WorksheetsTEST 2 FINAL
Total questions: 100
Worksheet time: 2hrs 40mins
Name
Class
Date
1.
Total spectrum = 600 channels, reuse factor N = 12. Channels per cell = ?
a)
40
b)
50
c)
60
d)
75
2.
If N decreases, what happens to system capacity?
a)
Decreases
b)
Increases
c)
No change
d)
Becomes zero
3.
Average call duration = 2 min, calls per hour = 3. Traffic/user = ?
a)
0.05 Erlang
b)
0.1 Erlang
c)
0.2 Erlang
d)
0.3 Erlang
4.
If path loss exponent n = 4 and distance doubles, power reduces by:
a)
4×
b)
8×
c)
16×
d)
2×
5.
Cluster size N = 7, total channels = 350. Channels per cell = ?
a)
40
b)
50
c)
60
d)
70
6.
If Q = 4 and n = 4, SIR ∝ ?
a)
4
b)
16
c)
64
d)
256
7.
Cell radius halves. Coverage area reduces by factor:
a)
2
b)
3
c)
4
d)
1
8.
Offered traffic = 18 Erlangs, system capacity = 15 Erlangs. Congestion = ?
a)
3
b)
15
c)
18
d)
33
9.
For i = 2, j = 1, cluster size N = ?
a)
3
b)
4
c)
7
d)
9
10.
Speed increases in a cellular network. Handoff rate:
a)
Decreases
b)
Increases
c)
Constant
d)
Zero
11.
Total channels = 840, cluster size = 7. Channels per cell = ?
a)
100
b)
110
c)
120
d)
130
12.
If 100 users generate 0.05 Erlang each, total traffic = ?
a)
2
b)
3
c)
5
d)
10
13.
Co-channel reuse ratio Q = √(3N). For N = 12, Q ≈ ?
a)
4.2
b)
5.1
c)
6
d)
7.3
14.
A cell has 60 channels, 30 Erlangs traffic. Avg traffic/channel = ?
a)
0.2
b)
0.4
c)
0.5
d)
0.6
15.
If N increases, SIR generally:
a)
Decreases
b)
Increases
c)
Same
d)
Zero
16.
Arrival rate = 0.2 calls/sec, holding time = 120 sec. Traffic = ?
a)
12
b)
18
c)
24
d)
30
17.
In omnidirectional cells, number of first-tier interferers = ?
a)
2
b)
4
c)
6
d)
12
18.
If TDMA provides 8 slots/carrier and 25 carriers exist, users supported = ?
a)
100
b)
150
c)
200
d)
250
19.
GoS improves from 5% to 2%. User experience:
a)
Worsens
b)
Improves
c)
Same
d)
Random
20.
Cell radius = 500 m, speed = 54 km/h. Dwell time ≈ ?
a)
33 s
b)
66 s
c)
90 s
d)
120 s
21.
If total BW = 30 MHz, channel BW = 25 kHz. Channels = ?
a)
1000
b)
1200
c)
800
d)
600
22.
If call holding time halves, traffic becomes:
a)
Double
b)
Same
c)
Half
d)
Zero
23.
If N = 7 and total cells = 70, number of clusters = ?
a)
5
b)
7
c)
10
d)
20
24.
If each channel supports 2 users via TDMA and original channels = 50, effective channels = ?
a)
50
b)
75
c)
100
d)
150
25.
If distance reduces by factor 2 and n = 4, signal increases by:
a)
2×
b)
4×
c)
8×
d)
16×
26.
If offered traffic = 25 Erlangs and channels = 30, blocking probability is:
a)
High
b)
Low
c)
0.5
d)
1
27.
If reuse factor changes from 4 to 9, reuse increases by:
a)
1.5×
b)
2×
c)
2.25×
d)
4×
28.
If spectral efficiency = 3 bps/Hz and BW = 5 MHz, data rate = ?
a)
5 Mbps
b)
10 Mbps
c)
15 Mbps
d)
20 Mbps
29.
If BTS power increases excessively, result is:
a)
Better QoS
b)
Less handoff
c)
More interference
d)
Less spectrum
30.
If load factor > 1, system is:
a)
Idle
b)
Balanced
c)
Overloaded
d)
Underloaded
31.
If 1 Erlang means channel occupied for:
a)
1 sec/hr
b)
Half time
c)
Full time
d)
Random
32.
If N = 3, Q = √(3N). Q = ?
a)
2
b)
3
c)
4
d)
5
33.
If traffic increases 20% from 10 Erlangs, new traffic = ?
a)
10.2
b)
11
c)
12
d)
15
34.
If handoff delay exceeds dwell time, result is:
a)
Smooth call
b)
No handoff
c)
Call drops
d)
Better QoS
35.
If MCC = 404 and MNC = 45, PLMN code length = ?
a)
4
b)
5
c)
6
d)
7
36.
If paging delay increases, effect is:
a)
Faster setup
b)
Slower setup
c)
Better SIR
d)
No roaming
37.
