Over the last few years, the use of the internet services and applications such as phone calls, e-mails, video conferencing, catch up TV, audio and video streaming in general, which heavily rely on the network communications has increased. Reliable connections between the end users are vital for providing such internet services. In such networks, link or node failures can occur suddenly and without any notifications which will make more interruptions for the data transmission between source and destination. Hence, the network performance will be reduced significantly since more time is needed to reroute the traffic, which can create sever interruptions for delay sensitive services such as voice and video. A pre-computed backup path in advance can provide a valuable solution to reroute the data packets during the network recovery time. In this book, we study several factors to compute the backup path between source and destination such as (network design, Bandwidth, Shortest path). We show results of several efficient algorithms that have been implemented to compute the best backup route until the routing protocol re-updates the new routing table.
Secure routing in Mobile Ad hoc Networks (MANETs) has emerged as an important MANET research area. Existing works in MANET focused mainly on the problem of providing efficient mechanisms for finding paths in very dynamic networks, without considering the security of the routing process. This work proposes a secure routing protocol after an in-depth evaluation and performance analysis of MANET protocols, and security.
The book presents the audio signals transmission over the fixed and mobile wireless networks. Also, it focus on the mobility effects on the amount of lost packet and the quality of the received audio signals. The mobility effects on the audio signals is studied with different velocity using the Jakes model. There are many the proposed approaches are presented for combating the mobility bad effects and enhancing the traditional techniques of the sender-based packet loss error recovery. an inefficient error recovery based on weak FEC scheme can be converted to efficient sender based error recovery if merged with powerful data randomizing tool.
Congestion management in multistage interconnection networks is a serious problem not completely solved. In order to avoid the degradation of network performance when congestion appears, several congestion management mechanisms have been proposed. Most of these mechanisms are based on explicit congestion notification. For this purpose, switches detect congestion and depending on the applied strategy, packets are marked to warn the source hosts. In response, source hosts apply some corrective actions to adjust their packet injection rate. Although these proposals seem quite effective, they either exhibit some drawbacks or are partial solutions. Some of them introduce some penalties over the flows not responsible for congestion, whereas others can cope only with congestion situations that last for a short time. We present different strategies to detect and correct congestion in multistage interconnection networks, and propose new mechanisms targeted to this kind of lossless networks, and based on more refined packet marking strategies combined with a fair set of corrective actions, that makes the mechanisms able to effectively manage congestion regardless of the congestion degree.
In Mobile Ad Hoc Networks (MANET) every node functions as transmitter, router and data sink. MANET is network without infrastructure. It discover its local neighbors and through them it will communicate to nodes that are out of its transmission range. The advantages of this mechanism are to overcome the interaction of three fundamental difficulties such as node connectivity, contention and congestion. The paper described the formal evaluation of performances of three types of MANET routing protocols when the node density or the number of nodes varies. Every ad hoc routing protocol on their performances in the network has their own advantages. The protocols included the Dynamic Source Routing (DSR), Ad Hoc On-demand Distance Vector (AODV), Optimized Link State Routing (OLSR) protocol and Destination-Sequenced Distance Vector (DSDV) protocol. The analysis had been done the theoretically and through simulation using an Optimized Network Engineering Tools NS-2.With the help of NS-2 software we can analysis the performances of the following metrics: packet delivery ratio, end-to-end delay, packet dropped, routing load and end-to-end throughput.
MANET field is one of the most vibrant and active research fields in wireless communications networking. MANET can be built around any wireless technology. Wireless communication networks have witnessed recently the introductory of a promising transmission technology called UWB. In MANET, routing protocols are needed to establish and maintain connections between nodes. The main goal of this thesis is to design efficient routing protocols for MANET based on UWB technology in a production line in a factory which is an industrial indoor application. The production line network scenario was defined and simulated in ns-2 simulator as basis for the investigations. In these investigations, AODV, DSR, and OLSR were considered. In addition, closed-form formulas were found for the channel capacity of MANET as a tool for benchmarking and validation. Based on the investigations, two approaches were proposed to design efficient routing protocols for the production line scenario. Based on the first approach, a new routing protocol was designed and it was called Ad-Hoc On-Demand Multipath Source Routing protocol.
Wide range of applications in Machine Learning and Data Mining (MLDM) area have increasing demand on utilizing distributed environments to solve certain problems. It naturally results in the urgent requirements on how to ensure the reliability of large-scale graph processing systems. In such scenarios, machine failures are no longer uncommon incidents. Traditional rollback recovery in distributed systems has been studied in various forms by a wide range of researchers and engineers. There are plenty of algorithms invented in the research community, but not many of them are actually applied in real systems. In this book, we proposed two failure recovery mechanisms specially designed for large-scale graph processing systems. To better facilitate the recovery process without bringing in too much overhead during the normal execution of the large-scale distributed systems, our mechanisms are designed based on an in-depth investigation of the characteristics of large-scale graph processing systems and their applications.
Mobile Ad hoc Networks or MANETs are networks in which multiple nodes, each possessing a wireless transceiver, from a network among them via peer-to-peer communication. There has been significant research activity over the past 5-10 years into performance of such networks with the view to develop more efficient and robust communication protocols. However, the vast majority of the research has concentrated on either developing appropriate mobility models for node movement or on developing performance metrics. The channel itself has been ignored. Some previous work had been done using Rayleigh channel model and Log-Normal model. However this work is based on Ricean channel fading model, which have not done till date.In the current work a more realistic wireless channel model is considered. In particular, we will consider one of the most well known wireless channel models, Ricean fading channel model. In this documentation, effects on the performance of mobile ad hoc networks due to presence of fading in Ricean channel is done by simulating experiments on QualNet simulator and then analyzing them.
