NAP is a protocol for supporting fault-tolerance in intinerant computations. It employs a form of failure detection and recovery, and it generalizes the primary-backup approach to a new compuational model. The guarantees ooered by NAP as well as an implementation for NAP in tacomaare discussed.
A problem with a ubiquitous device like a cellular phone is that it is not properly integrated with contemporary distributed systems. Our goal is to improve this, by enabling cellular phones as interacting clients in a distributed system. We have devised an architecture with two main components: 1) A cellular phone, and 2) a remote extensible server based… (More)
For seven years, the Tacoma project has investigated the design and implementation of software support for mobile agents. A series of prototypes has been developed, with experiences in distributed applications driving the effort. This paper describes the evolution of these Tacoma prototypes, what primitives each supports, and how the primitives are used in… (More)
The direct geo-referencing of sensors based on a combination of relative kinematic GPS-positioning and inertial measurement units (IMU) has reached a high accuracy level and growing application. It includes the advantage of a very flexible use, independent upon control points which are only required for the system calibration and independent upon block or… (More)
In this paper, we present experiences from adding software mobility to mobile, hand-held computers. In particular , we have built TACOMA Lite, a mobile code system, for this environment. With TACOMA Lite installed, hand-held computers can host and execute mobile code. TACOMA Lite has been used as platform for several mobile code applications. Through… (More)
Group communications systems have been designed to provide an infrastructure for fault-tolerance in distributed systems , including wide-area systems. In our work on master-worker computation for GriPhyN, which is a large project in the area of the computational grid, we asked the question should we build our wide-area master-worker computation using… (More)