For approximately 1/3 the total cost of silicon, SDM will deliver up to 238%
more digital capacity than QAM in the converted Analog RF Spectrum.

Deprecation of Analog RF Spectrum for Digital Capacity

Within the first decade of this century, the U.S. cable industry will likely witness the almost total conversion of its analog TV RF spectrum into digital spectrum. It is useful to compare the advantages of SDM over QAM for this conversion.

The following table summarizes the RF spectrum occupied by the U.S. cable channel plan as told by the recently issued CED Magazine 2003-2003 Frequency Allocations wall chart.

Due the wider channel size, 28 SDM channels can accommodate the RF spectrum used by the 82 analog TV channels. This represents a reduction of 66% of the ports used as compared to a conversion to 64/256QAM in 6MHz bandwidth. This reduction in ports directly relates to higher density head-ends: i.e., less power, less footprint, lower cost of ownership for support and maintenance.

The following table indicates digital data capacity differences for QAM vs. SDM for this RF spectrum. The table indicates the bulk digital capacity if all channels were converted to digital.