CDC 3D153 v3 Flashcards
State the types of traffic an AN/TRC–170 radio terminal set might handle.
Dedicated traffic such as analog and digital channels, point-to-point circuits, facsimile circuits, and teletype circuits.
List the equipment included in an AN/TRC–170 tropospheric scatter terminal.
Antennas, transmitting and receiving equipment, digital multiplexing equipment, voice and data orderwire facilities, built-in test equipment, and communications security equipment.
List the data rates processed by the tropospheric scatter modem.
Mission traffic at 128 through 4,096 Kbps in the 512 data rate family, and 72 through 4,608 Kbps in the 576 data rate family.
Describe the upconversion process of the transmit amplifier.
The IF signal is upconverted in the transmit amplifier converter by mixing it with a local oscillator input from the synthesizers. The difference frequency is selected as the final transmit frequency of 4.4 to 5.0 GHz.
Explain the difference in the transmission power requirements between tropospheric scatter and line-of-sight.
The HPA is necessary for transmission in the tropospheric scatter mode (1 kW, 60 dBm). It is also possible to transmit in LOS mode by not using the klystron. The output is 29 dBm (800 mW).
What is the minimum spacing used to separate receive antennas in space diversity, and what is the most common amount of antenna separation used?
Minimum of 50 wavelengths; common receive antenna spacing is 100 or more wavelengths.
What principle of propagation does frequency diversity use to its advantage?
Frequency diversity uses the principle that two different microwave frequencies fade independently of each other even though they travel the same propagation path.
What is the ideal frequency separation in frequency diversity?
A separation of 5 percent is ideal.
Define polarization diversity.
In polarization diversity, the same frequency radiates simultaneously in two different planes: horizontal and vertical.
Explain quadruple diversity.
Quadruple diversity is a technique that employs a combination of two or more of the diversity types: a combination of frequency and space diversity or space and polarization diversity—or a system that uses four reception paths.
Explain the purpose of the digital data group modem.
It interfaces up to four groups of conditioned diphase signals, or up to four groups of dipulse signals, or a mixture of the two.
Describe the main purpose of the digital data group modem.
Primarily, it changes cable-side conditioned diphase or dipulse signals to balanced NRZ signals, and vice versa.
Describe the purpose of the low-speed cable driver modem.
Changes the cable-side conditioned diphase signal to NRZ for use by the AN/TRC–170 and supplies power to cable low-speed pulse restorers if required.
What data rates are used by the low-speed cable driver modem?
It accepts data at 72 to 2,048 Kbps on the equipment side; 2,304 Kbps on the cable side.
What is the range of the low-speed cable driver modem with and without pulse restorers?
Up to 40 miles with pulse restorers and 1 mile without pulse restorers.
Describe the capabilities of the trunk group multiplexer.
It multiplexes up to four groups of the 512 Kbps data rate families or four groups of 576 Kbps data rate families into one supergroup. It will not process group data rates from both families simultaneously. It demultiplexes a supergroup into separate groups at their original data rates. It can control a KG–81 trunk encryption device on both the group and supergroup side.
Describe the purpose of the KG–81 trunk encryption device.
Full-duplex encryption and/or decryption of group or supergroup mission traffic.
Describe the purpose of the KG–84 dedicated loop encryption device and the KG–84A general purpose encryption equipment.
Encrypts and/or decrypts telemetry data, processed through the alarm monitor.
Describe the purpose of the KY–58 VINSON.
Encrypts and/or decrypts digital voice orderwire traffic originating and terminating at the voice orderwire control unit.
What is the purpose of the baseband patch panel?
Connects the digital group multiplex equipment with the tropospheric scatter modem.
Describe the three divided fields of the baseband patch panel.
- The upper jack field provides timing and data connections for the trunk group multiplexer, tropospheric scatter modem, and trunk encryption device 1. The right side provides patching for black station clock. Also provided are convenience patch groups A, B, and C, that are internally hard-wired to jacks in the center jack field.
- The center jack field provides connections to the equipment side of the loop group multiplexers, group modem groups, and the low-speed cable driver modem. The black side of the trunk encryption device 2 is also available. The dejitterizer input and/or output jacks provide for patching a group timingsignal directly into the tropospheric scatter modem. Inputs to trunk group multiplexer groups 3 and 4are available. Convenience patch groups A, B, and C pass data and timing signals to the upper jackfield.
- The lower jack field provides data orderwire connections for through patching or patching to and/or from the dedicated loop encryption device patch panel by way of the level converter jacks. Also
provided are connections for the digital voice orderwire and resync commands to the group and super group trunk encryption devices.
Describe the purpose of the dedicated loop encryption device patch panel.
Provides for patching the local telemetry signals to the radio and/or cable side of the AN/TRC–170 and for monitoring baseband and dedicated loop encryption device patch panel activity.
Describe the data rates of the tropospheric scatter modem.
128 through 4,096 Kbps in the 512 data rate family and 72 through 4,608 Kbps in the 576 Kbps data rate family.
List the types of inputs to the tropospheric scatter modem.
Mission data, digital voice orderwire, and up to four data orderwires.
What is the purpose of the loop back circuit in the IF patch panel?
Provides a calibrated means of applying the tropospheric scatter modem modulator IF output to tropospheric scatter modem demodulator inputs.
Why are the IF patch panels between the AN/TRC–170 V2 and V3 terminals not interchangeable?
The IF test panels are configured differently for each terminal.
Describe the outputs of the electrical frequency synthesizer.
Stable outputs in the 4.47 to 5.07 GHz range.
List the major subassemblies of the RF HPA and state their purpose.
- The microwave subassembly consists of a klystron amplifier, tuning, and built-in test equipment circuitry. The klystron is a continuous-wave, HPA that is air-cooled and mechanically tunable. It is bypassed, and the high voltage power supply is not used when operating in the LOS mode.
- The high voltage power supply provides beam and filament voltages for the klystron.
- The diplexer enables the transmitter and a receiver to operate from a common antenna port. The diplexers are used in the V2 model only.
Describe the purpose of the downconverters.
They preselect, amplify, and postselect the received microwave signal. The LNA and mixer combine the 4.4 to 5.0 GHz receive signal with a 4.47 to 5.07 GHz signal from the synthesizer to produce the 70 MHz
IF.
How does the alarm monitor determine overall system performance?
Equipment status information and performance data from all major components are reported to the alarm
monitor by the built-in test equipment circuits in each major subassembly. The data is sampled, processed, and evaluated. From this, overall system performance is determined.
List the orderwires and orderwire control units and describe each.
