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| Wireless LAN, Mobile Ad Hoc, and Wireless Mesh Networks |
Prasant Mohapatra
Department of Computer Science
University of California
Davis, CA 95616 USA
Email: prasant@cs.ucdavis.edu
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Recent proliferation of wireless devices had considerably increased the need for networking and provisioning intercommunication between these devices for various applications. Broadly, the wireless networks can be classified into three categories. The wireless local area networks
(WLANs) can be termed as infrastructure-based wireless networks. These networks provide wireless connectivity to the end hosts through one-hop to the nearest wireless access point. The access points are connected to the wired Internet. These ubiquitous networks are used for providing general wireless access in hot spots for generic Internet connectivity. The second category, termed as infrastructureless wireless networks include mobile ad hoc networks and sensor networks. Mobile ad hoc networks
(MANETs) have use in battlefields, disaster recovery areas, intercommunication between islands or in difficult terrains, and conferencing with any infrastructure support. Infrastructureless wireless networks do not need any infrastructure support for deployment. The nodes act both as hosts as well as routers. They operate in a self-organizing and adapting manner. The third category, WIreless MEsh NETworks
(WIMENETs) are composed of several wireless routers that provide multihop communication paths between wireless clients as well as facilitate connection to the wide area network and the Internet. The wireless routers are mostly stationary while the client nodes may be stationary or mobile. WIMENETs can be used as a very low-cost local area network because of the avoidance of the installation costs of wired infrastructure. These networks will not only be useful for applications that are supported by wireless local area networks or mobile ad hoc networks, but also will have scope for usage in providing Internet access to various community networks, enterprise networks, and home networks. WIMENETs can be deployed strategically or in an ad hoc manner. Recently, WIMENETs have become a very active area of research, which is being pursued by both academia and industry.
The tutorial will start with an overview of wireless networks, their applications, and how the issues in wireless networks differ from that of wired networks. A broad classification of the wireless networks will be discussed that will set the stage for the three major parts of the tutorial:
WLANs, MANETs, and WIMENETs.
We will overview the basic issues of WLANs, a description of the IEEE 802.11 protocol, its extensions, and other related issues. The lower layer issues that form the commanality of the three categories will be discussed.
In the context of MANETs, we will describe the architecture, operations, and the challenges to meet the effectiveness of these networks. We will study the MAC layer protocols that have been proposed. In the context of network layer, we will discuss a variety of routing protocols proposed for both unicast and multicast communications. We will also examine various techniques for enhancing performance of routing in MANETs
while considering the constraints of power, and other attributes. The performance of TCP and the enhancements proposed for TCP in MANET environments will be described. We will examine a layered view of QoS provisioning in
MANETs, followed by an overview of the security issues including denial of service attacks and intrusion detection mechanisms.
Considering the interests and activities in the areas of
WIMENETs, it may be useful to grasp an in-depth view of these networks in terms of their organization, applications, protocols, and unsolved problems. This tutorial will provide a comprehensive study of various issues in
WIMENETs. We will explore the issues associated with each of the protocol stack in a top-down manner. In addition, several issues that are unique to WIMENET will be discussed in the context of cross-layer aspects. We will also discuss the experiences and lessons learnt from various test-bed and experimental implementations. Techniques to build simple WIMENETs will be explained in this tutorial. We will overview the standard-related activities followed by the future outlook of
WIMENETs.
The tutorial will concluded with an overview of the open issues and challenges in the wireless networks. We will present the future directions in
WLANs, MANETs as well as WIMENETs. |
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