In the 1990s, telephone companies pushed their aging copper infrastructures against cable operators' primitive tree-and-branch networks. During the past decade or so, the cable guys have transitioned from creaky tree-and-branch networks to more robust mixes of fiber and coaxial cable while the telcos have deployed fiber in earnest.
The competition has evolved, but is just as fierce. Today, telco fiber is being pushed in initiatives from small and large players. The highest profile projects, of course, are Verizon's FiOS and AT&T's U-Verse. The cable industry still is using the fiber and coax mix -- which is known as hybrid fiber-coax (HFC). It is building on that basic infrastructure in a variety of ways, several of which are described in this Cable Digital News piece. The story details plans outlined by Comcast executive vice president and chief technology officer Tony Werner during the operators' analyst and investor day.
A key to the evolution of HFC is a series of specifications from industry consortium Cable Television Laboratories (CableLabs) called the Data Over Cable Service Interface Specification (DOCSIS). The story says that Comcast plans this year to test DOCSIS 3.0, which offers speeds of more than 100 Mbps, supports IPV6 and other features. It is expected that Comcast and other operators will deploy DOCSIS 3.0 in areas where telcos, especially Verizon, are rolling out fiber.
The story outlines other ways in which Comcast plans to increase bandwidth. Cable networks don't bring fiber to homes: The coaxial element in the HFC equation runs from the premise to a neighborhood node. The presence of a transition point offers operators a good deal of flexibility to adjust node size and thereby boost the amount of bandwidth available to a given home or business being served.
There are different ways of doing this, with actual physical creation of a new node being the most expensive and yielding the most additional bandwidth. Another method of adding bandwidth is the deployment of switched digital video (SDV). Traditionally, cable operators send all programming to all subscribers -- each of whom plucks off one channel to watch. SDV approaches free up capacity by only sending the desired programming to subscribers.
The bottom line is that the game of "can you top this" between the telephone and cable industries is continuing and, if anything, accelerating. That's great news for commercial and residential subscribers, who will continue to benefit from the steadily improving technology that both industries are bringing to the table.