Selecting the Appropriate Spectrum to Meet the Requirements of the Targeted Customers Propagation Characteristics Across the Radio Spectrum

Issues of spectrum should be dealt with during the market assessment phase of network planning,
at least to the extent of finding out what spectrum is available in the designated market.
Simply put, if the requisite spectrum is not available, then the project cannot go forward.
As indicated in Chapter 1, the 802.16 standard covers the bands between 2 gigahertz (GHz)
and 66GHz, but other bands are available above and below this region that can be used for
providing broadband access (I will cover these as well). As desirable as standards-based equipment
may be for the network operator, occupying the spectrum that is most useful is equally
desirable.
The 802.16 standard itself divides the radio frequency (RF) spectrum into large, slightly
overlapping blocks, the first of which extends from 2GHz to 11GHz and the second from 10GHz
to 66GHz. In terms of the propagation characteristics of the signal, these divisions are both too
coarse and so arbitrary as to be almost meaningless from an engineering perspective. In regard
to network planning, more useful divisions would extend from 700 megahertz (MHz) to 3GHz,
then from 3GHz to 10GHz, from 10GHz to 40GHz, and from 40GHz to 100GHz. I should point
out here that the IEEE’s decisions as to what spectrum to include in the standard are based
primarily on what bands are actually available for broadband deployments in the United States
and secondarily in other developed nations. They are not based on the natural divisions in the
spectrum reflecting the changing nature of wave propagation with respect to frequency.
Before you consider such natural divisions, I will give an overview of the useful spectrum—
useful, that is, from a communications viewpoint.