Composition and Development Suggestions of Airborne SATCOM System

1. Composition of airborne SATCOM system

The airborne SATCOM system consists of three parts, namely the space segment, ground segment, and onboard segment.

The space segment refers to the communication satellite, which mainly includes the satellite transponder. Currently, there are several available satellites covering the traditional Ku band in China, including Zhongxing-6A, 10, 11, 12, AsiaSat 5, 6, 7, and Asia-Pacific 5, 6, 7, 9. However, due to the high resource utilization rate of Ku transponders (over 70%), the resources available for onboard Ku business are limited.

The IPSTAR (Thaicom) covering the Asia-Pacific region is a Ku HTS satellite, with a bandwidth capacity of 12G available in China. However, aviation mobile services have not yet been launched.

China's own Ku HTS satellite has not been launched yet, and the earliest launch date would be 2018. China will launch its first Ka commercial satellite in 2017, and the fourth maritime satellite, GXpress, is expected to be launched in the second half of the year.

The ground segment mainly refers to the ground facilities responsible for sending and receiving satellite signals and managing the satellite network, usually called the ground station, including equipment such as antennas, RF, main station Hub, network management system, and network operation center (NOC).

The onboard segment refers to the communication equipment on the aircraft, including the external antenna, antenna control unit, high-power amplifier, modulation and demodulation unit, and wireless access equipment in the cabin.

2. Development suggestions for airborne SATCOM

The future trend and direction of SATCOM systems are the application of Ka band and HTS technology. However, considering that China does not yet have the commercial conditions for Ka or Ku HTS, (IPSTAR is currently being upgraded and has not been applied to aviation mobile services), the choice of airborne SATCOM for various airlines becomes a difficult problem.

Should mature traditional Ku airborne SATCOM solutions be selected, or should they actively experiment and wait for Ka/Ku HTS to mature?

Currently, the airborne SATCOM systems that can be deployed domestically in China include the L-band maritime SATCOM system and the Ku-band broadband SATCOM system.

Considering the airworthiness requirements of AOC voice communication by the Civil Aviation Administration, if the L-band maritime satellite solution is chosen, taking full advantage of its SBB link to find a narrowband earth-air link for the cabin Wi-Fi to solve text communication needs such as IM is also a good choice.

As for the selection of broadband earth-air link technology, considering the risks of regulatory policies, technology choices, bandwidth resources, onboard hardware, retrofitting, and return on investment, the key reason for conducting trial operations at this stage, there is a risk in selecting the scale of deployment decisions. Instead of betting everything on a single move, it is better to deploy and implement in stages, exploring different technology solutions' commercial models while actively building a cabin Wi-Fi network to solve in-flight entertainment issues. After technical verification and clear commercial models, decisions and deployments of airborne SATCOM systems can be made.