说明：  This paper proposes a novel and computationally efficient global I< optimization method based on swarm ntelligence for locating ti nodes in a WSN environment. The mean squared range error of a all neighbouring anchor nodes is taken as the objective function d for this non linear optimization problem. The Particle Swarm c Optimization (PSO) is a high performance stochastic global b optimization tool that ensures the minimization of the objective a function,