Impact of the clients' position on performance of VoD systems based on collocated APs
Leonardo Bidese de Pinho, Claudio Luis Amorim · 2006
This paper investigates the impact of clients' position in scalable wireless VoD systems, based on collocated access points. In particular, it evaluates the use of several transmission modes provided by the 802.11a standard, aiming to service different area sizes, using the CINAPS (Cluster of Inexpensive Access Points) system, which was extended with a novel distance-aware association control heuristic. Overall, our simulated results showed that the clients' position influences only when the blockage rate of requests given by the other system variables is up to the uncovered area coefficient. Moreover, they suggest that an adaptive approach of transmission mode choice could achieve a slightly better average blockage rate but significantly far from the ideal values.Este artigo investiga o impacto da posicao dos clientes no desempenho de sistemas de VoD sem fio escal´veis, baseados em pontos de acesso co-localizados. Em particular, e avaliado o uso de v´rios modos de transmissao do padrao 802.11a, visando atender ´reas de diferentes tamanhos, utilizando como base o sistema CINAPS (Cluster of Inexpensive Access Points), estendido com uma nova heuristica de controle de associacao distance-aware. Os resultados mostram que o posicionamento dos clientes influencia apenas quando a taxa de bloqueio determinada pelas demais vari´veis do sistema e inferior ao coeficiente de ´rea descoberta. Alem disso, eles sugerem que uma abordagem adaptativa de escolha de modo de transmissao poderia melhorar levemente a taxa de bloqueio media mas ainda distante dos valores ideais.