E02X Flashcards
E09: Identify in writing the frequency ranges of the bands in which the AN/MRC-142C operates
Band I
a. Frequency range = 225 to 400 MHz
Band III+
a. Frequency range = 1350 to 2690 MHz
E09: Identify in writing the maximum planning range of the AN/MRC-142C
Maximum range of 35 miles over level terrain
E09: Identify in writing the minimum allowable transmit/receive frequency separation given an operational frequency band for the AN/MRC-142C
Band I - Min frequency separation 25 MHz (TXMT and RCV)
Band III+ - Min frequency separation 50 MHz (TXMT and RCV)
E09: Identify in writing the maximum encrypted data rate of the AN/MRC-142C
Maximum encrypted data rate is 14,336 kbps.
E09: Given a MRC-142C antenna, identify in writing the frequency band in which it operates
Band I Antenna: (nomenclature AS-3875) Lightweight, high gain, high performance antenna. The antenna operates in the 225 – 400 MHz frequency range, and each AN/MRC-142C is equipped with one AS-3875 antenna.
Band III+ Antenna: (nomenclature AS-4515) Parabolic grid reflector and long, periodic, wideband feed cone. It operates in the 1350 – 2690 MHz range.
E09: Identify in writing the four (4) radio modes of the AN/MRC-142C
Standby: In this mode, the radio set does not transmit.
Analog Engineering Order Wire (AEOW): AEOW is unencrypted voice traffic. It should be used to establish a link. The analog handset (RA-250) is used in this mode.
- Digital Engineering Order Wire (DEOW): DEOW is encrypted voice traffic. It uses the external KY-57 and H-250 handset.
- Traffic: In this mode the radio transmits and receives a multiplexed data stream to and from distant end AN/MRC-142C systems. The DEOW function is available in this mode. Note: The radio must be in TRAFFIC mode with no faults for data to transmit across the AN/MRC-142C.
E09: Identify in writing three (3) basic operational configurations of the AN/MRC-142C
Single Link Terminal: Only one of the MRC-142C’s radio terminals and AS-4515s/AB-1356s is used. A single communications link is established between a local MRC-142C and a distant MRC-142C.
Dual Link Terminal: Both of the MRC-142C’s radio terminals and AS-4515s/AB-1356s are used. Two separate links are established by the local MRC-142C, with different distant stations. Note: The dual link terminal requires two TAC-300 multiplexers.
Through-Repeater: Used to extend range or overcome obstacles between two, distant MRC-142C’s. A third MRC-142C between the two points passing data is used to retransmit the signal. The repeating system receives it from one end on one RT and repeats the signal to the distant end on the other RT (and vice versa). Both RTs are used to repeat one link.
E09: Identify in writing the appropriate multichannel radio symbol for the AN/MRC-142C
Circle with triangle on bottom and M(c) 142 in center
E10: Define in writing Department of Defense Information Network
The Department of Defense Information Networks are a globally interconnected, end-to-end set of information capabilities, associated processes, and personnel for collecting, processing, storing, disseminating, and managing information on demand to warfighters, policy makers, and support personnel.
E10: Define in writing uplink frequency
Frequency used by a SATCOM terminal to the satellite is the uplink frequency
E10: Define in writing downlink frequency
The frequency from the satellite to the SATCOM terminal is the downlink frequency
E10: Define in writing transponder
Acting as a repeater in the sky, the transponder receives transmissions from the ground or user segments, amplifies the received signal, changes its frequency, and transmits the signal back to Earth.
E10: Define in writing Signal-to-Noise Ratio
Signal-to-Noise Ratio (S/N) is the proportion of the usable or desired signal (S) to the noise (N), or undesired signal.
E10: Define in writing Eb/N0
Energy per Bit to Noise Power Spectral Density Ratio (Eb/N0).
Signal-to-Noise Ratio per Bit. The ratio given by Eb/N0, where Eb is the signal energy per bit and N0 is the noise energy per Hertz of noise bandwidth.
E10: Define in writing Frequency Division Multiple Access
A technique used for sharing a single transmission channel among two or more users by assigning each to an exclusive frequency band within the channel.
E10: Define in writing Time Division Multiple Access
A technique used for allocating a discrete amount of frequency bandwidth to each user, in order to permit many simultaneous conversations with each user assigned a specific timeslot for transmission.
E10: Identify in writing the purpose of the Standardized Tactical Entry Point (STEP)/Teleport
Focusing primarily on reach-back services to the Department of Defense Information Systems Network, there are two key components that allow this to take place - they are the STEP and Teleport sites. Both serve as entry points for tactical forces to the Department of Defense Information Systems Network and are strategically located throughout the world.
E10: Identify in writing the purpose of the Satellite Access Request
Satellite Access Request (SAR). SARs are prepared and submitted for access to strategic satellite systems to provide worldwide connectivity in the tactical, warfighting environment.
E10: Identify in writing the purpose of the Gateway Access Request
GARs are prepared and submitted for access to the DISN in order to provide worldwide secure and non-secure voice, video, and data connectivity in the tactical, warfighting environment.
E11: Define in writing Antenna Control Unit
Antenna Control Unit (ACU) performs satellite acquisition and tracking.
E11: Define in writing High Power Amplifier
The High Power Amplifier (HPA) has one job – boost the transmit signal (uplink) to enable the antenna to beam the up to the satellite.
E11: Define in writing Low-Noise Block Downconverter
The Low-Noise Block Downconverter (LNB) is used in the receiving (downlink) of satellite signals. It is a combination of a low-noise amplifier and a frequency mixer.
E11: Define in writing Block Upconverter
The Block Upconverter (BUC) is used in the transmission (uplink) of satellite signals. It converts a band of frequencies from a lower frequency to a higher frequency usable by the satellite.
E11: Define in writing Modem
Modems are used to convert data into binary form and back.
E11: Identify in writing the definition of a point-to-point satellite communications network configuration
In a point-to-point (PTP) configuration, each terminal combines all information to be sent to the distant end into a single output and transmits it to the satellite. A unique transmit frequency is assigned to each terminal, and there is enough difference between the frequencies to prevent the signals from interfering with one another. Each signal is processed by the satellite and retransmitted toward the earth to become the receive signal for the distant end terminal.
E11: Identify in writing the definition of a hub-spoke satellite communications network configuration
The hub-spoke configuration performs the same communication function as four full duplex PTP satellite links. Unlike actual PTP operation, however, two frequency assignments are not required for each link. Instead, each terminal in the network requires only one frequency assignment. This is because outgoing signals from the hub terminal to all distant end terminals are combined and transmitted at the same center frequency. All distant end terminals (spokes) receive the same signal after the satellite retransmits it. Each spoke terminal then separates the information intended for that terminal from the combined signal and ignores the information intended for the other terminals. Since each spoke terminal communicates only with the hub, only signals destined for the hub are combined into the spoke transmissions.
