1. doc.: IEEE 802.15-<doc#>
<month year>
doc.: IEEE <doc#>
July, 2002
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [02292r0P802-15_TG3-SPS-Issue-Resolution.ppt]
Date Submitted: [05 July, 2002
Source: [Mark E. Schrader] Company [Eastman Kodak Co.]
Address [1447 Saint Paul St., Rochester, NY , USA]
Voice:[ ], FAX: [ ],
Re: [Draft 10 Comment Resolution for Power Management and Stream Management.]
Abstract: [This supplements 02/231 in discussing proposed changes to D10]
Purpose: [Communciate changes to D10 proposed in 02/231 and use of changes by the network members.]
Notice: This document has been prepared to assist the IEEE P It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein.
Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P
Mark Schrader, Eastman Kodak Co.
<author>, <company>

2. doc.: IEEE 802.15-<doc#>
<month year>
doc.: IEEE <doc#>
July, 2002
SPS Issue Resolution
Channel Time Request and Stream Management
Mark Schrader, Eastman Kodak Co.
<author>, <company>

3. doc.: IEEE 802.15-<doc#>
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doc.: IEEE <doc#>
July, 2002
Outline
In the context of the use of power management:
Proposed changes to CTRB and why.
Proposed adjustments for superframe loading control and documenting this capability.
Mark Schrader, Eastman Kodak Co.
<author>, <company>

4. Changes to CTRB Allow explicit choice of time base.
July, 2002
Changes to CTRB
Allow explicit choice of time base.
Time Base bit selects between “CTR Interval” field of CTRB and an “SPS Set” for either CTR Type.
PCTM setting in SPS.
Set PCTM bit allows the source DEV to tell the SPS DEV that it needs to listen to every beacon and change to ACTIVE mode.
Mark Schrader, Eastman Kodak Co.

5. July, 2002
Mark Schrader, Eastman Kodak Co.

6. July, 2002
Inputs
Outputs
Mark Schrader, Eastman Kodak Co.

7. July, 2002
Advantages of Changes
There are 3 scenarios that need to be covered by our standard
1. Active mode stream s1 created using “CTR Interval” time base: Suspend the stream s1 when switching to SPS mode.
A high-data-rate communication cannot be sourced by a DEV that has switched into SPS mode.
It will be begin again once the DEV has switched back to ACTIVE mode from SPS mode.
Mark Schrader, Eastman Kodak Co.

8. Power Save Transitions Affect on Stream s1 (see previous slide)
July, 2002
Power Save Transitions Affect on Stream s1 (see previous slide)
Mark Schrader, Eastman Kodak Co.

9. doc.: IEEE 802.15-<doc#>
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doc.: IEEE <doc#>
July, 2002
2. ACTIVE mode DEV wants to talk to an SPS DEV using SPS timing. The ACTIVE DEV creates stream s2 using an “SPS Set” as the time base. Stream s2 will continue when ACTIVE DEV switches to SPS mode.
An example is a power sensitive recording device with wireless remote control.
Remote control stays in SPS mode, Recording device alternates between SPS and ACTIVE mode.
Alternating mode DEV must maintain link with the SPS mode DEV, preferably without any overhead communication to the PNC.
Mark Schrader, Eastman Kodak Co.
<author>, <company>

10. Power Save Transitions Affect on Stream s2 (see previous slide)
July, 2002
Power Save Transitions Affect on Stream s2 (see previous slide)
Mark Schrader, Eastman Kodak Co.

11. doc.: IEEE 802.15-<doc#>
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doc.: IEEE <doc#>
July, 2002
3. A DEV is in ACTIVE mode. The DEV requests an SPS, CTR Type stream s3 using an “SPS Set” time base. s3 starts out suspended. When the DEV switches into SPS mode the stream s3 starts up.
Application space: A DEV wants to synchronously communicate with other SPS DEVs in a power sensitive application.
The application is exclusively for SPS mode.
When the DEV switches back to ACTIVE mode the stream s3 is suspended.
Mark Schrader, Eastman Kodak Co.
<author>, <company>

12. Power Save Transition Affect on Stream s3 (see previous slide)
July, 2002
Power Save Transition Affect on Stream s3 (see previous slide)
Mark Schrader, Eastman Kodak Co.

