Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: Provision of multiple grades of quality for the IEEE 802.15.4e Date Submitted: Sep., 2008 Source: Seong-Soon Joo, Anseok Lee, Chang-Sub Shin, Wun-Cheol Jeong, Jong-Suk Chae Company: ETRI Address: 161 Gajeong-dong, Yuseong-gu, Daejeon, KOREA Voice: +82-42-860-6333, FAX: +82-42-860-4197, E-Mail: ssjoo@etri.re.kr Re:15-08-0373-01-004e-call-for-proposals Abstract:For providing multiple grades of quality in WPAN, how to translate the grades of service quality onto MAC layer is discussed and a proposal for supporting fine granularity of QoS is presented. Purpose: This document is a response to Call for Proposals. 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. ETRI

2. Provision of multiple grades of quality for the IEEE 802.15.4e Seong-Soon Joo*, Anseok Lee, Chang-Sub Shin, Wun-Cheol Jeong, Jong-Suk Chae ETRI ETRI

3. Traffics and Quality in WPAN • Traffic specification • characteristics of information generation at a source • number of frames (MAC payload ~116B) at one time generation • temporal correlation among sequentially generated data • Quality specification • guaranteed performance level of end-to-end information delivery • end-to-end information delivery delay : tolerable max delay, delay variance • end-to-end information loss : tolerable frame loss rate, sequence error AP-1 AP-n AP-1 AP-n AP-1 AP-n frame train frame train Transport Transport Transport FR1l FR1l FR11 FR11 FR 1m FR 1m FR11 FR11 Network Network Network t1 t3 t2 MAC MAC MAC e2e delay = t2-t1 interarrival = t3-t2 sensor node sink ETRI

4. Quality Degradation Chain in WPAN • At one node • sender and receiver synchronized in active for transmission • contention on accessing media • no room for output queue • interfered with unexpected traffic from hidden sources • On the path • temporal load variation in each nodes on the path • multiple paths to the end • reconfigured path • quality budgeting on the path • How to specify the quality of end-to-end information delivery in terms of MAC ? PAN Coordin. Coordin. Device ETRI

5. Grades of Service Quality • Service performance requirements on quality • one single frame expected to be delivered to the sink with the probability 0.6 no later than 5sec • one single frame must be delivered to the sink within 20ms • train of frames must be delivered to the sink within 1sec • variance of inter-arrival time between consecutive frames needed to be within 100ms • Grades of Service Quality • quality attributes • (e2e bandwidth, tolerable frame loss rate, tolerable max delay, delay variance) • Specification of the Grades of Service Quality for WPAN MAC • specify required bandwidth, loss rate, delay, delay variance • average value, max/min value, distribution • classify the quality in discrete grades • high loss rate tolerable, low loss rate required • high delay tolerable, low delay required ETRI

6. MAC and Grades of Service Quality • Provide the grades of service quality to the applications by controlling the medium access • establish an access channel specified for an application session • provide an access channel for a class of applications • Provide an access channel for a class of applications • classify the quality in discrete grades with the required bandwidth • max required bandwidth • high frame loss tolerable or low frame loss required • high delay tolerable or low delay required • Grades of Service Quality in WPAN • class 0 : best effort (high frame loss tolerable, high delay tolerable) • class 1 : delay sensitive (high frame loss tolerable, low delay required) • class 2 : loss sensitive (low frame loss required, high delay tolerable) • class 3 : premium (low frame loss required, low delay required) ETRI

7. MAC Functions for Controlling the Quality • Functions for supporting the transmission quality • frame loss • ACK, reserved resource • delay • reserved resource, preemptive access, delay budget planning on a path • delay variance • reserved resource, inter-arrival time management • MAC functions for supporting the quality in 15.4-2006 • access channel groups • unslotted CSMA-CA • slotted CSMA-CA • GTS • frame loss • acknowledged transmission (macMaxFrameRetries: MAC PIB) • delay • reserved resource : GTS ETRI

8. MAC Functions for Fine Granularity of QoS • Support fine granularity of QoS • support low variance of delay at a device • prioritized transmission • support fine grained reserved resources on an access channel • TDMA • five classified access channels between device & coordinator • CSMA-CA • prioritized tx on CSMA-CA • GTS • prioritized tx on GTS • TDMA • access channel can be specified differently for the pairs • specify access channel type between RFD-FFD, FFD-PAN Cord. • manage the reserved resource on an access channel PAN Coordin. Coordin. Device ETRI

9. MAC PIB Attributes Slide 9 • macPrioritizedChannelAccess • Type : Integer (2bits) • Each bit represent supporting channel access method • (b0) • 0 : CSMA • 1 : Prioritized CSMA • (b1) • 0 : GTS • 1 : Prioritized GTS • macTDMAChannelAccess • Type : Boolean (1bit) • (b0) • 0 : No TDMA • 1 : TDMA in inactive period ETRI

10. MLME-START.request Slide 10 • MLME-START.request with MAC PIB • To support each coordinator operates with different superframe structures • BeaconOrder • SuperframeOrder • *PrioritizedChannelAccess (PCA) • 2 bits (b0 : Prioritized CSMA, b1 : Prioritized GTS) • *TDMAChannelAccess (TCA) • 1 bits (b0 : TDMA channel access in inactive period) ETRI

11. MCPS-DATA.request • Extend TxOptions for supporting five classified access channels • (b0, b1, b2) • b0 : 1= acknowledged transmission • b1 : 0= CSMA, 1= GTS • b2 : 1= indirect transmission • (b3, b4) • 00 : use 15.4-2006 TxOptions (priority level 0, low priority) • 01 : prioritized transmission (priority level 1) • 10 : prioritized transmission (priority level 2, high priority) • 11 : transmission on TDMA slot ETRI

12. Channel Access Method TDMA or Inactive CSMA GTS If PCA0 = 1, use prioritized CSMA If PCA1 = 1, use prioritized GTS If TCA1 = 1, use TDMA • Different Channel Access Method for each layer Slide 12 Superframe Structure ETRI

13. Operation Example BO=8, SO=6 PCA=01b, TCA=0 Duty Cycle : 1/4 Channel Access : Prioritized GTS PAN Coordin. Coordin. Coordin. Device Device BO=8, SO=3 PCA=00b, TCA=0 Duty Cycle : 1/32 Channel Access : CSMA BO=8, SO=4 PCA=10b, TCA=0 Duty Cycle : 1/16 Channel Access : Prioritized CSMA Slide 13 ETRI

14. Summary • Grades of Service Quality in WPAN • class 0 : best effort (high frame loss tolerable, high delay tolerable) • class 1 : delay sensitive (high frame loss tolerable, low delay required) • class 2 : loss sensitive (low frame loss required, high delay tolerable) • class 3 : premium (low frame loss required, low delay required) • Fve classified access channels between device & coordinator • CSMA-CA • prioritized tx on CSMA-CA • GTS • prioritized tx on GTS • TDMA • Access channel can be specified differently for the pairs • specify access channel type between RFD-FFD, FFD-PAN Cord. • manage the reserved resource on an access channel • Each coordinator operates with different superframe structures • MAC PIB : macPrioritizedChannelAccess, macTDMAChannelAccess • MLME-START.request: PrioritizedChannelAccess, TDMAChannelAccess • MCPS-DATA.request : extend TxOptions