In an effort to increase broadband access on aircraft, the U.S. Federal Communications Commission (FCC) is proposing to use Ku-band, on a secondary basis, for terrestrial-based air-to-ground mobile services.

According to IMS Research, by 2021 more than 15,000 global aircraft will have Wi-Fi – a five-fold increase from today’s numbers. Consumers’ unquenchable thirst for ubiquitous broadband connectivity has everyone looking for technical and regulatory solutions to meet this demand. Under the FCC’s proposed rules, the 14.0-14.5 GHz band could now be used for air-to-ground mobile, or what the FCC calls Aeronautical Mobile Services (AMS).

The Qualcomm Petition

On July 7, 2011, Qualcomm filed a petition for rulemaking with FCC that outlined the company’s proposal for providing AMS multi-gigabit wireless broadband to airborne aircraft using the 14.0-14.5 GHz band on a secondary basis. The proposal included an engineering study claiming that the system would not cause harmful interference to services already using the band. On May 9, 2013, the FCC issued a notice seeking comment on proposed rules for such air-to-ground mobile services.

How the Service Would Work

Qualcomm proposed to use a time-division duplex (TDD) system to link ground-based stations and aircraft. This could allegedly sustain data rates of 300 Gbps over the 500 MHz Ku-band using spatial diversity to avoid interference to satellite systems. To mitigate harmful interference, the company suggested placing ground antennas along the southern border of the United States. In contrast to satellite earth stations that point south, AMS antennas would point north and would be designed to radiate less energy as their elevation angle increased.

Potential Problems to Satellite Systems

While AMS would operate on a secondary basis – meaning that it would accept interference from primary systems – other satellite services already use part of the Ku-band on a secondary basis. This is the case of NASA’s tracking and relay services as well as the radio astronomy service. As such, AMS would operate co-secondary with these government systems and would have to coordinate with them, which is a challenge in itself. Furthermore, the danger of potential interference of AMS to satellite systems is real; especially since Ku-band earth stations are typically blanked licensed, often moved and their location is unpredictable.

Proposed Licenses

The FCC is seeking comment on whether to license the band on one nationwide 500 MHz block or two nationwide 250 MHz blocks. The Commission is also seeking comment on whether performance standards should be imposed on licensees in the form of serving a minimum number of airports.

Other Use of the Ku Spectrum

In its notice of proposed rulemaking, the FCC did not allude to additional allocations of the 14.0-14.5 GHz band other than to AMS. However, it called for comment to further explore the topic. At the time of the AMS notice, the FCC denied a petition by the Utilities Telecom Council to allocate the 14.0-14.5 GHz for fixed point-to-point and point-to-multipoint systems. In its reasoning, the FCC said that these users already had other spectrum available and that allocating the band to fixed systems would prove difficult to prevent harmful interference to satellite systems.

Conclusion

According to the FCC, AMS could potentially yield higher speeds and better price points than earth stations on board aircraft. But it remains to be seen if AMS will be able to protect incumbent satellite systems.

Raul Magallanes runs a Houston-based law firm focusing on telecommunications law. He may be reached at +1 (281) 317-1397 or by email at raul@ rmtelecomlaw.com.