Spatial Multipath Location Aided Routing

Mobile ad-hoc networks (MANETs) are infrastructure-free networks of mobile nodes that communicate with each other wirelessly. There are several routing schemes that have been proposed and several of these have been already extensively simulated or implemented as well. The primary applications of such networks have been in disaster relief operations, military use, conferencing and environment sensing. There are several ad hoc routing algorithms at present that utilize position information (usually in two dimensional terms) to make routing decisions at each node. Our goal is to utilize three-dimensional (3D) position information to provide more reliable as well as efficient routing for certain applications. We thus describe extensions to various location aware routing algorithms to work in 3D. We propose a new hierarchical, zone-based 3D routing algorithm, based on GRID by Liao, Tseng and Sheu. Our new algorithm called Hyper-GRID is a hybrid algorithm that uses multipath routing (alternate path caching) in 3D. We propose replacing LAR with Multipath LAR (MLAR) in GRID. We have implemented MLAR and are validating MLAR through simulation using ns-2 and studying its efficiency, scalability and other properties. We use a random waypoint mobility model and compare our MLAR approach versus LAR, AODV and AOMDV in both 2D and 3D for a range of traffic and mobility scenarios. Our simulation results demonstrate the performance benefits of MLAR over LAR and AODV in most mobility situations. AOMDV delivers more packets than MLAR consistently, but does so at the cost of more frequent flooding of control packets and thus higher bandwidth usage than MLAR

Exploiting the power of multiplicity: a holistic survey of network-layer multipath

The Internet is inherently a multipath network: For an underlying network with only a single path, connecting various nodes would have been debilitatingly fragile. Unfortunately, traditional Internet technologies have been designed around the restrictive assumption of a single working path between a source and a destination. The lack of native multipath support constrains network performance even as the underlying network is richly connected and has redundant multiple paths. Computer networks can exploit the power of multiplicity, through which a diverse collection of paths is resource pooled as a single resource, to unlock the inherent redundancy of the Internet. This opens up a new vista of opportunities, promising increased throughput (through concurrent usage of multiple paths) and increased reliability and fault tolerance (through the use of multiple paths in backup/redundant arrangements). There are many emerging trends in networking that signify that the Internet's future will be multipath, including the use of multipath technology in data center computing; the ready availability of multiple heterogeneous radio interfaces in wireless (such as Wi-Fi and cellular) in wireless devices; ubiquity of mobile devices that are multihomed with heterogeneous access networks; and the development and standardization of multipath transport protocols such as multipath TCP. The aim of this paper is to provide a comprehensive survey of the literature on network-layer multipath solutions. We will present a detailed investigation of two important design issues, namely, the control plane problem of how to compute and select the routes and the data plane problem of how to split the flow on the computed paths. The main contribution of this paper is a systematic articulation of the main design issues in network-layer multipath routing along with a broad-ranging survey of the vast literature on network-layer multipathing. We also highlight open issues and identify directions for future work

Topology Control, Routing Protocols and Performance Evaluation for Mobile Wireless Ad Hoc Networks

A mobile ad-hoc network (MANET) is a collection of wireless mobile nodes forming a temporary network without the support of any established infrastructure or centralized administration. There are many potential applications based the techniques of MANETs, such as disaster rescue, personal area networking, wireless conference, military applications, etc. MANETs face a number of challenges for designing a scalable routing protocol due to their natural characteristics. Guaranteeing delivery and the capability to handle dynamic connectivity are the most important issues for routing protocols in MANETs. In this dissertation, we will propose four algorithms that address different aspects of routing problems in MANETs. Firstly, in position based routing protocols to design a scalable location management scheme is inherently difficult. Enhanced Scalable Location management Service (EnSLS) is proposed to improve the scalability of existing location management services, and a mathematical model is proposed to compare the performance of the classical location service, GLS, and our protocol, EnSLS. The analytical model shows that EnSLS has better scalability compared with that of GLS. Secondly, virtual backbone routing can reduce communication overhead and speedup the routing process compared with many existing on-demand routing protocols for routing detection. In many studies, Minimum Connected Dominating Set (MCDS) is used to approximate virtual backbones in a unit-disk graph. However finding a MCDS is an NP-hard problem. In the dissertation, we develop two new pure localized protocols for calculating the CDS. One emphasizes forming a small size initial near-optimal CDS via marking process, and the other uses an iterative synchronized method to avoid illegal simultaneously removal of dominating nodes. Our new protocols largely reduce the number of nodes in CDS compared with existing methods. We show the efficiency of our approach through both theoretical analysis and simulation experiments. Finally, using multiple redundant paths for routing is a promising solution. However, selecting an optimal path set is an NP hard problem. We propose the Genetic Fuzzy Multi-path Routing Protocol (GFMRP), which is a multi-path routing protocol based on fuzzy set theory and evolutionary computing

