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If link bandwidth is 4 Mbps and packet size is 1,000 bits, transmission delay per packet is:
0.25 ms
0.5 ms
1 ms
2 ms
4 ms
Option 3
IP over satellite
Yes
null
If matched circular polarization improves signal by 2 dB, what is new Pr if initial Pr = −100 dB?
−102 dB
−98 dB
−100 dB
−95 dB
null
Option 2
Circular Polarization
Yes
Pr_new = Pr_old + improvement
If noise power doubles, what happens to SNR in dB?
Increases by 3 dB
Decreases by 3 dB
Increases by 6 dB
No change
null
Option 2
Signal-to-noise ratio
Yes
SNR = 10 × log₁₀(Psignal / Pnoise); doubling noise → SNR −3 dB
If packet loss probability is 0.01 and window size is 100 packets, what is the expected number of retransmissions per window?
1
0.1
10
100
null
Option 3
TCP over satellite
Yes
null
If packet loss rate is 2% and 1000 packets transmitted, expected lost packets are:
10
20
30
null
null
Option 2
IP over satellite
Yes
null
If path loss decreases by 3 dB, what happens to received power?
Power decreases by 3 dB
Power increases by 3 dB
Power doubles
null
null
Option 2
Satellite gateway
Yes
ΔPr = −ΔLp
If path loss increases by 5 dB, what happens to received power?
Power doubles
Power increases
Power decreases by 5 dB
No change
null
Option 3
Wireless communication systems
Yes
ΔPr = −ΔLp
If path loss is reduced by 10 dB, the required transmitter power to maintain same received power may:
Be cut by 10 dB
Remain the same
Increase by 10 dB
Increase by 3 dB
Double
Option 1
Link Budget
Yes
null
If Pr = −100 dBW and Pt = 20 dBW, find total loss.
L = Pt − Pr = 20 − (−100) = 120 dB
L = 100 + 20 = 120
L = −100 − 20 = −120
L = 10 × log₁₀(20/100)
null
Option 1
Inter satellite Link
Yes
L = Pt − Pr
If propagation delay = 0.1 s and distance doubles, what is new delay?
0.05 s
0.1 s
0.2 s
0.3 s
null
Option 3
NTN
Yes
Delay ∝ Distance
If Pt = 100 W, Gt = 30 dB, Gr = 25 dB, and path loss = 180 dB, find received power.
Pr = 10 log₁₀(100) + 30 + 25 − 180 = −105 dB
Pr = 10 log₁₀(100) + 30 + 25 − 180 = −105 dB
Pr = 180 − 30 − 25 = 125 dB
Pr = 10 × 180 / 100
null
Option 1
Link Budget
Yes
Pr = 10 log₁₀(Pt) + Gt + Gr − L
If received bits = 10⁶, errors = 1000, find BER.
BER = 1000 / 10⁶ = 10⁻³
BER = 10⁶ / 1000
BER = 1000 × 10⁶
BER = 10³
null
Option 1
BER
Yes
BER = Number of Errors / Total Bits
If received power Pr = −95 dBW and receiver minimum required power Pmin = −110 dBW, what is the link margin?
Link margin = −95 + (−110) = −205 dB
Link margin = −110 − (−95) = −15 dB
Link margin = Pr − Pmin = −95 − (−110) = 15 dB
null
null
Option 3
Link Budget
Yes
Link margin = Pr − Pmin
If round-trip delay increases, what happens to TCP throughput?
Throughput increases
Throughput decreases
Throughput decreases
Throughput decreases
null
Option 2
IP over satellite
Yes
TCP throughput inversely ∝ RTT
If RTT = 600 ms and TCP window size = 600 KB, find throughput.
1 Mbps
8 Mbps
10 Mbps
null
null
Option 2
TCP over satellite
Yes
Throughput = (window size × 8) / RTT = (600×8)/0.6 = 8 Mbps
If satellite bus power decreases from 100 W to 80 W, what % decrease?
10%
15%
25%
20%
35%
Option 4
Satellite bus
Yes
% decrease = (100−80)/100 × 100 = 20%
If satellite round trip delay is 500 ms, one-way delay is approx:
125 ms
250 ms
500 ms
750 ms
1000 ms
Option 2
IP over satellite
Yes
null
If satellite transmit gain doubles, what happens to received power in dB?
