The need for formal description techniques in validating communication protocols

The Consultative Committee for Space Data Systems (CCSDS) validation program to check the quality of the advanced orbiting systems (AOS) services and protocols is discussed. Formal description techniques (FDTs) and the need for using these techniques to validate the AOS communications services and protocols are then considered. In particular, the use of the language of temporal ordering specification (LOTOS) and FDT as part of the AOS validation program has proven to be useful in identifying ambiguities, inconsistencies, and imprecise statements in the English-language recommendation. By more completely and precisely specifying the AOS services and protocols, it will also play a major role in implementing them