Little LEOs

The low-Earth-orbit satellites operating at frequencies below 1 GHz are known as Little LEOs. (See: Who are the "Little LEO" Players?) Their claimed needs were not satisfied at WRC-97, so they are seeking more spectrum at WRC-99. Preparation for WRC-99 goes on in two tracks.

One is the technical track, that is studying technical sharing criteria in International Telecommunication Union Radiocommunication Sector (ITU-R) Study Groups. In the case of Little LEOs, that is underway in Working Party 8D (mobile-satellite services). So far, none of the draft documents we have seen in WP 8D specifically targets amateur bands for study, but the Little LEOs could study all bands from about 137 MHz to 1 GHz. The Working Party next meets October 19-30, 1998 in Geneva, at which time they are to complete their studies of bands that may be proposed for WRC-99 allocations.

The second track is that of national preparation leading to proposals to WRC-99. The FCC has established a WRC-99 Advisory Committee and placed the Little LEOs in Informal Working Group 2 (IWG-2). This group has held its organizational meeting in Washington and is expected to meet monthly. Again, none of our bands have been targeted and their interest seems to be on sharing with the land mobile service for uplinks. Two downlink possibilities are being studied: 405 - 406 MHz and the UHF TV band. Our bands in the 137 - 1000 MHz range could be considered for sharing by Little LEOs, particularly if sharing with other services looks difficult. League representatives will continue to participate in IWG-2 throughout the development of US proposals to WRC-99 to protect the interests of the Amateur and Amateur-Satellite Services.

70-cm Synthetic Aperture Radars

Operation of Synthetic Aperture Radars (SARs) at frequencies around 400 - 500 MHz would permit collection of data through the dense upper canopy of tropical rain forests. At WRC-97, the Netherlands failed to obtain an allocation of 3.5 MHz for this application within the band 410 - 470 MHz. At their insistence, a new agenda item was agreed at WRC-97 for consideration at WRC-99, namely up to 6 MHz at 420 - 470 MHz.

ITU-R Working Party 7C (responsible for active Earth exploration satellites) held a meeting in February/March 1988 to restudy the possibility of SARs operating in the 70-cm band (it's called "P-band" in radar-speak). It was clear at this meeting that the SAR proponents prefer the band 430 - 440 MHz. Rinaldo attended that meeting as part of the US delegation and presented a paper on potential interference to amateur stations. Ken Pulfer, VE3PU, represented IARU and introduced a document stating that amateurs would prefer SARs to use 450 - 470 MHz and pointing out that 430 - 440 MHz is the worst case for amateurs worldwide.

In preparation for WRC-97, the United States was opposed to SARs operating at 70 cm whenever they were within line-of-sight of North America or Europe, to protect the space-object-tracking network. It might be possible to operate SARs only when over the tropical rain forests without interference to the tracking radars, but they could cause interference to amateur stations in the tropical areas.

Technical studies are now underway by the League and by IARU to assess the potential interference from SARs to amateur stations, including amateur satellites in the 435 - 438 MHz band jointly with AMSAT. These studies will be considered at the next Working Party 7C meeting beginning September 28, 1998 in Geneva.

Global Positioning System

Ever since the Executive Order opening up GPS for use by civilian services with the same accuracy the military has enjoyed, the Federal Aviation Administration and the Department of Defense have been in endless debate over choice of downlink frequencies. While other candidate frequencies have been discussed, the present choices seem to be between 1205 MHz and 1250 MHz for the new civilian frequency (variously called L5 or LC). ARRL has expressed concern about the possible selection of 1250 MHz, particularly if it would lead to loss of the 1240 - 1260 MHz band for the amateur service.

Space Telecommand Frequencies

A WRC-99 agenda item calls for consideration of 3 MHz of spectrum between 100 MHz and 1000 MHz for telecommand links for space research and space operation services. There are no indications yet that amateur bands are targeted but we are watching this one carefully.

IMT-2000

IMT-2000 is the new name for Future Public Land Mobile Telecommunications Systems (FPLMTS)-in other words, third-generation cellular systems. WARC-92 designated some spectrum near 2 GHz for these systems. At WRC-99, proponents hope to expand the available frequencies. Parts of the 13-cm (2300 - 2450 MHz) band appear on their "shopping list."

Fixed Wireless Access

There is increasing use of radio (wireless) to connect user (telephone or data) equipment to the public network at a fixed interface point. Users themselves could be at fixed locations, such as at home or at the office, or they could be mobile. The mobile user equipment is likely to use frequencies no higher than 3 GHz because of propagation considerations (e.g., line-of-sight requirements and Doppler). Fixed terminals could use frequencies much higher, even into the millimetric wave bands (30 - 300 GHz). FWA systems appear to have a voracious appetite for frequencies and are studying some of our bands, particularly 13 cm.

Out-of-Band Emissions

Out-of-band (OOB) emissions are not those outside an allocated band but those emissions just outside the necessary bandwidth for a given type of emission. In other words: key clicks or splatter. ITU-R Task Group 1/5 is now studying limits for all radio services and classes of emission. ARRL and IARU contributed papers asking TG 1/5 to exempt the amateur services from any specific OOB limitations on the grounds that such limits are not needed in an experimental service such as ours, where everyone shares the bands on an equal basis, because it is already in everyone's best interest to keep their emissions as clean as possible. That was not accepted, so work is now underway within ARRL and AMSAT to develop some limits we can live with. TG 1/5 meets in Munich July 9 - 15. The IARU representative will be Frank Butler, W4RH. Rinaldo will be in the US delegation. Former RSGB president Peter Chadwick, G3RZP, is in the UK delegation.

What's at stake is the future cost of amateur equipment, whether we may need to retrofit existing equipment to meet new OOB standards or whether older equipment can be "grandfathered." It is almost certain that the FCC will adopt the ITU OOB standards once approved.