As microwave and lower-frequency millimetre-wave bands become congested, users of
those frequency bands, especially mobile operators have to extend the operating region
to higher millimeter-wave frequencies. The frequency bands around 50 ... 90 GHz, considered
in this study, exhibit significant differences regarding their propagation properties.
For instance the specific attenuation of oxygen varies non-monotonically over the
frequencies of interest: at 50 GHz, this quantity is about 0.03 dB/km and at 70 GHz
about 1 ... 2 dB/km whereas at about 60 GHz a peak attenuation of 16 dB/km is observed.
These and other propagation effects call for significantly different link planning
methodology. Moreover, they pre-determine the primary application of the various bands.
This study is intended to give an overview on the potential applications of these
frequency bands which are only recently employed for communication purposes.