TCP Performance Study and Enhancements Within Wireless Multi-hop Ad Hoc Network Environments
TCP Performance Study and Enhancements Within Wireless Multi-hop Ad Hoc Network Environments

Author: Alaa Seddik

Publisher:

Published: 2009

Total Pages: 0

ISBN-13:

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Wireless ad hoc networks are different from wired networks by the multitude of data packet loss situations they are subjected to. This is due to the characteristics of wireless channel that might obstruct the proper reception of data packet at the destination end. In some case, these vulnerabilities of wireless channel can result in a complete link failure. Although link failure is of low probability in wired networks, it is rather common in wireless networks. The volatility of communication channel is a typical problem with wireless links, which is not the case with wired cables. TCP is a transport protocol that aims at ensuring high reliability and guarantying reception of data packets. However, TCP was designed for wired networks to address congestion, which is the main cause for data packet loss in wired networks. Therefore, other types of data packet loss encountered in wireless networks are prone to misinterpretation by TCP, which will lead to TCP performance degradation within the network. To overcome the performance limitation of TCP when used within ad hoc networks, the aim of this thesis is twofold. First, a complete performance study of TCP over ad hoc networks is achieved. This evaluation concerns two performance metrics: the achievable throughput and the energy consumption of TCP within ad hoc networks. This study allows identifying the potential room of improvement to enhance TCP efficiency in ad hoc networks. Second, we propose a new TCP variant, TCP-WELCOME that optimizes the performance of TCP in ad hoc networks through its ability to distinguish among, and efficiently deal with, different data packet loss situations, within ad hoc networks.

Ad Hoc Wireless Networking
Ad Hoc Wireless Networking

Author: Xiuzhen Cheng

Publisher: Springer Science & Business Media

Published: 2004

Total Pages: 638

ISBN-13: 9781402077128

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Ad Hoc Wireless Networking is the next big thing in communication. This volume reveals the state-of-the-art of ad hoc wireless networking in addition to giving the fundamentals of routing protocols. It covers the topics of security, TCP performance over wireless links, power conservation, location discovery, scalability, proactivity, routing protocols, computational geometry, and more. The 15 self-contained chapters are authored by experts in wireless networking and mobile computing. Audience: Both specialists and uninformed readers will find this volume stimulating and helpful.

Multiaccess, Mobility and Teletraffic in Wireless Communications: Volume 4
Multiaccess, Mobility and Teletraffic in Wireless Communications: Volume 4

Author: Ezio Biglieri

Publisher: Springer Science & Business Media

Published: 2013-03-09

Total Pages: 313

ISBN-13: 1475759207

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The unrelenting growth of wireless communications continues to raise new research and development problems that require unprecedented interactions among communication engineers. In particular, specialists in transmission and specialists in networks must often cross each other's boundaries. This is especially true for CDMA, an access technique that is being widely accepted as a system solution for next-generation mobile cellular systems, but it extends to other system aspects as well. Major challenges lie ahead, from the design of physical and radio access to network architecture, resource management, mobility management, and capacity and performance aspects. Several of these aspects are addressed in this volume, the fourth in the edited series on Multiaccess, Mobility and Teletraffic for Wireless Communications. It contains papers selected from MMT'99, the fifth Workshop held on these topics in October 1999 in Venezia, Italy. The focus of this workshop series is on identifying, presenting, and discussing the theoretical and implementation issues critical to the design of wireless communication networks. More specifically, these issues are examined from the viewpoint of the impact each one of them can have on the others. Specific emphasis is given to the evolutionary trends of universal wireless access and software radio. Performance improvements achieved by spectrally efficient codes and smart antennas in experimental GSM testbeds are presented. Several contributions address critical issues regarding multimedia services for Third-Generation Mobile Radio Networks ranging from high rate data transmission with CDMA technology to resource allocation for integrated Voice/WWW traffic.

TCP Performance with Multipath Routing in Wireless Ad Hoc Networks
TCP Performance with Multipath Routing in Wireless Ad Hoc Networks

Author:

Publisher:

Published: 2003

Total Pages:

ISBN-13:

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Majority of applications on the Internet today use TCP for reliable communication. TCP has been designed for and fine tuned to wired environments, but recent studies have shown that its performance suffers in wireless network environments, particularly in ad hoc networks because of the presence of multiple wireless hops. Routing has been the most focused area of research in recent years in wireless ad hoc networking area. Many on-demand routing protocols have been proposed to improve robustness in the face of link and route failures and facilitate packet transmission. Using multiple paths to route packets is one of them. We examine the performance of the TCP protocol with multiple paths in mobile ad hoc networks (MANETs). We set up multiple routes between the TCP source and destination either manually or using an on-demand multipath routing protocol, and forward packets on both paths to reduce the load on one single path. Ordinarily one would expect the multiple paths to reduce conflict between TCP data and acknowledgement packets thus giving better overall performance. Our results do incidate that TCP performance with multipath routing shows some improvement for long routes; however, shorter routes may experience slight degradation in performance as compared to single path routing. This observation remains true even when contention-based scheduling is used to schedule packets on different paths, or the multiple routes are chosen such that they have a minimum radio interference among themselves. We conclude that the TCP could gain only limited benefits with multipath routing.

