Limbo: A Tuple Space Based Platform for Adaptive Mobile Applications

Mobile computing environments are characterised by significant and rapid changes in their supporting infrastructure and, in particular, in the quality-of-service (QoS) available from their underlying communications channels. Applications which can operate in these environments and take advantage of changing QoS require distributed systems support platforms. The current state-of-the-art in such platforms attempt to provide synchronous connection-oriented programming paradigms reflecting their fixed network origin. In this paper we argue that these paradigms are not well suited to operation in a mobile environment and instead propose a new platform called Limbo based on the tuple space communications paradigm. The design of Limbo is presented together with details of two prototype implementations. The use of the platform to re-engineer a number of existing adaptive mobile applications is also discussed

Experiences of Using Generative Communications to Support Adaptive Mobile Applications

Attention has recently begun to focus on the use of asynchronous paradigms to support adaptive mobile applications. To investigate this issue the authors have developed an asynchronous distributed systems platform based on the tuple space paradigm [Gelernter,85b] coupled with extensions to support operation in mobile environments. This paper presents our experiences of developing and using this platform. The benefits of the tuple space approach are highlighted and we discuss in some detail the design, implementation and performance of our platform. We subsequently focus on the critical issues of the tuple space API and the level of support for adaptation which can be provided without compromising the elegance and simplicity of the paradigm. The paper concludes with an analysis of the suitability of platforms based on the tuple space paradigm for use in mobile environments