A novel MAC protocol for supporting quality of services over IEEE 802.14 HFC network

In order to support quality of service (QoS) for real-time data, such as video on demand (VoD), voice over IP (VoIP) and other multimedia services, HFC (hybrid fiber coax) networks must provide an effective priority scheme. We study the IEEE 802.14 specification and discover that preemptive is insufficient. Therefore, we propose a new scheme to support QoS in HFC networks. The proposed scheme has three priority queues for constant bit rate (CBR), variable bit rate (VBR) and available bit rate (ABR) traffic and different competitive ratios are assigned to priority queues, respectively. As a result, the high priority queue has higher probability to compete with the contention slot (CS). A novel ideal microslot is also proposed to support CBR traffic. According to the microslot, CBR traffic can continuously transmit data without requesting the upstream bandwidth again. Through the proposed scheme, we offer guaranteed QoS for high priority traffic in HFC networks.