The introduction of Integrated Services Digital Networks (ISDNs) poses a variety of new questions on telecommunications network design and planning. Furthermore, the formulation of traditional network design and planning problems need to be revisited in the ISDN context. This paper presents an overview of the recent progress and new challenges in developing ISDN design and planning methodologies that exploit revolutionary new telecommunications technologies. It will cover some important issues for ISDN design and planning, and will concentrate on three issues that are of particular importance: Design of networks with digital information transfer capabilities, design of networks with advanced network/traffic control techniques, and use of reliability objectives for network design and planning.

Video-on-Demand (VOD)servers are becoming feasible. These servers are a building component in a heterogeneous multimedia environment but have voluminous data to store and manage. If only disk-based secondary storage systems are used to store and manage this huge amount of data the system cost would be extensively high. A tape-based tertiary storage system seems to be a reasonable solution to lowering the cost of storage and management of this continuous data. However, the usage of a tertiary storage system to store large continuous data introduces several issues. These are mainly the replacement policy on disks, the decomposition and the placement of continuous data chunks on tapes, and the scheduling of multiple requests for materializing objects from tapes to disks. In this paper we address these issues and we propose solutions based on some heuristics we experimented in a simulator.

The theoretical approximate model for packet switching multi-access system: the periodic reservation ALOHA (PR-ALOHA) is described. The performance tradeoffs of PR-ALOHA are discussed with analytic results using an approximate model obtained in this paper. By using these results, the optimum design parameters which maximize the channel utilization are given. Numerical results indicate that the PR-ALOHA offers the best throughput-delay performance at the medium throughput region.

The Active HYpermedia Delivery System (AHYDS) facilitates the access to multimedia information over a large-scale network and wide spectrum of media. We developed intelligent access facilities that build on the access paradigms supported by current web applications. This facility generalizes not only different kinds of logical data models (relational, object, hyperlink), but also access mechanisms of multimedia applications to make them customizable and scalable. This paper proposed the distributed management mechanism of the AHYDS platform. The major contribution of this paper is the mechanism for distributed multimedia delivery management over large-scale network and heterogeneous environment. We also propose the mechanism to manage huge multimedia data.