Performance Modeling Analysis Of Cooperative ARQ Systems In Wireless Sensor Networks

Wireless sensor networks have become an integral part of our lives. How to solve the challenges of sensor nodes in terms of reliability, validity and energy constrained is very real problems faced by wireless sensor networks. Cooperative ARQ can effectively increase the spatial diversity gain while guaranteeing high reliability data transmission, so it is widely used in wireless sensor networks. Based on discrete time Markov chain model、 discrete time Geom/G/1queue model and energy efficiency model, considering truncation and relay selection, this paper focuses on the steady state distributions、throughput、delay and energy efficiency performance of cooperative ARQ in wireless sensor networks. The contribution of this paper is listed as follows:1. The fundamentals of basic ARQ、multicast cooperative ARQ、multiple relays cooperative ARQ、multiple sources cooperative ARQ and multiple sources multiple relays cooperative ARQ systems in wireless sensor networks are systematically described. Considering the actual engineering applications, the main factors affecting the performance of three basic ARQ systems are parameterized, then the classical discrete time Geom/G/1queue model and the discrete time Geom/G/1queue model with setup time and stochastic vacation are established sententiously based on equivalent service time and equivalent vacation time. The analytical expressions for packet average waiting delay and channel utilization of the various ARQ systems are obtained respectively.2. Considering the actual background of communication network, a N+2state discrete time Markov chain general model is proposed, which is used to analyze the packet transmission process of cooperative communication networks. Based on this model, the equations for state transition probability matrix of multicast cooperative ARQ、 multiple relays cooperative ARQ、multiple sources cooperative ARQ and multiple sources multiple relays cooperative ARQ systems in wireless sensor networks are derived respectively. Further, the expressions for steady state distributions and throughput are obtained by solving the balancing equations and normalizing condition.3. In order to minimize the delay and data buffer of cooperative、multi-hop ARQ systems in practical applications in wireless sensor networks, the number of retransmission times is truncated. The mean number of transmissions that a packet has gone through when it is successfully received by the destination node of the not direct/direct multiple relays cooperative truncated ARQ and multiple relays cooperative GBn-ARQ systems in wireless sensor networks are solved respectively, then the expressions for the mean packet transmission delay are obtained respectively. To minimize system overhead, this paper introduced the relay selection ideas to multiple relays cooperative ARQ system in wireless sensor networks, and selected the optimal relay for cooperative transmission. The system performance of two hop truncated ARQ/multiple relays cooperative ARQ with relay selection systems in wireless sensor networks are analyzed.4. Based on the M-ary modulation, considering the power consumption of source nodes、relay nodes and destination nodes respectively, the energy efficiency model of cooperative ARQ systems in wireless sensor networks is presented, which is used to derive the analytical expressions for energy efficiency of multicast cooperative ARQ、 not direct/direct multiple relays cooperative truncated ARQ、multiple relays cooperative GBn-ARQ、multiple sources cooperative ARQ、multiple sources multiple relays cooperative ARQ、two hop truncated ARQ/multiple relays cooperative ARQ with relay selection systems in wireless sensor networks.5. For the analytical expressions obtained by theoretical analysis, the superiority of this paper proposed cooperative ARQ system embodied herein by some numerical simulations. The influence rules of packet length-number of relay nodes、power amplifier loss factor、truncated number and retransmit probability et.al on system performance are comparatively analyzed. This paper gives some theoretical suggestions in different environment which ARQ system should be adopted.