- The data orderwire consists of a 20-character telemetry status message that can be combined with a 12-telemetry status message from other stations to form a 2 Kbps composite bit stream that is transmitted to the communication nodal control element.
- The voice orderwire control unit connects a VINSON secure voice instrument with the 16 Kbps digital voice orderwire. This is a first-come, first-served party line system. The unit’s electronic bridge provides a through connection between the group modems and low-speed cable driver modem or tropospheric scatter modem.
- The remote orderwire control unit accesses the digital voice orderwire through the voice orderwire control unit. It does not provide secure voice transmission to the voice orderwire control unit.
- The analog voice orderwire (the maintenance orderwire) provides unencrypted, full-duplex voice connection with analog voice orderwire channels of the group modem and low-speed cable driver modem. It does not connect to the radio side of the AN/TRC–170 terminal.
What else does the power entry panel provide power to besides the equipment in the van?
The environmental control unit, an external convenience outlet, antenna feedhorn deicers, as well to as an external main breaker that controls the entire panel.
Describe how a surge protection circuit is used and whether it is required for an AN/TRC–170 terminal.
It is placed across each phase and the neutral line. It is not required for the van to operate, but without it there is no prime power surge protection.
List the functions of the power distribution unit.
It provides a central location to control equipment using primary power for fast power-up and power-down. It also powers the utility and convenience outlets and ceiling lighting. The front panel meters indicate current, voltage, and frequency.
Describe the purpose of the AC-AC converters.
They change the incoming AC signal to a 255 Vpp, 400 Hz quasi-square wave in order to operate the cooling fans in the shelter. AC-AC converter 1 runs all the blowers in the van, except those in RF HPA#2, these are run by AC-AC converter 2.
List the components and describe the function of the lightning protection assembly.
It consists of two, four-section telescoping masts approximately 30 feet tall (assembled), a sky wire 135 feet long, six anchors, two ground rods, and two mast base plates. The masts are installed 65 feet apart and slightly behind the two antennas. The sky wire is suspended between the two masts and is grounded on both ends. The lightning protection assembly acts as a large lightning rod by being the highest point at your station.
Describe the RF output power and frequency band of the TSSR.
14.4 to 15.25 GHz with RF output power of about 300 mW.
What are the two TSSR antenna lengths, and what are their maximum ranges?
1 foot and 2 feet; 10 and 25 miles respectively.
List the TSSR conditioned diphase waveform voltage and data rate.
3 Vpp conditioned diphase waveform ranging from 72 to 4,608 Kbps.
What is the maximum distance the TSSR’s RF and baseband assembly can be physically separated from each other, using the supplied cable?
150 feet.
What is the gain of the TSSR’s 1-foot antenna?
31 dB.
What is the gain of the TSSR’s 2-foot antenna?
37 dB.
What is the purpose of the input attenuator in the TSSR’s transmit baseband assembly?
Compensates for input signal amplitude variations caused by external equipment or varying cable lengths.
What is the transmitter deviation in the TSSR’s transmit baseband assembly?
±4 MHz.
What is the frequency of the transmitter subcarrier (orderwire) in the TSSR’s transmit baseband assembly?
8.5 MHz.
Describe the function of the TSSR’s diplexer.
It allows the use of a single piece of coaxial cable to pass the transmitter baseband signal from the baseband assembly to the RF assembly. Also transmitted on the same cable is the receiver 70 MHz IF signal from the RF assembly to the baseband assembly.
In the TSSR’s RF assembly, what is the frequency of the voltage-controlled oscillator, and how is its accuracy maintained?
7 GHz; by a phase-locked loop.
What is the purpose of the circulator in the TSSR’s RF assembly?
Permits the transmitter and receiver to be connected to the same antenna.
In the TSSR’s RF assembly, at what frequency is the tunable filter set?
Receive frequency.
How is noise generated by the transmitter prevented from interfering with the receiver, in the TSSR’s RF assembly?
The combination of tunable filter and three-port circulator is used to form a notch filter. The notch filter is tuned to the receiver’s frequency to reduce any noise generated by the transmitter that could interfere with the receiver.
Describe the frequency conversion process in the TSSR’s receive section.
The 14.4 to 15.25 GHz RF is mixed with the local oscillator frequency to produce a 70 MHz IF. The local oscillator frequency is always on the low side of the signal; that is, the local oscillator frequency equals the signal frequency minus 70 MHz.
What is the bandpass frequency range of the 70 MHz IF in the TSSR’s control and distribution unit?
20 MHz.
Which unit compensates for changes in the interconnecting cable length in the TSSR’s receive baseband assembly?
Automatic gain control amplifier.
In the TSSR’s receive baseband assembly, what type of waveform and data rate is used when operating in the fiber optic mode?
NRZ digital signals at a 6.144 Mbps rate.
What type of orderwire capability does the TSSR provide?
Full-duplex voice communication.
What usable frequency range propagates through the earth’s atmosphere?
30 to 100.000 MHz (VHF to EHF).
At what altitude are most geosynchronous satellites placed?
22,582 miles above the earth.
What are the terms for the nearest and farthest distances a satellite’s orbit comes to the earth?
Perigee (nearest); apogee (farthest).
What directions are descending and ascending nodes going?
A satellite ascends when it travels northward and descends when it travels southward.
Explain the term “slant range.”
The distance from the site to the satellite.
Name the two types of orbital control used on satellites.
Attitude control and station keeping.
What are the five types of attitude control?
- Spin stabilization.
- Gravity gradient.
- Momentum storage.
- Mass expulsion.
- Mixed systems.
How is tracking a satellite accomplished?
By using a transponder.
What terms describe the capabilities of communications satellites?
Passive and active.
What are the advantages of the passive satellite?
Simplicity, wider frequency range, and multiple accesses.
What are the disadvantages of passive satellites?
Larger required transmitter power, larger antenna systems, more sensitive receiving equipment, and a larger satellite size.
What does the use of active communications satellites make possible?
The use of smaller ground terminals.
Name the two types of active satellites.
Delay and real-time.
What disadvantages does CDMA present?
CDMA doesn’t use the power and frequency spectrum resources as effectively as does FDMA or TDMA, and it requires complex equipment at both ends of the link.
What’s the difference between TDMA and DAMA?
In TDMA, users have a dedicated time slot, whether they use it or not; in DAMA, the dedicated time slot can be used by other low-priority users when it isn’t in use.
State the purpose of DAMA.
To allocate and share satellite bandwidth on a demand-assigned basis.
What does the network control system do with a call?
Determines if the call is valid and establishes the channel between the originating site and the called site.
What component may function as a network control system?
Any unit with the required hardware and software.
What’s the primary disadvantage of DAMA?
Delay in service, particularly to lower-priority users.
