The CNR systems. CNR provides a communications means, independent of mobile subscriber
equipment (MSE), for C2 within the corps in divisional maneuver brigades, combat support (CS) units,
and combat service support (CSS) units. The primary role of CNR is voice C2 for the commander at
corps and below. The secondary role is to provide a means of data transmission. CNR is designed
around three separate radio systems which have unique capabilities and transmission characteristics.
These systems are the improved high frequency radio (IHFR), the single-channel ground and airborne
radio system (SINCGARS), and single-channel tactical satellite (TACSAT) radio.
a. New electronic counter-countermeasures (ECCM) modules and devices make radios more
survivable and less susceptible to enemy disruption. The combination of high frequency (HF), very high
frequency (VHF), and ultra high frequency (UHF) radios gives commanders redundant, but different,
means to communicate. Each system takes advantage of a different transmission path, increasing the
probability that at least one communications system will work at any given time.
b. IHFR is used in combat arms, CS, and CSS units. It is selectively replacing HF manpack and
vehicular radios, including the AN/GRC-106 and the AN/PRC-70/74. It uses ground or sky wave
propagation paths for short and medium-range communications. IHFR gives the tactical commander an
alternate means of passing voice and data communications, with voice C2 taking precedence over data
transmission. Passing data requires an interface device called a modem.
(1) IHFR is a modular design radio; that is, the components that make up the different radio
configurations are similar from set to set. There are three user-owned and operated IHFR
configurations. The high-powered AN/GRC-193A set (100-watt or 400-watt vehicular) is used in voice
networks that pass highly perishable C2 information, and for medium or long-range communications (50
kilometers to 300 kilometers, or 31 miles to 187 miles). The 20-watt AN/GRC-213 is adaptable for
manpack or vehicular use. Brigade and battalion level units primarily use this version (0 kilometers to
50 kilometers (0 miles to 31 miles). The 20-watt AN/PRC-104 is the manpack version. IHFR
transmissions should be secured with an approved cryptographic system.
(2) The antennas associated with the IHFR systems are the whip antenna (both manpack and
vehicular mounted), AN/GRA-50 doublet antenna, and AS-2259 near vertical incidence sky wave
c. SINCGARS is the primary means for short-range (less than 35 kilometers, or 22 miles)
secure-voice C2 below division level. It is also the secondary means for CS and CSS units throughout
the corps. SINCGARS can access the ACUS network using net radio interface (NRI). Retransmission
can increase its range. Data and facsimile transmission capabilities are available to tactical commanders
through simple connections with various data terminal equipment. Until the ADDS fielding is complete,
SINCGARS will fulfill the data transmission requirements on a limited basis.