If sectoring changes interferers from 6 to 2, SIR improves by factor:
a)
2×
b)
3×
c)
4×
d)
6×
38.
If 10% channels reserved in 120-channel cell, usable channels = ?
a)
96
b)
100
c)
108
d)
110
39.
If frequency band usable = 24 MHz and channel BW = 30 kHz, channels ≈ ?
a)
600
b)
700
c)
800
d)
900
40.
If traffic per channel = 0.8 Erlang and 100 channels exist, total traffic = ?
a)
60
b)
70
c)
80
d)
90
41.
Total bandwidth = 12 MHz, FDMA channel spacing = 25 kHz. Number of channels = ?
a)
360
b)
420
c)
480
d)
520
42.
A TDMA frame is 4.615 ms with 8 slots. Slot duration ≈ ?
a)
0.5 ms
b)
0.576 ms
c)
0.625 ms
d)
0.75 ms
43.
Chip rate = 3.84 Mcps, spreading factor = 16. Data rate ≈ ?
a)
120 kbps
b)
240 kbps
c)
480 kbps
d)
960 kbps
44.
OFDMA uses 2048 subcarriers spaced 15 kHz. Total bandwidth ≈ ?
a)
20.48 MHz
b)
30.72 MHz
c)
40 MHz
d)
50 MHz
45.
A GSM carrier has 8 time slots. If 2 slots are control, traffic slots = ?
a)
4
b)
5
c)
6
d)
8
46.
If processing gain = 128 and Eb/N0 = 7 dB, required SIR (dB) ≈ ?
a)
−20 dB
b)
−14 dB
c)
−6 dB
d)
+7 dB
47.
Total spectrum = 10 MHz, GSM carrier BW = 200 kHz. Number of carriers = ?
a)
40
b)
45
c)
50
d)
60
48.
If spreading factor halves from 128 to 64, processing gain becomes:
a)
Double
b)
Same
c)
Half
d)
Zero
49.
LTE RB bandwidth = 180 kHz. For 50 RBs, total BW ≈ ?
a)
7.5 MHz
b)
9 MHz
c)
10 MHz
d)
12 MHz
50.
In CDMA, near-far problem is controlled by:
a)
Frequency hopping
b)
Power control
c)
TDMA
d)
Sectoring only
51.
If 1 Erlang means channel is occupied for:
a)
10% time
b)
50% time
c)
Full time
d)
Random time
52.
If voice activity factor = 0.4, effective interference reduces by factor:
a)
0.4
b)
0.6
c)
1.4
d)
2.5
53.
A TDMA system has 30 carriers, each with 8 slots. Total slots = ?
a)
180
b)
210
c)
240
d)
300
54.
5G uses 60 kHz subcarrier spacing and 273 RBs. Total BW ≈ ?
a)
100 MHz
b)
150 MHz
c)
200 MHz
d)
300 MHz
55.
If interference increases by 3 dB, SIR becomes:
a)
Double
b)
Half
c)
Same
d)
4×
56.
CDMA capacity model: SIR = PG/(N−1). If PG=100 and SIR=10, N ≈ ?
a)
6
b)
10
c)
11
d)
20
57.
If spectral efficiency = 4 bps/Hz and BW = 15 MHz, peak rate = ?
a)
30 Mbps
b)
45 Mbps
c)
60 Mbps
d)
75 Mbps
58.
GSM has 40 carriers. Total time slots = ?
a)
200
b)
240
c)
320
d)
400
59.
If 64-QAM carries 6 bits/symbol at 1 Msps, data rate = ?
a)
2 Mbps
b)
4 Mbps
c)
6 Mbps
d)
8 Mbps
60.
If average call duration = 120 s and traffic = 210 Erlangs, calls/hour ≈ ?
a)
3150
b)
4200
c)
6300
d)
8400
61.
If cell radius halves, coverage area reduces by factor:
a)
2
b)
3
c)
4
d)
8
62.
If SDMA splits a cell into 3 beams, capacity increases by:
a)
1.5×
b)
2×
c)
3×
d)
4×
63.
If CDMA user data rate doubles, processing gain:
a)
Doubles
b)
Halves
c)
Same
d)
Zero
64.
LTE frame duration = 10 ms with 10 subframes. Subframe duration = ?
a)
0.5 ms
b)
1 ms
c)
2 ms
d)
5 ms
65.
If total received interference = 10 W and desired signal = 10 mW, SIR = ?
a)
0.001
b)
0.01
c)
0.1
d)
1
66.
If paging capacity = 100 msgs/sec and each call needs 2 msgs, max calls/sec = ?
a)
25
b)
50
c)
75
d)
100
67.
If Eb/N0 increases, CDMA capacity:
a)
Increases
b)
Decreases
c)
Same
d)
Random
68.
If TDMA slot duration = 577 µs and 8 slots exist, frame ≈ ?
a)
3.6 ms
b)
4.6 ms
c)
5.6 ms
d)
6.6 ms
69.
