A Robust 100 Mb/s Fiber Optic Network For Space Applications
John L. DeRuiter · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1986
Two years of effort have gone into the development and build of a high-speed fiber optic local area network suitable for space applications. In tailoring this system (Star*Bus ) to space applications, particular attention has been paid to system redundancy capabilities, radiation susceptibility, protocol versatility, network application flexibility, size, power, and weight. The result is a 100 Mb/s, autonomously redundant network incorporating a dual star topology and an extremely robust protocol that, with the incorporation of state-of-the-art VLSI technology, can provide a small, lightweight, low-power solution to multiple high-rate data transfers in a variety of applications. The network achieves both versatility and robustness through the use of a dual mode protocol that incorporates the advantages of both contention (Ethernet) and deterministic (token passing) types of protocols. In this manner, it achieves the short message delays under light network loading possible with a contention protocol while retaining the efficiency and deterministic characteristics of a token passing or timeslot protocol at high network loads. The network employs LED and PIN photodiodes to minimize power and to provide high reliability. It uses radiation-hardened optical fiber and passive star couplers. The initial network performance evaluation has been completed using an eight-node system and redundant, 20x20 optical couplers. Network delays correlated well with predicted values. Throughput has been measured at greater than 95 Mb/s and redundancy operation is as expected.