Lotos Study On The Technique And Its Application In Network Protocol Design

With the further development of computer network, communication network and the distributed system, communication protocols are more and more complicated, formal description technology plays the indispensable role in the network protocol design. LOTOS - as one of the ISO standards of FDT, is designed for distributed systems, especially for communication service and communication protocol.In this paper, the application of LOTOS technology in network communication protocol design is studied. The formal description technology based on LOTOS, the formal transformation, the formal validation and implemenation are generalized. Constructions of communication service and communication protocol, transformation from service specification into protocol specification based on bisimulation equivalence are also stated in detail. Application of LOTOS specification styles and architecture concept in service and protocol design is studied as an emphasis.This paper mainly including four parts:The first one: Briefly introduced the application field of ADT in protocol project, the background and the development of LOTOS technology; then described the foundation of LOTOS language.The second one: Discussed the application spectrum of technology based on LOTOS in network protocol design in detail, which including LOTOS specification styles, LOTOS transformation, LOTOS validation, LOTOS implementation, ELOTOS and LOTOS toolkit, etc.The third one: Described the composition of communication model, construction of service specification and protocol specification, and the approach of transform service specification into protocol specification.The last one: Produced the application method of LOTOS specification styles in network service and protocol design, the concept of formal structural model and its design approach, Macro-oriented specification style and its implementation, the transformation of LOTOS specification to C or C++. Then an example is taken to illustrate how to use the ADT to describle a protocol.