1. The 32nd KIPS Fall Conference 2009
An Efficient Duty Cycle Based Communication Scheme for Wireless Sensor Network
Md. Obaidur Rahman1, Muhammad Mostafa Monowar1, Cho Jin Woong2, Lee Jang Yeon2 and Choong Seon Hong1
1Kyung Hee University and 2Korea Electronics Technology Institute, South Korea.

2. Introduction
Energy is the most critical issue for wireless sensor network (WSN), due to the limited battery life time.
Especially, for a monitoring application the operation of a sensor network is quite challenging
Most of the time very low traffic
Possibility of high traffic burst on the detection of any event
To fulfill the demand of such WSN, network life time should be increased in low traffic, while increase the throughput in heavy traffic as well.
Considering this motivation, a receiver-initiated communication protocol is proposed in this paper.
21 April 2017

3. Problem Statement
Problems in synchronous S-MAC and asynchronous AS-MAC:
Sleep schedule caused packet delay
Single packet reception at each wake-up Tx
Receiver
Data
Data
Data Rx
Sender 1
Data Tx Rx
Data Tx
Sender 2 Rx Tx
Sender 3
Data Rx
21 April 2017

4. Goals Our proposed work has the following goals:
Energy efficient communication bypassing the most common sources of energy wastes, i.e., idle listening, overhearing etc.
Optimize delay in both low and high traffic load.
Better throughput assurance under heavy load.
21 April 2017

5. Preliminaries Operational Cycle Duty Cycle Two phase
This is the time period for the wake-up interval of the nodes in the network:
Duty Cycle
It is the ratio between node's active time to its entire cycle time.
Active time includes all the actions and activities of a node (i.e., channel access, transmission and reception of data, etc.).
Two phase
Fair Access Period (FAP)
Prioritized Access Period (PAP)
21 April 2017

6. Proposed Communication Protocol
Fair Access Period (FAP)
Receiver End:
Receiver-initiated channel access by sending a beacon packet
At this phase, a receiver wakes-up and receives only a single packet from each of the upstream senders and acknowledge those packets
After receiving the final packet at FAP, it announces the channel access schedule in the prioritized access phase
Sender End:
Receives the beacon and after contention resolution, send the data
Senders those looses the contention, waits for the ACK for previous data and contend again after receiving the ACK
Piggyback the information of additional data packet in the packet header and request for prioritized channel access
21 April 2017

7. Proposed Communication Protocol
Prioritized Access Period
Receiver End
Receiver assigns priority according to the current traffic at the senders and announces the prioritized channel access schedule
Receive back-to-back packet from the same sender and send a block ACK
Sender End
Follows the schedule assigned by the receiver
Send back-to-back packet
21 April 2017

8. Proposed Communication Protocol
Fair Access Period (FAP) and Prioritized Access Period
21 April 2017

9. Experimental Validation
Simulation in Ns-2 is performed.
Uniform random distribution of 100 nodes in 100 x 100 m2 area.
Wake-up interval is considered as 1 second.
Traffic load is varied between 0.1 to 4.0 pkts/s.
Simulation time is 100 seconds.
Compared only the energy, delay and throughput performance are measured from the simulation results.
21 April 2017

10. Experimental Validation
Energy Usage
21 April 2017

11. Experimental Validation
Delay
21 April 2017

12. Experimental Validation
Throughput
21 April 2017

13. Conclusion
This paper proposes a different idea in terms of multiple packet reception in each wake-up
Hence, reduce the packet delay
In event detection, increases the throughput
It is also energy efficient when the network traffic is low.
Future work
Extend the work for an asynchronous scheduled MAC with multiple wake-up provisions in each operational cycle
21 April 2017

14. References
W. Ye, J. Heidemann, and D. Estrin, “Medium access control with coordinated adaptiv e sleeping for wireless sensor networks," IEEE/ACM Trans. Netw., vol. 12, no. 3, pp , 2004.
J. Polastre, J. Hill, and D. Culler, “Versatile low power media access for wireless senso r networks," in SenSys '04: Proceedings of the 2nd international conference on Emb edded networked sensor systems. New York, NY, USA: ACM, 2004, pp
M. Buettner, G. V. Yee, E. Anderson, and R. Han, “X-mac: a short preamble mac protoc ol for duty-cycled wireless sensor networks," in SenSys '06: Proceedings of the 4th i nternational conference on Embedded networked sensor systems. New York, NY, U SA: ACM, 2006, pp. 307{320.
Y. Sun, O. Gurewitz, and D. B. Johnson, “Ri-mac: a receiver-initiated asynchronous dut y cycle mac protocol for dynamic traffic loads in wireless sensor networks," in SenS ys '08: Proceedings of the 6th ACM conference on Embedded network sensor syste ms. New York, NY, USA: ACM, 2008, pp
21 April 2017

15. Thank You
Question ?
21 April 2017