Satellite Networks: Architectures, Applications, and Technologies

Since global satellite networks are moving to the forefront in enhancing the national and global information infrastructures due to communication satellites' unique networking characteristics, a workshop was organized to assess the progress made to date and chart the future. This workshop provided the forum to assess the current state-of-the-art, identify key issues, and highlight the emerging trends in the next-generation architectures, data protocol development, communication interoperability, and applications. Presentations on overview, state-of-the-art in research, development, deployment and applications and future trends on satellite networks are assembled

Explicit congestion control algorithms for available bit rate services in asynchronous transfer mode networks

Congestion control of available bit rate (ABR) services in asynchronous transfer mode (ATM) networks has been the recent focus of the ATM Forum. The focus of this dissertation is to study the impact of queueing disciplines on ABR service congestion control, and to develop an explicit rate control algorithm. Two queueing disciplines, namely, First-In-First-Out (FIFO) and per-VC (virtual connection) queueing, are examined. Performance in terms of fairness, throughput, cell loss rate, buffer size and network utilization are benchmarked via extensive simulations. Implementation complexity analysis and trade-offs associated with each queueing implementation are addressed. Contrary to the common belief, our investigation demonstrates that per-VC queueing, which is costlier and more complex, does not necessarily provide any significant improvement over simple FIFO queueing. A new ATM switch algorithm is proposed to complement the ABR congestion control standard. The algorithm is designed to work with the rate-based congestion control framework recently recommended by the ATM Forum for ABR services. The algorithm\u27s primary merits are fast convergence, high throughput, high link utilization, and small buffer requirements. Mathematical analysis is done to show that the algorithm converges to the max-min fair allocation rates in finite time, and the convergence time is proportional to the distinct number of fair allocations and the round-trip delays in the network. At the steady state, the algorithm operates without causing any oscillations in rates. The algorithm does not require any parameter tuning, and proves to be very robust in a large ATM network. The impact of ATM switching and ATM layer congestion control on the performance of TCP/IP traffic is studied and the results are presented. The study shows that ATM layer congestion control improves the performance of TCP/IP traffic over ATM, and implementing the proposed switch algorithm drastically reduces the required switch buffer requirements. In order to validate claims, many benchmark ATM networks are simulated, and the performance of the switch is evaluated in terms of fairness, link utilization, response time, and buffer size requirements. In terms of performance and complexity, the algorithm proposed here offers many advantages over other proposed algorithms in the literature

System level performance of ATM transmission over a DS-CDMA satellite link.

PhDAbstract not availableEuropean Space Agenc

Quality of service over ATM networks

PhDAbstract not availabl

Space-Based Information Infrastructure Architecture for Broadband Services

This study addressed four tasks: (1) identify satellite-addressable information infrastructure markets; (2) perform network analysis for space-based information infrastructure; (3) develop conceptual architectures; and (4) economic assessment of architectures. The report concludes that satellites will have a major role in the national and global information infrastructure, requiring seamless integration between terrestrial and satellite networks. The proposed LEO, MEO, and GEO satellite systems have satellite characteristics that vary widely. They include delay, delay variations, poorer link quality and beam/satellite handover. The barriers against seamless interoperability between satellite and terrestrial networks are discussed. These barriers are the lack of compatible parameters, standards and protocols, which are presently being evaluated and reduced

Resource Allocation for Ka-Band Broadband Satellite Systems

Forthcoming high data rate geostationary satellite systems, which are planned to work in rain affected Ka-band, would need effective resource management from a network management perspective. In this thesis we have looked at satellite power and bursting time-slots needed for the downlink channel, as satellite resources that need to be managed. Some solutions are proposed in order to tackle the above-mentioned problem

Resource allocation in ATM networks

The areas of resource allocation ancl congestion control in ATM networks have been investigated. ATM networks and the guarantees given to users have been reviewed and a new model of ATM networking has been proposed. To aid the analysis of ATM network issues, performance modelling and simulation methods have been reviewed. Typical sources have been designed : a two-state Markov model for voice ; a multi-state Markov one layer variable bit rate video source model ; an empirical file transfer data source model ; and some basic network elements. The models have been verified and validated on a discrete event simulator. It was shown that there are problems when using ATM over satellite links. A model for the noise analysed from real satellite links was developed. Based on this model a new more efficient protocol for assembling ATM cells was proposed and simulated. Again at the cell level, the traffic that can pass the standardised conformance test and still produce the worst performance in the network was investigated. Counter to the traditional wisdom it was found that the on-off source does not always produce the worst case traffic. Users have been classified with new parameters, and it has been shown that these new classes of users can still be given guarantees without giving traffic descriptors. Adaptive user classes have been modelled mathematically. A new model for efficiency has been developed, which includes both network issues and economic issues. This new model defines congestion and also describes how to allocate resources when congested. It has been shown that this economic model coupled with the adaptive user classes allow for an increase in both network and economic efficiency simultaneously for some sample cases

ATM optical wireless networks

The aim of the research is to propose, design and evaluate a new wireless communication, local area network (LAN). Such a LAN will be able to extend the asynchronous transfer mode (ATM) wireline technology into indoor optical wireless networks