Unit 1: Introduction to Internet of Things

Content of the Unit

• Introduction of Internet of Things (IoT)
• Characteristics of IoT
• Building blocks of IoT
• Architecture Layers of IOT
• IoT levels
• The Physical Design
o Things in IOT
o Protocols in IOT
• Logical Design of IoT
o Functional blocks of IoT
o Communication Models
o Communication APIs
• Cloud Computing
• Fog vs Edge Computing
• Big Data Analytics

What is need of IOT

There is patient at home whose medical condition is continuously
monitoring through the life support system connected at the cloud.
Introduction

Figure 1 Explain Internet with the help of above Figure

Figure 2: Now explain Can we connect the other things connected to the Internet with the help of above
figure

Taking everyday things, embedding them with the electronics, software, sensors and then
connecting them to internet and enabling them to collect and exchange data without human
intervention is called as the internet of Things.
Figure 3: Explain how an IOT device is helpful to sprinkle the water when moisture is low in the Plant

The internet of things, or IoT, is a system of interrelated computing devices, mechanical and
digital machines, objects 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.
It is a network of physical objects or ‘things’ that can interact with each other in order to share
information and take action.
Characteristics of IOT
To make this technology an integral part of our lives, let’s have an understanding of the
characteristics of the IoT.
❖ The things should have a unique identification so that each of them can be distinguished
from various objects in the network.
❖ Things should be able to detect the presence of other objects.
❖ Things should be able to capture data autonomously
❖ Things should be able to operate at low power
❖ Things should be programmable by the user.
❖ Since there are various communication protocols and technologies that IoT devices will
work with, things should be interoperable among various communication technologies.

Building blocks of IOT

Four things are considered as basic building block of IOT System.
➢ Sensors
➢ Processors
➢ Gateway
➢ Application
Each of these nodes has their own characteristics in order to form a useful IoT system.
Sensors
Sensors form the front end of the IoT devices. These are the so called “Things” of the system. Their
main purpose is to collect data from its surrounding (sensors) or give out data to its surrounding
(actuators).
These have to be uniquely identifiable devices with a unique IP address so that they can be easily
identifiable over a large network.
These have to be active in nature which means that they should be able to collect real time data.
These can either work on their own (autonomous in nature) or can be made to work by the user
depending on their needs (user controlled).
Examples of sensors are: gas sensor, water quality sensor, moisture sensor etc.
Processors
Processors are the brain of the IoT system. Their main function is to process the data captured by
the sensors and process them so as to extract the valuable data from the enormous amount of
raw data collected. In a word, we can say that it gives intelligence to the data.
Gateways
Gateways are responsible for routing the processed data and send it to proper locations for its
(data) proper utilization.
In other words, we can say that gateway helps in to and fro communication of the data. It provides
network connectivity to the data. Network connectivity is essential for any IoT system to
communicate. LAN, WAN, PAN etc are examples of network gateways.
Applications
Applications form another end of an IoT system. Applications are essential for proper utilization
of all the data collected.
These cloud-based applications which are responsible for rendering effective meaning to the data
collected. Applications are controlled by users and are delivery point of particular services.
Examples of applications are: home automation apps, security systems, industrial control hub
etc.
IoT Enabling Technologies
IoT primarily uses standard protocols and networking technologies. However, the major enabling
technologies and protocols of IoT are –
• RFID
• NFC (Near Field Communication)
• Bluetooth
• Bluetooth Low-Energy (BLE)
• Wi-Fi (Wireless Fidelity)
• Low-power (energy) wireless
• Li-Fi (Light Fidelity)
• Low-energy Radio Protocols
• LTE-A
• Wi-Fi Direct
• VSAT (Very Small Aperture Terminal)
• Ethernet
These supporting technologies are there to ensure the data from IoT devices can be collected,
stored, and analysed. However, let’s take a closer look at the enabling technologies for the
Internet of Things.

