1. ATMA: Advertisement-based TDMA Protocol for Bursty Traffic in Wireless Sensor Networks Surjya Ray, Illker Demirkol, and Wendi Heinzeleman University of Rochester IEEE GLOBECOM 2010 1

2. Outline Introduction Advertisement-based TDMA (ATAM) Simulations Conclusion 2

3. Introduction Energy conservation is one of the primary goal for wireless sensor networks(WSNs). The major cause of energy wasting is idle listening. 3

4. Introduction TDMA – based ◦ High energy efficient ◦ Need Synchronization ◦ Not easy dynamically change the frame length Contention – based ◦ S-MAC ◦ T-MAC 4

5. Introduction S-MAC T-MAC 5

6. Activation event ◦ The reception of any data on the radio ◦ The sensing of communicational on the radio ◦ The knowledge, through overhearing prior RTS and CTS packets, that a data exchange of a neighbor has ended 6

7. Introduction T-MAC still waste energy ◦ Idle listening Advertisement-based TDMA (ATMA) ◦ Variable traffic loading ◦ Reduce Idle listening 7

8. ATMA Overview SYNC Advertisement Period Data Period Frame length 8

9. The Advertisement Period Divided into many small slots All nodes are awaked Advertisement Period ADV Sensor ID and data slots A-Ack S R 9

10. The Advertisement Period S R C D E Initial Slot Selection: Actual Contention: S, E D D ADV A-Ack ADV A-Ack ADV F F F 10

11. The Data Period Divided into slots All nodes will sleep until ◦ Sending ◦ Receiving Data Period S R DATA ACK 11

12. DATA ACK The Data Period Data Period S R DATA 12 Sender can reserve n data slots

13. Simulations ParametersValues NS-22.29 Duration of ADV period of ATMA5ms Duration of one ADV slot0.1ms Duration of frames236.4ms Transmission range100m Carrier Sense range200m Total simulation time200s 13

14. Simulations Single hop ◦ 20 nodes and area size : 50*50m 14

15. Simulations Multi-hop ◦ 312 nodes and area size is 700*700m 15

16. Conclusion The simulation results shows that ATAM outsperforms than other related works. In the future, the authors will plan an analytical model for the ATMA and to optimize the length for the ATMA period of ATMA. 16