SPEAKERS’ CORNER: Ku or Ka? A Summary of the Issues Shows Ku Makes More Sense – By Row 44’s John Guidon


Day two of Farnborough has come to an end and so far, the pundits who bet on Boeing and the aircraft leasing community were correct. The 737 MAX sales are North of 1,000 units while lessors have gobbled up a lion’s share of the orders. Airbus announced a $4.2B deal with Cathay today as both big plane vendors struggle in a down economy and the prospects of a declining military sales. So much for the bad news. The good news is Row 44’s CTO, John Guidon has agreed to grace our “Speaker’s Corner” series with (What else?) a treatise on Ku band inflight connectivity logic. What’s next, a refute by the Ka Community? We’ll see! Heeeeere’s Johnny:

Ku or Ka? A Summary of the Issues Shows Ku Makes More Sense
By Row 44’s John Guidon

I know that you’re hearing lots of opinions about whether Ku-band or Ka-band satellite technology makes the most sense for airlines to deploy for inflight Wi-Fi and entertainment now, next year and a few years forward.

In the quest for bandwidth, the satellite industry has moved through numerous bands (L, C, S, X, Ku and Ka) over time. Each has pros and cons, and all are still in use, having established their own defensible markets. Today the Airborne Mobile Satellite Services industry faces the choice between Ku and Ka bands for broadband service. The question is: Which serves the airline market better?

I’d like to give you the perspective of someone who has been deeply involved in the eight-year process of bringing to market the only airline connectivity system in production today on more than 300 aircraft worldwide. This system is supported by Ku-band because Ku is the most reliable, lowest risk and cost-effective technology available, and therefore, is the most sensible choice for supporting airlines’ Wi-Fi and entertainment content needs.

Universal: The Ku-band is a proven, mature commodity; more than 160 satellites in orbit create a global resource. Since one satellite can cover an entire continent or ocean, there’s enough overlap and redundancy to create real price competition. By contrast, the number of Ka-band satellites is just into double digits, and there is a disturbing trend: Typically, the requirements of each Ka satellite are somewhat incompatible with many or all of the others.

Antenna size: Advancements in antenna technology have made it possible to reduce the size of the Ku-band antenna to a very streamlined low profile addition. To that end, proponents of Ka-band satellites have touted the use of an even smaller antenna to support Ka. Prominent early claims hyped “50Mbps to an antenna the size of a paperback book” and so on. However, this is misleading. Industry experts believe that Ka-band antennas will be very similar in size to the Ku low-profile antennas used today. This is primarily due to regulatory factors and variations between Ka-band satellites, as well as needing to overcome the challenge of rain and cloud to Ka-band.

Radio Frequency (RF) subsystem cost: Airborne RF subsystems for Ku-band operation will cost 50 percent less than Ka-band in the near and mid-term. While costs will fall as time goes by, Ku-band is still estimated to remain more cost effective by approximately 30 percent. This is because Ka-band needs lower loss components at higher frequencies.

Consistency: A major concern for the end user is consistency of coverage, which is a critical area where broad-beam Ku-band satellites will continue to be superior. Ku satellites are typically built with a few beams that each cover a large area, often as big as a continent, and the service is consistent across the whole area. By contrast, Ka satellites are usually designed using “spot beams.” This means Ka-band will need to use up to hundreds of beams to cover the area of a single Ku beam. The problem in Ka-band is that the cost of provisioning service is determined by the maximum number of planes in each spot beam, but the revenue results from the average number of planes in that spot. Typically, the maximum number of planes in each small spot is several times the average. This means covering each spot costs several times more than it should; a cost which must be passed along to the airline customer. If service is under-provisioned, congestion will result, a well-known issue to users of tower-based services. The broader beams of Ku satellites suffer no such economic or infrastructural issues.

Television: Ku-band is the only satellite technology that can cost-effectively deliver live television programming to airlines. Ka spot beams make TV delivery cost prohibitive because of having to carry the TV live streams in every cell where even a single plane may fly. By contrast, all the planes under a broad Ku beam can receive the same, single broadcast of the live TV streams.

Fungibility: Ku-band satellites are broadly interchangeable and they compete for business. Conversely, there are no competitive free market equivalent offers for Ka-band, which may ultimately be a deterrent for widespread acceptance. Competition between rival services will bring the lowest priced and highest quality service to a global coverage solution, in any current or future band. Only the most competitive and cost-effective solutions should ultimately survive, and today Ku-band is the only satellite service to meet those standards.

Timing: In the event of a Ka-band satellite failure, what are the recovery options? Could it take days, months or years? Given a more than nine percent rate of launch/deployment/in-service failures, there is a risk to dependency on future Ka-band satellites that cannot be mitigated in the near and medium term. In addition, grant by the Federal Communications Commission (FCC) of licenses for airborne Ka terminals and antennas may well take years, especially given the need to consider other, non-geostationary, satellites, which are already in the Ka band. In sharp contrast, Ku band is available today, offers redundancy in the event of failures and is approved by the FCC and worldwide.

In conclusion, Ku-band satellites have been and will continue to be, for several years, the lowest risk and most dependable solution for delivering cost-effective, consistent broadband services to airlines. Row 44 will continue to focus on the issues that are meaningful to airlines, including development of migration paths to evolving technologies, and pushing for those technologies to be delivered with the same reliability and cost-structure that our airline partners desire. Only then will these technologies be ready to address the commercial airline connectivity market.

About the Author
John Guidon is the co-founder and Chief Technology Officer for Row 44. Mr. Guidon is an engineer and serial entrepreneur living in Southern California. Row 44 is the leading satellite based in-flight WiFi and device-based entertainment provider for commercial airlines.

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