Flexible HW-SW design and analysis of an MMT-based MANET system on FPGA

Recently there has been a rapid growth of research interests in Mobile Ad-hoc Networks (MANETs). Their infrastructureless and dynamic nature demands that new strategies be implemented on a robust wireless communication platform in order to provide efficient end-to-end communication. Many routing algorithms have been developed to serve this purpose. This thesis investigated Multi-Meshed Tree (MMT) algorithm, an integrated solution that combines routing, clustering and medium access control operations based on a common multi-meshed tree concept. It provides the robustness and redundancy inherent in mesh topologies and uses the tree branches to deliver packets. MMT is the first of its kind that enables a single algorithm to form multiple proactive routes within a cluster while supporting reactive routes between different clusters. Recent published research and simulations have shown its favorable features and results. To explore the MMT algorithm\u27s novel feature in real systems against simulation work, this work adopts Field Programmable Gate Arrays (FPGA) as the platform for wireless system implementations. Full hardware and various System-on-Chip Hardware-Software designs are developed and studied, providing a design practice that contributes to low-cost system development in the field of MANET by utilizing the evolving FPGA technology. The results show that the MMT-based systems functioned accurately and effectively; in all proposed test scenarios they demonstrated many of the features that a desired MANET routing algorithm should have: high transmission success rate, low latency, scalability, few queued packets and low overhead. The results give valuable insights into the MMT algorithm\u27s performance and facilitate its future improvements

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

Local Area Dynamic Routing Protocol: a Position Based Routing Protocol for MANET

A Mobile Ad Hoc Network (MANET) comprises mobile nodes (MNs), equipped with wireless communications devices; which form a temporary communication network without fixed network infrastructure or topology. The characteristics of MANET are: limited bandwidth; limited radio range; high mobility; and vulnerability to attacks that degrade the signal to noise ratio and bit error rates. These characteristics create challenges to MANET routing protocols. In addition, the mobility pattern of the MNs also has major impact on the MANET routing protocols. The issue of routing and maintaining packets between MNs in the mobile ad hoc networks (MANETs) has always been a challenge; i.e. encountering broadcast storm under high node density, geographically constrained broadcasting of a service discovery message and local minimum problem under low node density. This requires an efficient design and development of a lightweight routing algorithm which can be handled by those GPS equipped devices. Most proposed location based routing protocols however, rely on a single route for each data transmission. They also use a location based system to find the destination address of MNs which over time, will not be accurate and may result in routing loop or routing failure. Our proposed lightweight protocol, ‘Local Area Network Dynamic Routing’ (LANDY) uses a localized routing technique which combines a unique locomotion prediction method and velocity information of MNs to route packets. The protocol is capable of optimising routing performance in advanced mobility scenarios, by reducing the control overhead and improving the data packet delivery. In addition, the approach of using locomotion prediction, has the advantage of fast and accurate routing over other position based routing algorithms in mobile scenarios. Recovery with LANDY is faster than other location protocols, which use mainly greedy algorithms, (such as GPRS), no signalling or configuration of the intermediate nodes is required after a failure. The key difference is that it allows sharing of locomotion and velocity information among the nodes through locomotion table. The protocol is designed for applications in which we expect that nodes will have access to a position service (e.g., future combat system). Simulation results show that LANDY`s performance improves upon other position based routing protocols

Resource Efficient Urban Delay/disruptive Tolerant Networks

Ph.DDOCTOR OF PHILOSOPH

Efficient Passive Clustering and Gateways selection MANETs

Passive clustering does not employ control packets to collect topological information in ad hoc networks. In our proposal, we avoid making frequent changes in cluster architecture due to repeated election and re-election of cluster heads and gateways. Our primary objective has been to make Passive Clustering more practical by employing optimal number of gateways and reduce the number of rebroadcast packets

Collaborative Caching for efficient and Robust Certificate Authority Services in Mobile Ad-Hoc Networks

Security in Mobile Ad-Hoc Network (MANET) is getting a lot of attention due to its inherent vulnerability to a wide spectrum of attacks. Threats exist in every layer of MANET stack, and different solutions have been adapted for each security problem. Additionally, availability is an important criterion in most MANET solutions, but many security frameworks did not consider it. Public-Key Infrastructure (PKI) is no exception, and its deployment in MANET needs major design and implementation modifications that can fit constraints unique to this environment. Our focus in this dissertation is to adapt and increase the availability of Certificate Authority (CA) services, as a major PKI entity, in MANET. Several attempts have been proposed to deal with the problem of deploying CA in MANET to provide a generic public-key framework, but each either ends up sacrificing system security or availability. Here, the main goal of our work is to provide a solution that addresses performance and security issues of providing MANET-based PKI. Particularly, we would like to maintain the availability of the services provided by CA while keeping the network\u27s packet overhead as low as possible. In this dissertation, we present a MANET-based framework suitable for exchanging public-key certificates by collaborative caching between MANET clients. We show that our system can meet the challenges of providing robust and secure CA services in MANET. Augmented by simulation results, we demonstrate quantitatively the feasibility of our work as we were able to reduce network overhead associated with threshold based CA queries up to 92% as compared to related work in addition to having a very short response time. The dependency on CA servers has been reduced, and the system was able to tolerate as much as two-third inoperative CA servers without noticeable decrease in the service performance

Actas da 10ª Conferência sobre Redes de Computadores

Universidade do MinhoCCTCCentro AlgoritmiCisco SystemsIEEE Portugal Sectio