esa-sceva/satcom-mcqa huggingface dataset:
Topic: Satellite Bandwidth
Question: How do RCSTs (Return Channel Satellite Terminals) request and update bandwidth for MAC real-time traffic?
Option 1: At log-on, RCSTs request a fixed bandwidth (CRA) for MAC real-time traffic, which can later be updated via the dynamic QoS architecture using SIP proxy information.
Option 2: RCSTs are automatically assigned unlimited bandwidth without requests.
Option 3: RCSTs cannot update their bandwidth once the terminal logs on.
Option 4: RCSTs request bandwidth only via TCP acknowledgments, not QoS mechanisms.
Answer: Option1
Topic: Uplink
Question: How do satellite systems with on-board processing typically manage uplink and downlink access for multiple broadcasters?
Option 1: several systems incorporating on-board processing have been launched in such a way as to allow FDMA access by several broadcasters on the uplink and time division multiplexing (TDM) on a single downlink carrier of the sound programmes.
Option 2: TDM is used on the uplink, while FDMA is used on a single downlink carrier.
Option 3: Both uplink and downlink use analog FM modulation only, with no multiplexing.
Option 4: Uplink and downlink are restricted to a single broadcaster, with no multiple access methods.
Option 5: The satellite uses code division multiple access (CDMA) on the downlink instead of TDM.
Answer: Option1
Topic: SNR
Question: How do seismologists use Signal-to-Noise Ratio (SNR) in their work?
Option 1: They use SNR to predict earthquake magnitudes directly, without analyzing waveform data.
Option 2: Seismologists use SNR to assess the quality of seismic data recorded by seismometers.
Option 3: SNR is only used to calibrate the physical placement of seismometers, not data quality.
Option 4: SNR is irrelevant in seismology because all seismic signals are inherently strong.
Answer: Option2
Topic: Wireless communication systems
Question: How do users in a train communicate with Correspondent Nodes (CNs)?
Option 1: Users in the train can communicate with CNs (Correspondent nodes) through MR (Mobile Router) in the train.
Option 2: Users in the train connect directly to satellites without any Mobile Router.
Option 3: Communication with CNs occurs only through fixed ground gateways, not via a train-based router.
Option 4: Users communicate with CNs using wired Ethernet connections that bypass any router.
Answer: Option1
Topic: TCP over satellite
Question: How do you describe the performance of the Internet’s Transmission Control Protocol (TCP) over satellite systems?
Option 1: Performance of the Internet's Transmission Control Protocol (TCP) is degraded by the high latency and high degree
 of bandwidth asymmetry present in such systems.
Option 2: TCP performance improves with high latency because it allows longer acknowledgment intervals and smoother data flow.
Option 3: TCP experiences better throughput in satellite systems due to minimal propagation delay.
Answer: Option1
Topic: Link Budget
Question: How does a decreasing elevation angle affect satellite communication performance?
Option 1: propagation
losses, noise and depolarisation also increase with the decreasing elevation angle.
Option 2: It reduces propagation losses and improves signal strength.
Option 3: It eliminates the effects of atmospheric attenuation completely.
Option 4: It has no measurable effect on signal quality or noise.
Option 5: It increases the satellite’s transmission power automatically.
Answer: Option1
Topic: SNR
Question: How does a directional antenna affect SNR?
Option 1: Increases noise but not signal
Option 2: Increases signal, reduces noise
Option 3: No impact
Option 4: Decreases both signal and noise
Answer: Option 2
Topic: 5G NTN
Question: How does a VSAT differ from an IoT device?
Option 1: A VSAT typically has smaller dimensions and lower power than a handheld or IoT device used as user equipment.
Option 2: A VSAT has usually bigger dimensions and higher power than a handheld or IoT device serving as terminal or UE (user equipment).
Option 3: A VSAT generally operates with comparable antenna size and transmission power to standard handheld or IoT devices.
Answer: Option2
Topic: Link Budget
Question: How does absorption by air and water vapor affect loss in link budget?
Option 1: Absorption by air and water vapor increases significantly with elevation angle, causing several decibels of additional path loss at higher angles.
Option 2: Absorption by air and water vapor is nearly constant for higher elevation angles, adding only a few tenths of decibels to the path loss.
Option 3: Absorption by air and water vapor is independent of elevation angle, remaining constant for all satellite link geometries.
