Passengers on Bombardier jets will often have several communication links open, so it’s important to maintain data integrity for each connection.
Once aircraft are linked to satellites or ground-based stations, the design challenge shifts to disseminating signals to passengers. Design engineers have to ensure that network traffic doesn’t overwhelm the Wi-Fi link’s ability to provide satisfactory performance inside the aircraft.
The latest versions of the Wi-Fi networks used in coffee shops usually provide enough bandwidth for users on the plane, though the challenges are more daunting in aircraft. Some suppliers also provide cell-phone connectivity for the growing number of smart phone users.
“Our systems provide Wi-Fi connectivity with passenger devices using 802.11g/n,” said Frederick St. Amour, Sales Vice President for Row 44. “Our GSM option enables GSM services using a base station transceiver and leaky line antenna.”
These links must support users who are viewing movies, listening to music, and doing a wide range of Web searches while sending messages. When many passengers are doing three or four things at once, it puts a fair amount of strain on networks. Adding Wi-Fi routers is the obvious solution, though that adds cost and weight while increasing power requirements.
Another challenge for network designers is to ensure that all these data streams don’t suffer from errors when signals are interrupted. Momentary glitches are likely when planes must shift from one satellite or ground station to another. Designs must also account for routine interruptions that originate from the pilot or crew.
“When the pilot interrupts streaming video and audio, all those streams need to restart without any synchronization problems,” said Andrew Poliak, Director of Business Development at QNX Software Systems. “The operating system needs to meet these real-time requirements and have the capability to work in the consumer environment. Connecting to consumer products is very important on corporate jets, where everyone wants to connect their personal equipment.”
While providing speedy connections is a central focus, network developers also have to make it simple for users to get those connections started. Passwords and payments aren’t necessary on private jets, but commercial passengers can’t view signing on as a barrier to Internet access.
“Rapid, efficient activations are vital if airlines are to optimize their connectivity investments,” St. Amour said.
Network designers must also ensure that there is no interference when aircraft and satellites are using more than one communications link. Bombardier, which works closely with satellite provider Inmarsat, is among the companies that have resolved this issue.
“We have router usage rules that can be set to avoid this situation,” said Yannick Dansereau, Lead Product Manager for Cabin Systems at Bombardier. “With our multichannel Inmarsat SwiftBroadband solution, people logged onto one channel for Internet access do not affect the available bandwidth on the second available channel.”