Características

Question 1

WSN features

Answer 1

fault tolerance, scalability, lifetime, security, programmability, affordability, heterogeneity and mobility

Question 2

WSN lifetime and metrics

Answer 2

Duration for which the network can operate effectively before the nodes’ energy resources are depleted.

Time at which first/last node depletes battery, x% of nodes are alive and x% of area covered

Question 3

CPS features

Answer 3

real-timeliness, intelligence, predictability, interoperability, heterogeneity, scalability, security

Question 4

Properties of a sensor

Answer 4

Accuracy: How close to the actual value is it able to measure
Precision: Is the error always the same?
Resolution: The smaller the change able to capture, the more resolution.

Question 5

Actuator types

Answer 5

Hydraulic (agua a presión)
Pneumatic (aire/gas a presión)
Electrical
Thermal and Magnetic (energía térmica/efectos magnéticos)
Mechanical
Soft Shape Memory (smart materials)

Question 6

Bluetooth topologies

Answer 6

Piconet (Bluetooth devices form a network by connecting to each other in a master-slave relationship). Simplest form is P2P

Scatternet (multiple piconets)

Question 7

Bluetooth node modes

Answer 7

Active (up to 7) / Hold / Sniff / Park (up to 255)

Question 8

LPWAN protocols example

Answer 8

LoRaWAN / NB-IoT / Sigfox

Question 9

Zigbee modes

Answer 9

Non-beacon (power active, continuous connection)

Beacon (power saving, synchronized with coordinator with beacons)

Question 10

Constrained device types

Answer 10

Class 0 (Severely constrained, communication via proxy or gateway)
Class 1 (Some constrains, communication via CoAP)
Class 2 (Almost no constrains, allows HTTP)

Question 11

Routing modes in 6LoWPAN

Answer 11

Mesh-under (layer 2/MAC) for small networks
Route-over (layer 3/ IPv6) for large scale

Question 12

DODAG storing modes

Answer 12

Storing: each node keeps a routing entry for all the destinations reachable via its sub-DODAG.
Non-Storing: the root is the only network node maintaining routing information.

Question 13

RPL control messages

Answer 13

DIO/DAO/DIS/DAO-ACK

Question 14

Examples of application-layer protocols in IoT

Answer 14

MQTT / CoAP / HTTP

Question 15

CoAP reliability mechanism

Answer 15

CoAP uses UDP, so incorporates other mechanisms:

Duplicate detection of messages + Retransmission of messages until ACK is recieved

Question 16

Mechanisms to support for IoT push apps in WoT (like MQTT)

Answer 16

Webhooks: Thing and the client serve both as HTTP client and as HTTP server. Allowing for publish/subscribe
Long Polling: client sends the HTTP request to the server; the server holds the request till a new value of the resource is available, then it sends a response.

Question 17

FANETs challenges / problems

Answer 17

High latency, changing topology, no standard protocol.

Question 18

ROS topic actors

Answer 18

publishers and subscribers (asynchronous communication)

Question 19

ROS service actors

Answer 19

Servers and clients (synchronous communication)

Question 20

Gazebo and ROS differences

Answer 20

Gazebo provides simulation environment, ROS provides framework to create robots. can connect through ros_gz_bridge.