By Eric Schweitzer, PhD, Harmonic Inc.
The increasing deployment of Internet access, video-on-demand and other two-way services requires operators to use the most efficient means possible to maximize the limited bandwidth available in most HFC systems. A network is only as strong as its weakest link, which makes the return-path portion of a system critical when preparing for the delivery of two-way services.
The issue of return bandwidth becomes even more crucial in networks with minimal fiber counts. Because the return bandwidth is limited, it is inefficient to dedicate a single fiber to each return. Architectures which address these issues can make use of technologies such as Wave Division Multiplexing (WDM), block up conversion (frequency stacking), and digital transmission.