Transcript September 2001 doc.: IEEE 802.15-01/429r0 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: IEEE802.15.3: Overview of Power Save.

September 2001
doc.: IEEE 802.15-01/429r0
Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: IEEE802.15.3: Overview of Power Save Proposal.
Date Submitted: 19 September, 2001
Source: Jay Bain
Company: Time Domain
Address: 7057 Old Madison Pike
Voice: 256 922 9229 , FAX: 256 922 0853, E-Mail: [email protected]
Source: Mark E. Schrader
Company: Eastman Kodak Co.
Address: 4545 East River Road, Rochester, NY 14650-0898
Voice: 716-781-9561 , FAX: 716-781-9533, E-Mail: [email protected]
Abstract: This provides an overview of additional proposals on Power Management for incorporation
into the draft 0.8. Text is in 01/430r0
Purpose: To provide information and solicit comments on proposed power management updates
Notice: This document has been prepared to assist the IEEE P802.15. 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 P802.15
Submission
Slide 1
Jay Bain Time Domain, Mark Schrader Eastman Kodak
September 2001
doc.: IEEE 802.15-01/429r0
Topics of proposal (mostly from 01/425r0 and
editor notes in d0.7)
• Wake-on-WPAN – Jay Bain
• Unused bits in CTA to indicate mode and next
active SF – Mark Schrader
• Null-CTA element – Mark Schrader
• Current EPS state in device information
request – John Barr
• Definitions of EPS and related terms – Jay
Bain
Submission
Slide 2
Jay Bain Time Domain, Mark Schrader Eastman Kodak
September 2001
doc.: IEEE 802.15-01/429r0
Wake on WPAN
• Transition from EPS to Active mode in an EPS DEV
develops MLME-POWERMGT.indication primitive.
• Structure in place in d0.7, 6.3.1.3.
• Add tie between the 7.5.x commands changing
modes or indication of data and the clause 6
primitives. Add this text in clause 8.
• Consider addition of means for enable/disable of the
indication as a PIB item.
• Add differentiation of Wake to consider the three CTA
characters (awake, EPS, momentary)
Submission
Slide 3
Jay Bain Time Domain, Mark Schrader Eastman Kodak
September 2001
doc.: IEEE 802.15-01/429r0
Unused CTA Bits
CTA Mode
SST/NAB Switch
Submission
Slide 4
Jay Bain Time Domain, Mark Schrader Eastman Kodak
August 2001
doc.: IEEE 802.15-01/429r0
Outline
•
•
•
•
Issues from previous proposal
New CTA bits definitions
Advantages
Impact
Submission
Slide 5
Jay Bain Time Domain, Mark Schrader Eastman Kodak
August 2001
doc.: IEEE 802.15-01/429r0
Issue1
• There is no explicit indication in the CTA
element if it is an AWAKE or an EPS
type. There is a difference:
– If EPS CTA then the DEV will not be awake
for each beacon
– If AWAKE CTA then the DEV will be awake
Submission
Slide 6
Jay Bain Time Domain, Mark Schrader Eastman Kodak
September 2001
doc.: IEEE 802.15-01/429r0
Issue 2
• When a station is sleeping there is no
beacon info. communicated about the
state of the DEV. Information:
– Is it in EPS mode or AWAKE mode?
– When will the source be waking up or
simply having its next time (low QoS) slot?
• For destination DEVs losing
beacons/synchronization
• For a station wanting to establish a stream
Submission
Slide 7
Jay Bain Time Domain, Mark Schrader Eastman Kodak
September 2001
doc.: IEEE 802.15-01/429r0
Issue 3
• CTA elements are added and omitted
from the header depending on whether
the DEV has a slot (or will be awake) in
that superframe. This may be more
work for the PNC then always having
the CTA element and modifying the
values of CTA fields periodically.
Submission
Slide 8
Jay Bain Time Domain, Mark Schrader Eastman Kodak
September 2001
doc.: IEEE 802.15-01/429r0
Current CTA Element Fields
Destination DEV address = 1B
Source DEV address = 1B
Slot Start Time = SST = 2B
Stream ID = 1B
Unused = 1B
Submission
Slide 9
Jay Bain Time Domain, Mark Schrader Eastman Kodak
September 2001
doc.: IEEE 802.15-01/429r0
Proposed Use of Two Unused CTA Bits
• Bit 0: CTA Element Type & DEV Mode
• 0 = AWAKE CTA Element Type
• 1 = EPS CTA Element Type
• Bit 1: SST/NAB Field
Definition
• 0 = The field is the Slot Start Time, SST, as in
previous slide and the current draft D07, p78.
• 1 = Next Active Beacon, NAB. The field is
defined as, the 2 LSB’s of the beacon number,
of the next superframe in which the DEV will
have a time slot (or if asleep, wake up).
Submission
Slide 10
Jay Bain Time Domain, Mark Schrader Eastman Kodak
September 2001
doc.: IEEE 802.15-01/429r0
Result of These Changes
• An AWAKE DEV with a time slot every
N superframes will always have a CTA
element.
• A device that is asleep (EPS mode) will
always have a CTA element.
• Other DEVs reading the a CTA element
always know the mode of that DEV, and
either the slot time or the beacon
number of the next time slot.
Submission
Slide 11
Jay Bain Time Domain, Mark Schrader Eastman Kodak
September 2001
doc.: IEEE 802.15-01/429r0
What is the Impact?
• CTA element values will not change any
more often than before. Important for
the “CTA change bit”.
• CTA adds/deletes will occur less often
then before.
• The PNC will post the:
– CTA mode associated with a CTA element.
– next SF in which a slot will occur if it is not
in this SF.
Submission
Slide 12
Jay Bain Time Domain, Mark Schrader Eastman Kodak
September 2001
doc.: IEEE 802.15-01/429r0
Global Advantages
• The mode is always posted.
• Network robustness and
synchronization will be improved:
– If: hhThhhThhhDhhh
– Then: the next beacon will be enough to
restore the lost beacon information
regardless of mode or QoS.
• Minimal, if any, additional PNC
overhead.
Submission
Slide 13
Jay Bain Time Domain, Mark Schrader Eastman Kodak
September 2001
doc.: IEEE 802.15-01/429r0
Null CTA Element
Submission
Slide 14
Jay Bain Time Domain, Mark Schrader Eastman Kodak
September 2001
doc.: IEEE 802.15-01/429r0
Definition
• The null CTA element is a CTA element
with the same slot start time as the next
CTA element listed in the beacon. It is
used to indicate that a sleeping device
is awake on this superframe to listen to
the beacon, but does not have a time
slot allocated.
Submission
Slide 15
Jay Bain Time Domain, Mark Schrader Eastman Kodak