Regulatory support for direct air-to-ground communication system

A number of sharing studies were undertaken to identify the potential to allocate 5855–5875 MHz for Broadband Direct-Air-to-Ground Communications (DA2GC).  One of the studies investigated adjacent band operation to radiolocation operating in the band 5250–5850 MHz.  The main radiolocation use is military and the analysis concentrated on fixed land-based, ship borne and transportable platforms operating in the upper part of the band 5725 – 5850 MHz.  A range of radar types as defined in ITU-R Rec 1638 were considered with additional ones, the characteristics of which were provided by CEPT administrations, also considered.  The DA2GC system is a TDD system so air-ground and ground interference paths were modelled.  The analysis determined the level of additional filtering that would be required of the DA2GC system in order to protect radiolocation operations.  The study findings contributed to the ECC Report 210, “Studies related to Broadband DA2GC in the bands 5855-5875 MHz, 2400-2483.5 MHz and 3400-3600 MHz”, 31 January 2014.