This paper investigates the applicability of star, tree and mesh topology schemes for large scale Wireless Sensor Network (WSN) complying with IEEE 802.15.4 standard. The main focus of this work is to evaluate the performance of such network through simulation which is carried out via the discrete event OPNET simulator (version 14.5). The performance metrics of interest include throughput, end to end delay and packet drop rates. Performance comparison and analyses of different topologies have been made, and it is concluded that the selection of topology scheme depends on the application context.

This paper evaluates the performance of IEEE 802.15.4 standard Wireless Sensor Network (WSN) in tree topology for large scale applications. The performance of the network is analyzed in terms of number of nodes, packet size and packet interval time (PIT) by using the discreet event OPNET (version 14.5) simulator. Performance investigation started with a packet size of 1408 bit and PIT of 1 sec in order to determine the best network performance, then based on the comparison which has been made among the network performance parameters, it is found that the network performance for tree topology is optimized at 90 nodes number with packet size of 4096 bits when PIT equals 1 sec.

This paper evaluates the performance of IEEE 802.15.4 standard Wireless Sensor Networks (WSN) in star topology small scale applications. The performance of the network is analyzed in terms of end to end delay, maximum throughput and number of network devices with respect to payload. This analysis which is devoted for biomedical application is performed theoretically and compared with practical analysis using the network simulator Opnet modeler (version 14.5) in order to validate theoretical analysis.