1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: Delay Analysis of TDMA and CSMA and its implication to BAN
Date Submitted:
Source: Ranjeet Kumar Patro, Kiran Bynam, Giriraj Goyal, Arun Naniyat
Contact: Ranjeet Kumar Patro
Voice: ,
Re:
Abstract: Delay analysis of classical MAC protocols.
Purpose: Given that BAN traffic has stringent delay requirements, classical delay analysis may help TG6 to chose appropriate MAC parameters.
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 maybe made publicly available by P
Submission
Slide 1

2. Medical emergency data
Why Delay?
Traffic Types
Maximum Packet Delay
Medical periodic data
~ 1 sec
Medical emergency data
Least possible
Non-medical real-time interactive data
150 ms – 400 ms Audio
150 ms – 400 ms Video
250 ms for interactive gaming
Non-medical real-time streaming data
10 sec
Non-medical emergency data
Submission
Slide 2

3. T = Duration of the frame
TDMA
M = No. of slots in a frame
T = Duration of the frame
Submission
Slide 3

4. Si = Service time of the ith message
Wi = Waiting time of the ith message
Di = Delay of the ith message
Di = Si + Wi
Submission
Slide 4

5. Poisson arrival with λ messages per second
Number of packets in a message is a random variable L with first and second moments L1 and L2
DTDMA = L1T – T/2 + T/M + (λL2T2)/2(1- λL1T) [1]
DFDMA = L1T+ (λL2T2)/2(1- λL1T) [2]
DTDMA = DFDMA – T/2 + T/M
Submission
Slide 5

6. Results – TDMA C = 1Mbps, M = 50 and T = 0.2 sec
Packet Size = 4000 bits, Traffic Intensity = ρ = λL1T
Non-medical Interactive Region
Non-medical Streaming Region
Submission
Slide 6

7. Message delay increases with the size of the message
C = 10 Kbps, T = 1 sec, M = 50
Packet Size = 200 bits
Medical Periodic Region
Message delay increases with the size of the message
Normalized difference between TDMA and FDMA decreases as ρ increases
Submission
Slide 7

8. Message size is constant, 4000 bits
C = 1 Mbps, M = 50
Message size is constant, 4000 bits
Splitting up T increases message delay
Longer packet size may be preferred
Submission
Slide 8

9. C = 1Mbps, Ts = 0.0012s, Successfully transmitted bits = 1200 bits [3]
CSMA
C = 1Mbps, Ts = s, Successfully transmitted bits = 1200 bits [3]
Small transmission time leads to lesser collisions and lesser delay
But bandwidth utilization is low
Average delay with respect to load
Submission
Slide 9

10. Additional Delays due to…..
Propagation
Regulatory restrictions
In MICS band, first data burst transmission may suffer ms of delay
Superframe Structure
Submission
Slide 10

11. References
1. Lam, S., Delay Analysis of a Time Division Multiple Access (TDMA) Channel, IEEE Transactions on Communications, Volume 25, Issue 12, Dec 1977, Page(s): 1489 – 1494.
2. Kleinrock, L., Queuing Systems Vol. I: Theory, Wiley-Interscience, New York, 1975.
3. Mustafa Ergen, Pravin Varaiya., Delay Analysis of Distribution Coordination Function in IEEE ,
Submission
Slide 11

12. Thank You ?
Submission
Slide 12