N-policy Priority Queueing Model for Energy and Delay Minimization in Wireless Sensor Networks Using Markov Chains

Wireless Sensors are small devices, resources constrained and energy limited. Further, they are often deployed with large quantities in an inaccessible and hostile environment, where recharging or replacing their batteries to survive the Wireless Sensor Network (WSN) for a longer time is costly, difficult, and even impossible. Hence, it is essential to develop an approch which sensor nodes can follow so that their energy efficiency is increased. The N-policy is often used as an efficient technique to conserve energy. However, it should be mentioned that the N-policy increases waiting delays of data packets. This paper presents an analytical model based on priority vacation queueing theory for an N-policy that can save energy and reduce latency in WSNs. The model takes into consideration two distinct types of data traffic: high and low priority traffic. The Continuous-Time Markov Chains formalism is used to model and analyse the system. The formulas for the main stationary performance indices and energy consumption are determined as a function of the network parameters. Finally, numerical results are provided to demostrarte the efficiency of the proposed N-policy.