This brief provides an overview of the requirements, challenges, design issues and major techniques for seamless and secure communications over heterogeneous wireless networks. It summarizes and provides detailed insights into the latest research on handoff management, mobility management, fast authentication and security management to support seamless and secure roaming for mobile clients. The reader will also learn about the challenges in developing relevant technologies and providing ubiquitous Internet access over heterogeneous wireless networks. The authors have extensive experience in implementing such technologies over heterogeneous wireless networks, thus enabling them to bridge the gap between the theoretical results of research and the real practice. Combining basic theoretical concepts and practical implementation, this brief is ideal for professionals and researchers in the field. Advanced-level students interested in computer communication networks and wireless technologies will also find the content helpful.

The future telecom ecosystem will be composed by a set of heterogeneous wireless and cellular networks and user terminal capable to connect and communicate with any of these networks. This thesis contributes for evolution of convergence of wireless heterogeneous networks and to propose novel mechanisms to support low latency handover at authentication level using network selection, security context management and mobility in future telecom ecosystem to allow ubiquitous access to the Internet and services to any individual on the move. This access should be possible anytime anywhere while ensuring the right level of security to the end users as well to the networks. One main objective of the thesis is to define seamless secured roaming mechanisms to enable subscribers or users to roam along different access networks indifferent of access technologies, operators and accessing mechanisms. The proposed thesis provides a roaming & interworking solution using intermediary entity, called Roaming Interworking Intermediary (RII), which enable the secure handover across different access systems and different operator domains without service interruption. RII acts like a broker in the RII architecture between home and visited operator networks. RII provides mobility management, context transfer between service providers, security architecture for authentication and associations of users while roaming, network and presence management. The thesis also defines new mechanisms to enable low latency during handovers and roaming by optimizing and introducing new authentication and mobility models (post handover techniques) in heterogeneous networks. We have provided new methods to solve ever longing issue of user identity and routing of user authentication information from visiting access networks with or without a direct SLA with the home network. We have introduced dynamic authentication model with the proposed RII architecture where a user or subscriber gets authenticated at the visiting network without re-routing authentication information to home networks. The thesis also propose a new mobility mechanisms based on Proxy Mobile IP and extending AAA infrastructure to obtain very low latency during handover in WLAN, WIMAX and 3G networks. Testbeds and comparative studies between proposed and existing models for authentication and mobility are provided. This thesis also provides novel pre handover techniques in heterogeneous networks to ensure seamless handover during mobility and roaming. This method is a network centric approach where the access networks controls whole procedures of network selection, security, mobility etc... with the help of mobile terminals and visiting networks. Therefore, new models for location prediction based Network selection, security context management for authentications, context based mobility models are proposed in this thesis. New supporting protocols and extensions of existing protocol to achieve seamless handovers are proposed in this work. A full testbed is built with the implementation of the proposed protocols to evaluate the proposed of the efficiency of the proposed mechanisms.

Secure Roaming in 802.11 Networks offers a comprehensive treatise on Wi-Fi 802.11 roaming by comparing/contrasting it to cellular roaming theory and techniques. The book explores the fundamental concepts, basic theory, and key principles of 802.11 networks with roaming capabilities. It helps ensure secure and constant connectivity of laptops, PDAs and other emerging mobile devices. Today, we increasingly expect to find public Wide Local Area Network (WLAN) 802.11 access in our airports, public spaces, and hotels, and we want to maintain our connections when we’re mobile and using 802.11 WLANs. However, 802.11 was not originally designed with roaming capabilities and can’t, in its "pure" form, support seamless roaming between different hotspots and other 802.11 access points. This book details the theory behind various 802.11 extensions to permit roaming and describes how these extensions can be successfully implemented in 802.11 WLANs. It reviews coverage of user authentication in 802.11, as well as roaming between 802.11 and other wireless technologies. It also discusses wireless technologies and application programming interfaces. This book will appeal to RF/wireless engineers and designers, computer/data network engineers, and graduate students. * Offers a comprehensive treatise on Wi-Fi 802.11 roaming by comparing/contrasting it to cellular roaming theory and techniques * Emerges as a "one stop" resource for design engineers charged with fulfilling the market need for seamless 802.11 device roaming capabilities * Builds upon the knowledge base of a professional audience without delving into long discussions of theory long since mastered

Heterogeneous wireless networks (HWNs) provide flexible and diversified wireless network access (e.g., cellular, IEEE 802.11) by integrating cellular networks, wireless LANs, and ad hoc networks with the Internet. It has been emerging as a promising solution to offer a variety of exciting applications, anytime and anywhere. The flexibility and benefits of the HWN, for example, is to extend the service coverage of the existing cellular and WLAN infrastructure, to improve the communication throughput, and reduce packet transmission latency, based on availability of different types of radio network in the roaming area (cellular, WLAN, or others). In the study, we answer some fundamental questions in the design and deployment of a HWN. The first is how to effectively operate a mobile terminal in ad hoc mode to access the Internet through a cellular network, WLAN or other underlying wireless access networks. The second is how to design ubiquitous seamless mobility support for a roaming user, allowing ubiquitous and bi-directional Internet accessibility, connectivity, and mobility. Finally, it answers the questions that what is the security threats for a mobile terminal that is operating in the ad hoc mode, and how to provide information confidentiality for a continuously moving mobile terminal.

"This book offers an in-depth explanation of multimedia technologies within their many specific application areas as well as presenting developing trends for the future"--Provided by publisher.

This book constitutes the refereed proceedings of the Third International Conference on Autonomic and Trusted Computing, ATC 2006, held in Wuhan, China in September 2006. The 57 revised full papers presented together with two keynotes were carefully reviewed and selected from 208 submissions. The papers are organized in topical sections.

"This book serves as a vital resource for practitioners to learn about the latest research and methodology within the field of wireless technology, covering important aspects of emerging technologies in the heterogeneous next generation network environment with a focus on wireless communications and their quality"--Provided by publisher.