Dynamic bandwidth allocation for the HFC DOCSIS MAC protocol

DOCSIS (Data Over Cable Service Interface Specifications) is the new specification for data transmission over the HFC (hybrid fiber/coax) networks. In the DOCSIS media access control (MAC) layer, the headend or CMTS (cable modem termination system) controls transmissions in the upstream direction using a centralized reservation-based approach, and is also responsible for downstream transmissions. We explore mechanisms for delivering quality of service (QoS), in the upstream and downstream directions. We propose a CMTS architecture and study the performance of the bandwidth allocation mechanisms using a model which we implemented on the OPNET Common Simulation Framework provided by CableLabs.