Increases by 2 dB
Increases by 3 dB
Remains same
Decreases by 3 dB
null
Option 2
Link Budget
Yes
Doubling gain → +3 dB increase
If signal = 50 mW and noise = 5 mW, find SNR (dB).
SNR = 10 log₁₀(50/5) = 10 dB
SNR = 50/5 = 10
SNR = 5/50 = 0.1
SNR = log₁₀(50×5)
null
Option 1
SNR
Yes
SNR(dB) = 10 log₁₀(Ps/Pn)
If spectral efficiency = 4 bits/Hz, bandwidth = 10 MHz, find throughput.
Throughput = 4 + 10
Throughput = 4 × 10 = 40 Mbps
Throughput = 4 / 10
Throughput = 4² × 10
null
Option 2
3gpp
Yes
C = η × B
If TCP over satellite link has 20 Mbps throughput and round-trip delay 0.25 s, what is the bandwidth-delay product?
5 Mb
20 × 0.25 = 5 Mb
0.25 / 20
20 / 0.25
null
Option 2
TCP over satellite
Yes
BDP = Bandwidth × RTT
If telemetry bit rate = 128 kbps and Eb/N₀ = 10 dB, find carrier-to-noise ratio (C/N) for 1 MHz bandwidth.
C/N = 10 + 10 log₁₀(128/1e6)
C/N = 10 + 10 log₁₀(128 × 10³ / 10⁶) = −0.93 dB
C/N = 10 × 128
C/N = 128 − 10
null
Option 2
TT&C
Yes
C/N = Eb/N₀ + 10 log₁₀(Rb/B)
If the path loss increases by 10 dB, what happens to the received power?
Decreases by 1 dB
Decreases by 10 dB
Increases by 10 dB
null
null
Option 2
Link Budget
Yes
null
If the receiver antenna gain increases by 3 dB, what happens to received power?
Power decreases
Power doubles
Power increases by 3 dB
No change
null
Option 3
Link Budget
Yes
ΔPr = ΔGr
If the satellite transmit power doubles, how much does the received power increase in dB?
2 dB
3 dB
6 dB
10 dB
null
Option 2
Link Budget
Yes
Doubling power → 10 × log₁₀(2) ≈ 3 dB increase
If the terminal moves closer to the satellite, what happens to received power?
Power decreases
Power increases
No change
Power halves
null
Option 2
Satellite User terminal
Yes
Pr ∝ 1 / distance²
If the transmit power of an NTN payload is halved, what is the change in received power in dB?
−3 dB
+3 dB
−6 dB
+6 dB
null
Option 1
NTN
Yes
Halving power → 10 × log₁₀(0.5) ≈ −3 dB
If total system losses decrease by 2 units, what happens to Pr?
Received power increases 2
Power decreases
No change
Power doubles
null
Option 1
Link Budget
Yes
ΔPr = −ΔL
If transmit power = 60 W and system loss = 10%, received power?
50 W
54 W
48 W
55 W
null
Option 2
Link Budget
Yes
Loss = 10% of 60 = 6 W → Pr = 60 − 6 = 54 W
If transmit power doubles from 20 W to 40 W, what is change in received power in dB?
+1 dB
+3 dB
+6 dB
No change
null
Option 2
Link Budget
Yes
ΔPr = ΔPt (dB)
If transmit power halves, what happens to received power in linear scale?
Power halves
Power doubles
No change
Power increases slightly
Power decreases
Option 1
Link Budget
Yes
Pr∝Pt
If transmit power increases by 2 dB, what happens to received power?
Received power increases by 2 dB
Decreases by 2 dB
Doubles
decraeses
null
Option 1
Link Budget
Yes
ΔPr = ΔPt
If transmit power is 100 W (20 dBW) and antenna gain is 40 dBi, what is the EIRP in dBW?