RFID (Radio Frequency Identification)

RFID is an acronym for “radio-frequency identification” and refers to a technology whereby
digital data encoded in RFID tags or smart labels which are captured by a reader via radio waves.
Data from a tag or label which are captured by reader is stored in a database or process as we
want.
RFID systems consist of an RFID tag and an RFID reader. RFID tags contain an integrated circuit
(transponder) and an antenna, which are used to transmit data to the RFID reader (also called an
interrogator). The reader then converts the radio waves to a more usable form of data.
Information collected from the tags is then transferred through a communications interface to a
host computer system, where the data can be stored in a database and analysed at a later time.
RFID tags are typically made from durable plastic, and the tag is embedded between the layers of
plastic. RFID tags come in a variety of shapes and sizes and are either passive or active. Passive
tags are the most widely used, as they are smaller and less expensive to implement. Passive tags
must be “powered up” by the RFID reader before they can transmit data. Unlike passive tags,
active RFID tags have an on-board power supply (e.g., a battery), enabling them to transmit data
at all times.

NFC (Near Field Communication)

It is a variation of RFID technology that uses radio frequency communications to interact with
other NFC devices by bringing them with-in close contact of each other to exchange information
and data. It helps make life easier for businesses and consumers by making transactions, digital
content exchange.
The NFC chip acts as an antenna that interacts with another device once it is brought into close
proximity. The technology allows for devices such as smart phones to host applications that help
store and interchange data between devices when a user wants to provide information. The NFC
tags that transmit information are read only chips. This ensures that users only get data from
other NFC chips without transferring data from their chips.

Bluetooth
Bluetooth is a wireless technology and wireless Personal Area Network protocol that is designed
by the Bluetooth Special Interest Group (SIG). It is used for exchanging data between fixed and
mobile device over short distances using UHF radio waves.
Note: Ultra High Frequency, which is the radio frequency range between 300 megahertz and 3
gigahertz.

BLE (Bluetooth Low Energy)

BLE, or Bluetooth Low Energy, is wireless communication technology built to communicate and
exchange data within a short range. It requires little battery power to operate and can quickly
transfer small data packets to compatible devices.
There are two kind of devices are used in the BLE; one is peripheral and other one is central
device.
Companies use Bluetooth Low Energy for a variety of purposes, including supply chain
management. Because each beacon has a unique identifier and communicates with other nearby
beacons, companies use this technology to track equipment, assets, and employees. In addition,
its low battery consumption makes it the ideal technology for these applications.
BLE Examples:
• Fitness Trackers: Devices like Fitbit send occasional updates to smartphones using BLE.
• Smart Home Devices: Nest thermostats, smart lightbulbs, and other home IoT devices opt
for BLE for longevity.
• Wearable Medical Devices: The necessity for this type of tech to last longer is crucial. So,
items like blood pressure or glucose monitors tend to use BLE more often.
• Smart Watches: When your Apple Watch pairs with your smartphone.
Note: Bluetooth and BLE both works in the same frequency band 2.4 GHz ISM Band and one
Bluetooth classic device cannot directly communicate with the BLE device.

Wi-Fi (Wireless Fidelity)

Wi-Fi is a wireless networking technology that allows devices such as computers (laptops and
desktops), mobile devices (smart phones and wearable), and other equipment (printers and
video cameras) to interface with the internet. It allows these devices and many more to exchange
information with one another. The communication standard of Wi-Fi is IEEE 802.11.
Li-Fi (Light Fidelity)
The full meaning of Li-Fi is light fidelity, it was invented by Harald Haas, a professor/engineer
from the University of Edinburgh in 2011. This is also a wireless networking facility like Wi-Fi.
Wi-Fi is based on radio frequency, in contrast, Li-Fi is actually based on light, which exchanges
data 100 times faster than Wi-Fi.
Li-Fi is a wireless optical networking technology, which uses Light Emitting Diodes (LEDs) to
transmit data. Li-Fi is considered to be a light-based Wi-Fi that uses light instead of radio waves
to transmit information.
Advantage:
• It does not become a barrier to other radio signals like Wi-Fi. Therefore, it can be used in
places like airplanes where there is a problem of interference in radio signals.
• Due to shorter range, Li-Fi more secure than Wi-Fi.
• Li-fi consumes less power.
• Li-fi is called as a green technology.

Low Energy Radio Protocols

Low Energy Radio Protocols (LERPs) are wireless communication protocols designed to provide
low power consumption and longer battery life for devices that use them. These protocols are
optimized for low bandwidth and small data transmissions and are ideal for IoT devices that have
limited power and computational resources.
Examples of LERPs include Bluetooth Low Energy (BLE), Zigbee, Z-Wave, and LoRaWAN. BLE
is commonly used in consumer devices such as wearables and fitness trackers, while Zigbee and
Z-Wave are used in home automation and smart home devices. LoRaWAN is used for long-range
communications in industrial IoT applications.