What information do you need to make manual look angle calculations?
Latitude, longitude, and height of the satellite; latitude and longitude of your terminal; a calculator with scientific functions or a natural sine, cosine, and tangent chart.
When making calculations, how are ground distances measured on the earth’s surface?
In degrees, where 1° of arc equals 69 statute miles.
What must you do after finding the general direction from the ground terminal to the satellite (the calculated azimuth angle)?
You have to apply a correction factor to get the correct azimuth look angle.
Which time scale is equal to mean solar time when you make the correction at the zero meridian in Greenwich, England?
Universal time (UT0).
How is atomic time obtained?
From counting cycles of a signal from an atomic frequency source.
Why do atomic time scales give us very accurate time of day?
Because they use very stable atomic oscillators.
What are the characteristics of UTC that give us a universally agreed to standard time scale that we can depend on?
The stability and accuracy of atomic time and synchronous operation with the earth’s motion about the sun as in solar timekeeping.
What kind of clock system is UTC?
24-hour.
Where is UTC referenced? To what is it referred?
The zero meridian in Greenwich, England. Zulu time.
By international agreement, all UTC time scales must agree with the UTC time scale operated by the BIPM to within how many milliseconds?
±1 ms.
What is the USNO’s primary responsibility?
Making astronomical observations to determine UT1 for navigation purposes and to keep atomic frequency sources running for use by the DOD.
Which organization maintains our nation’s primary time/frequency standard?
NIST.
How does NIST distribute most time and frequency data?
By radio.
What are four uses of precision timing?
- Correlate test data from several instrumentation locations.
- Start and stop programmed instruments.
- Synchronize range instrumentation.
- Control firing operations.
List some examples of when timing errors must be reduced.
When predicting a missile’s flight path, predicting satellite tracking coordinates, and uploading navigation data to a satellite.
Define primary frequency standard.
A device used as the sole calibration reference for other frequency sources.
Against what is a secondary frequency standard calibrated?
A primary frequency standard.
Describe the piezoelectric effect of quartz crystals.
Mechanical compression of the crystal generates a charge across the crystal; conversely, the application of an external voltage across the crystal causes it to expand or contract depending on the polarity of the voltage.
What two factors influence quartz oscillator performance?
Temperature and aging.
What are the two solutions for the crystal oscillator temperature dependence?
- Enclosing the crystal in an electronically regulated oven.
- Using a temperature-compensated crystal oscillator.
What are two of the most common types of atomic oscillators?
- Rubidium gas cell.
2. Cesium beam oscillators.
What kind of frequency standard are cesium oscillators considered to be?
Primary.
Describe the overall purpose of the modem.
An modem is a device that converts digital signals into analog signals and analog signals into digital signals.
What tasks do the modulator (transmitter) and the demodulator (receiver) perform?
The modulator converts the digital data into an analog signal, which is suitable for transmission over telephone lines or radio links. The demodulator receives the telephone or radio transmissions and converts the audio signal back to the digital data.
Define multiplexing.
The combination of two or more signals into a single signal for transmission over a medium.
What is a multiplexer and what additional devices do fiber-optic multiplexers contain?
Any device that permits the combination of different signals onto a single line is called a multiplexer. The multiplexer provides various connectors to accept signals from multiple users and contains the circuitry to combine multiple channels into an aggregate output. Fiber-optic multiplexers contain both source and detector modems to provide transmit and receive capabilities over the fiber-optic link.
What multiplexing process assigns parts of each voice channel to specific time slots?
Time division multiplexing (TDM).
What standard uses time division multiplexing and makes better use of the increased bandwidth available in fiber optics?
Synchronous optical network (SONET).
Describe wavelength division multiplexing.
WDM assigns each incoming optical signal to a specific frequency of light (wavelength) within a certain frequency band. The signals are carried down the fiber simultaneously, but each signal is independent from the others.
Beside higher data rates, what other features does dense wavelength division multiplexing provide?
The ability to amplify all the wavelengths at once without first converting them to electrical signals, and the ability to carry signals of different speeds and types simultaneously and transparently over the fiber (protocol and bit rate independence).
What is the purpose of the space segment?
To provide the downlink information encompassing an area of coverage required by the program mission or the program Operational Requirements Document.
Define telemetry?
The science of measuring physical properties and other phenomena onboard mission satellites and transmitting these measurements to ground receiving elements.
What types of information do the telemetry, tracking, and command status contain?
Data on the receiver and demodulator units, command decryptor unit, downlink transmitter, telemetry formatting and encoding unit, telemetry encryptor, and satellite antenna configuration.
What are the two major sections of a basic satellite?
- The mission (or missions) payload.
2. The spacecraft bus.
Why is stability important to the satellite?
Because it allows the payload to operate with accuracy and the satellite bus to receive commands and uploaded data with reliability.
For what types of satellites are position and orientation control especially critical?
Those using highly directional antennas.
What is the function of the C2 segment?
To support the satellites and enhance the downlinked mission data for the user segment.
What do all satellites require, regardless of the program?
Telemetry, tracking and commanding support.
What is the purpose of antenna pointing data?
It is used to drive motors to move the antenna to the specific acquisition angles.
Why is satellite command verification so important?
To make sure commands have been executed properly.
Why is using the same reference time between the C2 segment and the satellite so important?
Without it, operations—such as commanding mission satellites, processing and evaluating tracking data, or processing telemetry data—would be impossible.
What is the purpose of the user segment?
To receive, process, use, or distribute mission data as required by program taskings.
What is the purpose of the DMSP user segment?
To receive, process, and distribute global weather data to support Air Force, Army, Navy, and Marine Corps operations worldwide.
In the DSP program, what agency operates SBIRS satellites?
The 460th Space Wing at Buckley AFB, Colorado.
Where do the DSP early warning centers forward their data?
To various agencies and operation areas around the world, varying with the Air Force’s changing mission.
What is the purpose of the GPS user segment?
To enable users to passively receive the satellite broadcast position, velocity, and time data for their operational mission.
What is the primary purpose of Milstar?
To support the National Command Authority and provide the Navy, Army, and Air Force with interoperable command, control, and communications (C3) at all levels of conflict for both strategic and tactical forces.
For what purposes do we use a satellite beacon?
To locate, identify, and track a satellite.
How does telemetry differ from the satellite beacons?
Telemetry refers to the data sent by the satellite to give on-board equipment status.
What is ephemeris data?
Data showing the calculated positions of a satellite at regular intervals of time.
How does computer programmed tracking differ from automatic signal tracking?
In computer programmed tracking, the position of the satellite is computed and the pointing signal is generated from that information. Automatic tracking follows the apparent position of the satellite based on the actual signals from the satellite.
