An increasing number of distributed applications will be written for mobile hosts, such as laptop computers, third generation mobile phones, personal digital assistants, watches and the like. Application engineers have to deal with a new set of problems caused by mobility, such as low bandwidth, context changes or loss of connectivity. During disconnection, users will typically update local replicas of shared data independently from each other. The resulting inconsistent replicas need to be reconciled upon re-connection. To support building mobile applications that use both replication and reconciliation over ad-hoc networks, we have designed xmiddle, a mobile computing middleware. In this paper we describe xmiddle and show how it uses reflection capabilities to allow application engineers to influence replication and reconciliation techniques. xmiddle enables the transparent sharing of XML documents across heterogeneous mobile hosts, allowing on-line and off-line access to data. We describe xmiddle using a collaborative e-shopping case study on mobile clients.
['Cecilia Mascolo', 'Licia Capra', 'Stefanos Zachariadis', 'Wolfgang Emmerich']
XMIDDLE: A Data-Sharing Middleware for Mobile Computing