Download Free A Comprehensive Optimization Model For Multi Hop Wireless Networks With Multicast Traffic Book in PDF and EPUB Free Download. You can read online A Comprehensive Optimization Model For Multi Hop Wireless Networks With Multicast Traffic and write the review.

Dotyczy: multi-hop wireless networks, TDMA, multicast traffic, optimization, integer programming, Internet of Things, kratowe sieci radiowe, TDMA, ruch multicastowy, optymalizacja, programowanie całkowitoliczbowe, Internet Rzeczy.
Interference is fundamental to wireless networks. It is hard to achieve good performance when design routing metrics or algorithms without taking it into account. We study interference in wireless networks through empirical experiments and simulations. We find out that current routing protocols face difficulties in effectively managing it, which can lead to severe problems. For instance, a simple network of two links with one flow is vulnerable to severe performance degradation if interference is not properly accounted for. Motivated by these observations, we develop a simple and effective model to capture effects of interference in a wireless network. Different from the existing interference models, our model captures IEEE 802.11 DCF under both homogeneous and heterogeneous traffic and link characteristics, and is simple enough to be directly used as a basic building block for wireless performance optimization. Based on thismodel, we develop optimization algorithms for several objectives, such as network throughput and fairness. Given traffic demands as input, these algorithms compute rates at which individual flows must send to achieve these objectives. We implement these algorithms in Qualnet simulations and 19-node testbed. Our experiment and simulation results show that our methods can systematically account for and control interference to achieve good performance. More specifically, when optimizing fairness, our methods can achieve almost perfect fairness; when optimizing network throughput, they can lead to 100-200% improvement for UDP traffic and 10-50% for TCP traffic.
The data capacity of a link within a wireless network depends in a nonlinear way on the communication resources allocated to it. Finding the optimal way to transmit data through a network consisting of many wireless devices can therefore be represented as a nonlinear optimization problem over network flow variables and communication resource variables. In this thesis we develop a nonconvex optimization problem for transmitting unicast and multicast messages through a time-slotted multi-hop wireless network. Multicast messages are handled in an optimal way through the use of network coding to allow data packets to be combined ensuring they are useful for multiple destinations. The benefits of network coding over other routing strategies are tested numerically. We look at simple networks to gain insight into the way various parameters affect the nonconvex behaviour before going on to develop algorithms which can be applied in a distributed manner, and make use of the coupled structure of the problem. We implement a subgradient method for solving the dual problem, and then look at ways to accelerate its convergence. We also investigate the behaviour and convergence of a simple but effective primal co-ordinate descent method before numerically investigating its performance.
This dissertation addresses certain key problems in the design of an efficient protocol stack for multihop wireless networks. We focus on the following issues: how to extend the network utility maximization (NUM) framework for resource allocation to handle both unicast and multicast traffic, and how to deal with practical issues which arise from the optimal back-pressure algorithm suggested by the NUM framework. Those practical issues consist of decentralization and complexity, as well as scalability and delay performance.
This book provides an introduction to opportunistic routing an emerging technology designed to improve the packet forwarding reliability, network capacity and energy efficiency of multihop wireless networks This book presents a comprehensive background to the technological challenges lying behind opportunistic routing. The authors cover many fundamental research issues for this new concept, including the basic principles, performance limit and performance improvement of opportunistic routing compared to traditional routing, energy efficiency and distributed opportunistic routing protocol design, geographic opportunistic routing, opportunistic broadcasting, and security issues associated with opportunistic routing, etc. Furthermore, the authors discuss technologies such as multi-rate, multi-channel, multi-radio wireless communications, energy detection, channel measurement, etc. The book brings together all the new results on this topic in a systematic, coherent and unified presentation and provides a much needed comprehensive introduction to this topic. Key Features: Addresses opportunistic routing, an emerging technology designed to improve the packet forwarding reliability, network capacity and energy efficiency of multihop wireless networks Discusses the technological challenges lying behind this new technology, and covers a wide range of practical implementation issues Explores many fundamental research issues for this new concept, including the basic principles of opportunistic routing, performance limits and performance improvement, and compares them to traditional routing (e.g. energy efficiency and distributed opportunistic routing protocol design, broadcasting, and security issues) Covers technologies such as multi-rate, multi-channel, multi-radio wireless communications, energy detection, channel measurement, etc. This book provides an invaluable reference for researchers working in the field of wireless networks and wireless communications, and Wireless professionals. Graduate students will also find this book of interest.
