Object Request Brokers in Mobile Computing

The widespread use of wireless and mobile networks and devices requiresspecial programming techniques and solutions. The object request brokers ofmobile environments have to adopt these techniques and offer servicesdealing with the problems of mobility. Most of the existing object request brokers however were developed for fixed networks assuming reliable transport protocols (mostly TCP), while the mobile networks cannot offer high qualitytransport.In this paper we give an overview of the challenges and solutions in mobilecomputing and present our ORB(M) framework implementing services based onthe solutions. Extending the framework doesn't require the assistance of itsdevelopers, the user can implement application-specific semantic elementsand deploy various new methods bound to the process of remote invocation.The user can form arbitrary new invocation semantics based on these elementsand customise the invocation semantics used by a given method. Our newmobility-related semantic elements offer solutions to the challengesof mobility allowing the user to concentrate on theessential problems of the application and handling.