OPNET Simulations of Multimedia Satellite Systems at COMSAT Laboratories

For almost a decade, COMSAT Laboratories has been using the OPNET tool for the simulation of multimedia satellite systems. Starting as one of the Beta sites for the first release of OPNET software, we have since applied the OPNET simulation environment to perform system evaluations and trade-offs in a variety of areas related to fixed and mobile multimedia satellite systems. This paper presents a chronology of the OPNET simulation work performed at COMSAT Labs, including a description of the scope and extent of many OPNET simulation efforts of satellite-based systems providing multimedia services. The projects described in this paper include simulations of on-board fast packet switching architectures, ATM congestion control in a satellite environment, a satellitebased cable ISP backbone network with on-board switching satellite payload, a next generation mobile data service with bandwidth on demand allocation, a fixed Ku/Ka band bandwidth on demand mesh network, an IP-based satellite networks over INTELSAT IDR service, and a model for Internet delay and loss behavior. For each of these simulation efforts we give an overview of the simulation effort and the scope of model development. This includes development of realistic traffic models, on-board switch fabric and congestion control models, protocol models, resource management and bandwidth on demand algorithms, among others. In conclusion, we describe additional planned OPNET simulation efforts in support of the design and performance evaluation of advanced multimedia satellite systems.