The Federal Aviation Administration (FAA) has unique requirements when it comes to radio bandwidth for Air Traffic Control (ATC). While it may seem counterintuitive, the FAA does not require a significant amount of bandwidth for its traffic control operations. However, there are certain circumstances where more bandwidth is necessary.

In regional centers, multiple carriers with multiple physically diverse entrances for remote connections are common. In the past, the FAA would request circuit paths that avoided certain central offices even when crossing small towns. In some cases, the agency might require physically different transports or three connections, all of which must be physically diverse in every aspect. Other locations may require two connections from different providers, while others may only need a single circuit.

The FAA has a strict listing of redundancy requirements for each of its 30,000-plus locations on record, which translates into uptime requirements. This level of detail has allowed the agency to save money over the years by optimizing its network design.

In the past, the FAA used digital bandwidth at a rate of 9600 bits per second (bps), which enabled them to stack five to six services on a single 64-kilobit digital channel. When digital bandwidth was expensive in the 1970s, the agency built most of its services around this rate. The use of Time-Division Multiplexing (TDM) technology allowed the FAA to build an entire network of equipment with over 150,000 unique service/location combinations, which still works today.

The regional ATC's require the most bandwidth, but the FAA is gradually moving away from TDM and transitioning to Ethernet. This is due to the high level of redundancy built into the system, with each part playing a crucial role in ensuring adequate air traffic control in its associated area.

In conclusion, while the FAA does not require significant radio bandwidth for its ATC operations, there are specific circumstances where more bandwidth is necessary. The agency's unique requirements and attention to detail have allowed it to optimize its network design and save money over the years.

Atc radio bandwith