Option 4: Absorption by air and water vapor decreases to zero for higher elevation angles, having no measurable effect on the link budget.
Answer: Option2
Topic: Handover procedure
Question: How does an integrated access router improve mobility management when multiple subnets exist behind a satellite terminal?
Option 1: By enabling hierarchical Mobile IP, so micro-mobility within the visited network is managed locally without involving the home agent.
Option 2: By forcing all mobility updates to be sent directly to the home agent, increasing signaling load.
Option 3: By preventing movement between subnets entirely.
Answer: Option1
Topic: Link Budget
Question: How does antenna polarization affect the link budget?
Option 1: No effect
Option 2: Improves signal with matching polarization
Option 3: Decreases transmitter power
Option 4: Changes frequency
Answer: Option 2
Topic: Beamforming
Question: How does beamforming improve performance in cellular networks?
Option 1: In cellular networks, Beamforming can be used to improve bandwidth efficiency and coverage by enabling base stations to focus signals on individual users, reducing interference and increasing data rates.
Option 2: By broadcasting signals uniformly in all directions, maximizing coverage at the expense of interference control.
Option 3: By only amplifying transmit power, with no effect on interference or data rates.
Answer: Option1
Topic: DVB-S2
Question: How does DVB-S2 contribute to the optimization of space segment design?
Option 1: DVB-S2 allows the optimization of the space segment  design, thus making possible a drastic reduction in the cost  of satellite-based IP services.
Option 2: DVB-S2 increases costs by requiring larger satellites and more complex payloads.
Option 3: DVB-S2 reduces costs by eliminating error correction, at the expense of transmission reliability.
Option 4: DVB-S2 contributes to cost reduction by replacing IP with analog transmission, limiting service flexibility.
Option 5: DVB-S2 reduces costs by removing modulation schemes, which decreases spectral efficiency.
Answer: Option1
Topic: DVB-S2
Question: How does DVB-S2 handle multiple input streams in a single transmission signal?
Option 1: DVB-S2 handles multiple inputs by transmitting each stream on a separate carrier, without merging.
Option 2: For multiple inputs, DVB-S2 provides merging of
 input streams in a single transmission signal and slicing in FEC code blocks. 
Option 3: DVB-S2 merges multiple input streams but does not use FEC, leaving error correction to the receiver.
Answer: Option2
Topic: DVB-S2X
Question: How does DVB-S2X support mobile applications?
Option 1: DVB-S2X includes 
very low SNR MODCODs to support mobile applications.
Option 2: DVB-S2X uses high SNR MODCODs exclusively, which are unsuitable for mobile applications.
Option 3: DVB-S2X supports mobile applications by removing error correction coding entirely.
Option 4: DVB-S2X supports mobile applications by removing error correction coding entirely.
Option 5: DVB-S2X requires fixed terminals only, making it incompatible with mobile applications.
Answer: Option1
Topic: Link Budget
Question: How does error correction coding improve transmission quality?
Option 1: error correction coding is used before the channel coding to correct possible
transmission errors.
Option 2: It improves transmission quality by eliminating the need for any error detection or correction.
Option 3: It improves transmission quality by only detecting errors at the receiver.
Answer: Option1
Topic: Link Budget
Question: How does Forward Error Correction (FEC) improve the error performance of satellite links?
Option 1: The FEC enables satellite links to tolerate higher
transmission errors than the uncoded data in terms of error performance.
Option 2: FEC increases error rates by removing redundancy, making the link more vulnerable.
Option 3: FEC has no effect on error performance and only adjusts signal power.
Option 4: FEC works only at the receiver, without adding redundancy at the transmitter, so error tolerance remains the same.
Answer: Option1
Topic: Link Budget
Question: How does free-space loss vary with frequency and distance in microwave and satellite communication links?
Option 1: Free-space loss increases with both higher frequency and longer distance.
Option 2: Free-space loss decreases as frequency increases.
Option 3: Free-space loss remains constant regardless of frequency or distance.
Option 4: Free-space loss is determined only by antenna gain and not by distance.
Option 5: Free-space loss becomes negligible for frequencies above 10 GHz.
Answer: Option1
Topic: Link Budget
Question: How does increasing the transmission line length generally affect system losses?
Option 1: Any increase in system losses due to a longer transmission line are usually more than offset by the decrease in path loss. 
