Hybrid redundancy mechanisms for soft real-time wireless networks

• Autor(a) principal: Pinto, Kevin Filipe Ganhito
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/23476
• topic: Engenharia electrónica e telecomunicações; Redes de telecomunicações; Sistemas de comunicação sem fios; Ethernet (Redes de computadores); Redundancia (Engenharia)

Video streaming in environments with high probability of packet losses requires the use of redundancy mechanisms. The WSRT protocol was created to improve the packet delivery probability in multi-hop mesh networks with lossy channels by employing IEEE 802.11 protocol. WSRT creates multiple disjoint paths which minimize common nodes between them, whenever possible, and relays the same data by each one of them, thus increasing the reception probability. Moreover, it also uses a TDMA scheme to avoid collisions and so improve energy and bandwidth utilization. To achieve these objectives the system is decomposed in 3 different phases, Announcement in which the system will have knowledge of every node in the network. Path Definition in which the multiple disjoint paths are distributed and Running in which the system relays usefull data between two points, source and sink. The protocol was implemented on Linux. This dissertation describes the architecture, implementation and a set of experimental results, which validate the main protocol features, is also included.