Multi Language and Multi Platform Suport for Agent Execution Using CORBA Platform-An Implementation

CABLE is the multi-agent architecture for EUCLID RTP 6.1. It provides a generic framework for building distributed agent based systems together with a method for specifying and designing agent organisations. Agent based applications of the type supported by CABLE offer many advantages including: plug-and-play of agent components, software reuse, a natural means of controlling concurrency, emergent behaviour, and a closer mapping of software implementation to the enterprise. CABLE has been developed to provide an open and portable architecture building on industry standard software and CABLE agents can utilise a wide variety of AI as well as conventional techniques and tools. CABLE agents can perform several activities concurrently to support the agent’s objectives, each activity running in its own thread. Agent communication is supported using a service-based interface. 1 Background and Introduction Euclid RTP 6.1 is a collaborative European military research project undertaken by the GRACE consortium (Grouping for Research into Advanced C3I for Europe) led by Logica and comprising 18 companies, from seven nations: the UK, Denmark, France, Italy, the Netherlands, Norway and Spain. The focus of this project is to accelerate the application of artificial intelligence (AI) techniques, advanced software engineering and Human Computer Interaction (HCI) techniques to Command, Control, Communications and Intelligence (C3I) systems. Such systems are increasingly important for battlefield, naval, and air operations, but also have civilian applications in areas such as air traffic control and the emergency services. The project has the following goals: • Methods and tools: to demonstrate key AI and HCI methods and tools of particular relevance to automated report analysis and time critical decision support in advanced C3I systems. • Architecture: to define and implement a workstation architecture able to accommodate existing and emerging methods and tools, and to forge new standards. • Simulations and testing: to form domain simulations drawn from tactical land and naval systems to aid the development and testing of the architectures and its methods. • Collaboration: to encourage European companies to work together effectively. The facilities and components created by the various parties in the project are integrated in the “GRACE demonstrator” application. CABLE, together with the HCI framework, FIONA, forms the GRACE system architecture upon which the facilities of the GRACE demonstrator are built. This paper presents a description of the CABLE agent architecture and method for developing agent applications, highlighting the benefits of an agent-based approach to software development. 1.1 Overview of the GRACE architecture The development of the GRACE architecture has been driven by the requirements for the GRACE demonstrator and the goals of the RTP 6.1 contract. These included: • flexible architecture based on open standards • run time plug-and-play components • “future proof” (easily adapted for future developments) The resulting architecture is based on the following concepts: • CABLE agents • FIONA applets which use a central presentation facility, the Digital Overhead Projector (DOHP) • agent-applets (a combination of agents and applets). A conceptual overview of the relationship between these concepts is shown in Figure 1. 1.1.1 CABLE agents CABLE is a generic framework for building distributed agent based systems. CABLE subscribes to a definition of agents which are intelligent, autonomous, self aware entities with beliefs, desires, and intentions, and an ability to interact with other agents to perform a task [1]. CABLE agents are more than just Internet helpers! Agent based applications of the type supported by CABLE offer many advantages including: plug-and-play of agent components, software re-use, a natural means of controlling concurrency, emergent behaviour, a closer mapping of software implementation to the enterprise, operation over heterogeneous platforms, and improved performance through distribution of control. 1.1.2 FIONA applets FIONA applets and the DOHP have been developed in order to provide a common presentation facility for distributed CABLE agent applications. FIONA applets are user interface components which execute as separate processes each providing its own menus, dialogs, and controls. Like agents, they can be distributed over multiple machines (though inter-applet interactions are more limited). Agent applets combine the features of CABLE agents and FIONA applets. 1.1.3 DOHP The Digital OverHead Projector (DOHP) is a central presentation facility used to display map and dynamic data owned by multiple applets in a fashion similar to a Geographical Information System. The DOHP supports presentation sharing (groupworking) allowing multiple users to view the same picture simultaneously. The DOHP can display a stack of overlays owned by different applets. It allows overlays to be turned on and off and users can manipulate the order of the overlays. The DOHP also supports a publish-subscribe mechanism allowing for flexible communication between the DOHP and the applets (or agent applets). Figure 1 The GRACE System Architecture DOHP1