Wikipedia
TADIL-J refers to "Tactical Digital Information Link" (TADIL) J used by the U.S. Navy, U.S. Army, U.S. Marine Corps, U.S. Air Force, the NSA, several NATO countries, and Japan as part of the Multi-Tactical Data Link Network ( MTN). TADIL-J refers to the system of standardized "J" series messages which are known by NATO as Link 16. These are defined by U.S. military standard (MIL-STD) 6016E.
TADIL J was designed as an improved data link used to exchange near real-time (NRT) information. It is a communication, navigation, and identification system that supports information exchange between tactical command, control, communications, computers, and intelligence (C4I) systems. The radio transmission and reception component of TADIL J is the Joint Tactical Information Distribution System (JTIDS) or its successor, the Multifunctional Information Distribution System (MIDS). These high-capacity, ultra high frequency (UHF), line of sight (LOS), frequency-hopping data communications terminals provide secure, jam-resistant voice and digital data exchange. JTIDS/MIDS terminals operate on the principal of time division multiple access (TDMA), wherein time slots are allocated among all TADIL J network participants for the transmission and reception of data. TDMA eliminates the requirement for a net control station (NCS) by providing a nodeless communications network architecture. .
Other TADILs included TADIL-A, TADIL-B, and TADIL-C, which were known by NATO as Link 11, Link 11B, and Link 4 respectively.
"J" series messages can also be exchanged over IP-based bearers using the NATO-defined SIMPLE protocol, JREAP and via satellite by S-TADIL J.