The ASAP project, together with the HyperNews and KryPict projects, is part of the MEDIA project supported by the Swiss Priority Programme for Information and Communication Structures (SPP-ICS). The objective of the MEDIA project is to develop a system for archiving and dissemination of electronic documents under similar conditions as printed documents, using an agent-based, distributed, and secure platform.
The ASAP project will address key issues in the construction of distributed applications over vast and dynamic networks of computers using mobile software agents. Mobile software agents embody a new paradigm for the design and implementation of distributed applications. Each agent is a self-contained, autonomous, entity, able to move around a network and interact with other agents as well as local services.
The concrete goal of our project is to deliver an execution platform that supports development of applications based on mobile software agents. This technology will be an infrastructure for developing commercial information systems in large scale, dynamic and heterogeneous networks of computers.
One application for our research is in the domain of digital documents. Both documents and user requests can be represented by mobile agents. Thus, a digital document, be it a user's request for information or a newspaper article, will be able to move around the network, knowing who its rightful owner is and what rights that owner has with respect to copying, displaying, and printing the document. Digital documents will be active -- behavior being provided by the agent substrate -- and thus, for instance, will know how to display themselves on different platforms.
The contribution of our project is a practical one: an efficient and open platform for the development of agent systems. Our main deliverable is the specification and implementation of a mobile software agent system with support for distributed programming over large scale networks, and platform services which include access to operating system services and a graphical WWW user interface. We will address security concerns by integrating state of the art commercial cryptographic technology in the agent platform.
Wide area networks have brought profound changes to the way we interact with computers. Now computer systems are composed of multiple data formats, applications, programming languages, hardware architectures and operating systems. The challenge for software engineers is to take advantage of the wealth of resources provided by these open systems and weave them into coherent and homogeneous applications. To this end, the following characteristics of open systems must be addressed by the software engineering tools: dynamicity, heterogeneity, autonomy and distribution.
In order to address the needs of open systems, mobile software agents are constructed according to the following five principles: Autonomy: A clear distinction between resources that belong to the agent and the environment is needed for mobility and security of agent systems. Mobility: The capacity to move data and running code across the network. Interoperability: The environment offers access to local services; thus an agent program can implement interoperability by coordinating different servers. Cooperation: Requires the means of setting up communication between agents which are unaware of each other. Disciplined Interactions: Protect host and agents from tampering by imposing a discipline on what the agent can do to its environment and to other agents. From these principles we describe some characteristics of agents:
The ASAP project will provide the infrastructure for developing agents with the characteristics outlined above and focus on applying this technology to commercial information systems. The ASAP architecture is composed of an Agent Execution Platform. The overall architecture of an agent system is depicted in Figure 1. A number of agents execute on an AEP. Each agent is composed of a set of objects. Agents may communicate with their environment, i.e. either other agents or platform services. The platform insulate the agents from the peculiarities of the operating system, hardware, windowing systems, local databases, and so forth. Other platforms may be accessible via a transport service.
|Prof. Dennis Tsichritzis
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