Medium Access Control for Wireless Sensor Networks based on Impulse Radio Ultra Wideband

This paper describes a detailed performance evaluation of distributed Medium Access Control (MAC) protocols for Wireless Sensor Networks based on Impulse Radio Ultra Wideband (IR-UWB) Physical layer (PHY). Two main classes of Medium Access Control protocol have been considered: Slotted and UnSlotted with reliability. The reliability is based on Automatic Repeat ReQuest (ARQ). The performance evaluation is performed using a complete Wireless Sensor Networks (WSN) simulator built on the Global Mobile Information System Simulator (GloMoSim). The optimal operating parameters are first discussed for IR-UWB in terms of slot size, retransmission delay and the number of retransmission, then a comparison between IR-UWB and other transmission techniques in terms of reliability latency and power efficiency

Shawn: A new approach to simulating wireless sensor networks

We consider the simulation of wireless sensor networks (WSN) using a new approach. We present Shawn, an open-source discrete-event simulator that has considerable differences to all other existing simulators. Shawn is very powerful in simulating large scale networks with an abstract point of view. It is, to the best of our knowledge, the first simulator to support generic high-level algorithms as well as distributed protocols on exactly the same underlying networks.Comment: 10 pages, 2 figures, 2 tables, Latex, to appear in Design, Analysis, and Simulation of Distributed Systems 200

A feedback based solution to emulate hidden terminals in wireless networks

Mobile wireless emulation allows the test of real applications and transport protocols over a wired network mimicking the behavior of a mobile wireless network (nodes mobility, radio signal propagation and specific communication protocols). Two-stage IP-level network emulation consists in using a dedicated offline simulation stage to compute an IPlevel emulation scenario, which is played subsequently in the emulation stage. While this type of emulation allows the use of accurate computation models together with a large number of nodes, it currently does not allow to deal with dynamic changes of the real traffic. This lack of reactivity makes it impossible to emulate specific wireless behaviors such as hidden terminals in a realistic way. In this paper we address the need to take into account the real traffic during the emulation stage and we introduce a feedback mechanism. During the simulation several emulation scenarios are computed, each scenario corresponding to alternative traffic conditions related to e.g. occurrence or not of hidden terminals. During the emulation stage, the traffic is observed and the currently played emulation scenario can be changed according to specific network conditions. We propose a solution based on multiple scenarios generation, traffic observers and a feedback mechanism to add a trafficbased dynamic behavior to a two-stage emulation platform. The solution will be illustrated with a simple experiment based on hidden terminals