1. <January 2002>
doc.: IEEE <02/139r0>
November, 2007
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [Superframe Sizing Procedure for Uncompressed Video Traffic]
Date Submitted: [November 10, 2007]
Source: [Wooyong Lee1, Jinkyeong Kim1, Yongsun Kim1, Kyeongpyo Kim1, Hyoungjin Kwon1, Kyungsup Kwak2, Seokho Kim2, Xizhi An2, Saurabh N. Mehta2, Zhiquan Bai2, Sangkyoon Nam2]
Company: [Electronics and Telecommunications Research Institute (ETRI)1, Inha University2]
Address: [ETRI, 161 Gajeong-dong, Yuseong-gu, Daejeon, , Republic of Korea]1, [6-141B, Inha University, 253 Yonghyun-dong, Nam-gu, Incheon, , Republic of Korea]2
Voice: [], FAX: [], (other contributors are listed in “Contributors” slides)]
Re: []
Abstract: [To propose a sizing method to find a proper superframe size]
Purpose: [To be considered in IEEE c standard]
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
Chuck Brabenac, Intel Labs

2. Contributors Name E-mail Affiliation Wooyong Lee wylee@etri.re.kr ETRI
November, 2007
Contributors
Name
Affiliation
Wooyong Lee
ETRI
Jinkyeong Kim
Yongsun Kim
Kyeongpyo Kim
Hyoungjin Kwon
Kyungsup Kwak
Inha University
Seokho Kim
Xizhi An
Saurabh N. Mehta
Zhiquan Bai
Sangkyoon Nam
ETRI

3. Overview Memory buffer size in receiver is very important.
November, 2007
Overview
Memory buffer size in receiver is very important.
Superframe size is related to the buffer size.
The application of uncompressed video transmission is delay sensitive and requires constant bandwidth allocation.
Allocating Bandwidth below the required throughput causes service failure.
So, PHY-SAP payload bit rate is key parameters
Simulation and analytical results show that we can find superframe size and payload length according to the requirements (data rate, delay and memory usage).
Propose a sizing procedure to find a proper superframe size according to the requirements of uncompressed video transmission.
ETRI

4. 802.15.3c Performance Metrics Throughput End-to-End Delay
November, 2007
c Performance Metrics
Throughput
measured in terms of bits per second, is the amount of data delivered successfully by the peer MAC-SAP.
End-to-End Delay
measured in terms of second, is the amount of time taken for a MAC SDU to be transferred from the MAC-SAP of the transmitter to the peer MAC-SAP of the receiver.
Memory usage (MAC)
Memory usage represent the minimum buffer size required for continuous video representation
ETRI

5. Uncompressed Video Streaming
November, 2007
Simulation Model (UM1)
PNC
Control/commands
Beacon
Uncompressed Video Streaming
DEV-0
DEV 1
1632 Mbps, 2000Mbps
Common mode (48.5 Mbps)
Uncompressed Traffic Model :1080p 30f 20b
- 2200( )*1125( )*30*20 = Gbps
- CBR traffic -> 44000bit (2200*20) / 29.63us
ETRI

6. CoMPA’s Superframe Structure
November, 2007
CoMPA’s Superframe Structure
BP: Beacon Period
CAP: Contention Access Period
CTAP: Channel Time Allocation Period
GT: Guard Time
PLCP: Physical Layer Convergence Protocol
ETRI

7. Considering Superframe Structure
November, 2007
Considering Superframe Structure
ETRI

8. Beacon Frame with CTA IE
November, 2007
Beacon Frame with CTA IE *
Note 1: It shows the minimal length of beacon frame with CTA IE included.
Note 2: In this example, there is one Channel Time Allocation (CTA) IE that contains one CTA block assigning the channel time for one traffic flow.
* PLCP header (17 octets) = PHY header (5 octets) + MAC header (10 octets) + HCS (2 octets)
ETRI

9. Preamble and PLCP Header
November, 2007
Parameters Assumed
Use common mode beacon to 47.8 Mbps
Assume error free PHY channel
Set video traffic to CBR traffic mode
One MAC SDU is composed of data bits transmitted in one horizontal line.
Assume no buffer delay due to higher data rate
Assume no propagation delay due to short distance ( < 10 meter)
Consider transmission delay in terms of Overhead & Payload Size
Simulate in the NS-2
Parameters
Value
Superframe Size
1 msec ~ 64 msec
Beacon Interval
usec
CAP Duration
0 / 200 usec
Guard Time
0.02 usec
SIFS
2.5 usec
Preamble and PLCP Header
8.157 usec
PHY-SAP Rate
1632, 2000 Mbps
Payload Size
2 KB ~ 64 KB
Sub-header Size
4 Bytes
ACK Policy
N/A
Aggregation Method
Applied
MAC-SDU Size
5.5 KB
ETRI

