Space link simulator for development of new packet-based space communication protocols

Terrestrial network-based file transfer protocol is known to be unacceptabl e for the space network environment. The Consultative Committee for Space D ata Systems (CCSDS) is about to propose a new file transfer protocol for us e in both space and ground-based networks, named CCSDS File Delivery Protoc ol (CFDP). CFDP is based on packet oriented protocols as its underlaying ne twork layer. The supported packet protocols include CCSDS packet standard p rotocol and TCP/IP. The space communication link displays specific characteristics different fr om those of terrestrial ones: larger link delay, higher bit error rates, bu rsts of errors, packet deordering, etc. For use in CFDP implementation a pa cket protocol-based space link simulator is designed and implemented. This space link simulator, named LinkSim, can simulate not only distance driven link delay, but also link quality and link diversity. This paper presents the organization of the space link simulator and the al gorithms used to emulate each link characteristic feature. The test shows t hat the LinkSim program simulates exactly the expected space link environme nt. An example configuration is also discussed at the end of this paper. Co pyright (C) 1999 John Wiley & Sons, Ltd.