If 5G spectral efficiency = 6 bps/Hz and BW = 100 MHz, peak rate = ?
a)
300 Mbps
b)
400 Mbps
c)
600 Mbps
d)
800 Mbps
70.
If GSM reserves 15% slots for control from 320 slots, traffic slots ≈ ?
a)
240
b)
260
c)
272
d)
300
71.
If handover delay exceeds dwell time, result is:
a)
Smooth call
b)
No handover
c)
Call drop
d)
Better QoS
72.
If chip duration Tc = 0.2 µs and SF = 128, bit duration ≈ ?
a)
12.8 µs
b)
25.6 µs
c)
40 µs
d)
64 µs
73.
If LTE latency = 20 ms and 5G latency = 1 ms, reduction factor = ?
a)
5×
b)
10×
c)
20×
d)
50×
74.
If location area has 30 cells, paging cost ∝
a)
1
b)
10
c)
20
d)
30
75.
If traffic per channel = 0.7 Erlang and 300 channels exist, total traffic ≈ ?
a)
150
b)
180
c)
210
d)
240
76.
If user speed increases, handoff rate:
a)
Decreases
b)
Increases
c)
Same
d)
Zero
77.
If BW = 400 MHz and SE = 6 bps/Hz, throughput ≈ ?
a)
1.2 Gbps
b)
2.4 Gbps
c)
3.6 Gbps
d)
4.8 Gbps
78.
If GPS accuracy = 5 m and network triangulation = 50 m, improvement = ?
a)
5×
b)
8×
c)
10×
d)
15×
79.
If 1G supports 1 call per 30 kHz and 2G supports 8 calls per 200 kHz, improvement ≈ ?
a)
1.2×
b)
2×
c)
4×
d)
6×
80.
A wireless link has bandwidth 5 MHz and spectral efficiency 2 bps/Hz. Peak data rate = ?
a)
5 Mbps
b)
10 Mbps
c)
15 Mbps
d)
20 Mbps
81.
If SNR = 20 dB, linear SNR ≈ ?
a)
10
b)
20
c)
100
d)
200
82.
Shannon capacity for BW = 1 MHz and SNR = 100 is closest to:
a)
1 Mbps
b)
3.32 Mbps
c)
6.64 Mbps
d)
10 Mbps
83.
If distance doubles and pathloss exponent n = 4, received power becomes:
a)
2026-02-01 00:00:00
b)
2026-04-01 00:00:00
c)
2026-08-01 00:00:00
d)
2016-01-01 00:00:00
84.
Propagation delay over 30 km at speed 3×10⁸ m/s is:
a)
0.1 ms
b)
0.5 ms
c)
1 ms
d)
5 ms
85.
Hidden terminal problem mainly affects which protocol?
a)
CSMA/CD
b)
CSMA/CA
c)
FDMA
d)
TDMA
86.
RTS/CTS mechanism is mainly used to reduce:
a)
Fading
b)
Hidden node collisions
c)
Handoff delay
d)
Routing overhead
87.
Packet size = 1500 bytes, link rate = 6 Mbps. Transmission delay ≈ ?
a)
0.5 ms
b)
1 ms
c)
2 ms
d)
5 ms
88.
If retransmission probability = 0.2, expected transmissions per success = ?
a)
1.1
b)
1.25
c)
1.5
d)
2
89.
If packet error rate improves from 10⁻² to 10⁻⁴, improvement factor = ?
a)
10×
b)
100×
c)
1000×
d)
10000×
90.
Mobile IP allows mobility while maintaining the same:
a)
MAC address
b)
IP address
c)
Port number
d)
DNS server
91.
In Mobile IP, Home Agent maintains binding between:
a)
MAC–IP
b)
Home address–CoA
c)
IP–Port
d)
DNS–IP
92.
Triangle routing path is best described as:
a)
CN → MN direct
b)
CN → HA → MN
c)
MN → FA → HA
d)
HA → CN → MN
93.
If CN→HA delay is 30 ms and HA→MN delay is 40 ms, total delay = ?
a)
40 ms
b)
60 ms
c)
70 ms
d)
80 ms
94.
If MN changes CoA 12 times/hour, average time between changes = ?
a)
2 min
b)
3 min
c)
5 min
d)
10 min
95.
Major cause of increased delay in Mobile IP is:
a)
Header size
b)
Triangle routing
c)
ARP resolution
d)
CRC
96.
If handoff latency = 250 ms and arrival rate = 400 packets/sec, lost packets ≈ ?
a)
50
b)
75
c)
100
d)
150
97.
Cellular networks are mainly:
a)
Decentralized
b)
Infrastructure-based
c)
Multi-hop always
d)
Battery-free
98.
In ad hoc networks, routing overhead increases when:
a)
Mobility decreases
b)
Mobility increases
c)
Nodes static
d)
Bandwidth increases
99.
AODV and DSR are examples of:
a)
Proactive protocols
b)
Reactive protocols
c)
Hybrid protocols
d)
Static routing
100.
If CDMA user data rate doubles, processing gain:
a)
Doubles
b)
Halves
c)
Same
d)
Zero
100 %
