Abstract
Lower part of the 27 GHz band is one of the most attractive for deployment of 5G networks. 3GPP identified two frequency bands n257 and n258 for the use of various frequency bands within the 27 GHz range with Time Division Duplex (TDD) frequency arrangements [1], [2]. However, the use of these bands needs provision of electromagnetic compatibility (EMC) between 5G networks and incumbent systems operating in the frequency band 25.5-27 GHz in Earth exploration-satellite service (EESS) and space research service (SRC) via space-to-Earth links on a primary basis as stated in Article 5 (Frequency allocations) of the Radio Regulations [3], as well as in the European Table of Frequency Allocations [4]. Experimental studies on estimation of interference from 5G network transmitters to EESS and SRS earth station receivers in the 27 GHz band performed by authors of the paper enable determination of actual protection criteria for incumbent services. Organizational and technical measure are proposed to resolve the EMC issue and ensure required protection from 5G network interference on the basis of necessary coordination zones around receiving earth stations in EESS and SRS.