An Adaptive Cross-Layer Design for Energy-Efficient Wireless Communications

Abstract: In this thesis we considered minimizing energy consumption with and providing QoS in WSN which is very important nowadays. In this work we developed a cross-layer protocol that operated with MAC and network layer, it introduces QoS and wake and sleep states. We evaluate to see if this new design has an effect on the energy consumption of the wireless sensor network deployment in the simulated environment. In recent years many researches have been done in WSN considering energy consumption which will increase the network lifetime. QoS, which enables reliable data transmissions by providing some guarantees, is also considered. QoS refers to the traffic controlling or traffic shaping by delivering the data in a best effort fashion, such as providing guaranteed packet delay or network throughput. There are several energy consumption protocols being investigated like S-MAC, TMAC, B-MAC, WISEMAC and X-MAC. S-MAC and T-MAC exchange the time schedules of data between nodes. This exchanging of time schedules is a heavy burden on the network and they reduce the life time of the network. B- MAC and WISEMAC depend on low power listening by sending long preamble that is long enough as sleep period of the receiver. This long preamble will create overhearing problem by making the non receivers to stay awake until preamble is fully received. Long preamble is a problem in target receivers because the target receiver must stay idle until the receiving of the preamble is finished, which will waste energy. In X-MAC short preamble is sent instead of long preamble and the time schedules are not exchanged between nodes which will save time and energy in the network. Because of this short preamble the source can get early acknowledgment so the data can be sent immediately and the node can go to sleep early, which is a big advantage compared to other protocols. In this work, we provide an adaptive cross-layer design for energy-efficient wireless communication in sensor networks. We modify and integrate the X-MAC protocol with random rerouting in the network layer to provide QoS in data delivery, while minimizing the energy consumption. We evaluate the performance of our design by extensive simulations in OMNET++ in terms of packet delay and energy consumption.