Multi-hop Ad Hoc Networks from Theory to Reality
Multi-hop Ad Hoc Networks from Theory to Reality

Author: Marco Conti

Publisher: Nova Publishers

Published: 2007

Total Pages: 322

ISBN-13: 9781600216053

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Mobile Multi-hop Ad Hoc Networks are collections of mobile nodes connected together over a wireless medium. These nodes can freely and dynamically self-organise into arbitrary and temporary, "ad-hoc" network topologies, allowing people and devices to seamlessly internetwork in areas with no pre-existing communication infrastructure, (e.g., disaster recovery environments). The aim of this book is to present some of the most relevant results achieved by applying an experimental approach to the research on multi-hop ad hoc networks. The unique aspect of the book is to present measurements, experiences and lessons obtained by implementing ad hoc networks prototypes.

A TCP Analysis
A TCP Analysis

Author: Rahul Gupta

Publisher:

Published: 2002

Total Pages:

ISBN-13:

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An Ad hoc network is a completely wireless network with a dynamic nature of topology, which rapidly changes with time. Due to the node movement there are sudden losses of packets and delays. Transport protocols like TCP have been designed for reliable fixed networks. TCP misapprehend these packet losses as congestion in the network and call upon congestion control, which leads to avoidable retransmissions and loss in overall performance. In this work we propose a receiver information based approach, so that source can distinguish between route failure and network congestion. Simulation results show that the use of this feedback approach provides a significant improvement in performance. TCP does not differentiate between congestion and packet loss due to transmission errors or route failures, because it is designed for use over fixed low-error networks like the internet. In internet route failures and disruptions are very sporadic since network is fixed, therefore, packet losses, which is detected by TCP as a timeout, can be interpreted as a symptom of congestion in the network. A lot of research has been done on reliable transport protocols for cellular wireless networks. All the mechanisms proposed heavily depend on the presence of wired base station network, and hence cannot be directly applied to ad-hoc networks. In this work we study TCP performance over ad hoc networks and propose receiver information based feed back scheme, to control the TCP window at the sender side. TCP performance is tested in ad hoc network routed with DSR routing protocol, with two versions of TCP, TCP-new Reno, and TCP-feecon (proposed). With this study, we see number of unique characteristic of ad hoc networks for TCP, such as increasing ratio of out-of-order packet delivery, multiple competing connections contending for the bandwidth-constrained wireless channel and induce network congestion, mobility-induced disconnection, and reconnection. We propose an adaptive feed back technique which uses receiver information to command and control the sender side TCP window. Our implementation complexity is on the receiver side and is stable.

Wireless Ad hoc and Sensor Networks
Wireless Ad hoc and Sensor Networks

Author: Jagannathan Sarangapani

Publisher: CRC Press

Published: 2017-12-19

Total Pages: 574

ISBN-13: 1351837338

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With modern communication networks continuing to grow in traffic, size, complexity, and variety, control systems are critical to ensure quality and effectively manage network traffic. Providing a thorough and authoritative introduction, Wireless Ad hoc and Sensor Networks: Protocols, Performance, and Control examines the theory, architectures, and technologies needed to implement quality of service (QoS) in a wide variety of communication networks. Based on years of research and practical experience, this book examines the technical concepts underlying the design, implementation, research, and invention of both wired and wireless networks. The author builds a strong understanding of general concepts and common principles while also exploring issues that are specific to wired, cellular, wireless ad hoc, and sensor networks. Beginning with an overview of networks and QoS control, he systematically explores timely areas such as Lyapunov analysis, congestion control of high-speed networks, admission control based on hybrid system theory, distributed power control of various network types, link state routing using QoS parameters, and predictive congestion control. The book also provides a framework for implementing QoS control using mote hardware. Providing a deeply detailed yet conveniently practical guide to QoS implementation, Wireless Ad hoc and Sensor Networks: Protocols, Performance, and Control is the perfect introduction for anyone new to the field as well as an ideal reference guide for seasoned network practitioners.