Supporting universal personal computing on the Internet with Java and CORBA

Abstract

Dept. of Computer ScienceUniversity of British ColumbiaVancouver, B.C., Canada V6T 1Z4AbstractUniversal Personal Computing (UPC) supports nomadic computing on the Internet by allowing mobileusers to access their personalized computing resources anywhere on the Internet using any available terminal.Since UPC must deal with heterogeneous systems in a mobile environment, independence of computing plat-forms and support of portable objects are imperative, which leads to the choice of Java. The system is mod-eled as distributed objects with CORBA as the common bus that facilitates distribution, interfacing, and inte-gration of the objects. The combination of Java and CORBA constitutes an ideal environment for UPC.1. IntroductionNomadic computing on the Internet has emerged as a new research area due to the popularity of Internet,the widespread use of portable computing devices such as PDAs (Personal Digital Assistants) and laptops,and users’ desire to be networked. In such an environment, nomadic computing should provide independenceof location, of motion, of platform and with widespread presence of access to remote files, systems and serv-ices [2]. In other words, the essence of such a computing paradigm is to retain one’s personal computing en-vironments and access capabilities wherever one happens to be. Typically, this is achieved by physically car-rying a computing device such as a laptop or a PDA with appropriate Internet connectivity (via wireless orwired links) and mobility support such as mobile IP [7].We envisage another form of nomadic computing on the Internet in which it is the user’s personal com-puting environment that is mobile. A personal computing environment consists of the set of resources, serv-ices, and personal preferences as configured by the user at his home network. When moving, the user doesnot carry any computing device but instead uses any available machine where he visits and yet his familiarpersonalized computing environment is still available to him. Imagine, for example, in a hotel, at an airport,or even in a cafe, there deployed many public terminals (much like public phones today) that were connectedto the Internet for customers to use. In such a case, it is desirable that one can simply use an idle terminal toaccess the network as well as his own computing resources within a familiar environment just as if he wasusing his home machine. He should not need to worry about what hardware or software platforms he is using,just like one does not need to wonder about the brand or vendor of a public phone. We call this form of mo-bility user mobility, as opposed to the terminal mobility where the physical device migrates [7,8]. The publicterminal being used is called a foreign terminal, while the network that the foreign terminal is attached to is aforeign network. The system that supports user mobility is called a Universal Personal Computing (UPC)system [3,4]. UPC accomplishes a global virtual network service independent of location, motion, and plat-forms. It is a new mobility-support service a step further from the basic terminal mobility support.To provide a personal computing environment to the user on any available networked machine, it re-quires a virtually homogeneous distributed processing environment that is independent of the computing plat-forms. Java, whose “Write Once, Run Anywhere™” model provides a portable object infrastructure thatworks on every major operating system, satisfies our need. Moreover, an object-oriented model is desired asthe personal computing environment consists of natural objects such as service profiles and configurations.The objects are also distributed and moving around based on the current location of the mobile user. Thiscalls for a distributed object oriented framework. The Common Object Request Broker Architecture(CORBA) developed by the Object Management Group (OMG) provides such a framework [1,5,9]. We fa-vor CORBA over Microsoft’s Distributed Component Object Model (DCOM) because CORBA is an openstandard supported by the majority of the industry and is available on most platforms. While Java Remote