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In this paper, we propose an adaptive quality of service (QoS) design approach via resource reservation and rate adaptation to support multimedia over wireless cellular networks. Three contributions of this work are: (a) an adaptive QoS model that seeks to provide QoS assurances within bounds for each packet flow and to make advance resource reservation in order to support seamless mobility, (b) a revenue-based resource adaptation design that seeks to maximize network revenue while satisfying the QoS requirements, and (c) a resource reservation protocol that supports both application-initiated resource reservation and network-initiated resource adaptation. Our initial implementation and measurements confirm the effectiveness of the proposed design. [ABSTRACT FROM AUTHOR]

In order to support diverse communication intensive real time and non real time data flows over a scarce, varying and shared wireless channel with location dependent and bursty errors, we define a service model that has the following characteristics: short term fairness among flows which perceive a clean channel, long term fairness for flows with bounded channel error, worst case delay bounds for packets, short term throughput bounds for flows with clean channels and long term throughput bounds for all flows with bounded channel error, expanded schedulable region, and support for both delay sensitive and error sensitive data flows. We present the wireless fair service algorithm, and show through both analysis and simulation that it achieves the requirements of the service model in typical wireless network environments. The key aspects of the algorithm are the following: (a) an enhanced fair queueing based service scheme that supports decoupling of delay and bandwidth, (b) graceful service compensation for lagging flows and graceful service degradation for leading flows, (c) support for real time delay sensitive flows as well as non real time error sensitive flows, and (d) an implementation within the framework of the simple and robust CSMA/CA wireless medium access protocol. [ABSTRACT FROM AUTHOR]

Recent years have witnessed the rapid evolution of commercially available mobile computing environments. This has given rise to the presence of several viable, but non-interoperable wireless networking technologies – each targeting a niche mobility environment and providing a distinct quality of service. The lack of a uniform set of standards, the heterogeneity in the quality of service, and the diversity in the networking approaches makes it difficult for a mobile computing environment to provide seamless mobility across different wireless networks. Besides, inter-network mobility will typically be accompanied by a change in the quality of service. The application and the environment need to collaboratively adapt their communication and data management strategies in order to gracefully react to the dynamic operating conditions. This paper presents the important challenges in building a mobile computing environment which provides seamless mobility and adaptive computing over commercially available wireless networks. It suggests possible solutions to the challenges, and describes an ongoing research effort to build such a mobile computing environment. [ABSTRACT FROM AUTHOR]

An ad hoc network is a multihop wireless network in which mobile hosts communicate without the support of a wired backbone for routing messages. We introduce a self organizing network structure called a spine and propose a spine-based routing infrastructure for routing in ad hoc networks. We propose two spine routing algorithms: (a) Optimal Spine Routing (OSR), which uses full and up-to-date knowledge of the network topology, and (b) Partial-knowledge Spine Routing (PSR), which uses partial knowledge of the network topology. We analyze the two algorithms and identify the optimality-overhead trade-offs involved in these algorithms. [ABSTRACT FROM AUTHOR]