PDF of this tutorialFigure 10 indicates how those economics play out in a typical cable network. For the base case, shown for three samples, the node size is roughly 900 homes, with four to five active devices per mile. The middle of the diagram shows deployment of a near-passive architecture, meaning one RF amplifier. This architecture yields six to eight times more available interactive bandwidth, at a very small cost in increased investment. At the same time, the active count is cut in half, meaning higher reliability with lower power and maintenance costs. In a passive architecture, two to three times more bandwidth is obtained for a reasonable cost premium. At this point, a fully interactive system goes above the median in the cost curve.
Figure 10. Raising Bandwidth While Lowering Costs
Today's deployable technology thus allows construction of fiber-deep, flexible broadband access networks capable of handling interactive video, data, and voice services. Again, the ultimate goal is to be able to connect to servers anywhere in the network, efficiently and flexibly. Achieving this goal requires a multimedia backbone transport network capable of carrying voice, data, and the various forms of video traffic.