60 dBW
40 dBW
50 dBW
70 dBW
80 dBW
Option 4
Uplink
Yes
null
If transponder bandwidth is 72 MHz and spectral efficiency is 5 bps/Hz, max throughput is:
360 Mbps
540 Mbps
720 Mbps
1080 Mbps
null
Option 3
DVB-S2X
Yes
null
If two orthogonal components of the wave have equal amplitude but phase difference of 60⁰, polarization is:
Linear
Circular
Elliptical
Random
null
Option 3
Circular Polarization
Yes
null
If two satellites are 5000 km apart and light speed is 300,000 km/s, approximate signal delay is:
5 ms
10 ms
15 ms
null
null
Option 1
Inter satellite Link
Yes
null
If uplink distance increases by 3×, and path loss ∝ distance², by how much does path loss increase?
12×
null
Option 3
Non-Terrestrial Networks
Yes
(3)² = 9 times → 9× path loss
In a digital radio link budget, doubling the data rate (bandwidth) typically requires:
Halving required SNR
Increasing required power
Reducing antenna gain
Using less bandwidth
null
Option 2
Link Budget
Yes
null
In an NTN link, if Bit Error Rate improves from 10⁻⁵ to 10⁻⁶, how much improvement is observed in orders of magnitude?
1
5
10
100
null
Option 1
BER
Yes
BER improvement = one order of magnitude (10× better)
In beamforming arrays, more antenna elements generally:
Increase noise
Decrease gain
Increase directivity
Reduce nulls
Reduce range
Option 3
Beamforming
Yes
null
In parabolic antennas, how does performance vary with design parameters?
For parabolic antennas of focal distance f, it varies as a function of the ratio f/D.
For parabolic antennas, performance depends only on frequency.
For parabolic antennas, performance varies solely with feed polarization, independent of f or D.
null
null
Option1
Link Budget
Yes
f/D
IP link sends 10 Mbps, RTT = 0.2 s. Find BDP.
1 Mb
5 Mb
2 Mb
0.5 Mb
0.1 Mb
Option 3
IP over satellite
Yes
BDP = Bandwidth × RTT
IP packets = 10,000, lost packets = 500. Packet loss %?
4%
5%
10%
null
null
Option 2
IP over satellite
Yes
Packet loss % = (500/10000) × 100 = 5%
Noise = 1 W, C/N = 10. Find required signal power.
Signal = 10 / 1
Signal = 10 × 1 = 10 W
Signal = 10 + 1
Signal = 10 − 1
null
Option 2
Inter satellite Link
Yes
Signal = C/N × Noise
Noise = 2 W, desired C/N = 12. Find required signal power.
Signal = 12 / 2
Signal = 12 × 2 = 24 W
Signal = 12 + 2
Signal = 12 − 2
null
Option 2
Uplink
Yes
Signal Power = C/N × Noise Power
Noise = 3 W, desired C/N = 12. Required signal power?
Signal = 12 + 3
Signal = 12 × 3 = 36 W
Signal = 12 − 3
Signal = 3 / 12
null
Option 2
Satellite gateway
Yes
Signal = C/N × Noise
Payload sends 40 W, gain = 45 dB, loss = 150 dB. Find Pr.
−100 dB
−110 dB
−105 dB
−120 dB
null
Option 3
Telecommunication Payload
Yes
Pr = 10 log₁₀(Pt) + G − L
Payload transmits 80 W, system loss = 20 W. Received power?
60 W
50 W
70 W
null
null
Option 1
Telecommunication Payload
Yes
Pr = Pt − Loss = 80 − 20 = 60 W
Pt = 40 W, C/N ratio = 10, noise power = 4 W. Find required Pt to achieve 20 dB C/N.
80 W
100 W
Pt = 4 × 100 = 400 W
200 W
null
Option 3
Link Budget
Yes
C/N = Pt / Pn → Pt = C/N × Pn
Pt = 50 W, Gt = 35 dB, Gr = 30 dB, path loss = 180 dB. Find Pr.
Pr = 50 + 35 + 30 − 180 = −65 dBW
Pr = 10 log₁₀(50) + 35 + 30 − 180 = −105 dB
Pr = 10 log₁₀(50) + 35 + 30 − 180 = −105 dBW
Pr = 50 − 180 = −130
null
Option 3
Link Budget
Yes
Pr = 10 log₁₀(Pt) + Gt + Gr − Lp
Pt = 80 W, Gt = 25 dB, Gr = 20 dB, loss = 160 dB. Find Pr.
