The effect of user´s geographical distribution on the utilization of radio spectrum

Cochannel and adjacent-channel interferences play a major role in determining the utilization level of the radio spectrum. It is shown that the geographical distribution of a station´s location in a given area can adversely affect the spectrum availability. When the variance of a station´s locations is small, the spectrum appears to be more congested, which reduces the possibility of finding interference-free frequencies for new systems. This apparent congestion can be looked at as a virtual shrinkage of available spectrum resources. A model is developed that can be used to calculate the true level of spectrum utilization in a given area. The model takes into account the geographical distribution of radio systems and quantifies the relation between the variance of a system´s locations and the amount of assignable spectrum. The validity of the model is verified by numerical examples and by data collected in three major Canadian cities.<>