Framework of a flexible computer communication network

‘Research Institute of Electrical Communication, Tohoku University, 2-l-l Katahira, Aoba-ku, Se&i 980, Japan bDepartment of Computer Science, Chiba Institute of Technology, 2-I 7-1 Tsudanuma, Narashino 275, Japan ‘Department of Computer Sojiware, The University of Aizu, Tsuruga, Aizu Wakamatsu Shi,ent of Information Engineering, Sung-Kyun-Kwan University, Seoul, Korea
Abstract
With the increasing speed of computers and communication links, and the successful convergence of both fields, computersconnectedby high speed links now represent an enormously large distributed computing system. At the same time, communication between man and machine is also becoming more diverse and personalized. Networking issues such as evolution of user services, seamless communication
between hosts, failure recovery and integration of new technologies arise daily. Problem-specific approaches and corresponding solutions are available at considerable cost. However, a common requirement is adaptability of the computer network to a variety of changes. In this paper, we propose Flexible Computer Communication Networks (FN) as a uniform solution to most of these networking problems. The framework of Flexible Networks can be considered as an intelligent shell enclosing existing networking architectures. An agent-oriented implementation of a flexible network is outlined. The conversion of existing networks to flexible networks is shown to be incremental, and therefore practicable.
N. Shiratori et aLlComputer Communications 19 (1996) 1268-1275
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something to a human. We aim to create a flexible computer communication paradigm which will be adaptive and try to offer the best service in all situations. In this new paradigm of the flexible computer communication environment, services and utilities are not restricted or confined to a fixed set. With the nature of the users’ applications being changed, the users need to be allowed to create new services according to their actual needs. On the other hand, the system should have the capability to recontigure itself autonomously to extend or restrict its services in accordance with any change in the underlying resource status. Thus, the change may be initiated by different constituent elements, e.g. the end user, the system designer, the computer system or the communication network, depending on the case. Different elements should be seamlessly connected and coordinated. To make the system flexible, as a basic requirement, we need the system to recognize changes. To recognize change, to understand it, the system needs to possess some intelligence. Also, there are some other transient and permanent changes occurring in the system and its environment which should be understood, and which may eventually require corrective action. The system needs to evolve with time. These basic requirements and the required properties to facilitate them are discussed in the next section. The computer communication field is already in an advanced stage, and it is impossible to scrap everything as of now to make room for a completely new proposal. With this basic constraint in mind, we proceed to design our goal of a flexible computer communication network. An ordinary computer network can be updated incrementally to a flexible network, and at every stage remain compatible with the existing system. In Section 2 we introduce the basic notions of a general flexible system with some intuitive definitions [3,4]. In Section 3 we explain the meaning of flexibility in computer communication. Section 4 describes the design methodology which is based on using autonomous agents. Section 5 is a description of the framework for generating agents on existing basic processes. Finally, the essence of the approach is explained, with a simple implementation of an application, flexible TV conferencing, in Section 6. Section 7 is a conclusion with some indication of future research direction.
Keywords: Flexible; Communication networks, Multi-agent model
1. Introduction As we see the history of computer development, from the beginning of the 1980s the trend has turned towards connecting small systems with communication links instead of creating large centralized systems and extending terminals. As a system becomes decentralized, managing the communication among the separate parts and directing the system as a whole towards achieving its goal become all the more important. If we note the major applications that are being processed by computers today, and the trend, we see that the nature of these applications is also changing [l, 21.Previously, many of the jobs were computation-intensive, like solving complex differential equations or matrix manipulation, or accounting. But now the volume of, for example, voice and graphics, is also great and the data are at different locations. The communication between computers is therefore a very important factor is we are to accomplish any useful work.