A Microprocessor based Communications Satellite Emulator

A communication system consisting of many relay satellites is simulated on a host computer. To understand the behavior of each satellite in a network, operation of a single satellite can be emulated by a microprocessor system. The microprocessor system is independent of the host, but receives and transmits all messages through the host. The purpose of this paper is to detail the design of such an emulator. The emulator performs the actual communication functions of one satellite in a network. Typical communication functions include receiving, buffering, transmitting, scheduling, and routing of packets. As part of link establishment, the emulator calculates its own position and the position of other satellites in the network. Simulator reliability is improved by comparing the simulator's theoretical delay times with the emulator's actual delay times.