chap 5 Flashcards
decoder
process of how intended information is interpretated
encoded
process of how info is organized through channel
half duplex
allows frequency to flow in 2 or more directions but not at the same time
trunked radio system
a sophisticated computer controlled radio system with multiple frequncies and repeaters
land mobile radio
encrypted radio used by most public services, operate in high frequency, ultra high frequency and 800MHZ bands
VHF low band
greatest distance, follow curvature of earth and can be blocked by physical items
VHF high bands
medium coverage, travel in straight lines and are generally used in rural areas
UHF bands
bounces off building and is least affected by noise but doesnt have great range, used in metropolitan areas
SAFECOM program
provides research testing, devolopment and guidance on interoperable channels
P25
always people from different agencies to communicate easily
base station radio
fixed location with most powerful transmitter
portable transceivers
handheld radio and have lower power, made for working away from the truck
mobile transceivers
vehicle and aircraft, 10-15 miles
repeaters
long range transceiver made to extend or strenghten the signal of handheld or vehicle radios
repeaters
long range transceiver made to extend or strengthen the signal of handheld or vehicle radios
CTCSS
encodes the radio signal always only radios with the proper toe to get the transmission
simplex mode
same frequency and data transmits in one direction
half duplex mode
each end of the transmission transfers in turn
multiplex mode
multiple streams on one signal, ambulance to hospital
sat receivers
low power units, picks the best frequency to talk on,
digital modes
wireless paging or alerting system, can be displayed or printed
computer
documents in real time, sorting info in many categories, creation of multiple repeating forms, quick online retrieval
5 phases of comm.
occurrence of event
detection of need of EMS
notify and EMS response
arrival of ems
prep for next response
vehicle telemetry
provides advanced crash notification,