Adaptação do mecanismo de controle de congestionamento TFRC do protocolo de transporte DCCP para redes em malha sem fio

• Ano de defesa: 2009
• Autor(a) principal: Ribeiro, Cesar Henrique Pereira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Programa de Pós-graduação em Engenharia de Telecomunicações; Engenharia de Telecomunicações
• Palavras-chave em Português: DCCP; redes mesh sem fio; TFRC; controle de congestionamentos; wireless mesh networks; congestion control; CNPQ::ENGENHARIAS::ENGENHARIA ELETRICA::TELECOMUNICACOES::SISTEMAS DE TELECOMUNICACOES
• Link de acesso: https://app.uff.br/riuff/handle/1/18883

This work proposes an adaptation of the TCP-Friendly Rate Control (TFRC) congestion control mechanism used by the Datagram Congestion Control Protocol (DCCP) transport protocol. DCCP is an unreliable transport protocol proposed to replace the use of the UDP transport protocol, mainly for multimedia applications, which are affected by the delay and overhead imposed by the TCP transport protocol. DCCP implements congestion control without increasing delay, avoiding applications with high bandwidth demand from consuming all network resources, which causes degradation in concurrent flows. However, as the TFRC congestion control mechanism was designed for wired networks, it does not perform well in multihop wireless networks (mesh networks). Specifically, IEEE 802.11 MAC layer medium access mechanisms, such as retransmission and exponential backoff, mislead the TFRC congestion control mechanism, resulting in an inaccurate sending rate adjustment. This dissertation shows how the default DCCP TFRC mechanism overloads the MAC layer in multihop wireless mesh networks and proposes a new mechanism, called M-TFRC, whose simulation results in significant performance improvements