Flexible Channel Capacity

In traditional cable TV and centralized antenna systems, channel capacity depends on the bandwidth of the coaxial infrastructure and the reception and distribution equipment.

In analog TV systems, each channel typically occupies about 6 MHz of bandwidth. The physical capacity of the infrastructure therefore directly affects how many channels can be carried. For example, an 860 MHz system has theoretical capacity for about 106 analog channels. In practice, system operators often leave an unused frequency between channels to prevent interference, so the usable capacity is much lower—typically no more than 40 to 50 channels over a centralized antenna cabling system.

Digital TV can carry many more programs by using modulation techniques such as QAM and digital compression. For example, a 6 MHz channel using 256-QAM can carry approximately 38 Mbps, enough for several compressed programs. However, DVB multiplexing equipment can be expensive and add significantly to system costs.

LanTV changes the distribution architecture by making received channels available to users over the computer network. In this model, distribution is not constrained by a fixed channel count in the same way as a coaxial system. The practical limits are the number of inputs supported by the LanTV device and the available network bandwidth. Network bandwidth is generally much greater than the bandwidth needed for the channels received by LanTV, giving administrators greater flexibility to provide users with many more channels.