Dear,

We are writing to you today to provide you with information aboutthe critical communication services that [company] is providing using satellite transmissions in C-band frequencies (3400-4200 MHz downlink and 5850-6700 MHz in the uplink). {Brief company description as introduction: e.g. Company is a VSAT Service provider in [country] providing connectivity via satellite throughout [region]}.

As you are aware, leading up to the World Radiocommunication Conference 2015 (“WRC-15”),organized by the International Telecommunication Union (“ITU”),various groups, including the terrestrial mobile industry, are lobbying heavily for additional spectrum below 6 GHz. If allowed to operate in the satellite C-band, terrestrial mobile services will severely disrupt important servicescurrently delivered by satellite. Because you as a [regulator/ministry] will be making important decisions about the spectrum that we rely on to satisfy end users’ needs, we thought it necessary to provide you with information about the extensive usage, nature, and criticality of the services we provide in C-band.

Service Provided in [Country/Region] via Satellite

{Please describe the services that your company provides and the impact these have for your country and your region: Information could include the following:

  • Region, countries and/or cities/areas to which services are being provided,
  • Number of end-users or viewers, number of sites connected,
  • Amount of bandwidth in C-band,
  • Types of services and applications being used (e.g. broadcasting, cellular backhaul, connecting schools, hospitals, corporations, etc.)
  • Any socio-economic or direct economic benefits, including jobs dependent on these C-band services,}

Characteristics and Advantages of C-band

[company] relies heavily on C-band becauseit has a number of advantages over other frequency bands, such as Ku- or Ka-band. These advantages include:

  • The large geographic coverage area of C-band satellite beams allows for whole regions or continents to be connected – resulting in a very cost-effective communications network. For example, one of our services connects [country] to numerous countries throughout [Latin America/to North America/to Europe- complete as appropriate] – all within the same satellite beam.
  • C-band is essentially resistant to rain fade. While services in higher frequencies sometimes experience degradation of their signal, services provided in C-band offer extremely high reliability, even during heavy rain.

Due to its longstanding good experience with and dependence on C-band,[company] has made a considerable investment into developing an overall network (ground infrastructure, satellite connectivity, and remote equipment) that is heavily reliant upon, and communicates with, C-band satellites.

Interference is a Problem

Satellite receivers are extremely sensitive devices because they are designed to receive extremely low-power signalsfrom satellites located in space 36,000 kilometers above the equator. Satellite services have co-existed with terrestrial microwave links from fixed points for many years, primarilybecause ofmicrowave’s use of highly directional antennas/dishes.By contrast, many of the newer applications which are seeking to utilize C-band spectrum, such as mobile or nomadic terrestrial wireless systems, emit signals from many locations and in all directions simultaneously. This transmission mode, coupled with the levels of power requested for such operations, can easilyinterfere with satellite receivers.

In some countries where regulators have allowed terrestrial wireless services to use C-band, there have been massive interruptions of satellite broadcasting services, affecting hundreds of millions of viewers.

Satellite broadcasting operations in Bahrain, Bolivia, Tanzania, Hong Kong, the U.S. and other nations have been negatively affected.

The interference caused by terrestrial wireless systems is not limited to same band operations. Out-of-band interference received from terrestrial wireless services in adjacent bands is also a problem; high power signals from wireless systems in an adjacent band are sufficient to make it impossible for sensitive satellite receivers to operate in an adjacent band.Thus,terrestrial mobile deployment in just a part of the C-band would negatively impact satellite services.

Sharing Studies

Various ITU technical studies have confirmed that separation distances in the tens and hundreds of kilometers are required to protect satellite receivers fromterrestrial mobile services if the latter were allowed to operate in C-band. Such large exclusion zones around every satellite earth station would render any terrestrial mobile service in this band economically unfeasible for wireless system operators.

Questionable Need for Additional Spectrum for IMT

While no one disputes that mobile data traffic is increasing, mobile operators should be encouraged to first improve the network density and efficiency within their existing spectrum before asking for additional spectrum which is already extensively used by other services. For example, large scale switchover by wireless operators to small cell system architecture would dramatically increase network capacity in wireless systems’ existing frequency bands. Similarly, technological advancements such as MIMO (multiple-in-multiple-out) can increase network capacity without any increase in spectrum.

Additionally, one of the large drivers behind the increase in terrestrial mobile data traffic is video. However, much of the video on mobile devices and tablets is consumed in Wi-Fi-connected areas (the home, the office, the public library or airport), and it is not clear that cellular networks need increased bandwidth for this purpose.

The above factors,when taken together, would seem to obviate the need for identification of additional spectrum for wireless systems – contrary to what wireless operators and their supporters claim.

Conclusion

[Company] is only one of the many users of C-band providing services in [country/region]. We hope that the information provided herein gives you a glimpse of the multitude of services and applications provided via satellite. C-band is the lifeblood of many of these services. Please keep the usage and importance of C-band satellite services in mind as your administration is preparing for WRC-15.

We hope that you found the information provided helpful. Please do not hesitate to contact us if you require further background information.

Sincerely,