10. November, 2007
Analytical Results (1)
ETRI

11. November, 2007
Analytical Results (2)
ETRI

12. November, 2007
Simulation Results (1)
Performance of video transmission, without CAP, PHY-SAP rate = 2000 Mbps
ETRI

13. November, 2007
Simulation Results (2)
Performance of video transmission, with CAP, PHY-SAP rate = 2000 Mbps
ETRI

14. November, 2007
Simulation Results (3)
Performance of video transmission, without CAP, PHY-SAP rate = 1632 Mbps
ETRI

15. November, 2007
Simulation Results (4)
Performance of video transmission, with CAP, PHY-SAP rate = 1632 Mbps
ETRI

16. Procedure of Sizing the Superframe Size
November, 2007
Procedure of Sizing the Superframe Size
ETRI

17. An Example for setting 1080p30f20b video (1.485 Gbps)
November, 2007
An Example for setting 1080p30f20b video (1.485 Gbps)
(with CAP = 200 us)
PHY-SAP rate
(Mbps)
Delay Bound
(us)
Payload length
(kB)
Proper
Superframe size
(ms)
2000
< 600
60.5 2
< 400
60.5 4
< 200 22 8
1632
< 600
60.5 8
< 400 44 16
< 200
N/A
N/A
Note:
1) According to the data rate and delay requirements, a groups of candidate <superframe size, payload> settings can be selected;
2) Then, according to the calculation of CTAP efficiency, as large as possible payload size tends to be selected to obtain higher efficiency.
ETRI

18. Consideration of Buffer and Its Utilization
November, 2007
Consideration of Buffer and Its Utilization
The buffer limit would be one of capability parameters of the device. It shows how many data can be temporarily stored in the device for the smoothly video representation.
The occupation of this kind of buffer is related with data rate, and superframe size, etc.
i.e. Minimal buffer required = data rate * superframe size
Given a buffer limit, however, we would want to fully utilize it in order to achieve better performance.
It is suggested that within the buffer limit of the device, select as large as possible superframe size in order to increase the CTAP efficiency additionally and reduce the delay.
ETRI

19. November, 2007
Conclusions
With this comparison we can propose the minimum requirement on PHY-SAP rate to transfer uncompressed video traffic.
To improve the transmission efficiency, the aggregation should be used, which results in larger payload length. However, the transmission delay is correspondingly increased.
By considering the expense of beacon period and CAP, the channel time for each flow and relevant superframe size should be lengthened. However, there would be more buffered data and then more memory would be required.
The superframe size should be set to relative bigger to achieve proper effective throughput, when the PHY-SAP rate is low. On the other hand, for the high PHY-SAP rate, the superframe size could be shortened to lower the memory requirement. In both cases, the delay should be considered in the selection of superframe size and payload length if the QoS is emphasized.
Our proposal provide the baseline for finding superframe size in terms of delay requirement and memory usage.
ETRI

20. November, 2007
Appendix
ETRI

21. Throughput Calculation
November, 2007
Throughput Calculation
Above formula is valid only for 1-1 Usage model, for other cases, formula will be changed a bit.
ETRI

22. Delay and Throughput Definitions
November, 2007
Delay and Throughput Definitions
Maximum achievable throughput represents the maximum MAC capacity. In real world scenario, we can’t achieve the maximum achievable throughput because of several reasons like MSDU size, collision , etc.
Minimum Delay bound is the minimum transmission time required by a MAC MSDU to reach destination MAC layer from Source MAC layer
ETRI

23. Frame Structure Basic Aggregation Mechanism and frame structure
November, 2007
Frame Structure
Basic Aggregation Mechanism and frame structure
ETRI

24. Parameters on Video Resolution
November, 2007
Parameters on Video Resolution
Formant
V Freq
HRES
VRES
DE_CNT
DE_LIN
Rate 24bit
Rate 20bit
Hsync (sec)
Vsync (sec)
1080i 30
2200
562/ 563
1920
1080
5760
4800
E-06 /
1080p
1125 60
E-06
ETRI