A hybrid multiplexing scheme for multi-service networks

In the past CATV networks were used for broadcasting television signals. Since the deployment of fiber, the CATV networks are being upgraded to so-called hybrid fiber coax (HFC) networks, providing the possibility to me the return channel as well. The presence of such a channel challenges the operators to implement bi-directional services, such as telephony, Internet or interactive television State-of-the-art products are in most cases ad hoc solutions implementing a single service on a dedicated system. This means that if a customer subscribes to a telephone service and a data service he ends up with two cable modems. In such a scenario also the number of interfaces at the head-end increases, so that the complexity of the total system increases for the operator. Although ATM is meant to be tbe multiplexing method to support all services, it is still not cheap enough to provide the wide variety of quality of services (like delay requirements for telephony in combination with efficiency and reliability requirements for data). In this paper a concept is presented that can deal with this problem in a cost effective way. The concept can be used to implement STM traffic (e.g. telephony) and ATM traffic in an efficient way. It is also shown that the system can be used for ATM traffic only so that it can be used as an intermediate step in the evolution of HFC networks to a full service network. simulation results show a very good overall performance. This is partly due to the flexibility that is inherent to the system concept.