Peer Service Period Date: 2008-1-15 Authors: January 2008 Month Year doc.: IEEE 802.11-yy/xxxxr0 January 2008 Peer Service Period Date: 2008-1-15 Authors: Jarkko Kneckt, Nokia John Doe, Some Company

Month Year doc.: IEEE 802.11-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

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

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

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

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

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

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

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