Mobile Ad-Hoc Networks

Being infrastructure-less and without central administration control, wireless ad-hoc networking is playing a more and more important role in extending the coverage of traditional wireless infrastructure (cellular networks, wireless LAN, etc). This book includes state-of-the-art techniques and solutions for wireless ad-hoc networks. It focuses on the following topics in ad-hoc networks: quality-of-service and video communication, routing protocol and cross-layer design. A few interesting problems about security and delay-tolerant networks are also discussed. This book is targeted to provide network engineers and researchers with design guidelines for large scale wireless ad hoc networks

ADTH: Bounded Nodal Delay for Better Performance in Wireless Ad-hoc Networks

© 2018 Delay is an unavoidable factor that occurs within networks and may be exacerbated by the nature of wireless ad-hoc networks. Maintaining a manageable level of delay may be required to provide satisfactory performance for each of the nodes that form the network. The variability of IoT devices, topologies and network conditions demand that a standalone and scalable scheme be used. ADTH is first shown to accomplish this through simulations with the NS-2 network simulator. The scheme was then used with testbed implementation with Gumstix devices and real-time traffic provided by an STC Traffic Generator. These demonstrated its effectiveness in managing flows of delay sensitive traffic, in addition to delivering superior bandwidth utilisation than standard policies

Quality of service differentiation for multimedia delivery in wireless LANs

Delivering multimedia content to heterogeneous devices over a variable networking environment while maintaining high quality levels involves many technical challenges. The research reported in this thesis presents a solution for Quality of Service (QoS)-based service differentiation when delivering multimedia content over the wireless LANs. This thesis has three major contributions outlined below: 1. A Model-based Bandwidth Estimation algorithm (MBE), which estimates the available bandwidth based on novel TCP and UDP throughput models over IEEE 802.11 WLANs. MBE has been modelled, implemented, and tested through simulations and real life testing. In comparison with other bandwidth estimation techniques, MBE shows better performance in terms of error rate, overhead, and loss. 2. An intelligent Prioritized Adaptive Scheme (iPAS), which provides QoS service differentiation for multimedia delivery in wireless networks. iPAS assigns dynamic priorities to various streams and determines their bandwidth share by employing a probabilistic approach-which makes use of stereotypes. The total bandwidth to be allocated is estimated using MBE. The priority level of individual stream is variable and dependent on stream-related characteristics and delivery QoS parameters. iPAS can be deployed seamlessly over the original IEEE 802.11 protocols and can be included in the IEEE 802.21 framework in order to optimize the control signal communication. iPAS has been modelled, implemented, and evaluated via simulations. The results demonstrate that iPAS achieves better performance than the equal channel access mechanism over IEEE 802.11 DCF and a service differentiation scheme on top of IEEE 802.11e EDCA, in terms of fairness, throughput, delay, loss, and estimated PSNR. Additionally, both objective and subjective video quality assessment have been performed using a prototype system. 3. A QoS-based Downlink/Uplink Fairness Scheme, which uses the stereotypes-based structure to balance the QoS parameters (i.e. throughput, delay, and loss) between downlink and uplink VoIP traffic. The proposed scheme has been modelled and tested through simulations. The results show that, in comparison with other downlink/uplink fairness-oriented solutions, the proposed scheme performs better in terms of VoIP capacity and fairness level between downlink and uplink traffic

Multicast networks : capacity, algorithms, and implementation

textIn this dissertation, we investigate the capacity and performance of wireless networks with an emphasis on multicast traffic. The defining characteristic of a multicast network is a network where a number of different destinations all require the information generated by a single source. The models that we explore differ in the nature of the nodes from all-mobile case where all nodes are mobile to hybrid case where some nodes are mobile and some are static. We investigate different performance measure for these wireless multicast networks: upper bounds, capacity scaling laws, and achievable rates. The understanding of these measures for such networks helps in the development of efficient algorithms for operating these networks. In addition, we study the practical realization of algorithms for real-time streaming of rich multimedia content in the context of mobile wireless networks for embedded and cyberphysical systems. Our initial work is in the context of unicast and multiple unicast systems over an autonomous aerial vehicle (AAV) network. Bandwidth requirements and stringent delay constraints of real-time video streaming, paired with limitations on computational complexity and power consumptions imposed by the underlying implementation platform, make cross-layer and cross-domain co-design approaches a necessity. In this dissertation, we propose a novel, low-complexity rate-distortion optimized (RDO) protocol specifically targeted at video streaming over mobile embedded networks. First, we test the performance of our RDO algorithm on simulation models developed for aerial mobility of multiple wirelessly communicating AAVs. Second, we test the performance of our RDO algorithm and other proposed adaptive algorithms on a real network of AAVs and present a comparative study between these different algorithms. Note that generalizing these algorithms to multicast settings is relatively straightforward and thus is not highlighted to a great degree in this thesis.Electrical and Computer Engineerin

Enabling reliable and power efficient real-time multimedia delivery over wireless sensor networks

There is an increasing need to run real-time multimedia applications, e.g. battle field and border surveillance, over Wireless Sensor Networks (WSNs). In WSNs, packet delivery exhibits high packet loss rate due to congestion, wireless channel high bit error rate, route failure, signal attenuation, etc... Flooding conventional packets over all sensors redundantly provides reliable delivery. However, flooding real-time multimedia packets is energy inefficient for power limited sensors and causes severe contentions affecting reliable delivery. We propose the Flooding Zone Initialization Protocol (FZIP) to enhance reliability and reduce power consumption of real-time multimedia flooding in WSNs. FZIP is a setup protocol which constrains flooding within a small subset of intermediate nodes called Flooding Zone (FZ). Also, we propose the Flooding Zone Control Protocol (FZCP) which monitors the session quality and dynamically changes the FZ size to adapt to current network state, thus providing a tradeoff of good quality and less power consumption