1. Resolution to TGaj Draft 0.01 CID 146
Month Year
doc.: IEEE yy/xxxxr0
March 2014
Resolution to TGaj Draft 0.01 CID 146
Date:
Presenter:
Dejian Li
John Doe, Some Company

2. March 2014
Author List
Dejian Li

3. March 2014
Abstract
This is a submission for comment resolution on D0.01 for comment #146. This submission provides an SP Dynamic Truncation mechanism for 11aj to improve spatial sharing and increase sleep chances in SP for PCP.
Dejian Li

4. Background: SP dynamic truncation in 11ad
March 2014
Background: SP dynamic truncation in 11ad
To support variable bit rate traffic, the STA can truncate SP or extend SP dynamically.
In ad, there are two types of SP truncation [1]:
The STA can truncate the SP and return to the PCP/AP the time left in the SP, thus allowing the PCP/AP to grant the released time to any other STA.
The STA can allocate any portion of its SP as a CBAP directly.
The Allocation Control field of Extended Schedule element comprises all the SP attributions, such as truncatable or extendable.
Dejian Li

5. Problems of the 11ad SP truncation
March 2014
Problems of the 11ad SP truncation
Releasing the remaining time in the SP as a CBAP by STA might lead to interference to some existing SPs.
An STA neither has the overall interference information of the BSS, nor the schedule information of the neighbor BSS that PCP/AP obtained by clustering mechanism.
A PCP that is battery powered can not save power during a truncatable SP according to 11ad.
The PCP should be awake in all truncatable SPs because the STA may releasing the remaining time in the SP to the PCP.
Making sure the two types of SP truncation can be controlled by PCP/AP is a solution for the two above problems.
Dejian Li

6. Resolution of the SP dynamic truncation
March 2014
Resolution of the SP dynamic truncation
Add Truncation Type field using a reserved bit (B12) in Allocation Control field to indicate the truncation type of the SP.
If the Truncatable field is set to 1 and the Truncation Type field is set to 0, the STA releases the remaining time of SP to the PCP/AP for dynamic SP allocation. If the Truncatable field is set to 1 and the Truncation Type field is set to 1, the STA releases the remaining time of SP as CBAP directly.
If the Truncatable field is set to 0, then the Truncation Type field is reserved.
PCP Active field
If the Extendable field is set to 1, then the PCP Active field is set to 1.
If the Extendable field is set to 0, Truncatable field is set 1 and Truncation Type is set to 0, PCP Active field is set to 1.
In all other cases, PCP Active can be set to 0.
Dejian Li

7. Benefits of the Improved SP Truncation
March 2014
Benefits of the Improved SP Truncation
Increase the sleep chances for a PCP
If the Truncation Type field is set to 1 to allow the STA to release the remaining SP as a CBAP by itself, then the PCP can sleep during the whole SP to save power.
For example, if the allocated SP1 is not time-overlapping with other SPs, and all SP requirements of STAs are meet during ATI, then PCP can set the Truncation Type field to 1.
Improve the spatial sharing
Scenario: SP1 is time overlapping with SP2, STA5 and STA6 still have unsatisfied SP requirement.
If the PCP/AP finds that the directional communication between STA5 and STA 6 does not interfere SP2, then PCP/AP can set the Truncatable and Truncation Type fields to 1 and 0 respectively, indicating the remaining SP should be allocated by PCP/AP. If STA1 and STA2 truncate SP1 and release the remaining time to PCP/AP, then the PCP/AP can allocate the remaining SP1 to STA5 and STA6 dynamically.
Dejian Li

8. March 2014
Summary
This submission provides solution for comment #146 on the comment resolution for D0.01.
The SP truncation type is determined by PCP/AP by adding Truncation Type field in Allocation Control field.
The determination of SP truncation type made by PCP/AP can mitigate interference that introduced by SP truncation.
PCP can sleep in some truncatable SPs, which helps to save power.
Modification to ad:
Add Truncation Type field (1-bit ) in the Allocation Control field;
Modify the setting method of the PCP Active field.
Dejian Li

9. March 2014
Reference
In the IEEE P802.11ad TM Standard “Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications – Amendment 3: Enhancements for Very High Throughput in the 60 GHz band,” December 2012.
Dejian Li