Mac And Routing Protocols For Multi Hop Wireless Networks

Abstract: "Wireless systems for industry have mostly used cellular-phone-style radio links, using point-to-point or point-to-multipoint transmission. Past research has indicated that these network architectures are not suitable for several industrial applications because of their rigid structure, meticulous planning requirements, and dropped signals. In contrast, wireless mesh networks are multi-hop systems in which devices assist each other in transmitting packets through the network, and they provide a reliable, flexible system that can be extended to thousands of devices. Some inherent advantages with mesh networks are scalability, non line-of-sight communications, high data rates, and low-cost deployment. Mesh networks have been deployed by MIT researchers and a few companies on a small scale. Mesh networks have not been deployed widely, in part because of some fundamental problems with the current protocols with regards to QoS support and scalability. To meet these requirements, the MAC protocol should be able to guarantee near constant capacity for networks of different sizes, and the routing protocol should perform admission control. Current CSMA-based MAC protocols have been shown to perform inadequately in terms of throughput and scalability in multi-hop deployments. The key problem with using protocols like IEEE 802.11 is that the link throughput is affected severely due to the exposed terminal problem, uncoordinated contentions, and wasteful backoffs. With the 802.11 MAC protocol, our results show that the capacity falls to about 1/10th for a chain and below 1/20th for a grid with horizontal constant bit rate flows. We have developed the WisperNet MAC and routing protocols, which provide end-to-end QoS guarantees over a multi-hop mesh network. By exploiting the topology information and the fact that fixed wireless nodes separated by 3 hops or more can transmit simultaneously, we eliminate collisions and maximize network utilization. The WisperNet routing protocol performs admission control. We show that the WisperNet MAC protocol can guarantee up to 9 times more capacity than IEEE 802.11, and this capacity remains nearly constant as the network grows. Also included is a performance analysis of different routing policies, and their effect on network utilization."

Doctoral Thesis / Dissertation from the year 2011 in the subject Computer Science - Internet, New Technologies, Lille 1 University (Laboratoire d'Informatique Fondamentale de Lille), course: Security in Wireless Multi-hop Networks, language: English, abstract: While the rapid proliferation of mobile devices along with the tremendous growth of various applications using wireless multi-hop networks have significantly facilitate our human life, securing and ensuring high quality services of these networks are still a primary concern. In particular, anomalous protocol operation in wireless multi-hop networks has recently received considerable attention in the research community. These relevant security issues are fundamentally different from those of wireline networks due to the special characteristics of wireless multi-hop networks, such as the limited energy resources and the lack of centralized control. These issues are extremely hard to cope with due to the absence of trust relationships between the nodes. To enhance security in wireless multi-hop networks, this dissertation addresses both MAC and routing layers misbehaviors issues, with main focuses on thwarting black hole attack in proactive routing protocols like OLSR, and greedy behavior in IEEE 802.11 MAC protocol. Our contributions are briefly summarized as follows. As for black hole attack, we analyze two types of attack scenarios: one is launched at routing layer, and the other is cross layer. We then provide comprehensive analysis on the consequences of this attack and propose effective countermeasures. As for MAC layer misbehavior, we particularly study the adaptive greedy behavior in the context of Wireless Mesh Networks (WMNs) and propose FLSAC (Fuzzy Logic based scheme to Struggle against Adaptive Cheaters) to cope with it. A new characterization of the greedy behavior in Mobile Ad Hoc Networks (MANETs) is also introduced. Finally, we design a new backoff scheme to quickly detect the greedy nodes that do not comply with IEEE 802.11 MAC protocol, together with a reaction scheme that encourages the greedy nodes to become honest rather than punishing them.

The military, the research community, emergency services, and industrial environments all rely on ad hoc mobile wireless networks because of their simple infrastructure and minimal central administration. Now in its second edition, Ad Hoc Mobile Wireless Networks: Principles, Protocols, and Applications explains the concepts, mechanism, design, and performance of these highly valued systems. Following an overview of wireless network fundamentals, the book explores MAC layer, routing, multicast, and transport layer protocols for ad hoc mobile wireless networks. Next, it examines quality of service and energy management systems. Additional chapters cover mobility models for multi-hop ad hoc wireless networks as well as cross-layer design issues. Exploring Bluetooth, IrDA (Infrared Data Association), HomeRF, WiFi, WiMax, Wireless Internet, and Mobile IP, the book contains appropriate examples and problems at the end of each chapter to illustrate each concept. This second edition has been completely updated with the latest technology and includes a new chapter on recent developments in the field, including sensor networks, personal area networks (PANs), smart dress, and vehicular ad hoc networks. Self-organized, self-configured, and self-controlled, ad hoc mobile wireless networks will continue to be valued for a range of applications, as they can be set up and deployed anywhere and anytime. This volume captures the current state of the field as well as upcoming challenges awaiting researchers.