Option 2: A longer transmission line always increases total losses without affecting path loss, thereby reducing overall link efficiency.
Option 3: Increasing transmission line length reduces both system loss and path loss equally, maintaining constant received power.
Option 4: System losses decrease with longer transmission lines because signal reflections improve power transfer.
Option 5: Path loss increases with shorter transmission lines due to reduced antenna separation.
Answer: Option1
Topic: DVB-S2X
Question: How does LDPC decoding determine the transmitted bit values?
Option 1: By iteratively exchanging information between bit nodes and check nodes until the transmitted bits are determined.
Option 2: By performing a single-pass, direct inversion of the received codeword.
Option 3: By using convolutional encoding to reconstruct the original bits.
Answer: Option1
Topic: Link availability
Question: How does one calculate the availability ratio AR?
Option 1: The Availability Ratio is calculated by dividing the total service available time by the duration of the
scheduled service time.
Option 2: The Availability Ratio is calculated by the average duration of continuous periods of available time.
Option 3: The Availability Ratio is calculated by dividing  the uplink signal to the downlink signal.
Option 4: The Availability Ratio is calculated by the average of network transactions over a period of time.
Answer: Option1
Topic: TCP over satellite
Question: How does satellite latency affect TCP performance?
Option 1: Increases throughput
Option 2: Decreases throughput
Option 3: No effect
Answer: Option 2
Topic: Telecommunication Payload
Question: How does TCP for Transactions (TCP-T) improve performance over satellite links?
Option 1: By reducing connection handshaking latency from two RTTs to one RTT for small transactions, significantly lowering user-perceived latency.
Option 2: By increasing the number of handshakes required per transaction.
Option 3: By converting TCP into a connectionless protocol.
Answer: Option1
Topic: Bit error rate
Question: How does the C/No (carrier-to-noise density ratio) influence the quality of a digital communication link?
Option 1: The values
of C/No, for the links which participate in the connection between the end terminals, determine
the quality of service, specified in terms of bit error rate (BER) for digital communications.
Option 2: C/No values only affect analog voice clarity and have no impact on BER in digital systems.
Option 3: Higher C/No values always result in greater noise levels and degraded link performance.
Option 4: C/No represents channel capacity only and is unrelated to transmission quality or BER.
Answer: Option1
Topic: Wireless communication systems
Question: How does the digital processing capability of a user terminal benefit satellite communication systems?
Option 1: It enables the satellite distribution of files on demand through the Internet, using a terrestrial request channel or a satellite-based channel.
Option 2: It allows the terminal to bypass the Internet entirely, sending files directly from one user to another without any satellite involvement.
Option 3: It restricts the terminal to voice-only services, preventing data or file transfers.
Option 4: It requires a ground station at every user location, as digital processing alone cannot support on-demand services.
Option 5: It primarily improves antenna tracking, with no impact on file distribution or Internet services.
Answer: Option1
Topic: Gateway station
Question: How does the feedback loop in FMT mechanisms enhance communication between the satellite terminal and the gateway?
Option 1: It allows continuous adjustment and optimization of signal parameters based on real-time feedback.
Option 2: It prevents the gateway from receiving any information from the satellite terminal.
Option 3: It eliminates the need for synchronization between the satellite terminal and the gateway.
Answer: Option1
Topic: Signal-to-noise ratio
Question: How does the FMT loop optimize spectral efficiency in a communication system?
Option 1: By regularly estimating the SNR and adjusting the modulation type, code rate, and symbol rate accordingly.
Option 2: By maintaining a fixed modulation type and code rate regardless of SNR changes.
Option 3: By only controlling the transmitter power without adjusting coding or modulation.
Option 4: By randomly changing the symbol rate without regard to channel conditions.
Answer: Option1
Topic: Handover procedure
Question: How does the localization of the access router affect satellite communication?
Option 1: The localization of the access router, separated or integrated, with the satellite terminal/base station determines the transport format over the satellite.
Option 2: It has no effect on transport format and only affects terrestrial routing.
Option 3: It decides the orbital position of the satellite.
Answer: Option1
Topic: Inter satellite Link
Question: How does the topology of an inter-satellite link (ISL) network change?
Option 1: The topology of the Inter-satellite link network changes with the movement of the constellation.
