Performance evaluation of Impulse Radio Ultra Wide band Wireless Sensor Networks This paper presents a performance evaluation of wireless sensor networks (WSN) based on impulse radio ultra wideband (IR-UWB) over a new simulation platform developed for this purpose. The simulation platform is built on an existing network simulator: global mobile information system simulator (GloMoSim). It mainly focuses on the accurately modeling of IR-UWB physical (PHY) and medium access control (MAC) layer. Pulse collision is modeled according to the used time hopping sequence (THS) and the pulse propagation delay in order to increase the simulation fidelity. It also includes a detection and identification application based on a new sensing channel and new sensor device models. The proposed architecture is generic so it can be reused for any simulation platform. The performance evaluation is based on one of the typical WSN applications: local area protection, where sensor nodes are densely scattered in an access regulated area in order to detect, identify and report non authorized accesses to a base station for analysis. Two networks topologies using different protocol stacks are investigated. Their performance evaluation is presented in terms of reliability and latency.