Definition
A digital telecommunications standard that carries voice, data, and other services over the same telephone lines, used historically by aviation service providers to deliver weather briefings, flight plan filing, and similar dial-up data services.
Plain English
A type of phone-line technology that lets voice and computer data travel on the same line at the same time. In aviation, it was used to connect to weather and flight planning services.
Context Anchor
A pilot may see ISDN in FAA acronym lists, older airport communication descriptions, or system documents that mention how information is sent between offices or equipment.
Derivation
Integrated means combined; services refers to voice and data carried together; digital means the signal is sent as numbers rather than as analog waves; network means the connected system of lines. Together: a network that integrates several services in digital form.
Why Pilots Care
Most pilots will only meet this term in passing, but recognizing it helps when reading older FAA material that describes how flight service stations and weather providers historically delivered information.
Intuition Check
ISDN is not a navigation system or cockpit instrument. It is a communications link used to move voice and data.
Example Sentence 1
Older flight planning terminals connected to the weather service over an ISDN line.
Example Sentence 2
The dispatcher checked the ISDN connection before transmitting the updated departure clearance.