1. doc.: IEEE 802.15-<doc#>
<month year>
doc.: IEEE <doc#>
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: Provision of multiple grades of quality for the IEEE e
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: , FAX: ,
Re: e-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 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
ETRI
<author>, <company>

2. Provision of multiple grades of quality for the IEEE 802.15.4e
<month year>
doc.: IEEE <doc#>
Provision of multiple grades of quality for the IEEE e
Seong-Soon Joo*, Anseok Lee, Chang-Sub Shin,
Wun-Cheol Jeong, Jong-Suk Chae
ETRI
ETRI
<author>, <company>

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 FR 1m
FR11
FR1l
frame train FR 1m
FR11
FR1l
frame train
Transport
Transport
Transport t1
Network
Network
Network t3 t2
MAC
MAC
MAC
e2e delay = t2-t1
interarrival = t3-t2
sensor node
sink
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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)
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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
access channel groups
unslotted CSMA-CA
slotted CSMA-CA
GTS
acknowledged transmission (macMaxFrameRetries: MAC PIB)
reserved resource : GTS
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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
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 macPrioritizedChannelAccess macTDMAChannelAccess
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)
0 : No TDMA
1 : TDMA in inactive period
Slide 9
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10. MLME-START.request 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)
Slide 10
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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 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
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12. Channel Access Method Superframe Structure
CSMA
GTS
TDMA or Inactive
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
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13. Operation Example Channel Access : Prioritized GTS
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
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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