Which autotracking method cannot sense the satellite location without moving off the satellite main beam?
Random step track.
What two IF frequencies are used by the DSCS earth terminal? What’s their nominal signal level?
(1) 70 MHz at –10 dBm.
(2) 700 MHz at –13 dBm.
How are the HPAs cooled in a DSCS earth terminal?
Air cooled.
What’s the downlink frequency range of a DSCS earth terminal?
7.25 to 7.75 GHz.
What’s the size of an AN/GSC–52 antenna reflector, and what are the azimuth and elevation limitations?
38-foot dish, ±174 degrees in AZ and from –1 to 92.5 degrees in EL.
How many feedhorns does a AN/GSC–52 terminal use to determine tracking errors?
Four.
Which downconverter is designated as the tracking downconverter?
Downconverter 1 in Downconverter Rack 1.
What’s the purpose of the memory-tracking mode in a DSCS earth terminal?
Maintains a 24-hour record of antenna movements by the memory track unit. This data can be used to control the antenna in memory track mode in the event of an autotrack failure.
What type of frequency standard is used in a DSCS earth terminal and what are its outputs?
Cesium. 5 MHz, 1 MHz, and 1 pps.
How does the operator control the AN/GSC–52 terminal?
Locally by the TP or RTP, or remotely by an ECE or the laptop from any of the terminal access ports (EER, pedestal base, etc.).
What feedhorns are in the AN/GSC–52 feedhorn assembly?
One center sum (communication) feedhorn and four peripheral error (tracking) feedhorns.
The AIA develops AZ and EL tracking error signals. What is done with those signals?
The tracking-error data from the AIA is sent to TS-B and is used to create antenna velocity commands. These velocity commands are sent to the antenna’s servo amplifier via the AIA. The servo amplifier converts the velocity commands to drive power outputs to move the antenna, and/or to correct for tracking error.
What type of HPA does the AN/GSC–52 use?
.Traveling wave tube.
How many HPAs are normally operating at one time?
Three are active online, and one is in standby mode
What happens if one of the AN/GSC–52 converters fails?
TS-A commands the appropriate switch assembly (DSA or USA) to automatically switch from the defective converter to the backup converter.
Which converter (up or down) is normally dedicated to auto-switchover?
Number 8 in each rack.
What is the purpose of the FTS?
To generate and distribute precise 1 MHz and 5 MHz reference frequencies and 1 pps timing signals.
What is the purpose of the terminal servers?
To serve as interfaces to separate individual subsystems within the equipment complex. Each terminal server is responsible for control and status of specific groups of terminal equipment, and must be operational to allow for any remote control of these specific equipment groups.
What can the terminal operator do with the terminal processor?
Manually configure the terminal equipment that will be online for any given operational plan up to the equipment complement. Receive audible and visual notification of terminal major and minor alarms. Direct testing of the system utilizing the rack-mounted test equipment.
What is the mission of the DMSP?
To generate terrestrial and space weather data for operational forces worldwide.
What types of data do the DMSP strategic elements receive?
Stored mission sensor and real-time telemetry data.
What is the primary weather sensor on the DMSP satellite?
The operational linescan system (OL-S).
What are the AFSCN control nodes?
The Environmental Satellite Operations Center at Schriever AFB, Colorado, and the NOAA Satellite Operations Control Center at Suitland, MD.
What are the DMSP tactical users?
The Mark IVB and Receiving Set, Satellite (RSS) series of transportable terminals, the Navy’s Shipboard Receiving Terminals and other Army and Marine terminals.
What type data does the MARK IVB receive and process?
Real-time imagery and mission sensor data from polar orbiting satellites, and imagery from geostationary satellites.
How far can the antennas be located from the Processing Area?
Up to 1500 feet.
Which MARK IVB subsystem receives and processes the geostationary and polar satellite data from the antennas?
Acquisition.
What equipment comprises the SDAS group and what does the SDAS group do?
Equipment in the telemetry processing rack (rack 2) and antenna control rack (rack 3) in the Processing Area. The SDAS group processes the signals received from the antenna group equipment and then sends the data to the Product Control Subsystem.
What unit functions as an automatic patch panel?
Switch Matrix (Switch Controller).
After leaving the bit synchronizer, where does the data and synchronous clock go next?
If the data is not encrypted, it goes directly to the Format Processor (in the FEP) by way of the Switch Matrix. If the satellite data is encrypted, the data and synchronous clock are sent through the Switch Matrix to the designated cryptographic unit (KG-44) and then back through the Switch Matrix to the Format Processor.
What operating system does the Product Control Subsystem use and what are the program languages of the software used to perform its tasks?
UNIX operating environment. Ada, C, C++, and FORTRAN software programming languages.
Name the major software responsibilities of the MDS.
- Antenna control.
- SDAS control.
- Ingest.
- Processing all user requests for data.
Before satellite acquisition, which unit instructs the Switch Controller (Switch Matrix) to make the necessary equipment selections?
MDS.
Which unit is the primary interface between the operator/maintainer and the MARK IVB system?
Maintainer workstation.
What is the purpose of DSP?
It is a highly available, survivable and reliable satellite warning and surveillance system with the capability to detect and report missile and space launches and nuclear detonations in near real time. It also detects and reports data of tactical and intelligence value.
List the DSP’s specific missions in priority order highest to lowest.
- North American warning.
- Theater warning.
- US retaliatory strike.
- Worldwide space launches.
- Intelligence collection.
Which program ground station replaced the legacy DSP control centers after achieving initial operational capability, and where is it located?
The SBIRS mission control station that is operated by the 2nd Space Warning Squadron; it is located at Buckley AFB, Colorado.
What does the MCS use the Remote Ground Stations for?
To detect and report on all detectable missile and space launches and other infrared activity in their satellite’s field of view. The MCS processes the raw infrared data from the satellites and outputs mission data (messages) by way of a communications network to users.
Which agency is responsible for DSP operational control?
SPACEAF (14 AF).
What are the functions of the MCS?
Monitors and interprets mission data, including reporting all significant events, and monitoring, interpreting, and reporting on the quality of all mission data. Monitors satellite housekeeping functions including interpreting indications of malfunctioning satellite subsystems and analyzing troubles to identify faulty components. Monitors the operational status of ground station equipment.
What does RGSM1 do?
Format command data into serial ternary 1, 0, and S bits. Receive L1/2 (I and Q) and discrete L2 downlink data/clock from the SRS and provides demultiplexing of L1/2 data and routing of L1 and L2 data/clock to the MCS. Frame synchronize, time tag, and format the downlink data into packetized L1, L2 and UTC messages.
