Análise de Estabilidade e Imparcialidade em um Novo Algoritmo para Transmissão Multicast em Camadas

Valter RoeslerGaspare Giuliano BrunoJosé Valdeni de Lima

This paper focuses on stability and fairness issues of a new congestion control algorithm to be used in receiver adaptation for layered multicast transmissions. Its main benefit is to allow multimedia transmissions in heterogeneous environments such as the Internet, providing access to clients with different bandwidths, adapting automatically to the network's capacity. The proposed algorithm is called ALM (Adaptive Layered Multicast), and the adaptation occurs on the receiver side, ensuring a great simplicity to the system, as the only function of the transmitter is to send data in different layers (multicast groups) using packet pairs [1], without any need of confirmation or response from the receivers. The internal elements of the network, such as routers, do not need any modification (like running a special piece of software or using QoS), and the protocol runs over today's Internet. To validate the method in terms of stability and fairness with concurrency of various ALM sessions, the ns2 [2] software was used (with modifications where required). Various simulations were undertaken to prove the algorithm's functionality using tail drop and RED discarding policies on the router queues, and the evaluation environment was almost the same as [3] and [4], in order to make a comparison with other works in this area. The idea behind the ALM's algorithm is as simple as that: "it gives more bandwidth to those who have less". That means that two concurrent sessions without losses will tend to reach equilibrium, because the session with less bandwidth will have a higher increasing rate in relation to the other one.

Caso o link acima esteja inválido, faça uma busca pelo texto completo na Web: Buscar na Web

Biblioteca Digital Brasileira de Computação - Contato:
     Mantida por: