PARIS — Global governments’ approval of radio spectrum permitting aircraft to provide additional tracking data to satellites reduces the chance of another lost jet like Malaysian Airlines MH370 and immediately improves the business case for mobile satellite services provider Iridium Satellites and its Aireon LLC aircraft-tracking affiliate.
The decision, made Nov. 11 by the 163 governments attending the World Radiocommunication Conference (WRC) in Geneva, came only after military users of nearby frequencies were assured that their Identification, Friend or Foe signals would not be upset by the civilian flight-tracking service.
Most modern aircraft for years have been equipped with Automatic Dependent Surveillance-Broadcast (ADS-B) transponders to communicate with ground radars. But these links disappear over oceans, the poles and large forested areas and deserts.
What WRC governments agreed was that this same radio spectrum – 1087.7-1092.3 megahertz – may now be extended for links between the aircraft and satellites carrying ADS-B payloads.
As is often the case with WRC meetings, held every four years under the auspices of the International Telecommunication Union (ITU), a United Nations body, the flight-tracking decision is intended to prepare for future uses of spectrum rather than to accommodate a service ready to use it right away.
In this case, McLean, Virginia-based Iridium and its Aireon flight-tracking affiliate are not just the most immediate beneficiaries, but the only ones actively pursuing a global ADS-B service.
Iridium’s 72 Iridium Next satellites, scheduled for launch into low Earth orbit in 2016 and 2017, are being fitted with ADS-B capability. The availability of Iridium, including the fact that its constellation features inter-satellite links that can speed messages around the world, combined with the March 2014 loss of MH370 to push WRC regulators into what, for the ITU, is a remarkably quick response.
Francois Rancy, director of the ITU’s Radiocommunication Bureau, said during a Nov. 11 press briefing that the year-plus of negotiations over ADS-B were not easy as the organization had to assure that no existing users of the band would be harmed.
That meant reassuring operators and manufacturers of IFF systems that their services, used mainly in military airspace, would not suffer if WRC gave ADS-B what is known as a primary allocation in the relevant spectrum.
Given that ADS-B frequencies are already used for links between aircraft and ground radars, the discussion went fairly quickly, Rancy said.
It is now left to Iridium and Aireon to deliver on what is promised by the WRC decision. There is no other company planning a similar service.
“It just so happened that Iridium was designing a network when the major air navigation authorities were mandating ADS-B [for air-to-ground links], and that Iridium was in low Earth orbit so there was no need to change the avionics already on the aircraft,” Aireon Chief Executive Don Thoma said in a Nov. 12 interview.
“Also, Iridium has cross-links enabling full, global coverage back to air traffic control, and the hosted-payload model makes it cost-effective. If you had to build an Iridium-type network solely for ADS-B, it would cost too much for the air-traffic-control authorities and the service providers. This way, it’s doable,” Thoma said.
The Iridium Next constellation is expected to cost about $3 billion. Iridium has stitched together what it says is a mosaic of financing sources to pay for it, and Aireon is one of those sources.
Aireon’s business model is straightforward: It will provide a global surveillance capability with the same performance level as the current ground-based ADS-B system. Air navigation authorities will use the information not only to track aircraft mid-ocean, but also to assign more optimal air routes to save fuel or avoid bad weather.
Ultimately, these same air navigation authorities should be able to reduce their investment in ground radars.
Some percentage of these savings will then be passed on to Aireon in the form of a service fee paid by national air traffic authorities in return for surveillance of aircraft in their national airspace.
For reasons still unknown, the communications gear aboard MH370 was shut down. With the ADS-B spectrum now approved, the International Civil Aviation Authority will need to determine whether these transponders will be activated automatically or will remain within pilots’ control.
