Modeling and evaluating Reliable Real-Time degree in multi-hop Wireless Sensor Networks

Wireless sensor network (WSN) should be capable of fulfilling its mission, in a timely manner and without loss of important information. In this paper, we propose a new analytical model for calculating RRT (Reliable Real-Time) degree in multihop WSNs, where RRT degree describes the percentage of real-time data that the network can reliably deliver on time from any source to its destination. Also, packet loss probability is modeled as a function of the probability of link failure when the buffer is full and the probability of node failure when node´s energy is depleted. Most of network properties are considered as random variables and a queuing-theory based model is derived. In this model, the effect of network load on the packets delay, RRT degree, and nodes energy depletion rate is considered. Simulation results are used to validate the proposed model. The simulation results agree very well with the model.