Link 16 is an encrypted, jam-resistant Tactical Data Link (TDL) network used by U.S. and NATO Allies to create situational awareness among dispersed battle elements by sharing information, over a common communication link. This enables the command and control centers to create Common Operating Pictures (COP), which allows friendly forces to electronically observe the battlespace, identify threats, and acquire targets.
Link 16 communications are used to transfer real-time combat data, voice communications, imagery, and relative navigation information in the battlefield. This network uses JTIDS-compatible communication terminals to transmit and receive data messages. Via Link 16 network, messages can be broadcasted simultaneously to as many users as needed. Link 16 is a nodeless network i.e., it does not depend on any one terminal to act as a node, instead all Link 16-capable terminals act as nodes.
This Tactical Data Link (TDL) network was developed by ViaSat Inc. and Data Link Solutions (DLS) LLC to improve interoperability and support joint operations of land, sea, and air forces.
The main application of Link 16 is as an air and missile defense command and control system. This network is being used by various countries for national air defense, linking their sea- and land-based vessels, ground-based sensors, and surface-to-air missile systems. This helps them to protect their airspace by identifying threats and neutralizing them. This link network has been credited by the US Air Force as a key factor for saving lives in multiple contested environments, owing to the high degree of situational awareness the network provides.
Link 16 uses Time Division Multiple Access (TDMA) techniques to provide multiple, simultaneous communication paths through different networks by assigning each user with a unique time duration slot. The network can be used to broadcast messages between two users or from a single user to multiple users at a time. It is referred to as a nodeless network i.e. a single Link 16 terminal does not act as the node for other terminals and thus, every terminal act as a node in the network.
Link 16 data links operate in the radio frequency (RF) band from 960 to 1215 MHz as allocated by the International Telecommunications Union (ITU) radio regulations. It supports data exchange by supporting any of the three data rates: 31.6, 57.6, or 115.2 Kbps. However, by incorporating more advanced high-performance radio architectures along with physical layer techniques such as frequency hopping spread spectrum (FHSS), Link 16 network can deliver data rates of more than 1 Mbps. It supports up to 128 time slots per second, 127 networks, and is appropriately assigned among the JTIDS radio units.
The information exchanged within the Link 16 network is typically coded based on J-series messages, a set of message formats that use binary data words with well-defined meanings. The J-series messages include network management-related information such as communication control, time slot reallocation, radio relay control, connection status, network time update, acknowledgement, and route establishment. Depending on the situational scenario, the data words are grouped under different functional areas and allocated to different network participation groups (NPGs) that include:
Precise Participant Location and Identification
Real-Time Surveillance
Airborne Communications Control
Mission Management, and
Electronic Warfare and Coordination
The Link 16 network consists of multiple terminals that are located in various ground, marine, and air defense vehicles. These terminals are military-grade radio equipment designed according to the IPO office in San Diego, California. Different governing bodies formulate policies, standards, plans, and requirements for radio equipment to be used by land, sea, or airborne platforms. For instance, in the US, the lead Air Force command for the MIL-STD-6016 military standard is the Air Force Global Cyberspace Integration Center located in Boston, Massachusetts.