ZigBee
Zigbee is a low-power, wireless communication standard designed for IoT devices that require a
low data rate and extended battery life. It operates on the IEEE 802.15.4 standard and is
commonly used in home automation, smart energy, and industrial applications.
Zigbee networks consist of three main types of devices:
• Coordinator
o Coordinator is the central device that initiates and maintains the network. It can
be a standalone device or integrated into a gateway.
o There can be one coordinator in a network
• Router
o Acts as intermediate node between the coordinator and the end devices.
o Route traffic between different nodes.
• End Devices
o The End Devices are typically battery-powered devices that collect and transmit
data to the Coordinator or Router.
Zigbee mostly uses a mesh networking topology, which allows the devices to communicate with
each other through intermediate nodes. This provides a self-healing network that can
automatically re-route messages if a device fails or is removed from the network.

General Characteristics of ZigBee Networks

Low Power Consumption hence extends the battery life of IoT devices
Low Data Rates
Short Range Communication but longer range than Bluetooth
Support thousands of devices, making it ideal for large-scale deployments
Very less network join time
Low cost of product and very cheap implementation
High Security

LTE-A (Long Term Evolution - Advance)

LTE-A, or LTE Advanced, delivers an important upgrade to LTE technology by increasing not only
its coverage but also reducing its latency and raising its throughput. It gives IoT a tremendous
power through expanding its range, with its most significant applications being vehicle, UAV, and
similar communication.

Wi-Fi Direct
Wi-Fi Direct eliminates the need for an access point It allows P2P (Peer-to-Peer) connection with
the speed of Wi-Fi, but with lower latency. Wifi-Direct Alliance is developed by the wifi Direct
standard.

VSAT (Very Small Aperture Terminal)

It is long-range wireless technology for Satellite communication by using small dish antennas for
narrowband and broadband data.
Ethernet
It is wired network technology and using twisted pair and fiber optic links in conjunction with
the help of hubs or switches.

LPWAN
LPWAN stands for Low Power Wide Area Network. It is a type of wireless network designed for
Internet of Things (IoT) and machine-to-machine (M2M) applications that require long-range
communication with low power consumption.
LPWANs are designed to provide long-range communication with low power consumption and
low data rates by using a combination of different technologies and techniques.
Firstly, LPWANs use low-power radio technologies that operate in unlicensed frequency bands,
such as LoRa or Sigfox. These technologies have a longer range than traditional wireless
technologies like Wi-Fi or Bluetooth, which makes them suitable for long-range communication.
Secondly, LPWANs use a star network topology, where multiple devices communicate with a
central gateway. This approach reduces the amount of energy required for each device to
communicate, as they only need to transmit over short distances to reach the gateway, rather
than directly to other devices in a mesh network.
Thirdly, LPWANs use a low duty cycle approach, where the device is in sleep mode for most of the
time and only wakes up periodically to transmit or receive data. This reduces the energy
consumption of the device, as it is not constantly transmitting or receiving data.
Lastly, LPWANs use a low data rate approach, where devices transmit small amounts of data at
infrequent intervals. This reduces the energy consumption of the device, as it does not need to
transmit large amounts of data over a short period of time.
In summary, LPWANs achieve long-range communication with low power consumption and low
data rates through a combination of low-power radio technologies, star network topology, low
duty cycle, and low data rate approaches.

LoRa (Low power Long Range)

LoRa (Long Range) is a low-power, long-range wireless communication technology that is

designed for IoT and M2M applications. LoRa uses spread spectrum modulation techniques to
enable long-range communication with low power consumption, making it suitable for battery-
powered devices that need to transmit small amounts of data over long distances.

LoRa is often used in LPWAN (Low-Power Wide Area Network) applications, where devices
transmit small amounts of data at infrequent intervals. Examples of LoRa applications include
smart metering, asset tracking, environmental monitoring, and agriculture. LoRa is an open
standard, meaning that it is not controlled by a single company or organization, and can be
implemented by anyone.
Architecture of IOT

The architecture of IoT is typically organized into several layers, each responsible for specific
tasks and operations within the IoT ecosystem.
The architecture layers includes the following five layers:
1. Perception Layer: Sensing and
gathering data from the physical
environment.
2. Network Layer: Transmitting data
between devices and networks.
3. Middleware Layer: Processing,
filtering, and managing data.
4. Application Layer: Providing IoT
services and user-facing applications.
5. Business Layer: Managing business
logic, policies, and decision-making
based on data.
This layered architecture ensures that IoT systems are modular, scalable, and secure, allowing
smooth communication, data processing, and interaction with the end users.

