1. Peer Service Period Date: 2008-1-15 Authors: January 2008 Month Year
doc.: IEEE yy/xxxxr0
January 2008
Peer Service Period
Date:
Authors:
Jarkko Kneckt, Nokia
John Doe, Some Company

2. Month Year
doc.: IEEE yy/xxxxr0
January 2008
Abstract
This presentation provides description of peer service period. Peer Service Periods are used in frame exchange with MPs in light or deep sleep power management mode.
Contents
Peer service period overview
Phases of peer service period
Initiation of peer service period
Data transmission in peer service period
Termination of peer service period
Jarkko Kneckt, Nokia
John Doe, Some Company

3. Phases in Peer Service Periods
January 2008
Phases in Peer Service Periods
The Peer Service Periods may be divided into three phases
Initiation
MP transmits a trigger frame to initiate a service period.
Power management mode specific times for triggering are introduced in 11-08/102
Data Transmission
Data transmission by using EDCA.
Termination
Last transmitted frame in contains set EOSP bit which is used to indicate the termination of the peer service period
Jarkko Kneckt, Nokia

4. Initiation of peer service period
January 2008
Initiation of peer service period
Null frames initiate a peer service period where a receiver MP may send data and management frames
Data and management frames initiate two peer service periods where both MPs may send data and management frames
Both the triggering MP and the MP receiving trigger frame have own independent peer service period
Both peer service periods are also terminated independently
Any null, management or data frame that is received and acknowledged is considered as trigger frame if no peer service period is ongoing between the peer MPs.
The peer service periods are independent from each other
One MP may have multiple peer service periods ongoing at a time
Jarkko Kneckt, Nokia

5. Data transmission in peer service period
January 2008
Data transmission in peer service period
The MPs are awake for the duration of the peer service period
May contain one or more TXOPs
802.11n or other enhancements may be used for the TXOP
Does not limit access categories of transmitted frames
Does not limit the amount of transmitted frames
Is directional and link specific
One peer service period exists at a time from MP to another
One MP transmits frames and another receives frames.
Jarkko Kneckt, Nokia

6. Termination of peer service period
January 2008
Termination of peer service period
The peer service period is terminated when a frame where EOSP is set is transmitted and acknowledgement is received
If acknowledgement is not received to the frame that contained EOSP, the frame shall be retransmitted at least once
Jarkko Kneckt, Nokia

7. MAC frame header bits used in peer service periods
January 2008
MAC frame header bits used in peer service periods
More Data (MD) bit in unicast data frames
Indicates the status of the buffered unicast frames for the receiver
MD bit in multicast and broadcast frames and bit 0 in Mesh TIM element
Indicates if more multicast or broadcast will be transmitted by the MP
End of Service Period (EOSP) Bit in unicast frames
Indicates termination of the service period
The separation of MD bit and EOSP enables the separate transmission buffer status information passing and control for service periods
802.11e and U-APSD uses both MD and EOSP bits
Jarkko Kneckt, Nokia

8. Example: peer service period
January 2008
Example: peer service period
MP A and MP C are both in light sleep mode
MP A might be also in deep sleep mode
MP A beacons and indicates buffered frames to MP C
MP C triggers with null frame peer service period
One from MP A to MP C
Jarkko Kneckt, Nokia

9. Example: two peer service periods
January 2008
Example: two peer service periods
MP A and MP B are both in light sleep mode
MP A might be also in deep sleep mode
MP A beacons and indicates buffered frames to MP B
MP B has also some frames buffered to MP A
MP B triggers with data frame two unidirectional peer service periods
One from MP A to MP B
One from MP B to MP A
Jarkko Kneckt, Nokia