Microwave Communication Basics Flashcards
Can be ____ when, in digital applications, the signal is demodulated and re-modulated before transmission to the next radio hop.
regenerative
For standard refractivity conditions, k = __ =___
1.33 = 4/3
Microwave radio provides a transmission medium for digital traffic of standard capacities typically ranging from 1.544 Mbps (1T1) to 45 Mbps (1DS3) in North America, and from 2.048 Mbps (1E1) to 34 Mbps (16E1) based on ITU standards.
Plesiochronous Digital Hierarchy (PDH)
Lowering the system gain will reduce the ___.
fade margin
The Earth’s radius model is most useful for __.
terrestrial paths
Makes it possible to utilize a common antenna for both the transmitter and receiver.
antenna-coupling unit
a calculation involving the gain and loss factors associated with the antennas, transmitters, receivers, transmission lines, and propagation environment, used to determine the maximum distance at which a transmitter and receiver can successfully operate.
link budget
The higher the frequency, the ____
narrower the Fresnel zone
Radio link typical distance can be up to ___.
25 mi (40 km)
defined as the factor that is multiplied by the actual Earth radius
effective Earth radius factor (k)
amplifies the received signal (which is at this point much weaker than when it was transmitted), filters out any undesirable signals (interfering signals)
receiver
can be described as any criterion to ensure sufficient antenna heights so that, in the worst case of refraction (for which k is minimum), the receiver antenna is not placed in the diffraction region.
Clearance
Radio stations between two terminal stations are called ___.
Repeater stations (active or passive)
lower k-values will lower the ___
LOS
The purpose of _____ to generate the carrier frequency that is to be used for the communication, to modulate this carrier frequency with the desired information, and finally, to amplify the signal
transmitter
microwave radios are typically used for high-capacity backbone systems.
Synchronous Digital Hierarchy (SDH) / Synchronous Optical Network (SONET)
Transmitted information can be ____.
Voice
data
video
to interconnect the antenna with the transmitter/receiver
transmission lines
antenna must have clearance of ___ percent or greater at k=4/3
100
Made by a number of intermediate repeaters with or without partial payload drop-insert.
Single connection links
Combination of these three components is called ____.
Radio terminal
A functionality provided in analog and digital repeaters, where only radio-system specific control and service channels, and possibly part of the payload, are made available for local traffic and system management and maintenance.
Drop-insert
the difference between the received signal and receiver threshold value (or sensitivity) for given Bit Error Rate (BER)
fade margin
Active repeaters can be ____ when signal is only filtered and amplified.
nonregenerative