What is the purpose of the RF set?
Receives L1/2, L2 and/or L4 (impact sensor) downlink signals in the 2.2 to 2.3 GHz bandwidth. Transmits the L3 signals in the 1.761 to 1.842 GHz range.
What comprises the TR set?
The TR set consists of three downlink equipment strings and two uplink equipment strings used to interface with two antennas. Downlink strings 1 and 2 are connected to antennas 1 and 2 espectively. Downlink string 3 is the standby and can be switched to either antenna. Each downlink string consists of an plink/downlink switch (UL/DL SW), an RF unit, a L1/2 receiver, and a L2/L4 receiver. Each uplink string is dedicated to one antenna and consists of an UL/DL SW (shared with downlink strings 1 and 2), an RF modulator, and an echo check receiver.
Which equipment group provides simulated satellite signals?
Spacecraft simulator.
What is the purpose of the DE set?
It provides configuration status of the satellite readout station equipment using a LAN.
What is the purpose of the DE set workstations?
They provide the ability to monitor the satellite readout station equipment operations.
What are the two primary GPS missions?
- Navigation.
2. Nuclear detection.
What is the purpose of the navigation mission?
Allows users on earth, or in lower earth orbits, to accurately determine their position and velocity.
What does the nuclear detonation detection part of the satellite payload use to determine if a NUDET has occurred?
Light, x-ray, radiation, and/or electromagnetic pulse sensors.
What time standard is the GPS program responsible for maintaining?
GPS time within 1000 nanoseconds (1 microsecond) of universal time code.
What are the components of the GPS space segment?
A constellation of at least 24 active satellites. That orbit the Earth every 24 hours.
How many orbital planes does GPS have?
Six.
What are the two L-band signals transmitted by the satellites?
- L1.
2. L2.
Where is the MCS and what is its purpose?
Schriever AFB, Colorado. Provides the C2 operations for the space segment.
What is the function of the ground antenna?
Provides the interface between the satellites (space segment) and the master control and monitor stations. Each ground antenna is basically a remotely controlled satellite ground station, transmitting signals and commands to the satellites (uplink), and receiving telemetry from the satellites (downlink).
What is the minimum number of GPS satellites that must be tracked to have accurate threedimensional navigation?
Four.
Name the major user segment military air operation applications.
Aircraft navigation, air interdiction, all-weather airdrops, weapon delivery and/or targeting, reconnaissance, mapping, and vertical short take-off and landing.
Describe the AN/PSN–13 Defense Advanced GPS Receiver (DAGR)?
The DAGR is a light weight, self-contained, hand-held unit with a built-in integral antenna, but can be installed in a host platform (ground facilities, air, sea, and land vehicles) using an external power source and an external antenna. The DAGR collects and processes the GPS satellite dual frequency Link One (L1) and Link Two (L2) signals to provide position, velocity, and time (PVT) information, as well as position reporting and navigation capabilities.
What allows the DAGR to operate in a jamming environment?
It is a SAASM based PPS receiver.
To ensure interoperability between all US armed services, in which areas must Milstar systems be compatible?
- Frequency range.
- Type of modulation.
- Tuning increments.
- Frame formats.
Name the DOD’s core C2 communications system for US combatant forces in hostile environments.
Milstar.
Name the three distinct segments of the Milstar communications system?
(1) Space.
(2) Mission control.
(3) Terminal.
What’s the benefit of satellite-to-satellite crosslinking?
Worldwide communications connectivity without the use of vulnerable and expensive ground relay stations for worldwide coverage.
Which Milstar element provides dedicated day-to-day satellite control?
Mission control.
Which Milstar element’s responsibilities include allocating communication resources?
Mission planning.
Briefly describe the primary function of Milstar.
To support the NCA and to provide the Army, Navy, and Air Force with interoperable C3 at all levels of conflict for both strategic and tactical forces.
Name the three types of EHF SATCOM terminals in use by the Navy.
- Surface ship.
- Submarine.
- Shore station terminals.
Briefly describe the Army’s SMART-T.
A 4.5-foot antenna and a small Milstar terminal mounted on a HMMWV. Provides user data rates through T-1 (1.544 Mbps).
On which types of military aircraft would you find the Milstar airborne terminal?
The Air Force’s E-4B NAOC aircraft and the Navy’s TACAMO aircraft.
How many satellites does the completed Milstar II constellation consist of?
Three.
Name the Milstar satellite uplink, downlink, and crosslink frequency spectrums.
Uplink (UHF and EHF), downlink (SHF and UHF), and crosslink (EHF).
What does the Milstar satellite payload management subsystem message processor control?
Frequency hopping, time and frequency permutation, and beam pointing for the downlink.
Briefly describe the purpose of the Milstar satellites’ spot beam antennas.
Provide selective coverage of any ground station visible on the earth’s surface within the antenna’s footprint.
How many DAMA networks and network members can a Milstar satellite support?
Three DAMA networks—each network allows for up to 1,021 NMs and one NC.
Each Milstar DAMA terminal can set up to act in one of four roles. What are they?
- NC.
- ANC.
- MNC.
- NM.
Name the types of Milstar DAMA communications channels.
- LC.
- CC.
- RC.
What are the most important factors when determining the impact of rain on the EHF
communications link?
- Instantaneous rain rate (i.e., mist versus downpour, or how hard it’s raining).
- The latitude of the earth terminal.
- Look angle to the satellite.
How does the Milstar waveform derive its anti-jam capabilities?
By using a large bandwidth to hide a relatively small information band (75 to 2,400 bps communication channel) and by the use of narrow antenna beamwidth.
Why can frequency hopping prevent intentional jamming?
A potential jammer doesn’t know the hopping pattern.
What benefit do encoding/decoding techniques in the Milstar EHF modem provide?
Enhances the link BER threshold.
What are the command post terminal functions within the constellation of Milstar communications satellites?
C3.
What are the FE terminal functions within the constellation of Milstar communications satellites?
Control and communications.
Briefly describe the difference between the EHF/UHF ground command post terminal and the EHF/UHF transportable ground command post CONTINGENCY) terminal.
The ground command post terminal has a 90-inch dish enclosed in a radome (EHF), and two 14dB gain “wagon wheel” antennas (UHF); the transportable ground command post (CONTINGENCY) terminal has a 96-inch dish without a radome (EHF), and two 14 dB AFSATCOM antennas (UHF).
What type of antennas are used with the EHF/UHF airborne command post terminals?
26-inch Cassegrain antenna (EHF), and a 3-blade antenna (UHF).
Which agency is the system manager for the DSCS?
DISA.
