TADIL-A/Link 11 is a secure half-duplex tactical data link used by NATO to exchange digital data. It was originally developed by a joint committee including members from the Royal Canadian Navy, US Navy and Royal Navy to pass accurate targeting information between ships. The final standard was signed in Ottawa in November 1957, where the British proposed the name "TIDE" for "Tactical International Data Exchange". It was later made part of the NATO STANAG standardization process.
The system operates on two frequencies, one in the high frequency (HF) range for over-the-horizon (OTH) communications, and another in the ultra high frequency (UHF) range that uses much smaller antennas and is suitable for smaller ships but lacks the OTH performance. The system broadcasts packets of 30 bits length, with 6 bits of error correction and 24 bits of payload data. The payload is encrypted.
Link 14 was adopted at the same time as a low-end counterpart to Link 11. Link 14 is essentially a digital teleprinter system lacking encryption and automation, intended for ships lacking the ability to use Link 11 data in an automated fashion.
The designation "Link 11" is derived from "Link II", the British designation using Roman numerals before NATO standardized on Arabic numerals. "Link I" was the data link used by the Comprehensive Display System. [1]
MIL-STD-6011 exchanges digital information among airborne, land-based, and shipboard tactical data systems. It is the primary means to exchange data such as radar tracking information beyond line of sight. TADIL-A can be used on either high frequency (HF) or ultrahigh frequency (UHF). However, the U.S. Army uses only HF. Link 11 relies on a single platform to report positional information on sensor detections. This positional information can be amplified with additional data to qualify the identity of the detected track. Link 11 was developed by Ralph Benjamin while with the Admiralty Surface Weapons Establishment (ASWE), Portsmouth.
Link 11 will be replaced by Link 22.[ citation needed ]
Link 11 is defined by the United States Department of Defense as MIL-STD-6011.
The NAUTIS (Naval Autonomous Tactical Information System) originally included the Link 11 system as installed in the Royal New Zealand Navy's Leander-class frigates as part of the mid-life upgrades in the 1980s HMNZS Canterbury; NAUTIS versions were also found on the Royal Navy Hunt-class minesweepers.
Link 11 is a half-duplex, netted link that normally operates by roll call from a data net control station (DNCS). Link 11 can also operate in the broadcast mode. The roll call mode of operation used in the Link 11 interface requires that each participating unit (PU) respond in turn while all other stations are receiving. A DNCS initiates the roll call by addressing and transmitting an interrogation message to a specific PU that then responds by transmitting its data. The DNCS then interrogates the next PU in the prescribed roll call. Link 11 can be transmitted on high frequency (HF) and/or Ultra High Frequency (UHF) bands. Data speed can be selected from bit rates of 2250 or 1364 bits per second. Dual sideband diversity operation and Doppler shift correction features improve reliability and accuracy of data exchange. Link 11 operates on HF (2-30 MHz) and/or UHF (line of sight (LOS)) (225-400 MHz). Some data terminal sets (DTS) provide the option to select either the conventional Link 11 waveform (CLEW) or the single tone Link 11 Waveform (SLEW). SLEW and CLEW are not compatible waveforms. SLEW, among other enhancements, provides increased propagation and a more powerful error detection and correction (EDAC) algorithm. While the option exists to operate in either CLEW or SLEW, all participants in a given Link 11 net must select the same waveform to achieve connectivity between units. Link 11 is defined in military standard (MIL STD) 6011, Tactical Data Link (TDL) A/B Message Standard.
The term Tactical Digital Information Link (TADIL) was obsolete (per DISA guidance) and is now more commonly seen as Tactical Data Link (TDL) [2]
Radioteletype (RTTY) is a telecommunications system consisting originally of two or more electromechanical teleprinters in different locations connected by radio rather than a wired link. Radioteletype evolved from earlier landline teleprinter operations that began in the mid-1800s. The US Navy Department successfully tested printing telegraphy between an airplane and ground radio station in 1922. Later that year, the Radio Corporation of America successfully tested printing telegraphy via their Chatham, Massachusetts, radio station to the R.M.S. Majestic. Commercial RTTY systems were in active service between San Francisco and Honolulu as early as April 1932 and between San Francisco and New York City by 1934. The US military used radioteletype in the 1930s and expanded this usage during World War II. From the 1980s, teleprinters were replaced by personal computers (PCs) running software to emulate teleprinters.
Automatic Link Establishment, commonly known as ALE, is the worldwide de facto standard for digitally initiating and sustaining HF radio communications. ALE is a feature in an HF communications radio transceiver system that enables the radio station to make contact, or initiate a circuit, between itself and another HF radio station or network of stations. The purpose is to provide a reliable rapid method of calling and connecting during constantly changing HF ionospheric propagation, reception interference, and shared spectrum use of busy or congested HF channels.
