Architecture-Based Semantic Evolution: A Study of Remotely Controlled Embedded Systems

Evolution of a software system is a natural process. In several systems, evolution takes place during the maintenance phase of their lifecycles. Those systems that have reached their limit in evolution have usually reached their end of useful life and may have to be replaced. However, there are several systems where evolution occurs during the working phase of their lifecycles. Such systems were designed to evolve or in other words, be adaptable. Semantically adaptable systems are of particular interest to industry as such systems adapt themselves to environment change with little or no intervention from their developing organization. Research in embedded systems is now becoming popular [1] and developing semantically adaptable embedded systems presents challenges of its own. Embedded systems usually have a restricted hardware configuration as well and several techniques applicable to “normal” systems cannot be directly transferred to embedded systems. This paper considers semantic evolution as applicable to embedded systems and develops the concepts and techniques for semantic adaptation in embedded systems. However, the field of embedded systems being vast, this paper concentrates on those embedded systems that can be remotely controlled (as opposed to remote controlled). In this application domain the embedded system is connected to an external controller by a communication link such as ethernet, serial, radio frequency, etc., and receives commands from (and sends responses to) the external controller via the communication link. Techniques for semantic evolution in this application domain give a glimpse of the complexity involved in tackling the problem of semantic evolution in embedded systems. The techniques developed in this paper are validated by applying them in a real embedded system – a test instrument used for testing cell phones.