Performance Modeling of TCP and UDP over Packet Radio Networks using the ns-2 Network Simulator

Live network tests are often used to obtain performance metrics associated with the transmission of data using TCP and UDP over packet radio networks. However, only individuals who hold an amateur radio license issued by the United States Federal Communications Commission, as specified by Title 47, Code of Federal Regulations, Part 97, are permitted to operate an amateur station. For this reason, we advocate using the ns-2 network simulator in academic environments to allow unlicensed students to evaluate the performance of packet radio networks. In this paper, we discuss four topics concerning packet radio network performance evaluation. First, the models used to evaluate the performance of packet radio networks are presented. We next introduce the ns-2 network simulator and discuss the advantages and disadvantages associated with using this tool to evaluate the performance of TCP and UDP data transmissions. Third, we discuss the structure of two ns-2 Tcl scripts that can be used to simulate the transmission of data over packet radio networks. Lastly, we examine the output generated by an example ns-2 Tcl script.