Spectrum Utilization in a Digital Radio-Relay Network

Digital radio-relay networks in urban areas have been proposed to connect telephone switching centers and to develop new broad-band services. This paper describes a methodology for evaluating the "amount" of radio spectrum "used" by a node in the network, on the basis of general criteria and definitions for spectrum use and efficiency. Several factors influencing the spectral efficiency of the system (antenna diagrams, propagation characteristics, network density, modulation techniques) are taken into account in the proposed approach. Some examples of application, allowing the assessment of trends and possible tradeoffs in spectrum utilization are given. Extensions and other applications of this approach are suggested.