−90 dB
−70 dB
−95 dB
−105 dB
null
Option 3
Link Budget
Yes
Pr = 10 log₁₀(Pt) + Gt + Gr − L
Pt doubles, what is dB increase in received power?
4 dB
3 dB
2 dB
1 dB
null
Option 2
Uplink
Yes
Doubling gain → +3 dB
Rain causes an extra 4 dB attenuation. What is the new received power if previous received power was -95 dBm?
-99 dBm
-91 dBm
-101 dBm
null
null
Option 1
Link Budget
Yes
null
Received power = 2 W, noise = 0.01 W. SNR in dB?
20 dB
23 dB
26 dB
null
null
Option 3
Signal-to-noise ratio
Yes
SNR(dB) = 10 log₁₀(Psignal / Pnoise) = 10 log₁₀(2 / 0.01) ≈ 26 dB
Received power = 5 W, transmit = 50 W, what is the SNR if noise = 0.01 W?
30 dB
35 dB
40 dB
45 dB
50 dB
Option 1
Link Budget
Yes
SNR(dB) = 10 × log₁₀(Psignal / Pnoise) = 10 × log₁₀(5 / 0.01) ≈ 27 dB → closest 30 dB
Receiver requires -100 dBm. If received power is -95 dBm, what is the link margin?
5 dB
-5 dB
100 dB
95 dB
-95 dB
Option 1
Link Budget
Yes
null
Represent Symbol rate mathematically:
Symbol Rate (SR) = Data Rate / (Modulation Efficiency × FEC Rate)
Symbol Rate (SR) = FEC Rate / (Modulation Efficiency × Data Rate)
Symbol Rate (SR) = (C/N) / (Modulation Efficiency × FEC Rate)
null
null
Option1
Satellite Bandwidth
Yes
Symbol Rate (SR) = Data Rate / (Modulation Efficiency × FEC Rate)
RTT = 500 ms, window = 50 kbits. Max throughput in kbps?
50
80
100
120
null
Option 3
TCP over satellite
Yes
Throughput = Window / RTT = 50/0.5 = 100 kbps
Satellite amplifies received signal by 10 dB. Original Pr = 2 W. New power?
12 W
15 W
20 W
25 W
null
Option 3
Link Budget
Yes
10 dB → 10^(10/10) = 10× → 2 × 10 = 20 W
Satellite downlink frequency = 12 GHz, distance = 1000 km. Approximate free-space path loss in dB?
180 dB
190 dB
200 dB
210 dB
null
Option 2
Downlink
Yes
FSPL(dB) = 20 log₁₀(d) + 20 log₁₀(f) + 32.44 ≈ 190 dB
Satellite link is down 2 hours/day. Find link availability %.
90%
91.60%
92%
null
null
Option 3
Link availability
Yes
Availability = (Total time - Downtime)/Total time ×100
Satellite processes 20 Mbps and compresses by 50%. What is output data rate?
5 Mbps
15 Mbps
10 Mbps
20 Mbps
null
Option 3
Onboard processing
Yes
Compressed data = 20 × 50% = 10 Mbps
Satellite transmits 100 W, link loss = 20 dB, received power?
1 W
10 W
5 W
2 W
null
Option 2
Link Budget
Yes
Pr = Pt / 10^(L/10) = 100 / 10^2 = 1 W
Satellite transmits 120 W, path loss = 15 dB, cable loss = 3 dB. Total received power?
9 W
10 W
12 W
15 W
25 W
Option 1
Link Budget
Yes
Total loss = 15 + 3 = 18 dB → Pr = 120 / 10^(18/10) ≈ 9 W
Satellite transmits 200 W, received 20 W. Link loss in dB?
5 dB
10 dB
15 dB
20 dB
null
Option 4
Link Budget
Yes
L = 10 × log₁₀(200/20) = 10 dB → closest 20 dB
Satellite transmits 60 W, received power = 6 W. Find link loss in dB.
5 dB
10 dB
15 dB
20 dB
25 dB
Option 2
Link Budget
Yes
L = 10 × log₁₀(Pt / Pr) = 10 × log₁₀(60 / 6) = 10 dB
Satellite transmits 60 W, received power = 6 W. Find link loss.
