IPTV transport architecture alternatives and economic considerations

Telecommunications companies are under increased pressure due to competition from multiple system operators, and the changing communications and entertainment needs of residential consumers. These pressures are driving the telecommunications companies to design and deploy metro networks capable of delivering broadcast video and VOD services through IP-based broadband connectivity (known as IPTV). One important architectural consideration for these IPTV networks is the core layer 1 transport infrastructure that supports economical delivery of these high-bandwidth services. This article surveys some of the major layer 1 optical transport network alternatives including DWDM, SONET, and Ethernet-on-fiber as well as its passive WDM/DWDM (PWDM) variation. The article analyzes the architectural and cost performance metrics for these transport options, and explores the economic crossover points with regard to the key network and service parameters such as bandwidth demand, number of subscribers, network topology, and operational constraints. DWDM technology, when coupled with native Ethernet aggregation, is found to have significant applicability for IPTV transport networks. DWDM offers value in capital cost and operations, while delivering the required bandwidth and performance. Ethernet aggregation capability within the transport infrastructure adds scalability, flexibility, and cost advantage for the multiservice network applications of the future.