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Satellite issues: non-GSO satellite systems with short-duration missions


Challenges and solutions

Non-GSO satellites with short-duration missions are currently treated the same as all other satellites under Articles 9 and 11 of the Radio Regulations (RR). Furthermore, there is no dedicated radiocommunication service associated with short-duration satellite system frequency usage, however non-GSO satellites with short-duration missions shall operate in spectrum allocated to satellite services in accordance with the relevant conditions of the allocation. It is noted that these short-duration satellite systems are beginning to operate outside the amateur-satellite service. Given their short development cycle, short lifetimes, and typical missions, a modified regulatory procedure for the advance publication, notification and MIFR recording may be beneficial for these systems.

Furthermore, it is important to ensure that any satellite radio-frequency operation avoids harmful interference to incumbent and authorized systems and services. The two frequency bands below 1 GHz under consideration for new or upgraded allocation to the SOS (150.05-174 MHz and 400.15-420 MHz) are used for a wide variety of terrestrial and space applications, including for safety of life purposes, and some are heavily used on a consistent basis. Nevertheless, if new allocations to the SOS in these frequency bands are considered, they should not put undue constraints on any incumbent services.

WRC and ITU’s contribution

Based on input contributions from the membership, ITU-R discussed the possibility of accelerating the timing of the processing of frequency assignments to non-GSO satellite networks and systems with a short-duration mission not subject to coordination under Section II of RR Article 9. This could be achieved, in part, by taking advantage of the recent development relating to the implementation of an online tool for the submission of all the notices. Other possibilities presented involved the reduction of the period provided to affected administrations to submit their comments. In both cases, the impacts of these modifications on the Radiocommunication Bureau or administrations may need to be further considered. These modifications to the existing regulatory procedures to facilitate the recording of non-GSO satellite systems with short-duration missions in the MIFR, including a draft new WRC Resolution, have been developed to address this issue.

Furthermore, ITU-R has performed studies on spectrum needs for telemetry, tracking and telecommand in the SOS for non-GSO satellites with short duration missions, to assess the suitability of existing allocations to the SOS and, if necessary, to consider possible new allocations. Typical technical parameters for space operations of non-GSO satellites with short duration missions were developed for use in the studies. In addition, technical and regulatory studies including sharing studies were carried out and resulted in different possible options to address the abovementioned spectrum requirements, such as new SOS (Earth-to-space) allocations in the frequency ranges 403-404 MHz or 404-405 MHz, or using the existing SOS allocations in the frequency bands 137-138 MHz (space-to-Earth) and 148-149.9 MHz (Earth-to-space) with associated regulatory provisions appropriately modified for non-GSO satellites with short duration missions.

Taking place in Egypt from 28 October to 22 November 2019, WRC-19 will decide on the modified regulatory procedures, as well as frequency allocations for telemetry, tracking and telecommand in the space operation service, for non-GSO satellite systems with short-duration missions.​​