Business Jet Connectivity: ATG or Satellite Pros & Cons

Imagine purchasing your first aircraft, or upgrading to a newer model only to discover there’s no Wi-Fi onboard... The feeling is like waking up and not being able to find your phone!

No doubt as you’ve planned the acquisition you’ve directed at least some focus on which system to install. But there is another important decision you must make first. Should you choose an Air-to-Ground (ATG) system or a Satellite-based system?

Of course, this decision will be determined by where the aircraft is based. ATG networks are prominent within the United States for Business Aviation. Although Europe, China and Australia are all in different stages of ATG implementation, primarily it is for use by the scheduled airlines for now.

Other than SwiftBroadBand systems (which we’re excluding from this article due to the very slow data rates), GEO-based satellite systems cover most of the earth’s surface and offer an alternative to those who are flying aircraft outside the stated ATG regions.

Understanding ATG and Satcom Infrastructure

To begin to measure the pros and cons of ATG and Satcom connectivity, it’s important to understand their infrastructure and how this impacts your jet’s connectivity.

The ATG network consists of ground-based towers strategically placed to provide overlapping coverage in the air. The signals are based on ‘Line-of-Sight’ technology – the same used by the VHF radios onboard the aircraft.

Since these towers transmit their signals upwards to the sky in a diverging path, the coverage usually takes place between 3,000-10,000 feet. In most cases, one or two antennas are installed on the belly of the aircraft’s fuselage to receive and send data to the towers.

Since an aircraft typically only flies 6 to 7 miles in the air, latency – the amount of time it takes for data to travel from one point to another across a network and usually measured in milliseconds – is drastically reduced.

In contrast, today’s Geostationary (GEO) satellite systems consist of three to four satellites strategically positioned 22,000 miles above the earth's surface. Like the beam of an adjustable flashlight, their signals overlap to provide coverage over most of the earth.

One antenna is installed on the top of the aircraft’s fuselage or empennage to transmit and receive signals to and from the satellite. Latency is increased due to the distance between the aircraft the satellites and ground stations.

Beginning later this year, Next Gen Low-Earth Orbit (LEO) satellite systems will reduce the latency by orbiting only 350-500 miles above the earth, with constellations ranging from hundreds to thousands of satellites.

What are the Advantages of ATG and Satellite Connectivity for Business Jets?

ATG Pros: In addition to the lower latency provided by ATG systems, they’re also less expensive to install, and downtime for the installation is less. There is also a noticeable weight saving since there are fewer Line Replacement Units (LRUs) than are required for satellite systems.

And monthly service plans tend to be more economical, with affordable unlimited plans for a wider group of Business Aviation users. Unlimited data plans tend to be very popular with customers since they allow operators to budget on a fixed cost each month.

Moreover, some ATG systems have an embedded In-Flight Entertainment (IFE) system that is internal to the LRU. (For example, Gogo Business Aviation provides an LRU that delivers movies, TV shows and e-magazines from a 1-Terabyte hard drive stored within the unit. A 3D moving map is another value-added feature.)

These additional features allow passengers to be entertained while keeping them off the internet, which helps to further reduce costs due to lower data usage (for those who are not on unlimited data packages). 

GEO-based Satellite Pros: Perhaps the most favorable advantage of the satellite system is the fact they provide operators coverage from gate-to-gate.

Whether your take-off is delayed and your jet is sitting on the tarmac indefinitely, or you are taking off or landing, satellite systems provide passengers with coverage. (You should ensure you check a specific system’s coverage map, though, to ensure they cover the areas to and from which you will fly.)

Of course, in most cases Satellite systems deliver faster data speeds and more bandwidth to the passengers than ATG.

What are the Disadvantages of ATG or Satellite Connectivity for Business Jets?

ATG Cons: The obvious disadvantage of ATG is the limited area the systems cover. Gogo, for example, encompasses the continental United States, southern Canada, and Alaska. 

Since the towers are ground-based, however, aircraft flying direct routes from Miami to Boston or Miami to Houston (for example) can face service interruption when flying over the ocean.

GEO-based Satellite Cons: Comparatively expensive to install and operate, GEO-based satellite systems’ current structural design (using a mechanically steered antenna, MSA) – limits the aircraft that can have them installed to Super Mid-size Jets and larger.

Installation can take four to six weeks to complete, especially if a new radome needs to be installed at the top of the aircraft’s empennage. The cost of the radome and associated certification can exceed $200k, on top of the cost of the satellite system itself.

Regarding monthly data plans, these are designed so that aircraft operators must pay to get a set level of service, however they remain exposed to data overage charges.

And finally, satellite systems don’t provide other ancillary features, so a separate LRU is required for a moving map, while movies and TV shows are streamed to the aircraft which increases data usage and costs.

ATG and Satellite Connectivity Hybrid Systems for Business Aviation

Redundancy with on board avionics systems is a common issue in aviation, but with connectivity being a vital requirement from Business Aviation passengers, many operators choose to install ATG and Satellite systems together. There’s a huge advantage to this hybrid approach.

Having discussed the lower latency and data costs of ATG, the router can be configured to offer the best and most economical service available within the appropriate coverage area.

By their nature, aircraft will move in and out of coverage areas – so, for example, as it leaves the coverage area of ATG and overflies the ocean, the Satellite connection can be switched on to enable continuous connectivity as the passengers require it.

Often the passenger profile aboard the aircraft changes – especially when it’s being made available for charter. So, on one flight the owner might send a team of executives to open an international location. On another occasion a family might charter the jet to fly on vacation in another part of the United States.

With hybrid connectivity, the aircraft will be equipped to provide coverage in both scenarios. And those making their business jets available for charter can always disable the satellite system and only provide ATG capability to save costs when the jet isn’t being used by them.

In the event the owner decides to sell the jet, provided the systems are not nearing obsolescence, the aircraft is equipped and ready to go for a wider pool of buyers. (I have seen many aircraft sales delayed or even fall through because the cabin connectivity does not provide coverage for where the new owners need to fly.)

ATG and Satellite Connectivity in Business Aviation: What’s Next?

Within the next twelve months, the next generation of satellite systems will come to fruition. LEO constellations and their newer, smaller Electronically Steered Antennas (ESAs) will provide satellite connectivity options for Light to Mid-size Jets that weren’t available before.

LEOs have the potential to eradicate all the ‘Cons’ highlighted in this article for GEO satellite systems.

While ATG within the United States is well-established and here to stay, beyond the US ATG is still in its infancy and must battle the challenge of LEO systems which will eat into the target market. And since international ATG’s early adoption has been with the airlines, the size and weight of the boxes and non- standard voltage selection must be addressed.

There is likely to be a lot of “wait and see” from aircraft owners in the next few months. Aircraft management and charter companies especially are being cautious. They want to feel comfortable that their next investment doesn’t become obsolete or prove financially unsound within a few years.

The next twelve months will be an exciting period for the Business Aviation connectivity industry and produce new options for operators. Be sure to invest your time finding the right solution for your flight department so your investment stays ‘connected’.

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