RES158 – 255 – c) that the technical characteristics of the earth stations in motion operating within a given geostationary-satellite network should be within the envelope of the coordination agreements reached between administrations, recognizing a) that Article 21 contains power flux-density (pfd) limits for geostationary fixed-satellite services; b) that earth stations in motion addressed by this Resolution are not to be used for safety-of-life applications; c) that this conference has adopted footnote No. 5.527A and Resolution 156 (WRC-15) related to earth stations in motion; d) that advances in technology, including the use of tracking techniques, allow earth stations in motion to operate within the characteristics of fixed earth stations of the FSS; e) that No. 1.21 defines the fixed-satellite service and No. 1.25 defines the mobile-satellite service (MSS); f) that the use of earth stations in motion under the FSS regime is not much different from MSS applications, taking into account the definition of mobile-satellite service in No. 1.25; g) that the main difference between earth stations in motion and mobile earth stations is that earth stations in motion comply with the technical requirements of fixed-satellite earth stations, recognizing further a) that parts of the frequency band 17.7-18.1 GHz are used by feeder links for the broadcasting-satellite service, subject to Appendix 30A (No. 5.516); b) that the frequency bands 18.3-19.3 GHz (Region 2), 27.5-27.82 GHz (Region 1), 28.35-28.45 GHz (Region 2), 28.45-28.94 GHz (all Regions), 28.94-29.1 GHz (Regions 2 and 3), 29.25-29.46 GHz (Region 2) and 29.46-29.5 GHz (all Regions) are identified for use by high-density applications in the fixed-satellite service (No. 5.516B); c) that use of the frequency band 18.1-18.4 GHz by the fixed-satellite service (Earth-to-space) is limited to feeder links of geostationary-satellite systems in the broadcasting-satellite service (No. 5.520); d) that use of the frequency band 18.6-18.8 GHz by the fixed-satellite service is limited to geostationary systems and systems with an orbit of apogee greater than 20 000 km (No. 5.522B); e) that the use of the frequency bands 17.8-18.6 GHz and 27.5-28.6 GHz by non-geostationary fixed-satellite service systems is subject to the application of the provisions of Nos. 5.484A, 22.5C and 22.5I; f) that use of the frequency bands 18.8-19.3 GHz and 28.6-29.1 GHz by geostationary and non-geostationary fixed-satellite service networks is subject to the application of the provisions of No. 9.11A, and No. 22.2 does not apply (No. 5.523A);