COMP4336/9336 Mobile data networking W8 Quiz: IoT and LoRa
1. Which of the following layer in LoRa protocol stack is based on proprietary technology?
c) Network
d) Application
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2. Duty cycle limit is imposed for LoRa end devices to
a) Save the energy cost of network servers
b) Save the energy cost of application servers
c) Save the energy cost of gateways
d) Increase the capacity of LoRa networks
3. LoRa gateways can decode the signals even if the received power is below the noise floor because
a) LoRa gateways are produced from novel materials with exceptional electromagnetic properties
b) LoRa uses ultra-wide bandwidth channels
c) LoRa spreads the power over all frequencies within the channel bandwidth as well as transmits the symbol over a long duration
d) LoRa uses high transmission power
4. For a 500kHz channel, the frequency sweeping speed of a LoRa transmitter configured with SF=7 can exceed
a) 1 GHz/s
b) 2 GHz/s
c) 3 GHz/s
d) 4 GHz/s
5. For a 125kHz channel, a LoRa transmitter configured with SF=8 can send
a) ~1024 sym/s
b) ~512 sym/s
c) ~488 sym/s
d) ~390 sym/s
6. Which of the following statements is incorrect?
a) Header is optional in LoRa packets
b) CRC is optional in LoRa packets
c) LoRa gateways are responsible for medium access control
d) LoRa network server is responsible for medium access control
e) None of these
7. Which of the following statements is correct?
a) Each LoRa chirp represents one or more symbols
b) Upchirps and downchirps are often mixed in a given LoRa payload
c) LoRa preamble contains both upchirps and downchirps
d) In LoRa chirps, frequency increases exponentially
e) LoRa chirps always start from the lowest frequency of the channel
8. If SF is downgraded from 12 to 10,
a) Symbol duration is increased by a factor of 2
b) Symbol duration is decreased by a factor of 4
c) Data rate is increased by a factor of 2
d) Data rate is increased by a factor of 4
e) Frequency sweeping speed is increased by a factor of 2
9. If SF is upgraded from 7 to 10,
a) Symbol duration is increased by a factor of 8
b) Power consumption of the client device is reduced significantly
c) Message air-time is reduced significantly
d) Data rate is increased by a factor of 8
e) Data rate is decreased by a factor of 8
10. If there are three gateways within the range of a LoRa device,
a) Only the gateway closest to the device would process the packets transmitted by the device b) All three gateways would process the packet received from the device
c) All three gateways would transmit the ACK packets to this device
d) Only the gateway farthest from the device would transmit an ACK packet for this device e) The gateways would coordinate to decide which gateway should act as the real gateway at any given time
End of W8 Quiz
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