Common Data Link (CDL) is a secure U.S. military

communication protocol A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any kind of variation of a physical quantity. The protocol defines the rules, syntax, semantics and synchroniza ...

. It was established by the

U.S. Department of Defense The United States Department of Defense (DoD, USDOD or DOD) is an executive branch department of the federal government charged with coordinating and supervising all agencies and functions of the government directly related to national secu ...

in 1991 as the military's primary protocol for

image An image is a visual representation of something. It can be two-dimensional, three-dimensional, or somehow otherwise feed into the visual system to convey information. An image can be an artifact, such as a photograph or other two-dimensio ...

ry and

signals intelligence Signals intelligence (SIGINT) is intelligence-gathering by interception of '' signals'', whether communications between people (communications intelligence—abbreviated to COMINT) or from electronic signals not directly used in communication ...

.L-3 Communication Systems – West Homepage
/ref> CDL operates within the at data rates up to 274 Mbit/s. CDL allows for

full duplex A duplex communication system is a point-to-point system composed of two or more connected parties or devices that can communicate with one another in both directions. Duplex systems are employed in many communications networks, either to allow ...

data exchange. CDL signals are transmitted, received, synchronized, routed, and simulated by Common data link (CDL) Interface Boxes (CIBs). The FY06 Authorization Act (Public Law ) requires use of CDL for all imagery, unless waiver is granted. The primary reason waivers are granted is from the inability to carry the 300 pound radios on a small (30 pound) aircraft. Emerging technology expects to field a 2-pound version by the end of the decade (2010). The Tactical Common Data Link (TCDL) is a secure data link being developed by the U.S. military to send secure data and streaming video links from airborne platforms to ground stations. The TCDL can accept data from many different sources, then encrypt, multiplex,

encode The Encyclopedia of DNA Elements (ENCODE) is a public research project which aims to identify functional elements in the human genome. ENCODE also supports further biomedical research by "generating community resources of genomics data, software ...

, transmit, demultiplex, and route this data at high speeds. It uses a K_u narrowband uplink that is used for both payload and vehicle control, and a wideband downlink for data transfer. The TCDL uses both directional and omnidirectional antennas to transmit and receive the K_u band signal. The TCDL was designed for UAVs, specifically the

MQ-8B Fire Scout The Northrop Grumman MQ-8 Fire Scout is an unmanned autonomous helicopter developed by Northrop Grumman for use by the United States Armed Forces. The Fire Scout is designed to provide reconnaissance, situational awareness, aerial fire support ...

, as well as crewed non-fighter environments. The TCDL transmits radar, imagery, video, and other sensor information at rates from 1.544 Mbit/s to 10.7 Mbit/s over ranges of 200 km. It has a

bit error rate In digital transmission, the number of bit errors is the number of received bits of a data stream over a communication channel that have been altered due to noise, interference, distortion or bit synchronization errors. The bit error rate (BER ...

of 10e-6 with COMSEC and 10e-8 without COMSEC. It is also intended that the TCDL will in time support the required higher CDL rates of 45, 137, and 274 Mbit/s.

References

L-3 business segments

Avionics Systems Standardisation Committee
Secure communication Military communications {{US-mil-stub