IoT Levels

There are 6 levels in IoT architecture.

IoT Level – 1
This level consists of single node that perform actuation, logical
analysis and controlling other devices in the system.
• The data sensed is stored locally.
• The data analysis is done locally but very less.
• Monitoring & Controlling is done using Mobile app or web
app.
• The data generated in this level application is not huge.
• All the control actions are performed through internet.
• It costs less to build an IoT system.

Example: A Smart Light Bulb

• The smart light bulb connects to a Wi-Fi network, allowing users to control it
remotely using a smartphone app.
 • Basic functionality includes turning the light on/off and adjusting brightness
levels.
• There is minimal intelligence or interaction beyond simple commands.

IoT Level – 2
Building a level – 2 IoT system is a bit more complicated than a level - 1 IoT system. Level 2 IoT
systems also have only one node which does the work of data analysis and controlling. In this
IoT system, the data is stored in the cloud. Which does not happen in Level-1 IoT system.

• This level has large size of data. Hence cloud storage is used.
• Data analysis is carried out locally. Cloud is used for only storage purpose.
• Based on data analysis, control action is triggered using web app or mobile app.

Example: Home Security System

• The home security system includes sensors for detecting motion, door/window
openings, and smoke.
• These sensors communicate with a central hub via a wireless protocol like Zigbee
or Z-Wave.
• The hub can trigger alarms or send notifications to homeowners' smartphones
based on sensor readings.
• Integration is limited to devices within the home, and there's no significant
external interaction.
IoT Level – 3
Level – 3 IoT system also has only one node but the applications and database are established in
cloud. Level 3 IoT systems are used where the data involved is large (big data). And data
analysis is quite complex. In this data is analysed in the cloud.
Example: Smart Thermostat
• A smart thermostat connects to a home Wi-Fi network and interacts with a cloud-
based service.
• Users can control the thermostat remotely using a smartphone app or a web
interface.
• The thermostat collects data on temperature, usage patterns, and energy
consumption, which is stored and analyzed in the cloud.
• It may offer features like scheduling, energy usage insights, and integration with
weather forecasts.
IoT Level – 4
This level consists of multiple nodes, independent sensors, analysis and control & monitoring
app.
• The data collected using these sensors are uploaded to the cloud separately.
• Data is analysed on cloud.
• The data involved is big and the analysis requirements are computationally intensive.
 Example: Industrial Equipment Monitoring
• Sensors are deployed on industrial machinery to monitor various parameters like
temperature, pressure, and vibration.
• Data from these sensors is transmitted to a central server or cloud platform.
• Advanced analytics algorithms analyze the data to detect patterns, anomalies, and
potential failures.
• Maintenance alerts are generated based on predictive analytics, allowing
proactive maintenance to be performed, thus reducing downtime.

IoT Level – 5
In this level the IoT system is used on a large scale. Its manufacturing process is also complex. IoT
systems of this level have many end nodes and a coordinator node.
• End node is the node which performs the function of data sensing and actuation and
coordinator node is the node which collects the data from the end node and after
collecting, sends it to the cloud.
• In this model we used Cloud-based Database to store and Analyse data.
• It is suitable for solutions based on wireless sensor networks, in which the data involved
is big and the analysis requirements are computationally intensive.
Example: Smart Grid
• A smart grid is a highly interconnected network of power generation, distribution,
and consumption infrastructure.
• It incorporates IoT devices such as smart meters, sensors on power lines, and grid
management systems.
• AI algorithms analyze data in real-time to optimize energy distribution, predict
demand, and balance supply.
• The smart grid can automatically reroute power in case of outages, manage peak
demand, and integrate renewable energy sources efficiently.

