Does ViaSat still want to use AeroSat’s antenna for in-flight Internet? Why yes!

With all the tit-for-tat, spit-for-spat playing out in FCC filings between rival satellite-based connectivity providers ViaSat and Row 44, it’s easy to forget they share a common antenna partner – AeroSat. Yes, that’s the same company that stands to be hurt financially should the FCC continue to delay approval of Row 44′s system, as repeatedly requested by ViaSat, and should commercial trials on Alaska Airlines and Southwest Airlines remain at bay.

AeroSat antenna.jpgAnd so, the big question is: “Does ViaSat still want to use the AeroSat antenna?” The short answer is “Yes”. Indeed you can download a big ole brochure on how AeroSat’s antenna fits into ViaSat’s in-flight connectivity system for VIP aircraft.

The long answer was given to me today by ViaSat director of regulatory affairs Daryl Hunter.

I understand his concerns but from a consumer standpoint, I’d love to see a Ku-band-based connectivity system flying soon. Wouldn’t you?

In any case, here are those notes in full (there is plenty in here to mull over but now it’s time for me to go to bed…if I dream about antennas I’ll know I have a problem).  

We still believe that the AeroSat antenna meets our needs for certain airborne applications and have no beef with them at all as a supplier/partner. Our concern is the total integrated Row 44 system and the high off-axis EIRP density levels that will result when this antenna is used with Row 44′s modem.

I entirely understand their desire to see the Row 44 trials move ahead as it would represent a significant financial boost to them once they start shipping these units in quantity. But to claim that the long term aeronautical internet business will be put at risk should AeroSat fail financially is, well, silly.

On the other hand, for AeroSat to claim financial hardship because their product is being used in an application that does not conform to FCC regulations and request that the FCC move ahead in spite of that is ridiculous. The financial stability of a small niche antenna product should not be a factor in bending FCC rules that affect the whole industry.

It was AeroSat’s choice to put their lot in with a system integrator (Row 44) with no established experience in the aeronautical broadband space, and who is using one of the modems that does not sufficiently lower the input power density.

The two-way Ku-band antenna business for aero has been somewhat of a chicken/egg problem. Antenna manufacturers don’t want to invest money in bringing a product to market if there’s no market, the airlines want a product that’s on the shelf, and so on.

Antenna manufacturers for any of the mobile satellite services (maritime, ground, and aero) tend to view their product as the chief enabler of the service. In reality, due to the very real concerns of adjacent satellite interference and current US and international rules, it is the total communications system that users need to consider rather than just the antenna.

Virtually all of the antennas made today or in work for future aero applications are too small physically to meet the narrow beamwidth requirements that are needed to protect adjacent satellite users from interference when used in conjunction with traditional modem modulation techniques. This is because there isn’t that much real estate available on top of the aircraft, and because of the need for a low profile to reduce drag – thus the antennas are too small physically to produce a narrow beamwidth.

In order to really use any of the antennas in today’s regulatory environment, what is needed is a means to sufficiently lower the power spectral density of the signal supplied to the antenna. This way when emitted by the antenna, the inevitable energy that spills out off the side of the antenna towards the adjacent satellites is low enough that no harmful interference results.

ViaSat recognized the importance of this issue years ago and has spent considerable time and money developing a technical solution to the problem. While the viability of our approach is clearly supported by the years of operational experience with our fielded systems, others have also employed similar techniques (e.g., Connexion by Boeing, and Omnitracs by Qualcomm).

The interference problem is complex and not well understood by users and industry participants who aren’t conversant with the FCC and international rules, or the whole satellite communications process as a system. We see time and again where modem, radio, and antenna vendors offer products to users claiming to be useable for these mobile applications, but which when considered as a system, fall short of passing muster with respect to the adjacent satellite interference issue.

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2 Responses to Does ViaSat still want to use AeroSat’s antenna for in-flight Internet? Why yes!

  1. Shizuko Earnshaw December 24, 2009 at 2:23 am #

    Thank your for the the great information.

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