Geneva hosted last 10-20 May the fifth meeting in the 2008-2011 study cycle of Working Party 5C (WP 5C) of Study Group 5 (SG5) of the Radiocommunications Sector (ITU-R). WP 5C handles issues involving fixed wireless systems, including systems in HF and other systems operating in frequency bands below 30 MHz in the scope of fixed and land mobile service. It is also responsible for items 1.5, 1.8 and 1.20 on the agenda of the next World Radiocommunications Conference (WRC-12).
The 86 documents submitted for consideration by WP 5C were spread among five subgroups, per the specific nature of the subject matter:
- Subgroup 5C-1 - issues concerning systems operating in frequencies below 30 MHz;
- Subgroup 5C-2 - issues concerning systems operating in frequencies between 30 MHz and 18 GHz;
- Subgroup 5C-3 - issues concerning systems operating in frequencies above 18 GHz;
- Ad Hoc Recommendations Subgroup - issues concerning updating of the ITU-R Recommendations;
- Ad Hoc Plenary Subgroup - issues not covered in the above subgroups.
Analysis of the documentation under review led to the production of 41 new documents, of which 17 are for liaison with other working groups and 18 will be passed on to the next meeting as they require further development. The remaining six documents were submitted to consideration by SG 5 for approval, namely:
- Document WP 5C-Temp/199rev2 proposing revision of ITU-R Report F.2106 on the characteristics, technical aspects and applications of fixed service of free space optical transmission systems (FSOL) operating above 3000 GHz. The modification concerned reorganisation and addition of new relevant content for implementation of these applications. Note that their advantages are include available bandwidth, equipment compactness and the near absence of co-ordination procedures to prevent interference between FSOL systems;
- Document WP 5C-Temp/201fev1 proposing revision of ITU-R Recommendation F.1764 on methodologies for evaluating interference between backhaul links using high altitude platform systems (HAPS) and fixed wireless service systems in frequency bands above 3 GHz. The revision aims to make clear that the Recommendation only covers backhaul links (links to users) and not backbone links (service links);
- Document WP 5C-Temp/216 proposing revision of ITU-R Recommendation F.758 concerning parameters of digital fixed wireless systems (in fixed service) and considerations for the development of spectrum sharing criteria or compatibility between theses systems and systems from other services and other interference sources. The Recommendation was profoundly amended and updated, with a view to helping meet certain availability goals for fixed service networks, bearing in mind the various interference environments considered and the most relevant technical data now available;
- Document WP 5C-Temp/193 proposing revision of ITU-R Recommendation F.1107 concerning probabilistic analyses in the calculation of interference in fixed service systems originating from space stations on board satellites in geostationary orbit, vis-à-vis spectrum sharing. The Recommendation was amended to update the text and withdraw Appendix 1, which contained obsolete spectrum sharing methods;
- Document WP 5C-Temp/195rev1 proposing revision of ITU-R Recommendation F.1191 on bandwidth definitions (occupied versus needed) and undesired radiation in fixed service digital systems. The revision updated this Recommendation’s text and added the concept of spurious emissions and out-of-band emissions, and also included a study concerning systems based on frequency blocs;
- Document WP 5C-Temp/227 proposing a new ITU-R Recommendation F.[HAPS Characteristics] on characteristics and technical parameters applicable to high altitude platform systems (HAPS), to be used in studies on sharing spectrum with conventional fixed service systems in the 5850-7075 MHz frequency band.
Regarding documents that will be examined at the next WP 5C meeting, the following stand out for their relevance:
- Three working documents (WP5C-Temp/225/226/228) proposing worldwide/regional harmonisation and spectrum sharing between terrestrial electronic news gathering (ENG) systems and fixed and mobile service stations (item 1.5 on the WRC-12 agenda);
- Three working documents (WP5C-Temp/203/204/229) aiming to establish regulatory directives and compatibility requirements between emerging systems and existing services in the frequency bands between 71 GHz and 238 GHz (item 1.8 on the WRC-12 agenda);
- Three working documents (WP5C-Temp/220/221/222) concerning high altitude platform systems (HAPS), with a view to studying co-existence between these systems and existing systems in the 5850-7075 MHz frequency band (item 1.20 on the WRC-12 agenda). Note that Resolution 122 (WRC-97) designated the 47.2-47.5 GHz and 47.9-48.2 GHz bands for implementation of these systems.
