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: 14-07-2008 Source: Ranjeet Kumar Patro, Kiran Bynam, Giriraj Goyal, Arun Naniyat Contact: Ranjeet Kumar Patro Voice: +91- 80 - 4181 9999, E-Mail: rkp.atd@samsung.com, ranjeet.patro@gmail.com 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 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 maybe made publicly available by P802.15. Submission Slide 1

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

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

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

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

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

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

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

C = 1Mbps, Ts = 0.0012s, Successfully transmitted bits = 1200 bits [3] CSMA C = 1Mbps, Ts = 0.0012s, 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

Additional Delays due to….. Propagation Regulatory restrictions In MICS band, first data burst transmission may suffer 10-100 ms of delay Superframe Structure Submission Slide 10

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 802.11, http://wow.eecs.berkeley.edu/ergen/docs/delay_icc.pdf Submission Slide 11

Thank You ? Submission Slide 12