In wireless communication, the finding from researchers at National Institute of Standards and Technology that transmission performance is consistent across different bands of the millimetre-wave spectrum targeted for data-rich, high-speed 5G systems has settled a key dispute in the area.
System operators are inclined for lower bands of new mmWave spectrum. This is because they are influenced by a formula by which higher frequencies cause more signal loss due to smaller wavelengths resulting in reduced useful area of the antenna.
Until so far, many organizations have disagreed over measurements of this effect if it is true.
Meanwhile, NIST researchers have developed a new method to compute frequency effects, using 26.5-40 GHz frequency band as a target example. Following extensive study in the laboratory and two real-world environments, results obtained by NIST researchers confirmed that the main signal path does not vary by frequency. This has been a generally accepted theory for traditional wireless systems so far not proven for mmWave spectrum.
The findings appear in a paper published in IEEE Open Journal of Antennas and Propogation.
Besides this, the team also found signal losses in secondary paths can vary by frequency to some extent depending on the type of path. Importantly, reflective paths lost only some signal strength at higher frequencies. The diffuse paths and weaker bent lost somewhat more.
Until so far, on the so-called multipath, the effects of frequency were unknown.
Importantly, the work may serve to demyth several incorrect conceptions propagated about higher frequencies in 6G and 5G.