25 dB
10 dB
50 dB
75 dB
null
Option 2
Link Budget
Yes
L = 10 × log₁₀(Pt / Pr)
Signal = 30 W, noise = 3 W. Find C/N.
C/N = 30 / 3 = 10
C/N = 30 + 3
C/N = 3 / 30
C/N = 10 + 3
null
Option 1
Circular Polarization
Yes
C/N = Signal / Noise
Signal travels 36,000 km GEO satellite, speed of light = 3×10⁵ km/s. One-way latency?
100 ms
120 ms
140 ms
150 ms
160 ms
Option 2
Communication Latency
Yes
Latency = distance / speed = 36000 / 3×10⁵ = 0.12 s = 120 ms
SNR = 10, bandwidth = 20 MHz. Find Shannon capacity.
C = 20 × 10 = 200 Mbps
C = 20 × log₁₀(10)
C = 20 × log₂(1+10) ≈ 20 × 3.46 = 69.2 Mbps
C = 20 / 10
null
Option 3
Satellite broadcasting
Yes
C = B × log₂(1 + SNR)
SNR = 12, noise = 3 W. Find signal power.
Signal = 12 / 3
Signal = 12 × 3 = 36 W
Signal = 12 + 3
Signal = 12 − 3
null
Option 2
Link Budget
Yes
Signal = C/N × Noise
SNR required = 15, noise = 3 W. Find required signal power.
Signal = 15 / 3
Signal = 15 × 3 = 45 W
Signal = 15 + 3
Signal = 15 − 3
null
Option 2
Satellite gateway
Yes
Signal Power = SNR × Noise Power
Terminal receives 0.5 W. If distance halves, received power?
0.25 W
2 W
0.5 W
1 W
null
Option 2
Satellite User terminal
Yes
Pr ∝ 1/d²
The maximum number of OFDM symbols per slot in normal CP for 15 kHz subcarrier spacing in LTE is:
7
12
14
10
null
Option 1
3gpp
Yes
null
The power of left-hand circular polarized wave into right-hand circular polarized antenna is:
Zero
Equal
Half
null
null
Option 1
Circular Polarization
Yes
null
The power received by a linearly polarized antenna from a circularly polarized wave is:
Equal to total power
Half the power
Double the power
null
null
Option 2
Circular Polarization
Yes
null
Total latency = Propagation + Transmission + Processing delay. If propagation=10 ms, transmission=20 ms, processing=5 ms, total is:
35 ms
30 ms
25 ms
null
null
Option 1
Communication Latency
Yes
null
Transmission delay for 1 MB file on 1 Mbps link is about:
8 sec
1 sec
0.5 sec
null
null
Option 1
Communication Latency
Yes
null
Transmit = 10 W, antenna gain improves 3 dB. New transmit power in linear scale?
13 W
15 W
20 W
10 W
null
Option 3
Uplink
Yes
3 dB → ×2 → 10 × 2 = 20 W
Transmit = 40 W, loss = 20 W. Find received power.
40 W
80 W
20 W
60 W
null
Option 3
Telecommunication Payload
Yes
Pr = Pt − Loss
Transmit = 50 W, cable loss = 5 W, received power?
40 W
45 W
35 W
50 W
null
Option 1
Link Budget
Yes
Pr = Pt − Loss = 50 − 5 = 45 W. Actually check: Pt − Loss = 50 −5 = 45 W
Transmit = 80 W, received = 8 W. If antenna gain improves 3 dB, new received power?
10 W
12 W
16 W
14 W
20 W
Option 3
Link Budget
Yes
3 dB → ×2 → 8 × 2 = 16 W
Transmit power = 120 W, received = 12 W. Find link loss.
5 dB
10 dB
15 dB
null
null
Option 3
Link Budget
Yes
L = 10 × log₁₀(120/12) = 10 dB → closest 15 dB
Transmit power = 20 W, cross-pol loss = 3 dB. Find effective transmitted power.
20 W
17 W
Practical Power = 20 × 10^(−3/10) ≈ 15.9 W
null
null
Option 3
Circular Polarization
Yes
P_eff = Pt × 10^(−Xpol_dB/10)
Transmit power = 40 W, Gt = 25 dB, Gr = 20 dB, path loss = 150 dB. Find Pr.
