Comm Flashcards
(36 cards)
Characteristics of Marine Corps Communications
Flexibility-need all types of comm for cerain situations
Reliability-needs to work
Security-COMSEC frequency hopping, measure taken to deny unauthorized persons info of value
Speed-set network up quickly
Types of Comm
radio wire sound visual Physical Comm-messengers, mail Data-includes all computers and data transmission device
Radio comm or waves
uses energy in the form of electromagnetic waves that propagate through space at the speed of light
Frequency
wavelength is directlyy related, mesasured in terms of the number of waves generated(cycles) per second. 1 cycle per second is one hertz, RO’s freqs in the megahertz (millions of cycles per second
Ground Waves
travel from transmitting antenna along the surface of the earth
wavelength
longer wavelength lower freq allowsthe wave to bend around and over larger obstacles.
shorter wavelength-increases in freq ability to bend around obstacles decreases.
Sky waves
radio waves that travel up into the atmosphere. lower freq 2-12 MHz. used to bounce back off the atmosphere back to earth. increases range of our comm
HF
lower frequencies can communicate over great distances.
Use when long haul comm are necessary and no SATCOM is available.
equipment AN/PRC-150 man-portable
AN/MRC-148 vehicle mounted
VHF
Extends slightly beyond LOS, freqs in the 30MHz, ancts like HF ground waves, range of 40 km.
used in infantry battalions
Equipment-AN/PRC-119 man packed SINCGARS, AN/VRC-88 vehicular monted low power SINCGARS, AN/VRC-89 vehicular mounted dual SINCGARS with one low power and one with high power amp
CONS power output, terrain, atmospheric conditions
UHF (LOS)
strictly LOS, unable to bend around obstacles, range may extend 500km as long as airplane is high enough to be in LOS
Use for ground to air comm and air to air
Equipment AN/PRC-117/152/148 man portable, AN/VRC-103 vehicle
UHF(SATCOMM)
extends from earth to satellites and back down, high speed data communications
Use for long range tactical comm, can access k or 25k channels DAMA or dedicated
Equipment AN/PRC-117/152/148 man portable, AN/VRC-103/110 vehicle with power amp. AN/PRC-148 can be used for SATCOM only
SINCGARS
single channel ground air radio system, primary MAGTF VHF. lightweight radios , primary means of comm for command, control and fire support. provides high securityagainst enemy electronic warfare by using frequency hopping.
Freq hopping
a transmission technique that changes the freq of a radio channel automatically at a pseudo random rate common to the transmitter and receiver
5 variables required to freq hop
Hopset-the VHF freq that SINCGARS will hop through in freq hopping mode
Transmission security key (TSK) sequence in which the radio will hop within a hopset
Transmission encryption key (TEK) Encrypts and decrypts the operators voice during the radio transmission
Time-time in radios must be sync, manually inputed
NET ID-3 digit numeric code that determines where a specific frequency hopping circuit begins the frequency hopping, manually entered
COMSEC
the protection resulting from all measures designed to deny unauthorized persons information of value that might be derived from the possession and study of telecommunications or to mislead unauthorized persons in their interpretation of the results fo such possession and study
4 areas of COMSEC
Crypto Security
emission security
physical security
transmission security
Crypto security
the componet of COMSEC that results from the provisions of technically sound crypto-systems and their proper use
Emission security
componet which results from all measures taken to deny unauthourized persons info of value that might be derived from intercept and analysis of compromising emanations from crypto-equipment and telecommunications systems
Physical security
all physical measures taken to safeguard classified equipment, material, and documents from access or observation by unauthorized persons
Transmissions Security
results from all measures designated to protect transmissions from interception and exploitation by means other than cryptanalysis
Electronic Warfare
term covering any militaryaction involving the use of electromagnetic or directed energy either to attack an enemy;s combat capapbility or to protect friendly combat capabilities against undesirable effects of friendly or enemy use of the electromagnetic spectrum
preventive measures
reduce radio traffic to a minimum
SOPs brevity codes, minimum power settings, directional antennas
Use alternate means(wire, visual, Messenger)
COMSEC crypt equipment to secure transmissions
Purpose of MC comm
To serve command
what adds time to comm gear
PSN-13
