A semi formal graphical approach to protocol design
Communication protocols play a central role in modern telecommunication systems. Protocols are developed to assure that a given service by a system can be provided to an end user in a reliable and efficient manner. The ever-growing influence of telecommunication and distributed systems over daily life require the protocols developed to be free from design errors. One can easily imagine the consequences of protocol failure in the automatic teller machines (ATM), the failure of protocols while making phone calls or failure of protocols in safety critical system such as nuclear power plants and aeroplanes. Any subtle design errors in these protocols can lead to expensive and dangerous consequences. The traditional methodologies such as simulation and design by intuition of protocols are already showing weaknesses and can no longer be relied upon in order to develop modern large complex communication and distribution systems. The formal methods are being deployed in the industry and research institute to develop protocols that are highly reliable and ideally do not contain any errors. Generally, speaking these formal methods can be divided into two categories namely analytic versus synthetic. The analytical methods to design protocols are relatively simple but by no mean guarantee the generation of protocols that are free from design errors. The methods used can only detect errors after the protocol has been designed by means of simulation and validation using automated tools. The synthetic methods allow the generation of protocols that are free from design errors using advanced discrete mathematical concepts and state theory. The complexity of the methods proposed makes it extremely difficult to use them for the protocol of even simplistic natures. The methods proposed so far as shown their usability to the protocol of academic nature only. A semi formal graphical method proposed by this study to design protocol suggest a synthesis method that uses formal graphical language to synthesis the protocols. It overcomes a number of difficulties that are present in formal synthetical methods and early results show that the method can be applied to the protocol of realistic nature. This method also has some weaknesses but it is hoped that future research in this area will overcome some of these.