Voice/data traffic management in the return path of two-way hybrid fiber-optic coaxial networks

Abstract

Two-way hybrid fiber-optic coaxial (HFC) networks have enabled the integrated services of high-speed Web surfing, additional phone lines and video on demand etc. on top of the existing CATV broadcast service. However, the key to the success of this technology relies on the quality of service (QoS) provided to the subscribers. In terms of the available bandwidth and channel quality of the two-way transmission system, the reverse path (from subscribers to the headend) is most likely the problematic factor toward subscriber satisfaction due to its limited bandwidth (5-42 MHz) and inherent noise characteristics in the tree-and-branch network topology. This paper investigates some traffic management issues in order to guarantee the diverse QoS of different traffic types in the return path of the HFC network where code division multiple access (CDMA) technique is employed as the medium access protocol. In particular, the tradeoff between the QoS of voice and data services, and strategies for the headend to improve the QoS of the integrated traffic are studied and quantified by numerical examples.