Option 2: The topology of an ISL network remains fixed, regardless of satellite movement.
Option 3: The ISL topology changes only when satellites are powered off, not due to normal orbit movement.
Answer: Option1
Topic: TT&C
Question: How does TT&C handle satellite control when ground station is not in line-of-sight?
Option 1: Uses direct communication only
Option 2: Uses other satellites via inter-satellite links
Option 3: Waits until line-of-sight is re-established
Option 4: Uses WiFi
Option 5: Automatic control onboard only
Answer: Option 2
Topic: Carrier-to-noise ratio
Question: How does varying the inner code rate affect the error protection?
Option 1: The inner code rate can be varied to increase or decrease the degree of error protection for
the satellite link at the expense of capacity.
Option 2: The inner code rate controls only the modulation bandwidth and has no impact on error protection.
Option 3: The inner code rate determines antenna gain and is unrelated to link capacity or error correction.
Answer: Option1
Topic: Satellite bus
Question: How is a BUS connected to a LEC identified?
Option 1: The BUS to which a LEC connects is identified by a MAC broadcast address shared by all clients.
Option 2: The BUS to which a LEC connects is identified by a unique ATM address.
Option 3: The BUS to which a LEC connects is identified by a VPI/VCI pair that changes dynamically per packet.
Option 4: The BUS to which a LEC connects is identified by a physical port number on the ATM switch.
Answer: Option2
Topic: Link Budget
Question: How is a digital bit stream encoded and transmitted in a wired network?
Option 1: In a wired network, a digital bit stream can be encoded into baseband signals and transmitted
directly along the wire.
Option 2: In a wired network, a digital bit stream is always converted to analog signals before transmission, never sent as baseband.
Option 3: In a wired network, a digital bit stream is transmitted as frequency-modulated radio signals over the wire.
Answer: Option1
Topic: Satellite bus
Question: How is a satellite bus controlled and communicated with from Earth?
Option 1: Satellite buses are controlled and communicated with from Earth using ground stations.
Option 2: Satellite buses are autonomously managed in orbit, requiring no ground-based communication or control.
Option 3: Satellite buses communicate directly with user terminals, bypassing any need for ground stations.
Answer: Option1
Topic: Link Budget
Question: How is antenna gain expressed in a link budget?
Option 1: Antenna gain figures used in a link budget are expressed in units of dBi; gain relative to a theoretical isotopic radiator.
Option 2: Antenna gain is expressed in watts, representing absolute power output.
Option 3: Antenna gain is measured in decibels relative to free space loss (dBfs), not relative to an isotropic radiator.
Option 4: Antenna gain is expressed in hertz (Hz), indicating frequency response.
Option 5: Antenna gain is measured relative to another directional antenna, not an isotropic radiator.
Answer: Option1
Topic: BER
Question: How is BER calculated?
Option 1: BER = Number of Bit Errors / Total Number of Transmitted Bits
Option 2: BER = Total Number of Transmitted Bits / Number of Bit Errors
Option 3: BER = Number of Correct Bits / Total Number of Received Bits
Option 4: BER = Number of Bit Errors × Total Number of Transmitted Bits
Option 5: BER = (Number of Bit Errors / Transmission Time), measured in bits per second.
Answer: Option1
Topic: SNR
Question: How is cable attenuation typically specified in technical documents?
Option 1: Cable attenuation figures are usually quoted in loss (dB) per 100 m.
Option 2: As gain in decibels (dB) per 1 kilometer of cable.
Option 3: As the absolute signal power in watts.
Option 4: As the cable’s physical diameter in millimeters.
Option 5: As the propagation speed of light in the cable only.
Answer: Option1
Topic: Beamforming
Question: How is digital beam formed in modern wireless communication systems?
Option 1: The phase and amplitude variation is applied to the digital signal before Digital to analog conversion at the transmitter's end to create a directional beam.
Option 2: The phase and amplitude variation is applied to the analog signal to create a directional beam.
Option 3: The signals from different antennas are summed up before the ADC conversion at the receiver's end.
Option 4: Beamforming can be achieved by applying a precoding matrix that weighs the transmitted signals to form a beam in a particular direction.
Option 5: By sending electromagnetic signals in a particular direction rather than sending them in all directions.
Answer: Option1
Topic: TCP over satellite
Question: How is Internet (TCP) traffic typically treated in terms of Quality of Service (QoS)?