"Wireless networks are undergoing rapid progress and inspiring numerous applications. As the application of wireless networks becomes broader, they are expected to not only provide ubiquitous connectivity, but also support end users with certain service guarantees. End-to-end delay is an important Quality of Service (QoS) metric in multihop wireless networks. This dissertation addresses how to minimize end-to-end delay through joint optimization of network layer routing and link layer scheduling. Two cross-layer schemes, a loosely coupled cross-layer scheme and a tightly coupled cross-layer scheme, are proposed. The two cross-layer schemes involve interference modeling in multihop wireless networks with omnidirectional antenna. In addition, based on the interference model, multicast schedules are optimized to minimize the total end-to-end delay. Throughput is another important QoS metric in wireless networks. This dissertation addresses how to leverage the spatial multiplexing function of MIMO links to improve wireless network throughput. Wireless interference modeling of a half-duplex MIMO node is presented. Based on the interference model, routing, spatial multiplexing, and scheduling are jointly considered in one optimization model. The throughput optimization problem is first addressed in constant bit rate networks and then in variable bit rate networks. In a variable data rate network, transmitters can use adaptive coding and modulation schemes to change their data rates so that the data rates are supported by the Signal to Noise and Interference Ratio (SINR). The problem of achieving maximum throughput in a millimeter-wave wireless personal area network is studied"--Abstract, page iv.
In this paper, we propose and investigate a bandwidth-efficient multicast routing protocol for ad-hoc networks. The proposed protocol achieves low communication overhead, namely, it requires a small number of control packet transmissions for route setup and maintenance. The proposed protocol also achieves high multicast efficiency, namely, it delivers multicast packets to receivers with a small number of transmissions. In order to achieve low communication overhead and high multicast efficiency, the proposed protocol employs the following mechanisms: (1) on-demand invocation of the route setup and route recovery processes to avoid periodic transmissions of control packets, (2) a new route setup process that allows a newly joining node to find the nearest forwarding node to minimize the number of forwarding nodes, and (3) a route optimization process that detects and removes unnecessary forwarding nodes to eliminate redundant and inefficient routes. Our simulation results show that the proposed protocol achieves high multicast efficiency with low communication overhead compared with other existing multicast routing protocols, especially in the case where the number of receivers in a multicast group is large.
This research investigates cross-layer design in multi-hop wireless networks with random access. Due to the complexity of the problem, we study cross-layer design with a simple slotted ALOHA medium access control (MAC) protocol without considering any network dynamics.
Nowadays, wireless communications and networks have been widely used in our daily lives. One of the most important topics related to networking research is using optimization tools to improve the utilization of network resources. In this dissertation, we concentrate on optimization for resource-constrained wireless networks, and study two fundamental resource-allocation problems: 1) distributed routing optimization and 2) anypath routing optimization. The study on the distributed routing optimization problem is composed of two main thrusts, targeted at understanding distributed routing and resource optimization for multihop wireless networks. The first thrust is dedicated to understanding the impact of full-duplex transmission on wireless network resource optimization. We propose two provably good distributed algorithms to optimize the resources in a full-duplex wireless network. We prove their optimality and also provide network status analysis using dual space information. The second thrust is dedicated to understanding the influence of network entity load constraints on network resource allocation and routing computation. We propose a provably good distributed algorithm to allocate wireless resources. In addition, we propose a new subgradient optimization framework, which can provide findgrained convergence, optimality, and dual space information at each iteration. This framework can provide a useful theoretical foundation for many networking optimization problems. The study on the anypath routing optimization problem is composed of two main thrusts. The first thrust is dedicated to understanding the computational complexity of multi-constrained anypath routing and designing approximate solutions. We prove that this problem is NP-hard when the number of constraints is larger than one. We present two polynomial time K-approximation algorithms. One is a centralized algorithm while the other one is a distributed algorithm. For the second thrust, we study directional anypath routing and present a cross-layer design of MAC and routing. For the MAC layer, we present a directional anycast MAC. For the routing layer, we propose two polynomial time routing algorithms to compute directional anypaths based on two antenna models, and prove their ptimality based on the packet delivery ratio metric.