Nowadays civil aviation is essentially using a dedicated aeronautical sub-band of the VHF frequency band for supporting their safety communications. In airspace not covered by the VHF system, HF communication band is used with a poor audio quality. With the continuous increase of air-traffic world-wide, shortage of the capacity required for supporting safety communications will be an issue in the order of 6 to 10 years.

"The development of a communications system using satellite technology is a very attractive proposition since it also provides a service in areas where terrestrial systems cannot be deployed. Alongside emerging satellite navigation systems, SDLS will contribute to much better accuracy in aircraft position monitoring, allowing greater numbers of aircraft to safely occupy a given segment of airspace at any one time. With this new system we want to prove that a "second generation" satellite system can meet the stringent requirements of the ATM's "safety of life critical functions"."

Claude Loisy, SDLS Project Manager, European Space Agency

Business Challenges

• High density air space and ability to offer global coverage in oceanic and desert regions
• Shortage of communication infrastructure to meet the continuous increase of air-traffic worldwide
• Maintaining the safety of aeronautical operations

Solutions

• Design and implementation of Satellite Access Control protocals, a real time software solution controlling access to satellite channels, transport for data communications, short messages and voice communications
• Centralized "polling" technique for satellite access modified to a general, flexible CDMA-ALOHA approach

Benefits

• Point-to-multipoint voice service allowing several pilots to listen to conversations between pilot and ground controller
• SDLS APR Service: emulates a radar system that can be used as back-up
• SDLS project is only satellite system matching strict requirements of safety communications