An infrastructure for mobile information systems based on the fragmented object model

Global information management systems based on the vision of the 'docuserve' - such as the World-Wide-Web (WWW) - show that on-line access to vast amounts of distributed information is possible not only for the expert, but also for the end user. At the same time, the availability of affordable mid- and long-range wireless data communication services, based, e.g., on cellular phone technology, has put the vision of ubiquitous mobile information access within the reach of viable projects. I is now an interesting challenge to combine both concepts into a system model granting everyone ubiquitous access to the global information repository. However, problems such as low bandwidth and limited resources make this a non-trivial task. This paper describes MIS/0, an experimental mobile information system based on wireless data communication which has been developed at the Computer Graphics Center during 1994. MIS/0 and its underlying concepts address the above mentioned problem areas by introdu cing a fragmented object model. This model provides the necessary mechanisms for a (partial) migration of object behaviour to the mobile system - acting as an intelligent data terminal - at runtime. In addition to conventional caching and compression techniques, this is required for coping with intrinsic system limitations and low communication bandwidth in an environment with a virtually unlimited number of information types and services such as the docuserve.