Option 1: Internet (TCP) traffic can be assigned to the lowest QoS requirements.
Option 2: It must always receive the highest QoS priority to avoid packet loss.
Option 3: It cannot be assigned any QoS and is always blocked in congested networks.
Answer: Option1
Topic: Satellite gateway
Question: How is Internet access service typically characterized in terms of network topology?
Option 1: By a star or multi-star topology with multipoint-to-point connectivity.
Option 2: By a ring topology with point-to-point connectivity only.
Option 3: By a fully meshed topology where every node connects directly to every other node.
Option 4: By a linear bus topology, with sequential connections between nodes.
Option 5: By a tree topology with exclusively multipoint-to-multipoint connectivity.
Answer: Option1
Topic: Uplink
Question: How is multicast typically handled across a satellite link in a network using downlink routers?
Option 1: Multicast channels are statically configured to be transmitted across the satellite link to each downlink router, while IGMP traffic operates only between the router and the end-user terminal.
Option 2: IGMP traffic is exchanged directly between all end-user terminals and the satellite gateway.
Option 3: Multicast channels are dynamically configured at the terminal level based on each user’s subscription.
Answer: Option1
Topic: Onboard processing
Question: How is the role of satellite networks viewed in modern Global Network Infrastructure (GNI)?
Option 1: As an integral part of GNI, due to the stabilization and maturity of satellite communication technology.
Option 2: As a highly complicated system that cannot be integrated with terrestrial networks.
Option 3: As obsolete technology that is no longer relevant to GNI.
Option 4: As only a backup system for terrestrial networks, not a core component.
Option 5: As a purely experimental system with no practical integration into networks.
Answer: Option1
Topic: Link Budget
Question: How is the sensitivity specification for the RF320 series of radios expressed?
Option 1: The sensitivity specification for the RF320 series of radios states the RF input 
level in units of microvolts.
Option 2: Sensitivity is specified in watts (W), representing total power consumption.
Option 3: Sensitivity is given in decibels relative to 1 watt (dBW), not microvolts.
Option 4: Sensitivity is measured in bits per second (bps).
Option 5: Sensitivity is expressed in ohms (Ω), indicating the input impedance of the radio.
Answer: Option1
Topic: Signal-to-noise ratio
Question: How is the Signal-to-Noise Ratio (SNR) typically calculated in Wi-Fi networks?
Option 1: By measuring the strength of the wireless signal and the background noise level.
Option 2: By measuring only the transmitted signal power without considering noise.
Option 3: By comparing the downlink and uplink data rates.
Option 4: By counting the number of connected devices on the network.
Option 5: By measuring the interference from neighboring networks only.
Answer: Option1
Topic: Satellite broadcasting
Question: How is the transmission of digital television possible without
requiring a huge amount of radio-frequency spectrum?
Option 1: The TV signal has a
baseband signal of a few Mbit/s, hence the transmission of digital television is possible without requiring a huge amount of radio-frequency spectrum.
Option 2: Television broadcasting is able to combat the time dispersion due to multipath,
frequently encountered over mobile satellite channels.
Option 3: Digital Video Broadcasting (DVB) uses MPEG-2 compression for video and either MP2, hence the transmission of digital television is possible.
Answer: Option1
Topic: TT&C
Question: How is tracking of a satellite accomplished?
Option 1: Tracking of the satellite is accomplished by  the satellite beacon signals which are received at the TT&C earth stations. 
Option 2: Tracking of the satellite is done using user terminal feedback only, without any beacon signals.
Option 3: Satellite tracking is achieved using ground-based radar only, with no reliance on satellite beacons.
Option 4: Tracking of satellites is not necessary, as satellites remain perfectly stationary in space.
Answer: Option1
Topic: NTN
Question: How should a UE (User Equipment) that can use both NTN and terrestrial RATs manage timers?
Option 1: It is proposed that the UE uses regular timers or extended timers based on the RAT type in use.
Option 2: The UE should ignore timers entirely, relying solely on signal strength.
Option 3: The UE must use fixed timers, regardless of whether it is connected to NTN or terrestrial RAT.
Option 4: Timers are only required for satellite-to-satellite communication, not for UEs.
Option 5: The UE uses randomized timers unrelated to the RAT type to avoid collisions.
Answer: Option1