Ad hoc network security and modeling with stochastic petri nets

Advances in wireless technology and portable computing along with demands for high user mobility have provided a major promotion toward the development of ad hoc networks. These networks feature dynamic topology, self-organization, limited bandwidth and battery power of a node. Unlike the existing commercial wireless systems and fixed infrastructure networks, they do not rely on specialized routers for path discovery and traffic routing. Security is an important issue in such networks. Typically, mobile nodes are significantly more susceptible to physical attacks than their wired counterparts. This research intends to investigate the ad hoc network routing security by proposing a performance enhanced Secure ad hoc On-demand Routing protocol (SOR). Specifically, it presents a method to embed Security Level into ad hoc on-demand routing protocols using node-disjoint multipath, and to use maximum hopcount to restrict the number of routing packets in a specific area. The proposed scheme enables the use of security as a marked factor to improve the relevance of the routes discovered by ad hoc routing protocols. It provides customizable security to the flow of routing protocol messages. In general, SOR offers an alternative way to implement security in on-demand routing protocols. Ad hoc network is too complex to allow analytical study for explicit performance expressions. This research presents a Stochastic Petri net-based approach to modeling and analysis of mobile ad hoc network. This work illustrates how this model is built as a scalable model and used to exploit the characteristics of the networks. The proposed scheme is a powerful analytical model that can be used to derive network performance much more easily than a simulation-based approach. Furthermore, the proposed model is extended to study the performance of ad hoc network security by adding multipath selection and security measurement parameters. This research gives a quantificational measurement to analyze the performance of a modified SPN model under the effect of multipath and attack of a hypothetical compromised node

A Mobile Ad Hoc Network Routing Protocols: A Comparative Study

Mobile Ad hoc NETworks (MANET), are complex and distributed networks that are dynamic. Which are infrastructure less and multi-hop in nature. The communication of a node can be either direct or through intermediate nodes without a fixed and dedicated infrastructure. Hence it is necessary to design an efficient routing protocol for ad hoc network which can address the issues of MANET efficiently. In ad hoc, routing algorithms are classified into nine categories namely: source-initiated (reactive), table-driven (proactive), hybrid, hierarchical, multipath, multicast, location-aware, geographical-multicast and power-aware. This paper presents a survey and to review a comparative study about various routing protocols under each of these categories. Additionally, brief discussions about major routing issues are addressed. This survey paper focuses on the taxonomy related to ad hoc routing techniques and compares the features of routing protocols

Improving routing performance of multipath ad hoc on-demand distance vector in mobile add hoc networks.

The aim of this research is to improve routing fault tolerance in Mobile Ad hoc Networks (MANETs) by optimising mUltipath routing in a well-studied reactive and single path routing protocol known as Ad hoc On-demand Distance Vector (AODV). The research also aims to prove the effect of varying waiting time of Route Reply (RREP) procedure and utilising the concept of efficient routes on the performance of multipath extensions to AODV. Two novel multipath routing approaches are developed in this thesis as new extensions to AODV to optimise routing overhead by improving Route Discovery Process (RDP) and Route Maintenance Process (RMP) of multipath AODV. The first approach is a Iinkdisjoint multipath extension called 'Thresho)d efficient Routes in multipath AODV' (TRAODV) that optimises routing packets ~verhead by improving the RDP of AODV which is achieved by detecting the waiting time required for RREP procedure to receive a threshold number of efficient routes. The second approach is also a link-disjoint mUltipath extension called 'On-demand Route maintenance in Multipath AoDv' (ORMAD) which is an extension to TRAODV that optimises routing packets and delay overhead by improving the RMP of TRAODV. ORMAD applies the concepts of threshold waiting time and efficient routes to both phases RDP and RMP. It also applies RMP only to efficient routes which are selected in the RDP and when a route fails, it invokes a local repair procedure between upstream and downstream nodes of the broken link. This mechanism produces a set of alternative subroutes with less number of hops which enhances route efficiency and consequently minimises the routing overhead. TRAODV and ORMAD are implemented and evaluated against two existing multipath extensions to,AODV protocol and two traditional multipath protocols. The existing extensions to AODV used in the evaluation are a well-known protocol called Ad hoc On-demand Multipath Distance Vector (AOMDV) and a recent extension called Multiple Route AODV (MRAODV) protocol which is extended in this thesis to the new approach TRAODV while the traditional multipath protocols used in the evaluation are Dynamic Source Routing (DSR) and Temporally Ordered Routing Algorithm (TORA). Protocols are implemented using NS2 and evaluated under the same simulation environment in terms of four performance metrics; packet delivery fraction, average end-to-end delay, routing packets overhead, and throughput. Simulation results of TRAODV evaluation show that the average number of routes stored in a routing table of MRAODV protocol is always larger than the average number of routes in TRAODV. Simulation results show that TRAODV reduces the overall routing packets overhead compared to both extensions AOMDV and MRAODV, especially for large network size and high mobility. A vital drawback of TRAODV is that its performance is reduced compared to AOMDV and MRAODV in terms of average end-to-end delay. Additionally, TORA still outperforms TRAODV and the other extensions to AODV in terms of routing packets overhead. In order to overcome the drawbacks of TRAODV, ORMAD is developed by improving the RDP of TRAODV. The performance of ORMAD is evaluated against RREP waiting time using the idea of utilising the efficient routes in both phases RDP and RMP. Simulation results of ORMAD show that the performance is affected by varying the two RREP waiting times of both RDP and RMP in different scenarios. As shown by the simulation results, applying the short and long waiting times in both phases tends to less performance in terms of routing packets overhead while applying the moderate waiting times tends to better performance. ORMAD enhances routing packets overhead and the average end-to-end delay compared to TRAODV, especially in high mobility scenarios. ORMAD has the closest performance to TORA protocol in terms of routing packets overhead compared to ~M~a~M~OW . Relevant concepts are formalised for ORMAD approach and conducted as an analytical model in this thesis involving the\vhole process of multipath routing in AODV extensions. ORMAD analytical model describes how the two phases RDP and RMP interact with each other with regard to two performance metrics; total number of detected routes and Route Efficiency.EThOS - Electronic Theses Online ServiceGBUnited Kingdo