The focus of this brief is to identify what unifies and what distinguishes the routing functions in four wireless multi-hop network paradigms. The brief introduces a generic routing model that can be used as a foundation of wireless multi-hop routing protocol analysis and design. It demonstrates that such model can be adopted by any wireless multi-hop routing protocol. Also presented is a glimpse of the ideal wireless multi-hop routing protocol along with several open issues.

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.

The rapid development of wireless digital communication technology has cre ated capabilities that software systems are only beginning to exploit. The falling cost of both communication and of mobile computing devices (laptop computers, hand-held computers, etc. ) is making wireless computing affordable not only to business users but also to consumers. Mobile computing is not a "scaled-down" version of the established and we- studied field of distributed computing. The nature of wireless communication media and the mobility of computers combine to create fundamentally new problems in networking, operating systems, and information systems. Further more, many of the applications envisioned for mobile computing place novel demands on software systems. Although mobile computing is still in its infancy, some basic concepts have been identified and several seminal experimental systems developed. This book includes a set of contributed papers that describe these concepts and sys tems. Other papers describe applications that are currently being deployed and tested. The first chapter offers an introduction to the field of mobile computing, a survey of technical issues, and a summary of the papers that comprise sub sequent chapters. We have chosen to reprint several key papers that appeared previously in conference proceedings. Many of the papers in this book are be ing published here for the first time. Of these new papers, some are expanded versions of papers first presented at the NSF-sponsored Mobidata Workshop on Mobile and Wireless Information Systems, held at Rutgers University on Oct 31 and Nov 1, 1994.

This text introduces the principles of routing protocols and metrics as they affect wireless networking environments, specifically in urban areas. Timely because of the recent rise in small city life, this topic includes the consideration of ad hoc, mesh, vehicular, sensor, and delay tolerant networks. These approaches are each unique, and author Miguel Mitre Campista provides a thorough, but accessible, explanation of their individual characteristics for engineers, computer scientists, IT professionals, and curious Internet users.

AD HOC NETWORKS: Technologies and Protocols is a concise in-depth treatment of various constituent components of ad hoc network protocols. It reviews issues related to medium access control, scalable routing, group communications, use of directional/smart antennas, network security, and power management among other topics. The authors examine various technologies that may aid ad hoc networking including the presence of an ability to tune transmission power levels or the deployment of sophisticated smart antennae. Contributors to this volume include experts that have been active in ad hoc network research and have published in the premier conferences and journals in this subject area. AD HOC NETWORKS: Protocols and Technologies will be immensely useful as a reference work to engineers and researchers as well as to advanced level students in the areas of wireless networks, and computer networks.

Following the pattern of the Internet growth in popularity, started in the early 1990s, the current unprecedented expansion of wireless technology promises to have an even greater effect on how people communicate and interact, with considerable socio-economic impact all over the world. The driving force behind this growth is the remarkable progress in component miniaturization, integration, and also devel- ments in waveforms, coding, and communication protocols. Besides established infrastructurebased wireless networks (cellular, WLAN, sat- lite) ad-hoc wireless networks emerge as a new platform for distributed applications and for personal communication in scenarios where deploying infrastructure is not feasible. In ad-hoc wireless networks, each node is capable of forwarding packets on behalf of other nodes, so that multi-hop paths provide end-to-end connectivity. The increased flexibility and mobility of ad-hoc wireless networks are favored for appli- tions in law enforcement, homeland defense and military. In a world where wireless networks become increasingly interoperable with each other and with the high-speed wired Internet, personal communication systems will transform into universal terminals with instant access to variate content and able of handle demanding tasks, such as multimedia and real-time video. With users roaming between networks, and with wide variation in wireless link quality even in a single domain, the communications terminal must continue to provide a level of Quality of Service that is acceptable to the user and conforms to a contracted Service Level Agreement.