Pr = 40 + 25 + 20 − 150
Pr = 10 log₁₀(40) + 25 + 20 − 150 ≈ −104 dBW
Pr = 25 + 20 − 150
Pr = 40 − 150
null
Option 2
Satellite broadcasting
Yes
Pr = 10 log₁₀(Pt) + Gt + Gr − Lp
Transmit power = 60 dBW, path loss = 190 dB, Gr = 35 dB. Find received power.
Pr = 60 × 35 / 190
Pr = 60 + 35 − 190 = −95 dBW
Pr = 60 − 35 + 190
Pr = 60 × 190 × 35
null
Option 2
Satellite broadcasting
Yes
Pr = Pt + Gr − Lp
Two satellites separated by 2000 km, λ = 0.1 m, gains = 10 each. Pr via Friis equation?
0.5 W
1 W
3 W
15 W
null
Option 2
Inter satellite Link
Yes
Pr = Pt × Gt × Gr × (λ/4πd)² ≈ 1 W
Uplink transmit = 20 W, uplink path loss = 20 dB. Received power?
0.2 W
0.5 W
1 W
null
null
Option 1
5G NTN
Yes
Pr = Pt / 10^(L/10) = 20 / 10² = 0.2 W
Uplink transmits 20 W, noise = 2 W. Find C/N in dB.
5 dB
10 dB
25 dB
35 dB
null
Option 2
Uplink
Yes
C/N_dB = 10 log₁₀(C/N)
Uplink transmits 30 W, noise = 3 W. Find C/N ratio.
5
8
10
17
null
Option 3
Uplink
Yes
C/N = P_signal / P_noise
What is the carrier power-to-noise power spectral density ratio for total link?
It is given by (C/{N}_{0})_{T}.
It is given by (S/{N}_{0})_{T}.
It is given by (C/{R}_{0})_{T}.
It is given by (C/{P}_{0})_{T}.
null
Option1
Carrier-to-noise ratio
Yes
(C/{N}_{0})_{T}
What is the conversion rate of a high speed ADC?
Conversion rate of high speed ADC is given by {50*{10}^{6}/sec}.
Conversion rate of high speed ADC is given by {25*{10}^{6}/sec}.
Conversion rate of high speed ADC is given by {30*{10}^{3}/sec}.
Conversion rate of high speed ADC is given by {45*{10}^{6}/sec}.
null
Option1
Satellite bus
Yes
{50*{10}^{6}/sec}
What is the formula for effective isotropic radiated power (EIRP)?
{EIRP={P_{T}G_{T}} \ (W)}
{EIRP={G_{T}F_{T}} \ (W)}
{EIRP={N_{T}} \ (W)}
null
null
Option1
Link Budget
Yes
{EIRP={P_{T}G_{T}} \ (W)}
what is the given formula used for? {p}_{r}=\frac{{p}_{r}{g}_{t}{g}_{r}{c}^{2}}{(4\pi)^{2}{R}^{2}{f}^{2}}
The link between the satellite and Earth station is governed by the optical free-space propagation equation, rather than the basic microwave radio link equation.
It is the link between the satellite and Earth station is governed by the basic microwave radio link equation.
The link between the satellite and Earth station is governed by the basic microwave radio link equation only for uplink signals, not for the downlink.
null
null
Option2
Link Budget
Yes
{p}_{r}=\frac{{p}_{r}{g}_{t}{g}_{r}{c}^{2}}{(4\pi)^{2}{R}^{2}{f}^{2}}
What is the length of a 5G NR slot at 30 kHz subcarrier spacing?
0.25 ms
0.5 ms
1 ms
2 ms
4 ms
Option 2
3gpp
Yes
null
What is the max bits per symbol for 256QAM?
6
7
8
9
10
Option 3
3gpp
Yes
null
Wireless system transmits 25 W, path loss = 100 dB. Find Pr.
−80 Db
−75 dB
−110 dB
−90 dB
−120 dB
Option 2
Wireless communication systems
Yes
Pr = 10 log₁₀(Pt) − L
With turbo code rate 2/3 and 8PSK modulation, effective bits per symbol are:
1.5
2
2.67
null
null
Option 3
DVB-S2
Yes
null