Over the years, scientific applications have become more complex and more data intensive. Although through the use of distributed resources the institutions and organizations gain access to the resources needed for their large-scale applications, complex middleware is required to orchestrate the use of these storage and network resources between collaborating parties, and to manage the end-to-e...

We propose and analyze a class of admission control algorithms based on reward optimization for multimediaservers designed to provide on-demand services to clients in an environment where workload characteristics of clients can change dynamically. These admission control algorithms are developed based on two strategic choices, namely, \deterministic" or \best-eeort" regarding quality of service...

In a basic communication system, the data’s are modulated onto a single carrier frequency. The available bandwidth is then totally occupied by each symbol. This kind of system can lead to InterSymbol-Interference (ISI) in case of frequency selective fading. The basic idea of Orthogonal Frequency Division Multiplexing (OFDM) is to divide the available spectrum into several orthogonal sub channel...

Routing in Low-earth-orbit (LEO) satellite system involves the choice of inter-satellite links (ISLs) that connects two home satellites of the mobile terminals. We use a mesh model to formulate the LEO system and proposed 4 mesh-based algorithms. The objective is to minimize the new call blocking probability and the forced termination probability. Also, due to the dynamic topology of the LEO sy...

Future microcellular systems will require distributed network control. A packet-switched network is particularly suitable for this requirement. Moreover, packet switching naturally accommodates speech activity detection to improve Vation-ALOHA protocol for packet speech transmission from wireless terminals to a base station. Because PRMA is a statistical multiplexer, the channel becomes congest...

Much work has been done on establishing resource reservations over the Internet 3, 2, 8], but almost all of this work has consisted of establishing a reservation that begins immediately and has indeenite duration. An important issue is how to request an advance reservation, a reservation made now for resources that are to be reserved in the future. In this paper, we propose an architecture for ...

The development of a seat reservation system by JNR (Japanese National Railways) named MARS has been sustained by the growth in passenger transportation operations and the progress of computer technology in Japan. But passenger operations of JNR handled only 23 percent of total passenger traffic in 1985 and the growth in the share of JNR is trifling today. Therefore more efficient and economica...