L13 - IoT

Question 1

IoT definition

Answer 1

system of interrelated computing devices, mechanical and digital machines, objects, animals or people that are provided with unique identifiers (UIDs) and the ability to transfer data over a network without requiring human-to-human or human-to-computer interaction.

Question 2

starting point of IoT

Answer 2

when the number of devices connected to the internet exceeded the number of people on earth. (~2008)

Question 3

actuator

Answer 3

An actuator is a device that produces a motion by converting energy and signals going into the system.

Question 4

3 IoT Architectures

Answer 4

• IoT Cloud Architecture
• IoT Edge Architecture
• IoT Fog Architecture

Question 5

IoT Cloud Architecture

Answer 5

IoT devices (microcontrollers that can communicate to an actuator) are connected via a gateway to the Wide Area Network (WAN) that connects to the cloud.

• connection to gateway can be wired or wireless
• ## sensor data is forwarded to the IoT platform in the cloud

Question 6

WAN

Answer 6

A wide area network (WAN) is a telecommunications network that extends over a large geographic area.

Question 7

Which data storage is used in the IoT Cloud Architecture?

Answer 7

NoSQL data storage with eventual consistency.

Question 8

Iot Edge Architecture

Answer 8

• you have an edge computer connected to the gateway
• less latency compared to IoT Cloud Architecture
• bandwidth requirements are reduced because the edge computer which is near to the IoT device can already pre-process the data and only forwards important data (not all of it)

Question 9

How are edge computers cooled?

Answer 9

Without a fan. Passively cooled.

Question 10

3 characteristics of edge computing

Answer 10

• computation and data shifted to computers at the edge of the network
• extends the centralized cloud model into a distributed model
• intention to bring computation and storage closer to the location where it is needed, improve response time and save bandwidth

Question 11

IoT Fog Architecture

Answer 11

• extension of the edge –> set of coupled edge systems for adaptivity (more compute power in a distributed fashion )
• replacement of cloud with edge: distributed location-aware shared infrastructure

Question 12

Fog Computing definition -> do not really have to know

Answer 12

Fog computing is a layered model for enabling ubiquitous access to a shared continuum of scalable computing resources. Fog nodes can be physical or virtual. Fog nodes operate in a centralized or decentralized manner and can be federated to form clusters that provide horizontal scalability over disperse geolocations.

Question 13

6 essential characteristics of fog computing

Answer 13

• contextual location awareness and low latency
• geographical distribution
• heterogeneity
• interoperability and federation
• real-time interaction
• scalability and agility of federated, fog node clusters

Question 14

contextual location awareness and low latency of fog computing

Answer 14

• fog nodes are aware of their location in the context of the entire system
• they are also aware of latency costs

Question 15

Heterogeneity of fog computing

Answer 15

• supports collection and processing of data of different form factors

Question 16

Interoperability and federation in fog computing

Answer 16

• services like real-time streaming require the cooperation of different providers
• hence, fog computing components must be able to interoperate to enable federated services across domains.

Question 17

real-time interaction in fog computing

Answer 17

• fog computing has support for real-time interactions instead of batch processing

Question 18

Scalability and agility of federated, fog node clusters in fog computing

Answer 18

• fog computing is adaptive in nature
• support for elastic compute and resource pooling
• adaptation to data-load changes and network condition variations

Question 19

What are possible Fog Computing Service Models?

Answer 19

• Software as a Service (fog provider’s applications run)
• Platform as a Service (provider provides a platform for the customer’s applications)
• Infrastructure as a Service (provision of fundamental compute resources to the customer)

Question 20

What is the most used fog node deployment model?

Answer 20

private fog node

Question 21

What are the 4 fog node deployment models?

Answer 21

Private (provisioned for exclusive use by a single organization), community , public (open use), hybrid (composition of two or more distinct (private, community, or public) fog nodes

Question 22

When would you use the cloud architecture?

Answer 22

• ## power hungry ecosystem but have to run from battery power –> edge computers use too much energy

Question 23

IoT Network

Answer 23

• wireless network
• connecting sensors and actuators to a gateway
• gateway forwards data to the internet/ Cloud

Question 24

Sensor Network

Answer 24

• when not all the sensors have a direct connection to the gateway (e.g. in rural areas)
• sensors communicate with each other so that one of them can connect to the gateway

Question 25

3 categories of IoT Networks

Answer 25

10-100m: Wireless Personal Area Network (WPAN) (e.g., Bluetooth) 100m-1km: Wireless Local Area Network (WLAN) to 30km: Wireless Wide Area Network (WWAN) (e.g., LTE)

Question 26

Low Power Wide Area Networks (LPWAN)

Answer 26

- connect sensors over long distances - enables a long lifetime of battery-powered sensor devices - low bandwidth

Question 27

Long Range Wide Area Network (LoRaWAN)

Answer 27

I think this is one example of LPWAN - low-power wireless communication technique for long distances > 10 km in rural areas; excellent connection in buildings --> trading communication bandwidth for low power and long-range (suitable for transferring of message of a few bytes, but not for streaming videos etc.)

Question 28

Is LoRa a physical layer?

Answer 28

Yes. The physical layer is the LoRa Modulation with the regional ISM band (radio frequency).

Question 29

What are the 3 classes of device types in LoRa?

Answer 29

The device types depend on the bi-directional communication support. Class A: Transfer to gateway followed by two receive windows --> best power efficiency Class B: Download window at a predetermined point in time Class C: Permanent receive state

Question 30

What does the spreading factor determine?

Answer 30

Determines the #bits and time per symbol. --> Higher --> more reliable transmission.

Question 31

LoRaWAN secure?

Answer 31

Yes messages are encrypted on two levels - payload is encrypted by application session key - additionally the entire packet is encrypted by network session key

Question 32

Infrastructure of LoRaWAN

Answer 32

The Things Network - about enabling low power devices to use long range gateways and connect to an open-source decentralized network to exchange data with applications - intermediate between low power devices and (IoT infrastructure, mobile applications) - takes care of receiving messages from the device, ensuring integrity and security, and forwarding the payload

Question 33

The Things Network Architecture

Answer 33

Gateway send messages to router --> broker > handler (knows where to deliver message to, which application) --> application - discovery service (so that router, broker, and handler can find each other) - network server (keeps track of information of keys and the devices that are connected via the gateway to the infrastructure)

Question 34

Data Flow in TTN

Answer 34

G (receives LoRa message)-> R -> B (de-duplication so that the same message is not sent multiple times)|NS --> H (decryption) --> A (application) --> then the whole process the other way around back to the gateway.

Question 35

5 functions of an IoT platform

Answer 35

- device management - data collection - data analysis - device control - user management

Question 36

What is AWS Greengrass

Answer 36

- extension of AWS IoT to the edge - local preprocessing of data with ML - can work without connection to the cloud - integration with AWS security functions - software running on own hardware - Cloud level programming model FAAS (install functions on the edge device that are triggered when necessary)

Question 37

AWS IoT Greengrass Core

Answer 37

Provides local services and communicates locally with devices that run the AWS IoT Device

Question 38

AWS IoT Device SDK

Answer 38

Allows devices to interact locally with AWS IoT Greengrass Cores

Question 39

AWS IoT Greengrass SDK

Answer 39

Allows Lambda functions to interact with local services inside an AWS IoT Greengrass Core