On June 22, 2006, the United States Air Force (USAF) posted a solicitation on FedBizOpps for the purchase of cellular communications surveillance equipment manufactured by Digital Receiver Technology, Inc. (DRT). FedBizOpps is a website used by federal entities to purchase products and services from private companies. DRT is one of those companies, selling surveillance equipment to the Department of Defense and federal law enforcement. DRT’s cellular and radio communications surveillance equipment, which includes a cell site simulator capability, is nicknamed “DRTBOX.”

The solicitation included a sole source justification letter explaining that the USAF’s purchase of a “DRT1201B Portable Receiving System” will be used to monitor the cell phone communications of USAF personnel for classified information. The letter also explains that the DRTBOX equipment has “been proven in concept and is currently in use by NSA and the Joint community.” Further, the “National Security Agency (NSA) identified the DRT as the original and most widely utilized RF and Cellular telecommunications monitoring device.”

On October 28, 2013, Jacques Follorou and Glenn Greenwald reported that the NSA collected 70.3 million records over the course of a month relating to the telephone communications of French citizens. The source was an intelligence document leaked by former NSA contractor Edward Snowden. The document labels the collected records as DNR, an abbreviation for “dialed number recognition,” which refers to the collection of phone numbers dialed by phones under surveillance. In a box titled “Top 5 Techs,” the document indicates that 62,522,568 of the collected dialed numbers were a result of DRTBOX.

On November 27, 2013, Electrospaces linked the term DRTBOX to equipment manufactured by Digital Receiver Technology, Inc. DRT equipment is capable of wireless collection of metadata (such as dialed phone numbers) and communications content transmitted by radio communications devices such as cell phones and push-to-talk radios. Although the Snowden document relates only to the collection of dialed phone numbers, Electrospaces theorized that DRT equipment could have been “used at the joint NSA-CIA Special Collection Service (SCS) unit in the US embassy in Berlin, which intercepted the mobile phone [communications] of German chancellor Merkel.” Adding credence to this theory, the USAF letter quoted above confirms that DRT equipment is capable of monitoring communications content, and the NSA has been using the equipment since at least 2006.

One version of the DRT1201B surveillance equipment used by the NSA and others “consists of eight RF tuners (2-3000 MHz frequency coverage), 240 channels of processing, and embedded/GUI software for all supported wireless formats, with carrying case and laptop controller.” The successor to the DRT1201B (i.e., DRT1201C) can be used with the “DRT Pickaxe encryption/decryption device with SledgeHammer interface, Rising Edge Technologies 6200 series recorder/playback unit, Rising Edge Technologies Signal Archive Management System (SAMS), [and] EPG Advanced Signals Integration and Test Tool data reduction system[,] [with] recording capability for 8 full-duplex/16 half-duplex communications links.”

The USAF letter notes that the DRT1201B recommended by the NSA “implements hardware appliances and software applications capable of isolating and recording USAF cellular and RF communications.” In other words, the USAF is using the DRTBOX surveillance equipment to monitor and collect the communications content of its own personnel. These so-called “Blue Force” (e.g., friendly) communications are collected in order to “determine if they are being used to transmit sensitive or classified information that could adversely affect U.S. and allied forces.”