Broadband access-comparing the alternatives

The two choices for broadband access that are currently being most heavily debated in the United States are loosely termed "hybrid fiber coax" (HFC) and "switched digital video" (SDV). The thrust of this paper is to explain why these two alternatives overshadow all others and to highlight decision factors facing network providers in choosing between them. The HFC/SDV terminology has evolved from industry technology and marketing discussions; these imprecise terms confuse basic understanding of the two architectures. Both architectures support on-demand digital video services and, as practically deployed, both architectures incorporate logical buses. The distinctions are in the digital modulation scheme and the position of the bus relative to the customer. The SDV architecture utilizes baseband digital modulation and point-point distribution to individual customers off of a logical fiber bus. Whereas, the HFC architecture utilizes QAM digitally modulated subcarriers and a coax bus fed by point-point fiber for distribution to customers.