13. July, 2002
4. The same as 3 except that the DEV uses a “CTR Interval” time base rather than the “SPS Set” time base.
This is an example of a DEV that wants to save power without any data communication, and idle power save condition.
The “CTR Interval” is used as the time base to avoid wasting an SPS Set when no synchronization is required.
This “stream” only has awake beacons, no GTS slots.
Mark Schrader, Eastman Kodak Co.

14. Power Save Transitions Affect on Stream s4 (see previous slide)
July, 2002
Power Save Transitions Affect on Stream s4 (see previous slide)
Mark Schrader, Eastman Kodak Co.

15. July, 2002
Power Save Transitions Summary Affects on Streams s1, s2, s3 and s4 (see previous slides)
Mark Schrader, Eastman Kodak Co.

16. Proposed Addition to Standard
July, 2002
Proposed Addition to Standard
Mark Schrader, Eastman Kodak Co.

17. APS and SPS After Changes
July, 2002
APS and SPS After Changes
Convergence?
Mark Schrader, Eastman Kodak Co.

18. SPS/APS Overlap With Proposed Changes
<month year>
doc.: IEEE <doc#>
July, 2002
SPS/APS Overlap With Proposed Changes
Combined SPS and APS major capabilities:
1. PCTM traffic indication.
2. Flexible listen-to-beacon schedule up to a maximum.
3. Synchronous communication.
4. Predictable listen-to-beacon times.
5. Single DEV defines sleep duration.
The only APS-unique capability left will be number two in the list above. Is this close enough to eliminate APS?
Mark Schrader, Eastman Kodak Co.
<author>, <company>

19. July, 2002
Superframe Loading
Mark Schrader, Eastman Kodak Co.

20. Concern: Superframe Loading
<month year>
doc.: IEEE <doc#>
July, 2002
Concern: Superframe Loading
Superframe loading is the number of GTS slots allocated to a superframe
Differential superframe loading is the ratio of the largest number of GTS slots allocated to a superframe to the smallest number of SF’s allocated to a superframe. This can be caused by a large number of DEVs using the same SPS Set.
Mark Schrader, Eastman Kodak Co.
<author>, <company>

21. Can there be some control over SF loading?
July, 2002
Can there be some control over SF loading?
Yes by noting that the maximum power save always occurs if the SPS mode DEV’s awake superframes only occur when a GTS slot is needed.
In this case any SPS DEV using the same SPS Set to achieve the same GTS slot allocation rate must have a slot in the exact same super frame.
For this case the CTR Interval is always “1”, meaning “one awake beacon per Slot”.
Mark Schrader, Eastman Kodak Co.

22. SF Loading Control Continued
July, 2002
SF Loading Control Continued
What if the SPS Set is specified with a an SPS interval that makes the SPS DEV wake up 4 times as often as it needs a slot, then the power saved is less and the possible loading is less also.
The next two charts show how the PNC may allocate slots to distribute the loading.
It is up to the SPS DEV to trade off superframe loading for power.
Mark Schrader, Eastman Kodak Co.

23. July, 2002
Mark Schrader, Eastman Kodak Co.

24. July, 2002
Mark Schrader, Eastman Kodak Co.

25. Changes Required to the Draft
July, 2002
Changes Required to the Draft
Include the two diagrams shown here to show possible slot distribution by the PNC.
Make the mininum number SPS Sets 2 in order to facilitate an SPS DEV transitioning from one SPS Set to another, when a large number of DEVs have joined.
Add an indication of “Superframe Overloading” as a return code for a DEV trying to allocate channel time and have the PNC tell the SPS Set creator DEV if necessary.
Mark Schrader, Eastman Kodak Co.

26. July, 2002
Appendix
Mark Schrader, Eastman Kodak Co.

27. A More Detailed Version of Slide 6
July, 2002
A More Detailed Version of Slide 6
Mark Schrader, Eastman Kodak Co.