{{Short description|Military communications protocol}} {{Use dmy dates|date=May 2023}} {{More citations needed|date=April 2008}} '''Common Data Link (CDL)''' is a secure [[U.S. military]] [[communication protocol]]. It was established by the [[U.S. Department of Defense]] in 1991 as the military's primary protocol for [[image]]ry and [[signals intelligence]].<ref>http://directory.eoportal.org/auth/8127/pres_TacSat2Roadrunner.html{{Dead link|date=July 2019 |bot=InternetArchiveBot |fix-attempted=yes }} Accessed 28 June 2007.</ref><ref>[http://www.l-3com.com/csw/ L-3 Communication Systems – West Homepage<!-- Bot generated title -->]</ref> CDL operates within the {{Ku band}} at data rates up to 274 Mbit/s. CDL allows for [[full duplex]] 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 {{nat|109-163}}) 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).{{update inline|date=August 2014}}
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]], [[multiplexing|multiplex]], [[Code|encode]], transmit, demultiplex, and route this data at high speeds. It uses a [[Ku band|K<sub>u</sub>]] 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<sub>u</sub> band signal. The TCDL was designed for [[UAV]]s, specifically the [[MQ-8B Fire Scout]], 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]] 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 == <references/> * [https://web.archive.org/web/20110809114838/http://www2.l-3com.com/csw/product/specs/Airborne/TCDLAir.asp L-3 business segments] * [https://web.archive.org/web/20111003180634/http://www.assconline.co.uk/documents/ASSC_Study_Application_MPEG2_Digital_Video_Compression_Standard.pdf Avionics Systems Standardisation Committee]
[[Category:Secure communication]] [[Category:Military communications]]
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