Wireless Sensor Networks Wsn Set 8
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This set of Wireless Sensor Networks (WSN) Multiple Choice Questions & Answers (MCQs) focuses on Wireless Sensor Networks Wsn Set 8
Q1 | In the S-MAC protocol, ___________is designed to reduce energy consumption during the long idle time when no sensing events happen, by turning off the radio periodically
- periodic listen only
- periodic listen and sleep
- message passing
- periodic sleep only
Q2 | __________in S-MAC is similar to the using an RTS/CTS exchange
- collision avoidance
- overhearing avoidance
- both
- one of above
Q3 | Following aspects of the energy cost in a sensor network make it challenging to reason about optimizing energy
- multi-hop communication can be more efficient than direct transmission
- when a node transmits, all other nodes within range can hear
- neither a nor b
- a and b both
Q4 | select the correct statement
- since the nodes operate independently, their clocks may not be synchronized with one another
- for time synchronization, the wired protocols assume the existence of highly accurate master clocks on some network nodes such as skew clock
- a and b both
- neither a nor b
Q5 | select the correct statement
- since the nodes operate independently, their clocks may not be synchronized with one another
- for time synchronization, the wired protocols assume the existence of highly accurate master clocks on some network nodes such as atomic clock
- a and b both
- neither a nor b
Q6 | The latency in channel can be decomposed into following components
- send time
- access time and receive time
- propagation time
- alln of above
Q7 | The latency in channel can be decomposed into following components
- send time and access time
- receive time and propagation time
- a and b both
- neither a nor b
Q8 | The Send time is
- this is the time taken by the sender to construct the message
- this is the delay incurred while waiting for access to the transmission channel due to contention, collisions etc
- this is the time for message to travel across the channel to the destination node
- this is the time for the network interface on the receiver side to get the message and notify the host of its arrival
Q9 | The Access time is
- this is the time taken by the sender to construct the message
- this is the delay incurred while waiting for access to the transmission channel due to contention, collisions etc
- this is the time for message to travel across the channel to the destination node
- this is the time for the network interface on the receiver side to get the message and notify the host of its arrival
Q10 | The Propagation time is
- this is the time taken by the sender to construct the message
- this is the delay incurred while waiting for access to the transmission channel due to contention, collisions etc
- this is the time for message to travel across the channel to the destination node
- this is the time for the network interface on the receiver side to get the message and notify the host of its arrival
Q11 | The Receive time is
- this is the time taken by the sender to construct the message
- this is the delay incurred while waiting for access to the transmission channel due to contention, collisions etc
- this is the time for message to travel across the channel to the destination node
- this is the time for the network interface on the receiver side to get the message and notify the host of its arrival
Q12 | Receiving power additionally influenced by
- fading (frequency dependent) & shadowing
- reflection & refraction depending on the density
- scattering & diffraction
- all of above
Q13 | Incorrect statement about Time and frequency multiplexing in combination is
- better protection against tapping
- protection against frequency selective interference
- higher data rates compared to code multiplex
- no precise coordination required
Q14 | in case of hidden terminal problem
- two senders are in the communication range of each other
- two senders are not in the communication range of each other
- independent of sender range
- none of the above
Q15 | in case of exposed terminal problem
- two senders are in the communication range of each other
- two senders are not in the communication range of each other
- independent of sender range
- two receivers are in the communication range of each other
Q16 | Throughput is defined as the number of bits or bytes successfully
- received per time unit t
- lost per time unit t
- transmitted per time unit t
- retransmitted per time unit t
Q17 | Design Criteria for Medium Access Protocols
- maximize the throughput by minimizing the delay and energy spent.
- maximize the throughput by maximize the delay and minimizing energy spent.
- minimize the throughput by minimizing the delay and energy spent.
- maximize the throughput by maximize the delay and energy spent.
Q18 | Design Criteria for Medium Access Protocols
- maximize the throughput by maximize the delay and energy spent.
- to minimize the time in listening mode as much as possible.
- to maximize the time in listening mode as much as possible.
- avoid the switched off devices handling
Q19 | Microcontroller has current drawn typically of 1.8 mA and 5.1 µA respectively in
- active mode and sleep mode
- sleep mode and active mode
- ideal mode and active mode
- sleep mode and ideal mode
Q20 | RF Transceiver draws more current in
- sleep mode
- receive mode
- transmit mode
- search mode
Q21 | In centralized TDMA,
- the schedule is calculated online and provided when required
- the schedule is calculated offline and provided to the sensor nodes at startup.
- the schedule is calculated offline and provided when required
- the schedule is calculated online and provided when after regular interval of time
Q22 | When a node has a packet to send, it listens for traffic on the channel.
- if the channel is free, it initially sends message, cts.
- if the channel is free, it initially waits for message, cts.
- if the channel is free, it initially sends message, rts.
- if the channel is free, it initially waits for message, rts.
Q23 | If the channel is busy, continues sensing the channel until it becomes idle again.
- 1-persistent csma
- non-persistent csma
- p-persistent csma
- o-persistent csma
Q24 | If the channel is busy, it back-offs for a random amount of time and then retries.
- 1-persistent csma
- non-persistent csma
- p-persistent csma
- o-persistent csma
Q25 | This version is time scheduled. A central controller in the network assigns a fixed transmission order
- 1-persistent csma
- non-persistent csma
- p-persistent csma
- o-persistent csma