The Sensor Networking Laboratory at Louisiana State University has published SENSIM, a new sensor simulator framework for OMNeT++. The paper "Simulating Wireless Sensor Networks with OMNeT++" by C. Mallanda, A. Suri, V. Kunchakarra, S.S. Iyengar, R. Kannan, A. Durresi, and S. Sastry can be accessed at their web site, as well as the manual, generated documentation and the source code of the model framework. See http://csc.lsu.edu/sensor_web/simulator.html.
Quote from the paper:
"There is an urgent need to develop simulation platforms that are useful to explore both the networking issues and the distributed computing aspects of wireless sensor networks. [...]
Work is underway to develop a simulation platform that allows developers and researchers to investigate topological, phenomenological, networking, robustness and scaling issues related to wireless sensor networks. As a first step, we have developed simulations for the 802.11 MAC and the well-known sensor network protocol called Directed Diffusion. We demonstrate the performance of our simulator by comparing its performance to that of the well-known simulator ns2. Our results indicate that our simulator executes at least an order of magnitude faster than NS-2 and makes more efficient use of the available memory. The ease of modifying the sensor network and scalability, which is defined as the number of nodes that can be simulated, are two distinguishing features of our simulator."</FONT>