CABIN AVIONICS

Taking care of business aloft

Contented passengers on long flights need more than good catering. They need reliable cabin communications and entertainment systems.




ICG ePhone is expandable to up to 4 handsets per base station, each of which will support up to 3 simultaneous calls. The ability to make a phone call anywhere at any time has become a "must" in corporate jets.

While a smoothly operating IFE system that allows each passenger to do his/her own thing at his own schedule is quite an achievement, the communications part is even more complex. Now, in addition to watching the latest movies, passengers may want to communicate, no matter where the aircraft is. This can be achieved worldwide, including the poles, via HF.

This author still remembers that passengers had to fill out forms if they wished to place a phone call via the HF frequencies of Stockholm Radio—a company with a huge antenna park in Sweden and worldwide HF ability. But today, except for the poles, the obvious choice is satellite communication.

Satellite phone calls became available in the 1980s, but the cost was high—$10 per minute—since they used the limited bandwidth of L-band frequencies. The 2003 world communications conference allocated further frequencies to airborne satellite communications—notably the Ku-band frequency spectrum, which has a large bandwidth and is also used for TV transmissions to aircraft, such as JetBlue's inflight TV service.

Some airlines started to offer in­flight Internet around this time together with Boeing (Boeing Connexion). Antennas were still a limiting factor, as the mechanically-steered satellite tracking antennas required huge domes on the upper side of the aircraft.

JetBlue's Ku-band-based TV service is even available during takeoff and landing.

Israeli defense company Starling was the first to offer a civilian phased array antenna for light and midsize business aircraft which could track satellite signals without mechanical movement. The size is so compact that today even landlocked trains, vans or SUVs may have these antennas installed on the roof.

Starling's line of antennas for aircraft and land vehicles allows real-time streaming video, voice and high-speed data connectivity for military, emergency, police, firefighting, search-and-rescue, news gathering, homeland security, and military air, sea and land vehicles.

Even though Ku-band is available for airborne satellite transmissions—except over the high seas and domestic airspace—there may still be restrictions to its use over another nation's airspace. This is a sensitive issue. Some countries expend a lot of effort to restrict free access to the Internet, and to have someone fly in with their own unrestricted connectivity does not sit well with these states.

Worldwide inflight comms

The Danish company Thrane & Thrane, founded in 1981 and now owned by Cobham, is well established in the marine communications industry, and has been pioneering satellite communications solutions based on the Inmarsat system.

By developing a voice over Internet protocol (VoIP) for satellite communications, similar to Skype, they were able to bring down telephone communication costs via satellite to $1 per minute from amounts much higher then that.

I actually use Thrane & Thrane's system on the yacht I am lucky to sail once in a while. It's a great system—you just pick up the handset and dial from anywhere in the world. And you may be called as well under your own number.

Thrane & Thrane then brought this experience to the corporate aviation world. The company's newest system is the Aviator 700, which it says can be tailored to any airframe, mission profile and budget. The system integrates Inmarsat Aero-H+ and Swift­Broadband services, meaning that it can be used for both aeronautical flightdeck applications and cabin communications.

This is important because satellite connectivity is becoming increasingly important for ATC communications while operating internationally over the oceans and other controller–pilot datalink communications (CPDLC) airspace, such as the north and south Atlantic, important Pacific routes and airways in India and China.

Voice calls can be placed via the aircraft's audio system and multipurpose control and display unit (MCDU) dialing. The ACARS can also be connected and receive worldwide weather and oceanic clearances via satellite.

In the cabin, Thrane & Thrane's Aviator 700 gives operators full "office in the sky" features. The system provides up to 4 channels of simultaneous voice and data at speeds up to 432 kbps. Thrane & Thrane claims that the system gives access to a true IP-based network in flight using Inmarsat's I-4 satellite constellation to connect global voice and data calls.

This satellite constellation has global coverage except at extreme polar latitudes (above 70° N or S). Thrane & Thrane was actually contracted by Inmarsat to built the ground-based radio access network for the I-4 satellites.

Through the onboard router, users can make phone calls, connect their PDAs, log on to corporate networks, e-mail, surf the Internet or send a fax all while in flight. Several phone calls can be made at the same time from multiple handsets.

All this is surely fun, and frequently useful too, but it comes with a significant monthly bill for transmission costs. Thrane & Thrane claims that its system reduces airtime cost significantly because users pay only for bandwidth used instead of paying for connection time (as was the case with Inmarsat's previous-generation Swift64 service).

To save costs, Aviator 700 can operate in different data modes depending on user requirements. The operator can choose quality of service (QoS), which ensures guaranteed bandwidth and pay per minute, or select the always-on background connection, where the operator pays only for the amount of data transferred.

While the multichannel Aviator 700 requires a high-gain antenna, the smaller single-channel Aviator 200, 300 and 350 systems can work with low and medium-gain antennas and are "right-sized" for lighter executive aircraft.

Thrane & Thrane was the first manufacturer to receive STCs for a SwiftBroadband SB200 system. STCs exist for Citation models 500/560 (developed by Banyan Air Services in Florida) and for the system's use aboard the King Air 200 (developed by Hawker Beechcraft Services).

With the introduction of the Avi­ator 200, the company now offers a SwiftBroadband solution for any system size or connectivity speed—or budget. The systems are marketed to everyone from turboprop operators to large executive jet fleets. Even unmanned aerial vehicles (UAVs) and government and military transports benefit from these systems.

A large choice of systems exists for IFE and office-in-the-sky communications. Cost and functionality are always a factor, but operators should be sure to select a highly experienced installer. The quality of the installation is of utmost importance, because all this entertainment and connectivity still happens in the complex and interdependent environment of an aircraft.

2


1 | 2| 3 | next