By Oleh J. Sniezko & Tony E. Werner
During the last decade, the tree-and-branch cable TV architectures have evolved into HFC architectures. These changes were inevitable due to advanced service requirements for increased quality, increased reliability, and interactivity. Most of the advanced HFC networks introduce secondary hubs with a star configuration from secondary hubs to the nodes and a ring between the primary hub and the secondary hubs. This paper analyzes the transport layer choices in this ring. Four basic alternatives are presented and compared. The three of them have been analyzed before, the fourth, dense wavelength division multiplexing (DWDM), became a feasible alternative in 1997. The paper compares advantages and disadvantages for all four of them and their capital and operating costs. Finally, it presents a possible implementation path for DWDM transport system.