Publications

Since the spectrum is a limited natural resource, the spectrum management community has a major interest in identifying spectrum conservation techniques that will provide more efficient spectrum utilization. Advances in new technology for fixed microwave systems in antennas, modulation schemes and signal processing techniques offer increased efficiency in spectrum utilization. This report analyzes the spectrum conserving properties of the various new technologies for fixed microwave systems applying the concepts in CCIR Report 662-2, and was defined as the spectrum conservation factor (SCF). The report concludes that the SCF technique is an effective indicator of the spectrum conserving properties of technologies which can be used to develop new spectrum standards.

This report is a spectrum resource assessment of the HF band (3-30 MHz). It incudes information on rules, regulations, allocations, technical standards, frequency assignments, system characteristics, and special uses unique to the HF band. The impact on HF services brought about by new technologies is discussed along with potential impacts of HF Over-the-Horizon (OTH) radars and ionospheric sounders. The importance of domestic emergency communications in the HF band is discussed along with new standards for interoperability presently being drafted.

This technical report details a procedure for calculating the mainbeam off-axis power density in the near- and far-field of a parabolic circular reflector antenna. In the report, the on-axis procedures of an earlier report are extended to off-axis analysis. Like its predecessors, it is intended for general use in system planning and evaluation and gives a worst-case estimate for radiation hazard assessment.

Use of Government and non Government flood warning systems in the 162-174 MHz band are growing rapidly in the US. The report investigated ways of improving the spectrum efficiency of these systems to allow for continued growth. Recommendations for narrowing channel widths and allotting certain channels for their use have been adopted.

Interference from high powered weather radars to digital microwave systems is a growing problem in the US. The study identified procedures to avoid these problems. The study was completed in coordination with the FCC and industry. Recommendations dealing with exchange of data bases, coordination procedures and other technical areas have been adopted.