Which agency ensures that GMFSC terminals and their assigned DSCS GMFSC gateway stations are technically compatible?
DISA.
Which agency operates and maintains all DSCSOCs?
SMDC/ARSTRAT.
Which agency operates the MCC to provide DSCS spacecraft control?
AFSPACECOM.
How does the director of DISA exercise operational control of the DCS?
Through the DOCC.
What’s the purpose of the TCCC?
To coordinate DCS status information between the DOCC and user elements.
What are the functions of the DOCS?
- Resource allocation.
- Satellite link establishment.
- Maintenance of link quality.
- Satellite signal monitoring.
- Satellite housekeeping.
What’s the function of the DSCSOCs?
Provide direct operational control of DSCS earth terminals and satellite payload by using DOCS equipment to maintain the corrected network parameters.
How many DSCS III satellite orbital positions are used to provide worldwide coverage?
Five.
Who is responsible for satellite control (i.e., launch support, orbit maintenance, and relocation)?
AFSPC.
How many independent transponder channels does the DSCS III satellite have?
Six.
Name some ways the DSCS satellites have been upgraded.
- Higher reliability and higher power amplifiers.
- More selective filters.
- More sensitive receive amplifiers.
- More efficient gallium arsenide solar cells.
What three configuration choices are available on the DSCS III satellite?
- Receiving antenna.
- Transmitting antenna.
- Transponder gain level.
What information is derived from the receive power levels of the 61 discrete ports of the BFN?
The position of an undesirable radiation signal.
What are the capabilities of transmit MBA assemblies?
Capability to shape antenna patterns to suit user coverage and connectivity requirements. The antennas can be commanded from the ground to form patterns ranging from individual spots, to multiple individual spots, to large composite patterns all the way up to earth coverage.
What’s the difference between transmit and receive MBAs?
Transmit MBAs don’t have nulling capability, and they have lower resolution.
What types of modulation can the six independent RF channels of the DSCS III satellite handle?
FM, BPSK, OQPSK, and pseudo noise/frequency-hopping spread spectrum modulation.
What’s the frequency translation for channel 6?
200 MHz.
Describe the UFO’s purpose.
The UFO’s purpose is to provide satellite communications for DOD and other government agencies through satellites in geosynchronous orbit.
Which UFO flights contain an EHF package for secure, anti-jam communications, telemetry, and command data?
Flights 4 thru 10 also contains an EHF package for secure, anti-jam communications, telemetry, and command data.
What is the main reason the DOD uses commercial satellite systems?
Because even with planned upgrades, MILSATCOM cannot meet the increasing data rate and bandwidth demands of the warfighters.
What additional factors favor using commercial systems?
- Financial savings because research and development are done by the owner/operator.
- Financial savings because there are no maintenance costs.
- Quick access to the latest technology.
- Service can be changed or discontinued once the mission is completed.
List the negative factors that must be considered when using commercial systems.
- Since the military does not control the satellite, there is a chance the owner/operator could terminate access involuntarily.
- The DOD must compete with private organizations, businesses, and news media for bandwidth.
- Satellites are vulnerable to jamming but commercial operators are not usually trained to rapidly identify that jamming is happening to resolve the problem and restore service.
- If the transmit carrier of a DOD terminal interferes with another customer, the DOD could incur penalty fees from the service provider.
(5) Service may not be available when or where the DOD needs it due to coverage limitations or difficulty getting a host nation’s approval.
What agency is designated with the responsibility to procure all commercial SATCOM services for the DOD?
DISA.
List some of the services provided by the CSB.
- Evaluate requests to see if commercial service is the best option.
- Obtain required transponder capacity (using DITCO contracts).
- Recommend and/or obtain ground terminals (using DITCO contracts).
- Supervise terminal installation.
- Help obtain HNA.
- Monitor the operation of the network and respond to any problems or needs.
When dealing with host nation approvals, what are landing rights, approvals and certifications?
Landing rights are a set of agreements between a country and a satellite provider to receive the satellite’s signals in that country. Approvals are permissions to operate a terminal within a country’s borders. Licenses deal with the technical issues including beamwidth and transmission frequency clearance.
List some of the responsibilities of the AFCA.
- Act as the day-to-day Air Force MSS System Manager on behalf of HQ USAF Installations and Logistics Directorate of Communications Operations.
- Provide a single point of contact for HQ USAF, MAJCOMs, vendors, and other parties to improve MSS support and formulate policy changes for HQ USAF review and approval.
- Monitor MSS technological advances and changes to identify the types of systems that can best satisfy Air Force requirements and provide recommendations to MAJCOM/FOA/DRU MSS managers.
- On request, provide training to MAJCOM/FOA/DRU MSS managers in activation, deactivation, and procurement of MSS systems and service.
What is another name for narrowband services, and to what does it refer?
MSS. It refers to satellite-based services (digital voice, data, paging, fax, etc.) provided by existing and emerging commercial communications providers through increasingly smaller and lighter mobile terminals.
Narrowband services are typically below what data rate?
64 Kbps.
The DOD Policy on Procurement of MSS required that handheld MSS services be provided by Iridium unless a waiver was granted. Is that policy still effective?
The policy is still active but was amended in 2006 to allow the DOD to use other MSS providers, for unclassified purposes only, when both the source and destination are within the CONUS.
What allows Iridium to offer coverage to all parts of the globe including the poles?
A constellation of 66 cross-linked satellites in near polar LEO.
What is the purpose of the dedicated government EMSS gateway?
Provides a dedicated entry point from the Iridium network into the DISN for secure and non-secure services. Also provides entry to non-secure commercial telephone services.
What is required when using the Iridium handheld phone for voice communications?
Handheld voice communications must be secured using the ISM.
What company besides Iridium is now providing unclassified CONUS-based handheld MSS services?
Globalstar.
What is a major requirement of the Inmarsat charter?
That the Inmarsat system must be used exclusively for peaceful purposes.
List the peaceful purpose clause guidelines for military use of the Inmarsat system?
- Armed forces not involved in armed conflict or any threat to or breach of peace may use Inmarsat.
- UN peacekeeping or peacemaking forces acting under the auspices of the UN Security Council may use Inmarsat, even if engaged in armed conflict to accomplish their mission.
- Armed forces not acting under the auspices of the UN Security Council involved in international or non-international armed conflict (civil war) may not use Inmarsat, except in the case of legitimate
individual or collective self-defense against armed attack within the limitations established by UN charter, Article 51. This exception excludes preventive action and self-help involving armed force in the absence of armed attack. - Armed forces engaged in armed conflict may use Inmarsat for distress and safety communications, and for communications relating to the protection of the wounded, sick, shipwrecked, prisoners of war and civilians, pursuant to the Geneva Red Cross Conventions, 1977. Personal and private, non-tactical communications by members of the armed forces are permitted; however, use of Inmarsat for nontactical governmental communications related to or in support of the war effort are not permitted unless they originate from governments of, or are directed to armed forces engaged in activities sanctioned by the UN Security Council, or self-defense pursuant to UN Charter, Article 51.
