Module 3

Question 1

nodes and base stations

Answer 1

1. wireless hardware used in base stations
2. nodes or clients , devices that connect to the base station
3. base stations are the routers or gateway

Question 2

IoT protocol

Answer 2

1. common language that allows devices to interact with other IoT devices
2. IoT protocol lay down standards that adopted in every IoT ecosystem for proper functioning and avoid security threats.

Question 3

iot protocol model
(explain each layer)

Answer 3

->analytics/visualization layer
->application/integration layer
->data/database layer
->network layer
->physical/device layer

Question 4

three layer protocol suite
(explain each layer)

Answer 4

-> application layer
-> network layer
-> perception layer

Question 5

five layer protocol suite
(explain each layer)

Answer 5

-> business layer
-> application layer
-> processing layer
->transport layer
-> perception layer

Question 6

functions of physical layer
(explain points)

Answer 6

1. Representation of bits
2. data rate 3. synchronization
3. interface 5. topologies
4. line configuration
5. transmission modes

Question 7

link layer

Answer 7

includes protocol that defines communication between local network nodes which fulfill the purpose of maintaining link states between the local nodes

Question 8

BLE

Answer 8

1. Bluetooth low energy
2. BLE is an intelligent and a low power version of Bluetooth wireless technology
3. not suitable for sending real time data
4. short range communication protocol with PHY and MAC layer

Question 9

benefits of BLE

Answer 9

1. lower implementation costs
2. multi-vendor interoperability
3. enhanced range
4. much improved pairing speed

Question 10

application of BLE

Answer 10

1. battery powered devices developed for industries like healthcare, fitness, security and home industries

Question 11

features of BLE

Answer 11

1. Location detection accuracy
2. proximity detection
3. power consumption

Question 12

BLE architecture

Answer 12

1. BLE follows master/slave technology . slave node sent the advertising frame to discover one or more dedicated advertisement channels. master nodes sense this advertisement channels to find slaves and connect them
2. BLE always remains in sleep mode except when the connection between devices is intiated.

Question 13

LoRAWAN

Answer 13

1. Low Power Wide Area Networking communication protocol
2. Low power, wide area networking protocol built on top of the LoRa radio modulation technique
3. architecture- star to stars topology

Question 14

application of LoRAWAN/LoRa

Answer 14

usage in smart cities and industrial spaces because it is an affordable long range , bi-directional communication protocol with very low power consumption
3. device can run for 10 years on a small battery

Question 15

LoRa

Answer 15

1.radio manipulation technique that is essentially a way of manipulating radio waves to encode information.
2. physical layer protocol that supports long range communication at the cost of a narrower bandwidth

Question 16

why LoRAWAN?

Answer 16

1. ultra low power 2. long range
2. deep indoor penetration
3. license free spectrum
4. geolocation 6. high capacity
5. public and private deployments
6. end to end security 9. roaming
7. firmware updates over air
8. low cost

Question 17

architecture LoRAWAN

Answer 17

1. star to stars topology

[end to end nodes]->[gateway]->[network server]->[application server]

Question 18

characteristics of LoRAWAN technology

Answer 18

1. Long range communication
2. long range battery duration upto 10 years
3. low cost for devices and maintenance
4. license free radio spectrum nut regulations apply
5. Low power

Question 19

Security in LoRA

Answer 19

1.LoRA achieved by implementing security at two different layers:
-> one for the network
-> one for the application
2. to achieve the required levels of security for LoRa networks, several layers of encryption have to be employed.

Question 20

use cases of LoRaWAn

Answer 20

1. vaccine cold chain monitoring
2. animal conservation
3. dementia patients
4. smart farms
5. water conservation
6. food safety 7. smart waste bins
7. smart bikes 9. airport tracking
8. efficient workspace
9. cattle health 12. LoRa in space

Question 21

network layer

Answer 21

this layer is divided into two parts
->routing layer: sends packages from origin to destination
-> encapsulation layer: largely responsible for creating packages

Question 22

transport layer

Answer 22

1. main role is to provide communication services directly to the application processes running on different hosts.
2. TCP,UDP two transport layer protocols that provide different set of services to the network layer
3. application communicates to either one of these protocols. These applications can read and write to the transport layer. So communication is a two way process

Question 23

services offered by transport layer

Answer 23

1. end to end delivery
2. addressing 3. reliable delivery
3. flow control 5. multiplexing

Question 24

multiplexing

Answer 24

1. upward multiplexing: multiple transport layer connections use the same network connection
2. downward multiplexing: means one transport layer connection uses the multiple network connections

Question 25

MQTT

Answer 25

1. Message Queue Telemetry Transport 2. used for machine to machine communication 3. simple and lightweight messaging protocol , uses publish/subscribe model 4. supports messaging between devices to the cloud and the cloud to the device

Question 26

why is MQTT important? (explain points)

Answer 26

1. lightweight and efficient 2. Scalable 3. reliable 4. secure 5. well-supported

Question 27

MQTT client

Answer 27

1. client sends messages then its a publisher , if it receives messages then its a subscriber are the two roles of a client 2. a device is a client if it opens a network connection to the server, publishes messages that other clients want to see, subscribes to a message

Question 28

MQTT broker

Answer 28

backend system which coordinates messages between the different clients. broker include receiving and filtering messages, identifying clients subscribed to each message

Question 29

MQTT connections

Answer 29

1. clients and brokers begin communicating by using an MQTT connection. Clients initiate connection by sending a CONNECT message to the MQTT broker. 2. the broker confirms that a connection has been established by responding with a CONNACK message 3. clients never connect with each other, only with broker

Question 30

MQTT architecture

Answer 30

[Publisher]->(message)->[MQTT Broker]->(message)->[subscriber] in the middle there is a central server or broker that acts as a mediator. Each incoming message is filtered by the broker who then send them to appropriate customers

Question 31

QoS 0

Answer 31

1. provides bare minimum of data transfer. 2. Every message is transmitted to a user only once at this stage with no verification

Question 32

QoS 1

Answer 32

1. This broker tries to send the message and then checks for the user's approval reply 2. with no verification received in a certain amount of time, the message is resent. 3. if broker does not get user's confirmation on time, message maybe sent to user multiple times using this approach

Question 33

QoS 2

Answer 33

1. four step handshake used by the client and broker to ensure that information is received and only once 2. optimum solution in cases where communication are inconsistent but links aren't as resource- constrained

Question 34

CoAP

Answer 34

1. Constrained Application protocol 2. a lightweight protocol for M2M communication 3. particularly used in IoT scenarios where constrained devices and networks are involved

Question 35

features of CoAP (explain points)

Answer 35

1. lightweight 2. request-response model 3. RESTful interaction 4. reliable and unreliable messaging 5. resource discovery 6. security

Question 36

application of CoAP (explain points)

Answer 36

1. smart home automation 2. industrial monitoring and control 3. asset tracking 4. environmental monitoring 5. smart agriculture 6. healthcare and wearable devices

Question 37

CoAP vs MQTT

Answer 37

to be gone through along with diagram