A fast and efficient algorithm for computing bandwidth requested mini-slots over HFC

Firstly, this paper proposes an algorithm which can calculate accurately the total amount of mini-slots requested in the request frame over DOCSIS-based hybrid fiber-coax (HFC) networks. According to the size of user data packet, the algorithm calculates the least amount of mini-slots to transmit upstream frame in the case of different radio frequency (RF) parameters. Secondly, this paper also proposes an optimized and high-speed implementation for the algorithm by introducing a hash function. The algorithm has been successfully applied to the bidirectional system platform for high definition television (HDTV), which consists of the PHY chip and MAC chip developed in our lab. The algorithm meets the demands of applications, including bidirectional VOD of HDTV, VoIP, and Internet data service etc. The tests in real network conditions show that the system provides a good performance and reliability.