Describe the Inmarsat constellation and its area of coverage.
The Inmarsat constellation currently consists of nine geosynchronous satellites and provides coverage from about 75 degrees North latitude to about 75 degrees South latitude. Services are provided using overlapping earth coverage beams and spot beams. Each earth coverage beam covers roughly one third of the earth’s surface. Spot beams provide tighter coverage with more power.
Over what frequencies could you expect to operate when using commercial wideband services?
C-band (3.625-6.425 GHz), Ku-band (10.95-14.5 GHz), and Ka-band (20.2-31.0 GHz).
List some of the common commercial wideband applications.
- Private communication networks using VSAT.
- Deployable video teleconferencing.
- Real-time command, control, communications and intelligence functions for unmanned aerial vehicles.
- Emergency response and restoral.
- International high-speed internet connectivity.
What are some of the major wideband service providers currently used by the DOD?
INTELSAT, PanAmSat, EUTELSAT, and XTAR.
Which commercial wideband service system is specifically designed to interface with current Xband terminals?
XTAR.
Name some of Global Hawk’s primary functions.
- Autonomous, long endurance, all weather, day/night wide area reconnaissance.
- Surveillance imagery and SIGINT collection.
- Imagery dissemination.
Global Hawk is an integrated system. What are the major components?
- UAV.
- Ground stations.
- Support segment.
What SATCOM equipment does Global Hawk carry?
Ku-band, UHF and Inmarsat equipment used for control of the air vehicle and transmit of sensor data to the ground stations.
What data rate can Global Hawk’s Ku-band system handle?
8.48 Mbps.
What does the MCE GICS contain?
UHF SATCOM system, Inmarsat system, Ku-Band SATCOM subsystem and a CDL subsystem to provide command and control, wideband communications, and imagery processing and dissemination to exploitation stations for the UAV while en-route and in the collection area.
What is the purpose of the Global Hawk MCE SATCOM subsystem and what capabilities does it provide?
To communicate through a Ku-Band satellite to the Global Hawk AICS onboard the UAV. It provides backup capability for C² of one UAV from the MCE, and a full-duplex encrypted digital voice channel.
Name some of Predator’s primary functions.
- Autonomous, long endurance, day/night wide area reconnaissance.
- SIGINT collection.
- Hunter/killer operations.
- Video dissemination.
What are the major components of the Predator system?
- RPA.
- GCS(s).
- Support Segment.
What SATCOM equipment is on board the Predator?
Ku-band SATCOM equipment used for control of the air vehicle and to transmit sensor data, video, and voice to the ground stations.
What data rate can the Predator’s Ku-band system handle?
200 kbps to 3.2 Mbps.
What is the purpose of the Predator GCS SATCOM subsystem, and what capabilities does it provide?
To communicate through a Ku-Band satellite to the Predator PCM onboard the RPA. C² of four RPA’s from the GCS, and a full-duplex encrypted digital voice channel.
Define SIPRNet?
SIPRnet is a system of interconnected computer networks used by DOD to transmit classified information (up to and including SECRET) in a completely secure environment.
Describe the information that should be in a request for service.
- Type of service required.
- Its purpose.
- Equipment location.
- Hours of operation.
- A point of contact.
- Any other pertinent information.
Describe the purpose of a TSR.
It’s a request to DISA to start, stop, or change circuits, trunks, links, or systems.
List the information included in a TSR.
- Service date.
- Nature of requirement.
- Type of action required.
- Funding code.
- Restoration priority.
- Contact people.
- Users’ locations.
- Details of service and user equipment.
- DCS interface data.
- Type and grade of service required.
Describe what DISA uses TSOs for.
To order the activation, deactivation, or change of circuits, trunks, links, or systems.
What document authorizes operation and maintenance agencies to procure specific devices and ancillary equipment?
TSO.
Are verbal TSOs allowed? If so, what are the guidelines?
Verbal TSOs are issued when there’s insufficient time to prepare and distribute a record TSO. They are issued as an operational direction message, when possible, and confirmed by record TSO within five working days of issue.
Describe the numbering system used for TSOs.
Each TSO is assigned an alphanumeric TSO number, derived as follows: The beginning letter designates the issuing office. The first digit designates the year the TSO is issued. The next four digits represent sequential TSO serial numbering within the year, beginning 1 January. The next character is a diagonal (/) to show separation. Following the diagonal are the last four characters (circuit number) of the CCSD of the circuit or the entire six-character designator of the trunk being acted upon. The next character, a dash (–), shows separation. Next, a two-digit number identifies the sequential action being taken on the circuit or trunk. The number 01 always designates the first action, or start; numbers 02 through 99 show changes in and discontinuance of the service.
What’s the purpose of a CCSD?
It provides identification and information about a circuit.
Describe the numbering system used for CCSDs.
Each CCSD has eight characters. The first character shows the military department or agency requiring the service. The second and third characters identify the purpose or use of the circuit. The fourth character shows the type of service provided. The fifth through eighth characters identify the individual circuit; they may be all letters, all numbers, or a combination; for example, a temporary CCSD is composed of letters only, while a permanent CCSD usually has a combination of letters and numbers.
Who validates all Satellite Communication (SATCOM) network requirements?
All Satellite Communication (SATCOM) network requirements must be documented and submitted for validation by the Joint Staff.
What is the official Department of Defense (DOD) centralized database containing current and future SATCOM requirements on all satellite systems?
The SDB is the official DOD centralized database containing current and future SATCOM requirements on all satellite systems, to include military owned, commercial, allied, and civil.
Where do the SATCOM connectivity requirements originate from?
SATCOM connectivity requirements originate from users who recognize there is an unfulfilled need for SATCOM services. Requirements can also be generated from the Services or agencies who may have determined a need will exist based upon future changes to the force structure or doctrine.
Differentiate current and future SATCOM connectivity categories.
Current requirements are SATCOM connectivity needs associated with existing or soon-to-be warfighting systems (normally within two years). Future requirements are those anticipated needs that extend beyond the timeframe of current requirements, usually two years or more. Normally, future equirements are submitted by Services and agencies.
Under CJCSI 6250.01C, when do all requirements contained in the SDB get revalidated?
CJCSI 6250.01C directs a complete revalidation of all requirements contained in the SDB every year.
