurement Mode field (section 7.3.2.19) Olson & Skellern, Cisco Systems

  9. Motion • Move to instruct the editor to incorporate the changes to the text described in 03/xxxr0 into the TGk 0.6 draft document Moved ___________________ Second ___________________ Yes _______ No _______ Abstain _______ Olson & Skellern, Cisco Systems

More Related