An Research Of Token-Bus Protocol In Bi-directional HFC Networks

Aiming that astral-type central allocation in bi-directional HFC networks is not worth utilizing conventional HFC network frameworks, we propose, in this paper, the method of ATM based on bi-directional HFC networks. We raise the access type of Token-Bus protocol creatively, contrasting characteristic of CSMA/CD, Token-Ring and Token-Bus protocol in MAC, and considering the demand of HFC network.Our design reforms standard Token-Bus protocol, brings forward the design idea and key technology of new Token-Bus, simplifies the standard Token-Bus protocol, makes it adapt to bi-directional HFC networks and improves network efficiency. In the new Token-Ring protocol, all CM stations are organized by fiber-node machines. In order to get better performance of low-efficiency in a few stations in standard Token-Bus protocol, we present the algorithm in new Token-Ring protocol that provides more than one token each time and then invited stations contend. At the same time, fiber-node machines manage the number of token intellectively according to reality each time. This way raises the system efficiency and realizes dynamic distribution of bandwidth.We describe that how bus stations apply token, CM stations start work, and CM stations stop work, also we suggest how CBR and VBR data can be transmitted easily. The performance of token-claim algorithm is analyzed by computer software in the paper. The simulation results are also shown to verify the analytical results.