RELAX : An Energy Efficient Multipath Routing Protocol for Wireless Sensor Networks Bashir Yahya, Jalel Ben-Othman University of Versailles, France ICC 2010
Outline Introduction Related Work RELAX Protocol Performance Evaluation Conclusion
Introduction Routing in sensor networks is a very challenging task and different from routing in either wired or other wireless networks
Introduction Routing techniques can be classified according to the protocol operation into ◦ Negotiation based ◦ Query based ◦ QoS based ◦ Multipath based
Introduction Routing techniques can be classified according to the protocol operation into ◦ Negotiation based Have the objective to eliminate the redundant data ◦ Query based ◦ QoS based ◦ Multipath based
Introduction Routing techniques can be classified according to the protocol operation into ◦ Negotiation based ◦ Query based Sink broadcast a query for data over the network ◦ QoS based ◦ Multipath based
Introduction Routing techniques can be classified according to the protocol operation into ◦ Negotiation based ◦ Query based ◦ QoS based Make a tradeoff between the energy consumption and some QoS metrics before delivering ◦ Multipath based
Introduction Routing techniques can be classified according to the protocol operation into ◦ Negotiation based ◦ Query based ◦ QoS based ◦ Multipath based Improve the network performance in terms of reliability and robustness
Introduction Classical multipath routing has been explored for two reasons ◦ Load balance Disjoint paths Longer lifetime ◦ Increase reliable data delivery
Related Work Directed Diffusion ◦ Maintain an interest cache ◦ Selecting good paths Drawback ◦ Requires periodic interest broadcast ◦ More energy consumption in control traffic C. Intanagonwiwat, R. Govindan, D. Estrin “Directed Diffusion: A Scalable and Robust Communication Paradigm for Sensor Networking.”, ACM MobiCom 2000.
Related Work N-to-1 ◦ Finds different node-disjoint paths ◦ Spanning tree structure ◦ Distribute the traffic in order to improve the reliability and security of the data transmission Drawback ◦ Not consider the node’s energy level ◦ Lacks of an efficient load balancing mechanism to distribute the traffic in an energy efficient manner W. Lou, “An efficient N-to-1 mutlipath routing protocol in wireless sensor networks”, MASS 2005.
Motivation Improving energy efficiency in routing protocols mainly is based on ◦ Reducing the overhead caused by Control traffic during construction and maintenance phase Selecting good routes that reduce energy through an appropriate cost function
Goal Minimize the energy consumption through distributing and balancing the load across the multiple paths
RELAX Protocol Assumption ◦ N identical sensor nodes ◦ Distributed randomly ◦ Multihop ◦ Same transmission range ◦ Two alkaline batteries(15 mins) ◦ Each node compute its Residual energy Available duffer size Link quality between itself and its neighboring node’s SNR
RELAX Protocol Battery Issues ◦ Capacity 、 Recovery(Relaxation Phenomenon) : Battery capacity (245,910) : non-linear battery behavior during charging and discharging periods(4,034) : Battery lifetime : Discharging current D. Rakhmatov, S. Vrudhula, “An Analytical High Level Battery Model for Use in Energy Management of Portable Electronic Systems,” ICCAD, 2001.
RELAX Protocol Initialization phase ◦ Hello message ◦ Cost function ◦ RREQ message ◦ Total cost The set of neighbors of x Current residual energy of y Available buffer size of y SNR for the link xy Y. M. Lu, V. W. S. Wong, “An energy multipath routing protocol for wireless sensor networks”, International Journal of communication system, (SNR) nodeslink costs
RELAX Protocol Path discovery phase ◦ Accept only one RREQ message
RELAX Protocol Route Refreshing ◦ Source periodically floods a KEEPALIVE message Next-Hop-ID
RELAX Protocol Traffic allocation and Data Transmission ◦ A subset of the available paths(N paths) to transfer the message in order to Distribute the load Avoid the fast battery drains
RELAX Protocol Traffic allocation and Data Transmission ◦ Paths Selection S. Dulman, T. Nieberg, J. Wu, P. Havinga, “Trade-off between Traffic Overhead and Reliability in Multipath Routing for Wireless Sensor Networks”, WCNC-2003.
RELAX Protocol Traffic allocation and Data Transmission ◦ Message Segmentation and FEC Codes Generation (where M < k) Z. Xiong; Z. Yang; W. Liu; Z. Feng, “A Lightweight FEC Algorithm for Fault Tolerant Routing in Wireless Sensor Networks”, WiCOM 2006.
RELAX Protocol Message Forwarding and Recovery
Performance Evaluation
Average Energy Consumption
Performance Evaluation Average Delivery Ratio
Performance Evaluation Average Delay
Performance Evaluation Average Node Lifetime
Performance Evaluation Average Energy Consumption
Performance Evaluation Average Delivery Ratio
Performance Evaluation Average Delay
Performance Evaluation Average Node Lifetime
Conclusion RELAX protocol utilizes the relaxation effect of the battery to increase the overall lifetime of the sensor network Simulation results show that RELAX protocol achieves more energy savings, lower average delay, higher delivery ratio, and long node lifetime duration than other protocols