Abstract: Energy consumption is a hot topic in wireless sensor networks. This paper describes the arrival process and departure process of traffic for wireless sensor networks based on network calculus and constructs energy consumption mode, gives constraint of model and analyzes the effect of SNR in the model. By introducing depart curve and optimal depart curve, the paper obtains the relationship of depart rate and SNR. Based on this, it studies and calculates the optimal energy consumption of the sensor network in a particular state, deduces the optimum energy consumption formula. Optimal energy efficiency condition is verified by the simulation depart rate and distance relationship etc. corresponding conclusions.

Key words: signal to noise ratio, green network, energy consumption