[Author's abstract] Short term fairness, low delay jitter and high throughput are required to provide differentiated Quality of Service (QoS) levels in wireless ad hoc networks and wireless Local Area Networks (LAN). This thesis presents a study of differentiated service mechanism via Cooperative Medium Access Protocol in wireless LANs. The IEEE 802.11 MAC can provide service differentiation via Point Coordination Function (PCF) by polling or Distributed Coordination Function (DCF) by Static Priority (SP) and Dynamic Priority (DP). The DP and PCF in highly loaded networks and SP in lightly loaded networks perform poorly and can not support QoS levels of wireless LANs efficiently. This thesis proposes a novel and efficient differentiated service mechanism via Cooperative Medium Access Control (C MAC). Proposed mechanism performs very well under both cases, highly loaded and lightly loaded. It protects high priority classes from greedy sources while providing short term fairness within the priority classes and high network goodput. However, it encounters a small amount of additional packet loss and goodput degradation and it requires additional counter, Backoff Increment Counter, and additional knowledge, priority level of the transmitted packet.

This book focuses on the design and analysis of protocols for cooperative wireless networks, especially at the medium access control (MAC) layer and for crosslayer design between the MAC layer and the physical layer. It highlights two main points that are often neglected in other books: energy-efficiency and spatial random distribution of wireless devices. Effective methods in stochastic geometry for the design and analysis of wireless networks are also explored. After providing a comprehensive review of existing studies in the literature, the authors point out the challenges that are worth further investigation. Then, they introduce several novel solutions for cooperative wireless network protocols that reduce energy consumption and address spatial random distribution of wireless nodes. For each solution, the book offers a clear system model and problem formulation, details of the proposed cooperative schemes, comprehensive performance analysis, and extensive numerical and simulation results that validate the analysis and examine the performance under various conditions. The last section of this book reveals several potential directions for the research on cooperative wireless networks that deserve future exploration. Researchers, professionals, engineers, and consultants in wireless communication and mobile networks will find this book valuable. It is also helpful for technical staff in mobile network operations, wireless equipment manufacturers, wireless communication standardization bodies, and governmental regulation agencies.

This brief focuses on radio resource allocation in a heterogeneous wireless medium. It presents radio resource allocation algorithms with decentralized implementation, which support both single-network and multi-homing services. The brief provides a set of cooperative networking algorithms, which rely on the concepts of short-term call traffic load prediction, network cooperation, convex optimization, and decomposition theory. In the proposed solutions, mobile terminals play an active role in the resource allocation operation, instead of their traditional role as passive service recipients in the networking environment.

With the rapid growth of multimedia applications and the advances of wireless communication technologies, quality-of-service (QoS) provisioning for multimedia services in heterogeneous wireless networks has been an important issue and drawn much attention from both academia and industry. Due to the hostile transmission environment and limited radio resources, QoS provisioning in wireless networks is much more complex and difficult than in its wired counterpart. Moreover, due to the lack of central controller in the networks, distributed network control is required, adding complexity to QoS provisioning. In this thesis, medium access control (MAC) with QoS provisioning is investigated for both single- and multi-hop wireless networks including wireless local area networks (WLANs), wireless ad hoc networks, and wireless mesh networks. Originally designed for high-rate data traffic, a WLAN has limited capability to support delay-sensitive voice traffic, and the service for voice traffic may be impacted by data traffic load, resulting in delay violation or large delay variance. Aiming at addressing these limitations, we propose an efficient MAC scheme and a call admission control algorithm to provide guaranteed QoS for voice traffic and, at the same time, increase the voice capacity significantly compared with the current WLAN standard. In addition to supporting voice traffic, providing better services for data traffic in WLANs is another focus of our research.

"This book further explores various issues and proposed solutions for the provision of Quality of Service (QoS) on the wireless networks"--Provided by publisher.

Abstract: In this dissertation, we investigate the issue of Quality of Service (QoS) provisioning for IEEE 802.11 MAC protocols. We propose a multiple class p-persistent version of the IEEE 802.11 protocol to support QoS differentiation in wireless local area networks (WLANs). A theoretical analysis model is proposed to predict the performance of this protocol. Through analytical modeling and simulation, we demonstrate that by assigning appropriate different transmission probabilities to wireless nodes of different classes, it is feasible to provide service differentiation and achieve the targeted throughput ratio among different classes, while at the same time, maximizing the total channel utilization. We also consider several implementation issues to practically implement the proposed work conforming to the IEEE 802.11 standard. In particular, we derive an approximate solution for the analytical model to reduce the computational complexity and estimate the performance deterioration due to such an approximate solution. We point out that as long as the average packet collision period is much longer than the basic slot duration in the backoff algorithm, (which is true in all the 802.11 family standards such as 802.11, 802.11b, 802.11a and 802.11g, as well as many potential new systems with higher transmission rates,) the loss in channel utilization is limited when the approximate solution is used to determine the protocol parameters. We associate the contention window based backoff scheme in the current 802.11 mac protocol to the proposed p-persistent MAC protocol through a simple relation between the contention window, $cw$, and the persistent probability, p. We also propose a simple yet effective mechanism to on-line estimate the number of active stations in a QoS basic service set (QBSS) so as to handle the network dynamics and optimize system parameters dynamically. By extending the analytical model, we study the impact of AIFS values in IEEE 802.11e on rate differentiation between different traffic classes, demonstrate that the per flow throughput ratio between different traffic classes is a function of both the persistent probability (or the contention window size) and AIFS values. Under the asymptotic condition, we derive a closed-form relation. Through analytical modeling and simulation, we evaluate the effect of tuning AIFS values to provide throughput differentiation. We recommend to only adjust the persistent probability p or equivalently the contention window size cw to achieve the desired rate differentiation, while keeping the AIFS values of all traffic classes to the same value (e.g., at DIFS). This keeps the dimension of design freedom small and the parameter fine-tuning process tractable.

This book is a printed edition of the Special Issue "QoS in Wireless Sensor/Actuator Networks and Systems" that was published in JSAN