1
What does the "A" in ADSL stand for?
A
Asynchronous
B
Asymmetric
C
Automatic
D
Advanced
2
What is the typical frequency range used for downstream transmission in ADSL?
A
0-4 kHz
B
4 kHz - 138 kHz
C
138 kHz - 1.1 MHz
D
Above 1.1 MHz
3
Which modulation technique is commonly used in ADSL systems?
A
QPSK only
B
DMT (Discrete Multi-Tone)
C
FSK (Frequency Shift Keying)
D
ASK (Amplitude Shift Keying)
4
What is the primary reason for the asymmetry in ADSL data rates?
A
Technical limitations of copper wires
B
User behavior patterns (more downloading than uploading)
C
Government regulations
D
To reduce power consumption
5
Which device separates voice and data signals at the customer premises in ADSL?
A
DSLAM
B
Splitter (Microfilter)
C
Modem
D
Router
6
What is the maximum theoretical downstream data rate of ADSL2+?
A
8 Mbps
B
12 Mbps
C
24 Mbps
D
100 Mbps
7
Which phenomenon causes signal attenuation to increase with frequency in ADSL?
A
Skin effect
B
Bridge taps
C
Crosstalk
D
Impulse noise
8
What is the purpose of the guard band in DMT modulation used in ADSL?
A
To increase data rate
B
To prevent interference between adjacent subchannels
C
To reduce power consumption
D
To synchronize transmitter and receiver
9
Which ADSL variant provides equal upstream and downstream data rates?
A
ADSL2
B
ADSL2+
C
SHDSL (Symmetric HDSL)
D
RADSL
10
What is the typical reach (distance) limitation for ADSL service from the central office?
A
1-2 km
B
3-5 km
C
10-15 km
D
20-25 km
11
Which technique does ADSL use to adapt to varying line conditions?
A
Fixed bit loading
B
Bit swapping and rate adaptation
C
Constant power spectral density
D
Time division multiplexing
12
What is the main advantage of using OFDM/DMT in ADSL compared to single-carrier modulation?
A
Lower complexity
B
Better spectral efficiency and resistance to narrowband interference
C
Higher peak-to-average power ratio
D
Simpler equalization requirements