Located actions in process algebra with timing

Abstract. We propose a process algebra obtained by adapting the process algebra with continuous relative timing from Baeten and Middelburg [Process Algebra with Timing, Springer, Chap. 4, 2002] to spatially located actions. This process algebra makes it possible to deal with the behaviour of systems with a known time-dependent spatial distribution, such as a protocol transmitting data via a mobile intermediate station. It is a reformulation of the real space process algebra from Baeten and Bergstra [Formal Aspects of Computing 5:481{529, 1993] in a setting with urgent actions. This leads to many simplifications. Keywords: process algebra, continuous relative timing, spatially located actions, distributed systems, state operator, maximal progress, asynchronous communication, urgent actions. 1998 CR Categories: C.2.4, D.2.1, D.2.4, F.1.2, F.3.1