Transient data sharing among mobile programs

Mobile computing represents a major point of departure from the traditional distributed computing paradigm. The potentially very large number of independent computing units, a decoupled computing style, frequent disconnections, continuous position changes, and the location-dependent nature of the behavior and communication patterns present designers with unprecedented challenges in the areas of modularity and dependability. This paper describes a modular approach to specifying and reasoning about of mobile computing. Its novelty rests with the notion of allowing transient (location-dependent) data sharing among programs which move in space. The notation is a direct extension of that used in UNITY and reasoning about mobile computations relies on the UNITY proof logic. Several examples explain the notation, demonstrate the modularity of the approach, and illustrate the verification methodology. An electronic-mail distribution problem is presented in some detail. ... Read complete abstract on page 2.