The Enhanced Position Location Reporting System (EPLRS) is a secure, jam-resistant, computer-controlled communications network that distributes near real-time tactical information, generally integrated into radio sets, and coordinated by a Network Control Station. It is primarily used for data distribution, position location, and reporting. It enhances

command and control Command and control (abbr. C2) is a "set of organizational and technical attributes and processes ... hatemploys human, physical, and information resources to solve problems and accomplish missions" to achieve the goals of an organization or e ...

of tactical units by providing commanders with the location of friendly units. It was first fielded by the

US Army The United States Army (USA) is the land service branch of the United States Armed Forces. It is one of the eight U.S. uniformed services, and is designated as the Army of the United States in the U.S. Constitution.Article II, section 2, c ...

in 1987. EPLRS is a

Time Division Multiple Access Time-division multiple access (TDMA) is a channel access method for shared-medium networks. It allows several users to share the same frequency channel by dividing the signal into different time slots. The users transmit in rapid succession, ...

System that uses a

frequency hopping Frequency-hopping spread spectrum (FHSS) is a method of transmitting radio signals by rapidly changing the carrier frequency among many distinct frequencies occupying a large spectral band. The changes are controlled by a code known to both tra ...

, spread spectrum

waveform In electronics, acoustics, and related fields, the waveform of a signal is the shape of its graph as a function of time, independent of its time and magnitude scales and of any displacement in time.David Crecraft, David Gorham, ''Electron ...

in the

UHF Ultra high frequency (UHF) is the ITU designation for radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter ...

band. It incorporates the Thornton family of COMSEC devices, and has the capability for

Over the Air Rekeying Over-the-air rekeying (OTAR) refers to transmitting or updating encryption keys (rekeying) in secure information systems by conveying the keys via encrypted electronic communication channels ("over the air"). It is also referred to as over-the-a ...

(OTAR). EPLRS uses the Army Data Distribution System version of the

X.25 X.25 is an ITU-T standard protocol suite for packet-switched data communication in wide area networks (WAN). It was originally defined by the International Telegraph and Telephone Consultative Committee (CCITT, now ITU-T) in a series of drafts a ...

CCITT and IEEE 802.3 protocols to interface with Army Tactical Command and Control System (ATCCS). Situation Awareness Data Link (SADL), installed on USAF

F-16 The General Dynamics F-16 Fighting Falcon is a single-engine multirole fighter aircraft originally developed by General Dynamics for the United States Air Force (USAF). Designed as an air superiority day fighter, it evolved into a successful ...

and

A-10 The Fairchild Republic A-10 Thunderbolt II is a single-seat, twin-turbofan, straight-wing, subsonic attack aircraft developed by Fairchild Republic for the United States Air Force (USAF). In service since 1976, it is named for the Republic ...

fighters, coordinates with EPLRS for ground support missions.SADL/EPLRS Joint Combat ID Through Situation Awareness

Raytheon Raytheon Technologies Corporation is an American multinational aerospace and defense conglomerate headquartered in Arlington, Virginia. It is one of the largest aerospace and defense manufacturers in the world by revenue and market capitaliz ...

Network Control Station

Each network is controlled by a Network Control Station (NCS), AN/TSQ-158. These have gone through several iterations.

First Gen

AN/UYK-7 The AN/UYK-7 was the standard 32-bit computer of the United States Navy for surface ship and submarine platforms, starting in 1970. It was used in the Navy's NTDS & Aegis combat systems and U.S. Coast Guard, and the navies of U.S. allies. It ...

computer *3

AN/UYK-20 The AN/UYK-20 "Data Processing Set" was a ruggedized small computer manufactured by Univac and used by the United States Navy for small and medium-sized shipboard and shore systems built in the 1970s. It featured non-volatile magnetic core memory ...

computers

Second Gen

computer *3

AN/UYK-44 The AN/UYK-44 is the standard 16-bit minicomputer of the United States Navy. The AN/UYK-44 was developed in the early 1980s by Sperry Corporation and was completed in early 1984. The AN/UYK-44 was used in surface ships, submarines, ground C4I plat ...

(V) computers

Third Gen

Downsized version to fit in

HMMWV The High Mobility Multipurpose Wheeled Vehicle (HMMWV; colloquial: Humvee) is a family of light, four-wheel drive, military trucks and utility vehicles produced by AM General. It has largely supplanted the roles previously performed by the o ...

, first fielded in 1991. Dimensions: 8.5'x7'x6', 4000 lbs *1

(V) Enhanced Processor (EP) computer

Fourth Gen

The AN/TSQ-158(V)4 is produced by

. Housed in a HMMWV replacing the AN/UYK-44 computer with a

Toughbook Toughbook is a line of rugged computers produced and marketed by Panasonic Corporation. The Toughbook, introduced in 1996 with the CF-25, is designed to withstand outside forces which would damage or destroy normal laptops. Toughbook mobile com ...

laptop computer. Data is displayed through the

FBCB2 Force XXI Battle Command Brigade and Below (FBCB2) is a Linux-based communication platform designed for commanders to track friendly and hostile forces on the battlefield. It increases a vehicle commander's situational awareness of the battlefi ...

platform.

Sources

{{Reflist Military electronics of the United States