MIL-STD-188 is a series of U.S. military standards relating to telecommunications.
In NATO, a standardization agreement defines processes, procedures, terms, and conditions for common military or technical procedures or equipment between the member countries of the alliance. Each NATO state ratifies a STANAG and implements it within its own military. The purpose is to provide common operational and administrative procedures and logistics, so one member nation's military may use the stores and support of another member's military. STANAGs also form the basis for technical interoperability between a wide variety of communication and information systems (CIS) essential for NATO and Allied operations. The Allied Data Publication 34 (ADatP-34) NATO Interoperability Standards and Profiles which is covered by STANAG 5524, maintains a catalogue of relevant information and communication technology standards.
The Joint Tactical Radio System (JTRS) aimed to replace existing radios in the American military with a single set of software-defined radios that could have new frequencies and modes (“waveforms”) added via upload, instead of requiring multiple radio types in ground vehicles, and using circuit board swaps in order to upgrade. JTRS has seen cost overruns and full program restructurings, along with cancellation of some parts of the program.
Link 16 is a military tactical data link network used by NATO members and other nations, as allowed by the MIDS International Program Office (IPO). Its specification is part of the family of Tactical Data Links.
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) 6016. It is used by the U.S. Navy, U.S. Army, U.S. Marine Corps, U.S. Air Force, U.S. Coast Guard, the NSA, several NATO countries, and Japan as part of the Multi-Tactical Data Link Network, a Tactical Data Link.
A United States defense standard, often called a military standard, "MIL-STD", "MIL-SPEC", or (informally) "MilSpecs", is used to help achieve standardization objectives by the U.S. Department of Defense.
Multiple frequency-shift keying (MFSK) is a variation of frequency-shift keying (FSK) that uses more than two frequencies. MFSK is a form of M-ary orthogonal modulation, where each symbol consists of one element from an alphabet of orthogonal waveforms. M, the size of the alphabet, is usually a power of two so that each symbol represents log2M bits.
Link 22 is a secure digital radio link in the HF and UHF bands, primarily used by military forces as a tactical data link.
Operations Specialist is a United States Navy and United States Coast Guard occupational rating. It is a sea duty-intensive rating in the Navy while most of Coast Guard OS's are at ashore Command Centers.
The AN/PRC-150(C) Falcon II Manpack Radio, is a tactical HF-SSB/ VHF-FM manpack radio manufactured by Harris Corporation. It holds an NSA certification for Type 1 encryption. The PRC-150 is the manpack HF radio for the Harris Falcon II family of radios, introduced in the early 2000's.
The AN/PRC-117 translates to "Army/Navy, Portable, Radio, Communication". It is a man-portable, tactical software-defined combat-net radio, manufactured by Harris Corporation, in two different versions:
The Joint Range Extension Applications Protocol (JREAP) enables tactical data messages to be transmitted over long-distance networks, e.g. satellite links, thereby extending the range of Tactical Data Links (TDLs).
Variable Message Format, abbreviated as "VMF" and documented in MIL-STD-6017, is a communications protocol used in communicating tactical military information. A message formatted using VMF can be sent via many communication methods. As it does not define the method, it is not a Tactical Data Link (TDL).
S-TADIL J, or Satellite TADIL J, is a real-time Beyond Line-of-Sight (BLOS) Tactical Digital Information Link (TADIL) supporting the exchange of the same J Series message set that is implemented on Link-16 via the Joint Tactical Information Distribution System (JTIDS). S-TADIL J provides for robust continuous connectivity between Navy ships that are beyond JTIDS line-of-sight (LOS) transmission range. S-TADIL J is designed to support and significantly improve long-range TADIL connectivity between widely dispersed fleet operational forces. With the deployment of S-TADIL J, operational units will have three possible data link paths that can be used to support multi-ship data link-coordinated operations. S-TADIL J supports the same levels of surveillance and weapon coordination data exchange provided by Link-11 and Link-16. The TADIL J message standard is implemented on S-TADIL J to provide for the same level of information content as Link-16.
A tactical data link (TDL) uses a data link standard in order to provide communication via radio waves or cable used by NATO nations. All military C3 systems use standardized TDL to transmit, relay and receive tactical data.
Multifunctional Information Distribution System (MIDS) is the NATO name for the communication component of Link-16.
The Standard Interface for Multiple Platform Link Evaluation (SIMPLE) is a military communications protocol defined in NATO's Standardization Agreement STANAG 5602.