Performance improvement in mobile ad-hoc networks.

The objective of this research is to enhance the network performance under realistic mobile ad-hoc networks environments without modification of the standard. Overview of this research is summarized as follows: First, a packet-fragmentation technique to improve network throughput under the worst channel conditions is proposed. While the conventional packet-fragmentation technique research focuses only on random-bit errors, the proposed technique employs both random bit errors and hidden-node collisions. The analytical models based on Markov-chain model shows that the optimal fragmentation technique can effectively reduce the number of retransmissions caused by both collisions from hidden nodes and corrupted packets by random bit errors, and eventually improving throughput in noisy VANETs channels. As a second contribution, a dynamic service-channel allocation (DSCA) scheme is proposed to maximize the network throughput by dynamically assigning different service channels to the users. The theoretical analysis in this thesis will consider wireless access in the vehicular environment (WAVE) protocol, which is the main characteristic of the vehicular ad-hoc networks standard (the IEEE 802.11p). To summarize, the main contribution of this research is that two schemes will improve the network throughput significantly without modification of the standard. Therefore, there is no implementation issue to deploy the proposed schemes in real devices.PhDCommittee Chair: Copeland, John; Committee Co-Chair: Chang, Yusun; Committee Member: Ammar, Mostafa; Committee Member: Beyah, Raheem; Committee Member: Owen, Henry; Committee Member: Taylor, Davi

Cellular Multihop Networks: State of the Art

This paper presents the summary of some research in the area of cellular multihop networks that contains the improvement in network performance also the difficulties and the complexities of the networks. The combination of two different networks, mobile cellular networks and WLAN ad hoc networks will be presented. The main purpose of the combination is to minimize the weaknesses of both network types when they are deployed separately. By having this combination then it is possible to provide higher mobility for WLAN ad hoc networks user and higher data transfer rate for cellular network users in multimedia applications. The cellular multihop networks will reduce blocking probability, balance the cells load and increase the network capacities. Although there are improvement on the performance of the combine networks, but there are additional aspects that should be considered seriously, especially for WLAN ad hoc users. Authentication, Authorization and Accounting (AAA) functions, the dynamic routing and relay path discovery, maintenance and security issues are aspects to be considered for cellular multihop network

Performance Improvement of Topology-Transparent Broadcast Scheduling in Mobile Ad Hoc Networks

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Performance comparisons of AODV, secure AODV and adaptive secure AODV routing protocols in free attack simulation environment.

There have been various secure routing protocols proposed for mobile ad hoc networks. Most of these protocols are analyzed by three standard techniques: simulation, security analysis and real network testbed. In this paper, Ad Hoc On-Demand Distance Vector (AODV) routing protocols was selected as the basis of the entire simulations. Due to the needs of securing the routing in the wireless ad hoc networks, Secure AODV (SAODV) was developed to add security to original AODV which includes cryptographic operations that can have a significant impact on the routing performance. To get better performance while maintaining the secure routing, Adaptive SAODV (A-SAODV) was developed based on the SAODV implementation, which was claimed to introduce some improvement on the routing compared to the SAODV. Based on this justification, some analysis and studies are made on the performance and impacts using AODV, Secure AODV (SAODV) and Adaptive Secure AODV (A-SAODV) in a free-attack simulation environment to analyze these routing protocols and make some comparisons on the performance. The collection of simulation results will show the performance impact of security implementation into the original AODV after the implementations of SAODV and A-SAODV into the networks

P-AODV Routing Protocol for Better Performance in MANET

MANET (Mobile Ad-Hoc Network) is an independent collection of mobile nodes that communicate over quite bandwidth constrained wireless links. In Mobile Ad hoc Networks (MANETs), the performance of various on-demand routing protocols significantly affected by the changing network topology.in the route discovery process, AODV (Ad-hoc On-Demand Distance Vector) is the mostly studied on-demand routing protocol that uses single route reply packet with reverse path for answering to the source node. Due to increase in the variability of the network topology, the possibility of route reply packet loss increases & destroys the performance of the routing protocol. It includes related material and details of other modified AODV protocols like R-AODV, Multipath Routing Protocol. This protocols makes better performance as compared to AODV but there we need more modification for efficient. We then focus on the end-to-end delay, throughput and overhead for the performance improvement. As by, we proposed a new AODV routing protocol that uses R-AODV for route discovery and Multipath routing protocol for data(packet) sending from source to the destination. Our proposed Protocol (P-AODV) would improve performance in terms of Average End-to-End Delay, Throughput and Routing Overhead. DOI: 10.17762/ijritcc2321-8169.15058

