In 2015, the World Radiocommunications Conference (WRC-15), identified several frequency bands between 24.25 GHz and 86 GHz for future 5G networks. The WRC-15 invited ITU-R to conduct and complete sharing and compatibility studies, including adjacent bands, for protection of the terrestrial and satellite services occupying the band as primary users.
In December 2016, the Radio Spectrum Policy Group of the European Commission selected the 24.25-27.5 GHZ (’26 GHz’), 31.8- 33.4 GHz (’32 GHz’) and 40.5 – 43.5 GHz (‘40 GHz’) bands, as pioneer, promising, and viable option bands respectively, for introducing 5G terrestrial wireless systems across the Union, and mandated the European Conference of Post and Telecommunications, (CEPT) to develop harmonized technical conditions for spectrum use [1].
With that aim, CEPT is conducting sharing studies between 5G terrestrial wireless systems and the existing or foreseen incumbent users in these bands, such as terrestrial backhaul links, earth exploration satellite service, space research service, fixed satellite service and data relay satellite systems.
The sharing studies require the technical parameters of the 5G and incumbent systems, together with appropriate propagation models, to calculate interference levels at receivers.
Millimetre frequency bands have never been used in the past for mobile communications services, hence propagation models for this particular service at these frequencies are lacking.
ITU-R recently approved (March 2017) a series of P. Recommendations containing the propagation models required in the sharing studies: ITU-R P. 1411- Planning of short-range outdoor radiocommunications systems, ITU-R P. 1238- Planning of indoor radiocommunications systems, ITU-R P.2109- Prediction of building entry loss and ITU-R P. 2108- Prediction of clutter loss. All the propagation models proposed in the recommendations rely on experimental measurements except for the statistical clutter loss model for Earth –space proposed in ITU-R Recommendation P. 2108. This model is non site specific, i.e., it is independent of the scenario,( urban, suburban…etc), it takes as input parameters only the frequency and the elevation angle from the clutter to the satellite, it does not consider either the distance from the terminal to the clutter, or the height of the clutter. The model considers reflections and diffractions from building walls in an urban scenario. The JRC is investigating the validity of this model through comparisons of physical measurements with simulations done with a commercial ray-tracing software tool.
In sharing studies, clutter loss models calculate the losses due to buildings or other man made constructions that are not part of the terrain. JRC has also investigated the combination of ITU-R Recommendations P. 2109 and 2108, i.e., combination of building entry loss and clutter loss, in sharing scenarios when one terminal is inside a building, and the incumbent is outside, as there was a concern at ITU-R level on possible overstimation of the losses when combining the result of both recommendations.
MONTENEGRO VILLACIEROS Belen;
BISHOP James;
CHAREAU Jean-Marc;
VIAUD Philippe;
PINATO Tiziano;
BASSO Marco;
CHAWDHRY Pravir;
2022-04-29
Publications Office of the European Union
JRC107436
978-92-76-08557-7 (online),
1831-9424 (online),
EUR 29775 EN,
OP KJ-NA-29775-EN-N (online),
https://publications.jrc.ec.europa.eu/repository/handle/JRC107436,
10.2760/316416 (online),
