WRC-07 Decisions and Next Steps for Protecting the Satellite C-band

The ITU 2007 World Radiocommunication Conference (WRC-07) concluded its work last November having made a number of important decisions affecting satellite users around the world. One of the most highly debated issues at WRC-07 was Agenda Item 1.4 which tasked ITU Members to identify additional radio-frequency spectrum for existing and future International Mobile Telecommunications (IMT).

At WRC-07, the global satellite industry was particularly focused on the detrimental interference that can be caused to satellite earth stations and essential satellite communications services when terrestrial services, such as IMT, are implemented in 3400-4200 MHz (satellite “C-band”). Numerous technical studies and actual interference cases have demonstrated that three types of interference are caused by terrestrial wireless services and can severely disrupt reception of Fixed-Satellite Service (FSS) signals: (a) co-frequency, in-band interference to FSS earth stations; (b) out-of-band interference to FSS earth stations; and (c) overload of FSS earth station receivers operating in adjacent bands.

WRC-07 considered a short list of candidate frequency bands for additional IMT identification: 410-430 MHz; 450-470 MHz; 470-806 MHz; 2300-2400 MHz; 2700-2900 MHz; 3400-4200 MHz; and 4400-4990 MHz (which includes the downlink frequencies 4500-4800 MHz of the Fixed-Satellite Service Plan). After four weeks and many late hours of debate on all the candidate bands, the WRC-07 concluded that it was not feasible to identify any part of the C-band on a global basis for IMT. CITEL, and its Member Administrations in ITU Region 2 (the Americas and the Caribbean), demonstrated landmark leadership as an organization at this WRC by leading the way to a regional solution for both the terrestrial wireless and FSS requirements.

Specifically, for Region 2, it was decided to retain the primary status of the Fixed-Satellite Service throughout the 3400-4200 MHz band, and to not identify any spectrum for IMT in the C-band. Instead, through a footnote, fourteen countries [1] in Region 2 were permitted to change their national allocation for terrestrial mobile services from 3400-3500 MHz to primary status, subject to coordination and agreement from adjacent nations that operate satellite earth stations that could be affected (Radio Regulations 9.21). In the absence of successful coordination, mobile services in the band 3400-3500 MHz in the fourteen opt-in countries will have to restrict IMT use near the border with surrounding countries, and will have to shut down any operations that cause interference to existing satellite earth stations in adjacent countries. Policies to address interference to C-band satellite earth stations within a country implementing mobile services will be established by national regulators. The new allocation of mobile services in the Region 2 opt-in countries will enter into force in February 2009.

In order to protect existing satellite earth stations, all C-band earth stations need to be formally registered in the ITU Master Register. As a result, it is imperative for service providers and Region 2 Administrations wishing to protect vital satellite communications links in the C-band to ensure that all C-band satellite earth stations (receive-only and transmit-receive stations) are recorded in the ITU Master Register. This includes C-band earth stations that are located near the borders of countries that will implement IMT (or other terrestrial wireless services) in the C-band, as well as C-band earth stations located within a country’s territory. It is also essential for Administrations to respond quickly to bilateral requests for coordination to complete the process for protecting satellite earth stations in their country.

Although Region 2 did not adopt the power flux density (“pfd”) limit at the border between opt-in and adjacent countries that was adopted in the rest of the world, Region 2 Administrations are urged to consider in their bilateral discussions the internationally-agreed threshold of -154.5 dBW/m2/4 kHz as the maximum power level to protect C-band satellite earth stations.

Satellite operators will continue to work with regulators throughout the region to demonstrate that the whole 3400-4200 MHz band continues to be heavily used by the satellite industry on many of the FSS and MSS satellites serving the region today. Satellite users throughout the region continue to require bandwidth across the entire 3400-4200 MHz C-band. It should remain a high-level policy objective for regulators to protect the vital services [2] provided via C-band satellites that enables the economic, robust communications and availability that cannot be achieved in other satellite bands.

Joslyn Read
Vice President
SES NEW SKIES
Joslyn.read@ses-newskies.com