Efficient Routing for Wireless Mesh Networks Using a Backup Path

Wireless Mesh Network (WMN) has a proven record in providing viable solutions for some of the fundamental issues in wireless networks such as capacity and range limitations. WMN infrastructure includes clusters of Mobile Ad-Hoc Networks (MANETs) connected through a fixed backbone of mesh routers. The mesh network can be constrained severely due to various reasons, which could result in performance degradation such as a drop in throughput or long delays. Solutions to this problem often focus on multipath or multichannel extensions to the existing ad- hoc routing protocols. In this paper, we propose a novel solution by introducing an alternative path to the mesh backbone that traverses the MANET part of the WMN. The new routing solution allows the Mobile Nodes (MNs) to establish direct communication among peers without going through the backbone. The proposed alternative ad-hoc path is used only when the mesh backbone is severely constrained. We also propose, for the first time in WMNs, using MNs with two interfaces, one used in the mesh backbone communication and the other engaged in the ad-hoc network. A scheme is presented for making the MN aware of link quality measures by providing throughput values to the AODV protocol. We use piggybacking on route reply messages in AODV to avoid incurring additional costs. We implemented our solution in an OPNET simulator and evaluated its performance under a variety of conditions. Simulation results show that the alternative ad-hoc path provides higher throughput and lower delays. Delay analysis show that the throughput improvement does not impose additional costs

PERFOMANCE EVALUATION OF TWO IMPORTANT PROTOCOLS FOR INTER-NAVAL COMMUNICATION (AODV AND DSDV) WITH DARS SIMULATOR: A CASE STUDY OF THE SEAPORT OF VLORA

The aim of this paper is to use simulations to evaluate the performance of two existing protocols, AODV (ad hoc on-demand distance vector routing) and DSDV (Destination-sequenced Distance-Vector routing). However, they are designed for use in mobile ad hoc networks (MANET) and for increasing the effective point to point (ship to ship) communication. Simulations will be performed with the DARS simulator. The simulation result shows that when the number of nodes increased and consequently the distance between nodes narrows, there is an improvement in the communication process and a "Message Transmission Successful’. In fact, routing in these networks is based on a simple and intuitive approach. Thus, this approach shows that the retransmission of the packets by each node allows propagation through the network

Efficient P2P data dissemination in integrated optical and wireless networks with Taguchi method

The Quality of Service (QoS) resource consumption is always the tricky problem and also the on-going issue in the access network of mobile wireless part because of its dynamic nature of network wireless transmissions. It is very critical for the infrastructure-less wireless mobile ad hoc network that is distributed while interconnects in a peer-to-peer manner. Toward resolve the problem, Taguchi method optimization of mobile ad hoc routing (AODVUU) is applied in integrated optical and wireless networks called the adLMMHOWAN. Practically, this technique was carry out using OMNeT++ software by building a simulation based optimization through design of experiment. Its QoS network performance is examined based on packet delivery ratio (PDR) metric and packet loss probabilities (PLP) metric that consider the scenario of variation number of nodes. During the performing stage with random mobile connectivity based on improvement in optimized front-end wireless domain of AODVUU routing, the result is performing better when compared with previous study called the oRia scheme with the improvement of 14.1% PDR and 43.3% PLP in this convergence of heterogeneous optical wireless network

An Intelligent Routing Protocol Based on DYMO for MANET

in this paper, intelligent routing protocols for mobile ad-hoc networks (MANET) will be proposed .Depending on the concepts of fuzzy and neural networks. The goal is to get good quality service by finding the most convenient data transfer paths, therefore a Fuzzy-based, Neural-Fuzzy based and Energy aware are three approaches have been proposed to enhance Dynamic Manet On-demand (DYMO),All approaches were implemented in ns-2 simulator and compared with original protocol in terms of performance metrics, which showed that there was an improvement in route efficiency