Who makes the final decision on the restoration priority of circuits?
The NCS.
What’s the exception to the restoration priority system numbering system?
When no restoration priority is assigned.
What’s the primary method of circuit restoration for outages?
Using spare channels and equipment. This is called “rerouting.”
List the suggested sequence for restoring circuits.
- Spare channels.
- Channels containing on-call circuits, when the circuits aren’t active.
- Circuits having no assigned restoration priority code.
- Circuits in ascending order of restoration priority, commencing with the lowest-priority circuit.
What’s more important, an individual circuit or a trunk?
A trunk.
Do trunks have restoration priority codes?
Most trunks don’t have restoration priorities.
What’s the function of the RSSC?
It’s a planning cell that provides GMF access to the unified and specified commands on the DSCS.
Which agency approves the satellite access requests (SAR) submitted by the GMFSC mission planner?
RSSC.
Which agency initiates SAAs for nonstandard tactical terminals?
DISA.
What must be done before a GMFSC terminal can operate on a given frequency?
It must be authorized access to the DSCS satellite by the RSSC.
What’s the function of the GMF network controllers?
Ensures each GMFSC terminal is operating according to the satellite access authorizations.
List the components of the GIG QC program.
- In-service performance monitoring.
- Out-of-service testing.
- Trend analysis.
What is the benefit of an efficient QC program?
An efficient QC program may prevent interruption to user service by detecting and correcting adverse trends before user service is affected.
What is the purpose of in-service performance monitoring and out-of-service testing?
In-service performance monitoring provides performance information that indicates the quality of the operating signal traversing the network without interruption to the signal. The purpose of out-of-service testing is to periodically verify the quality of prescribed specifications from terminal equipment to terminal equipment, and to make necessary end-to-end adjustments to interface and transmission equipment.
What is trend analysis?
Comparing the results of the periodic readings to the established standards to point out any degrading trend in the system.
Define CCM.
CCMs are those measures taken to ensure the continued use of the frequency spectrum by DOD and friendly forces.
List some of the CCM techniques.
Applying communications security (transmission, cryptographic, physical and emission security), using data burst transmission, using directional and mobile antennas, using spread spectrum modulation (direct sequence (CDMA) or frequency hopping).
Which of the three primary functions of the Promina addresses its “dynamic bandwidth allocation” capability?
Economic use of bandwidth.
Which of the four methods used by the Promina to assign bandwidth is the most efficient?
Demand assigned bandwidth allocation.
What bandwidth assignment method does the Promina use to set aside bandwidth for specific dates or times?
Time-of-day restrictions.
Which companding scale do European telephone networks use for analog-to-digital conversion? Which method is used in the US?
European: “A-law”; and US: “Mμ-Law.”
What’s the purpose of “transcoding” in telephone networks?
It’s used when transmitting voice/data between the US and European countries, and is equivalent to converting metric measurements back to old English measurements, and vice-versa.
What NCTE was specifically designed to police one’s density on a network and to aid in performing loopbacks to the network?
CSU.
Name the four basic requirements for the Promina to function in a communications network.
- Timing.
- Space.
- Power.
- A path for connectivity.
Describe the term “logical slot” as it applies to a Promina system.
It’s the amount of bandwidth required for the operation of a specific card or module in the Promina.
What’s the purpose of the operator interface in a Promina system?
It’s a menu driven software program that allows easy programming and operation of the Promina nodes.
What advantage does the Promina 400 have when comparing it to the Promina 200?
The common modules perform the same basic functions but with an expanded capability.
What’s the purpose of the HSS in the Promina 800?
It allows processing and movement of data at rates up to 256 Mbps (depending on how your node is configured).
What’s the purpose of the SX–2?
It provides the clocking and switching functions for the high-speed, extension, and standard shelves in a Promina 800 and is the interconnecting point for all the shelves in the node.
What module functions as the communications path between the SX–2 card and the standard or expansion shelves on the Promina 800?
BX.
Describe the term “load unit” and how it applies to a Promina series node.
It’s a measurement of the processing capability of each processor module in the node. The load unit capacity must first be calculated in order to determine the approximate number of processor modules required to operate the node.
List the two steps needed when you’re performing load unit calculations for a Promina node.
- Determine how many of each module shown on the load unit table is on the node.
- Multiply that number times the load units for the module, and add the totals.
When you’re building a node, what three critical items must you monitor to ensure a reliable network?
- The number of load units being tasked to the processors.
- The logical slot capacity of each shelf (not to exceed 16 logical slots per shelf).
- The power consumption of each module.
What three things must you consider in order to ensure better survivability of a node?
- If power or logical slots are critical on a particular shelf, rearrange modules in the node.
- Build redundancy in critical trunk modules or priority circuits by installing backups in spare shelves.
- If processor power is low, add another processor to the node.
In a Promina system, what user equipment is also referred to as a T–1 multiplexer?
Channel bank.
In a Promina system, what user equipment is best described as a local business switchboard?
Private branch exchange.
In a Promina system, what user equipment is a commonly used as a source for network timing?
CSD-10.
In order for previously multiplexed user data to integrate with a Promina system, with what format must it be compatible?
TTL logic.
What user equipment is a high-end statistical multiplexer that uses packet technology to establish virtual circuits, connecting data devices in a WAN?
SPX–50.
How are nodes connected to each other in a Promina system?
By using trunk modules.
Why is SCLP so important in a node?
It’s the sole means by which nodes communicate with each other, and it carries data that allows users to configure, query, and monitor all nodes from anywhere in the network.
Briefly describe the two operating modes of the TRK–3 module.
In the span mode, the TRK–3 is connected directly to the transmission line or span. Span trunks support proprietary and clear channel port bundles. In tandem mode, only the front TRK–3 card is used as a server to support a span mode TRK–3 when there are more than six proprietary bundles.
Describe the purpose of the two- and three-position switches found on most Promina front cards.
Two-position switches are found mainly on the common cards. They allow you to physically enable or disable the module. Three-position switches are found mainly on trunk, data, and voice cards. They allow you to physically perform loop testing (loop in, loop out, or normal) of the modules.
Prior to removing and replacing modules in a Promina, what must you do first (regardless of module type)?
Ensure the card slot is disabled.
Why must you always be aware of any changes or modifications you do on a node?
Because they can have profound effects on the network as a whole.
During a communications unit deployment, at least one person deployed with a Promina system must have what minimum access level assigned in order to first bring up the mission? Why?
Level 4. Because the “initialize node” function requires a Level 4 operator. Anytime you start up for the first time, or if your processors experience a hard crash, it may be necessary to perform a system initialization.
