Investigation of the consumer electronics bus

The objectives of this dissertation are to investigate the performance of the Consumer Electronics Bus (CEBus) and to develop a theoretical formulation of the Carrier Sense Multiple Access with Contention Detection and Contention Resolution (CSMA/CDCR) with three priority classes protocol utilized by the CEBus A new priority channel assigned multiple access with embedded priority resolution (PAMA/PR) theoretical model is formulated. It incorporates the main features of the CEBus with three priority classes. The analytical results for throughput and delay obtained by this formulation were compared to simulation experiments. A close agreement has been found thus validated both theory and simulation models Moreover, the performance of the CEBus implemented with two physical media, the power line (PL) and twisted pair (TP) communication lines, was investigated by measuring message and channel throughputs and mean packet and message delays. The router was modeled as a node which can handle three priority levels simultaneously. Satisfactory performance was obtained. Finally, a gateway joining the CEBus to ISDN was designed and its perfor-mance was evaluated. This gateway provides access to ISDN-based services to the CEBus. The ISDN and CEBus system network architecture, gateway wiring, and data and signaling interface between the CEBus and ISDN were designed, analyzed, and discussed. Again, satisfactory performance was found

Performance Analysis of a Cooperative Search Algorithm for Multiple Unmanned Aerial Vehicles under Limited Communication Conditions

This research investigates the impacts of realistic wireless communications upon a group of unmanned aerial vehicles (UAVs) utilizing a distributed search algorithm. The UAVs are used to survey an area for mobile targets and they require communication to cooperatively locate the targets. The mobile targets do not continually radiate energy, which exacerbates the search effort; a UAV could fly directly over a target and not detect it. A simulation of cooperative UAVs is implemented using the OPNET Modeler network simulation tool. The search performance of a group of UAVs is observed when communication range, data rate, and the number of UAVs are varied. The performance is evaluated based on the total time it takes for the UAVs to completely detect all the targets in a given search area, the number of times internal areas are scanned, the amount of communication throughput achieved, the network traffic generated, network latency, and number of network collisions. The results indicate that the number of UAVs was found to have the greatest impact on the group\u27s ability to search an area, implying that the data shared between the UAVs provides little benefit to the search algorithm. In addition, it was found that a network with a 100 Kbps or faster data rate should allow for minimal congestion and a large degree of scalability. The findings demonstrate that the proposed four-stage search algorithm should operate reasonably well under realistic conditions

Some aspects of a code division multiple access local area network

Not Availabl

Redes de transmissão de dados em meios submarinos

Dissertação de Mestrado, Engenharia Eletrica e Eletrónica, Instituto Superior de Engenharia, Universidade do Algarve, 2015Há um crescente interesse nas comunicações submarinas e aos dados oceanográficos nos últimos anos, devido à importância dos oceanos para o ser humano. As redes acústicas submarinas têm grande potencial para suportar uma grande variedade de aplicações, monitorização ambiental, vigilância submarina, prevenção de catástrofes, exploração de petróleo e monitorização de poluição. Apesar da comunicação acústica submarina ter sido estudada durante várias décadas, trabalhos em redes acústicas submarinos, projectos de implementação de protocolos de acesso ao meio (MAC) e protocolos de encaminhamento apenas estão numa fase inicial como campo de pesquisa devido ao elevado custo dos nós e dos navios de distribuição. Neste âmbito, a simulação torna-se como uma ferramenta fundamental para avaliação do desempenho da rede e um grande auxiliar no projecto de implementação dos protocolos em aplicações onde os cenários são complexos, devido ao elevado custo e inviabilidade em pôr na prática. Neste sentido, tendo como objectivo proporcionar um ambiente fiável de simulação de redes acústicas submarinas, optámos pelo simulador de rede WOSS (World Ocean Simulation System) de forma a fornecer uma reprodução mais detalhada da propagação acústica. O Objectivo central desta dissertação consiste na implementação de um protocolo de acesso ao meio DACAP (Distance Aware Collision Avoidance Protocol) para redes ad-hoc acústica submarina -caracterizadas por longos atrasos de propagação e diferentes requisitos de potência de Transmissão/Receção- e de seguida testá-lo no referido simulador de rede. Os resultados são mostrados fazendo comparação do desempenho da rede acústica submarina para diversos parâmetros, entre o protocolo DACAP e diversos mecanismos de acesso ao meio existentes no simulador de rede, para um conjunto de topologias diferentes e para diferentes tamanhos de tramas

Emerging Communications for Wireless Sensor Networks

Wireless sensor networks are deployed in a rapidly increasing number of arenas, with uses ranging from healthcare monitoring to industrial and environmental safety, as well as new ubiquitous computing devices that are becoming ever more pervasive in our interconnected society. This book presents a range of exciting developments in software communication technologies including some novel applications, such as in high altitude systems, ground heat exchangers and body sensor networks. Authors from leading institutions on four continents present their latest findings in the spirit of exchanging information and stimulating discussion in the WSN community worldwide