Satellite-based internet: A tutorial

In a satellite-based Internet system, satellites are used to interconnect heterogeneous network segments and to provide ubiquitous direct Internet access to homes and businesses. This article presents satellite-based Internet architectures and discusses multiple access control, routing, satellite transport, and integrating satellite networks into the global Internet.published_or_final_versio

Satellite-based internet: A tutorial

In a satellite-based Internet system, satellites are used to interconnect heterogeneous network segments and to provide ubiquitous direct Internet access to homes and businesses. This article presents satellite-based Internet architectures and discusses multiple access control, routing, satellite transport, and integrating satellite networks into the global Internet.published_or_final_versio

Wireless industrial monitoring and control networks: the journey so far and the road ahead

While traditional wired communication technologies have played a crucial role in industrial monitoring and control networks over the past few decades, they are increasingly proving to be inadequate to meet the highly dynamic and stringent demands of today’s industrial applications, primarily due to the very rigid nature of wired infrastructures. Wireless technology, however, through its increased pervasiveness, has the potential to revolutionize the industry, not only by mitigating the problems faced by wired solutions, but also by introducing a completely new class of applications. While present day wireless technologies made some preliminary inroads in the monitoring domain, they still have severe limitations especially when real-time, reliable distributed control operations are concerned. This article provides the reader with an overview of existing wireless technologies commonly used in the monitoring and control industry. It highlights the pros and cons of each technology and assesses the degree to which each technology is able to meet the stringent demands of industrial monitoring and control networks. Additionally, it summarizes mechanisms proposed by academia, especially serving critical applications by addressing the real-time and reliability requirements of industrial process automation. The article also describes certain key research problems from the physical layer communication for sensor networks and the wireless networking perspective that have yet to be addressed to allow the successful use of wireless technologies in industrial monitoring and control networks

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

Energy-efficient wireless communication

In this chapter we present an energy-efficient highly adaptive network interface architecture and a novel data link layer protocol for wireless networks that provides Quality of Service (QoS) support for diverse traffic types. Due to the dynamic nature of wireless networks, adaptations in bandwidth scheduling and error control are necessary to achieve energy efficiency and an acceptable quality of service. In our approach we apply adaptability through all layers of the protocol stack, and provide feedback to the applications. In this way the applications can adapt the data streams, and the network protocols can adapt the communication parameters

Improving VBR voice performance in integrated services broadband wireless networks

The integration of multimedia applications into future wireless networks is expected to accelerate the demand for incorporating broadband infrastructure into wireless arena. Providing an efficient broadband wireless infrastructure capable to carry a mixture of different services brings a large set of new technical challenges. The current wireless networks that have been designed to carry low bit-rate voice and data are not able to carry bandwidth consuming and delay sensitive multimedia traffic. Consequently fundamental changes at different layers of current technology used in wireless networks are required. In this thesis we focus on Medium Access Control protocols (MAC) suitable for broadband wireless networks. Wireless ATM (WATM) has been considered in this work. This is mainly because it is widely accepted that ATM is the foundation of future broadband networks and integrating ATM into wireless networks provides a seamless interface between wired and wireless environments. We investigate the major recent proposals for MAC protocols for broadband wireless networks and propose a new reservation mechanism for the reservation part of a FDD-based MAC protocol. This novel mechanism is called “Dynamic Hybrid Partitioning with Adjustable Repeat” which helps to improve the performance of the Variable Bit Rate (VBR) voice traffic in a broadband wireless network with integrated traffic. Through a number of simulation experiments based on AKAROA2 [Ewi99J, we analyze the different aspects of our proposed mechanism and show how it improves the performance of the VBR voice traffic sources in a network with different classes of traffic

Improving VBR voice performance in integrated services broadband wireless networks

The integration of multimedia applications into future wireless networks is expected to accelerate the demand for incorporating broadband infrastructure into wireless arena. Providing an efficient broadband wireless infrastructure capable to carry a mixture of different services brings a large set of new technical challenges. The current wireless networks that have been designed to carry low bit-rate voice and data are not able to carry bandwidth consuming and delay sensitive multimedia traffic. Consequently fundamental changes at different layers of current technology used in wireless networks are required. In this thesis we focus on Medium Access Control protocols (MAC) suitable for broadband wireless networks. Wireless ATM (WATM) has been considered in this work. This is mainly because it is widely accepted that ATM is the foundation of future broadband networks and integrating ATM into wireless networks provides a seamless interface between wired and wireless environments. We investigate the major recent proposals for MAC protocols for broadband wireless networks and propose a new reservation mechanism for the reservation part of a FDD-based MAC protocol. This novel mechanism is called “Dynamic Hybrid Partitioning with Adjustable Repeat” which helps to improve the performance of the Variable Bit Rate (VBR) voice traffic in a broadband wireless network with integrated traffic. Through a number of simulation experiments based on AKAROA2 [Ewi99J, we analyze the different aspects of our proposed mechanism and show how it improves the performance of the VBR voice traffic sources in a network with different classes of traffic

Resource management for multimedia traffic over ATM broadband satellite networks

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The application of forward error correction techniques in wireless ATM

Bibliography: pages 116-121.The possibility of providing wireless access to an ATM network promises nomadic users a communication tool of unparalleled power and flexibility. Unfortunately, the physical realization of a wireless A TM system is fraught with technical difficulties, not the least of which is the problem of supporting a traditional ATM protocol over a non-benign wireless link. The objective of this thesis, titled "The Application of Forward Error Correction Techniques in Wireless ATM' is to examine the feasibility of using forward error correction techniques to improve the perceived channel characteristics to the extent that the channel becomes transparent to the higher layers and allows the use of an unmodified A TM protocol over the channel. In the course of the investigation that this dissertation describes, three possible error control strategies were suggested for implementation in a generic wireless channel. These schemes used a combination of forward error correction coding schemes, automatic repeat request schemes and interleavers to combat the impact of bit errors on the performance of the link. The following error control strategies were considered : 1. A stand alone fixed rate Reed-Solomon encoder/decoder with automatic repeat request. 2. A concatenated Reed-Solomon, convolution encoder/decoder with automatic request and convolution interleaving for the convolution codec. 3. A dynamic rate encoder/decoder using either a concatenated Reed-Solomon, convolution scheme or a Reed-Solomon only scheme with variable length Reed-Solomon words