MANET-Performance Optimization And Issues Akhilesh K. Sharma Mobile Ad-hoc networks are used in many places, especially for the military and flood affected areas are having major concern with the mobile adhoc networks, for establishing the connection with the affected areas. There are several issues are explained and discussed in this book to establish the connection in optimized way. Several routing protocols have been proposed for MANET which can be classified as proactive, reactive and hybrid routing protocols. All of these protocols use blind flooding mechanism for the purpose of broadcasting of route request and route reply messages. This Blind flooding leads to a severe broadcast redundancy causing contention and collision in the network. This book will highlight all the points related to these issues. Key Features : 1. Use of NS-2 Simulator for better understanding of the moving environment of moving Nodes. 2. GUI programming & Sample code to build and simulate the nodes protocols and to change the performance related variables. 3. Topics to cover different topological and network study. 4. Techniques like DSDV, CGSR, AODV etc. for demonstration with examples.
Fundamental changes have been brought in data networking and telecommunications by the wireless communication revolution. Wireless networks: Mobile ad hoc networks (MANETs) and Vehicular ad hoc networks (VANETs) are characterized by the movement and self organization of the nodes. VANETs uses vehicles like cars, trucks etc as nodes. The data transfer take place using these vehicles. We will be applying an efficient and effective algorithm over large and dense VANETs of the type Vehicle-to-Vehicle (V2V). The VANET networks communicate using the standards for wireless communications. Thus,in order to communicate with the vehicles or nodes outside the communication range, it is required that other nodes(vehicles) are being used. Our proposed algorithm considers the transmission of the communication packets from some source to a particular destination in a way that will increase the connectivity and reduce the conflicts or collisions between various nodes in a networks.
Mobile Ad hoc Network (MANET) is a system of wireless mobile nodes that dynamically self-organize in arbitrary and temporary network topologies without communication infrastructure. This network may change rapidly and unpredictably. Application of ad hoc networks includes Academic Environment Applications, Health Care Applications, Military Applications, Bluetooth, and Personal Area Network. A service can be any tangible or intangible thing that can be useful for someone, a service can be a hardware service like a printer that can be used by a mobile device to print a file. Service discovery is defined by using one or two of Pull and Push Mechanisms. Security is a main challenge in MANETs. We propose a Secure Service Discovery Protocol for ad hoc networks (SPDPh). Simulation results of (SPDPh) and (PDP) using simulator (Ns-2) shows the extent of efficient secure service discovery protocol for ad hoc networks.
Broadband wireless networks are becoming increasingly popular due to their fast and inexpensive deployment and their capabilities of providing flexible and ubiquitous Internet access. While the majority of existing broadband wireless networks are still exclusively limited to single hop access, it is the ability of these networks to forward data frames over multi-hop wireless routes which enabled them to easily extend the network coverage area. Unfortunately, achieving good multihop throughput has been challenging due to several factors, such as lossy wireless links caused by interference from concurrent transmissions, and intra-path interference caused by transmissions on successive hops along a single path. In this work, we focus on the IEEE 802.16 WiMAX mesh multi-hop and multi-channel. To maximize the network performance of mesh networks (e.g., throughput), it is essential to consider a cross-layer design, exploiting the dependency between protocol layers such as the routing network layer and the scheduling resource allocation MAC layer. Therefore this book considers a cross-layer design approach for designing efficient wireless mesh multi-hop networks.
Recent advances in communication technology are enabling implementation of different types of network in various environments. One such network is Mobile Ad-Hoc Network (MANET). The primary challenge in building a MANET is equipping each device to continuously maintain the information required to properly route traffic which is done by several routing protocols. The design problem of such a routing protocol is not simple since an ad-hoc environment introduces new challenges that are not present in fixed networks. With the advent of the scenarios seeking infrastructure-less network with wireless nodes, security concerns have made the required personnel to mull over the MANET configuration using different protocols for various sized networks. This work is carried out to simulate the MANET using GloMoSim and to propose the enhancement in the quality of service by addressing the security concerns that loom on this specific network.The project discusses various categories of protocols proposed for the MANET, applications that are found out of this network, overview of the AODV protocol and most importantly the simulations that are carried out.
Recent advances in Wireless Communication and Embedded Microprocessors have led to the development of small, low cost sensor devices. A wireless Sensor Network consists of a large number of sensors distributed over a geographical area with their locations either previously fixed or randomly deployed. Energy consumption is the most important factor to determine the life of a sensor network. Sensor nodes are driven by a battery and have very low energy resources. We have achieved optimization of energy and maximizing the network life through Network Coverage, Optimal deployment of multiple base stations to overcome bottleneck in single base station and clustering scheme that is completely controlled by the base station, Optimal Scheduling, Solving Dead End problem results in high packet delivery ratio to the base station and Impact of mobility models on performance of routing protocol with respect to Packet Delivery Ratio, Latency and Throughput in wireless sensor networks. Energy Efficient Algorithms and Performance Analysis are useful for students and research community pursuing in the field of Wireless Sensor Networks, Ubiquitous and Pervasive Computing.