IoT Level – 6
Level 6 IoT systems are used in large companies. Its manufacturing process is more complex than
that of level-5. It is used with artificial intelligence and data science.
• There are also many end nodes in it, in which a controller is used to control the end node.
• Controller holds all the information about the end node.
• The data analyzed in this is stored in the cloud database.
• Whether the problem has been solved or not, it is seen through the cloud application.
• They go beyond Level 5 systems by incorporating advanced capabilities such as self-
optimization, self-healing, and self-awareness.
• Level 6 IoT is often associated with futuristic concepts like the Internet of Autonomous
Things (IoAT) or autonomous ecosystems.
• Examples include fully autonomous smart grids, self-driving vehicles operating within a
connected transportation network, and self-optimizing industrial processes in smart
factories.
 Example: Autonomous Transportation Network
• An autonomous transportation network comprises self-driving vehicles, traffic
management systems, and infrastructure sensors.
• Vehicles communicate with each other and with central control systems to
coordinate movements and optimize traffic flow.
• AI algorithms predict traffic patterns, adjust traffic signals, and reroute vehicles
to minimize congestion and accidents.
• The system dynamically adapts to changing conditions, such as accidents or road
construction, without human intervention, creating a seamless and efficient
transportation ecosystem.

Design of IoT
• Physical Design
• Logical Design

Physical Design of IoT

Physical design of IoT consists of the
• Things in IoT
• Protocols in IoT
Things in IoT
The word things refer to the IoT devices which have unique identities and can perform remote
sensing, actuating and monitoring capabilities. These devices can exchange data and
communicate with each other.
 ❖ Home appliances: smart TV, smart refrigerator, smart AC, etc.
❖ Smart phones and computers
❖ Wearables: smart watch, smart sensors, etc.
❖ Automobiles like self-driving cars
❖ Energy systems
❖ Retail : smart payment
❖ Printers
❖ Industrial machines
❖ Healthcare: smart watch, smart healthcare, etc.
❖ Surveillance: smart cameras, smart trackers, etc.

IoT devices consists of several interfaces-

Things can exchange data with other connected devices and applications, collect data
from other devices, and process the data either locally or send it to centralized servers
or cloud.
IoT devices can have several interfaces like:
• I/O interfaces for sensors
• Interface for Internet connectivity
• Memory and storage connectivity interfaces
• Audio/video interfaces
An IoT thing or device is made up of different components.
Memory interfaces like RAM & ROM, Storage interface like secondary memory

IoT Protocols
A protocol is a set of rules that governs the communication between two or more
devices. A protocol defines the rules, syntax, semantics and synchronization of
communication and possible error recovery methods.
IoT Protocols help to establish communication between IoT devices and cloud
server over the internet. It helps to send commands to IoT devices and receive data
from IoT devices.
1-Link Layer
The link layer is responsible for establishing and terminating links between the nodes. The
packets or datagrams travel through these links. The link layer also defines the format of
packet (coding) that is to be communicated across the link and is responsible for physical
addressing. The link layer also handles error detection, retransmission, flow control and
access of the link. Protocols generally used at this layer are Ethernet, Wi-Fi, WiMax, LR-WPAN,
cellular technologies, etc.
The summary of link layer protocols is as shown below:

This protocol determines how the data is physically sent over the network layer.

2-Network / Internet Layer

The network layer is responsible for routing the packets received from the transport layer. It
responsible for sending of IP datagrams (packets) from the source network to the destination
network. It performs host addressing and packet routing. . The network layer is also
responsible for logical addressing (like IP address) and for congestion control which prevents
the network from being overloaded with traffic.
We use IPv4 or IPv6 for host identification.
• IPv4 (32 bit address)
• IPv6 (128 bit address)
• 6 LoWPAN (Ipv6 over Low power Wireless Personal Area Network)

3-Transport Layer
The transport layer protocols provide end to end message transfer capability. The message
transfer capability can be set up on connection, either using hand-shakes (TCP) or without
handshake / acknowledgements (UDP). The transport layer provides functions such as error
control, segmentation, flow control, and congestion control.
TCP (Transmission Control Protocol)
• Connection oriented protocol
• Provides extensive error checking
• Reliable as it guarantees the delivery of data to the destination.
• Retransmission of lost packets.
UDP (User Datagram protocol)
• Connection Less protocol
• Provides basic error checking
• Does not guarantee delivery.
• No retransmission of lost packets.

4-Application Layer
The application layer is where the users of an IoT application interact with the IoT
application/system. The application layer allows the users to interact with the IoT sensors
and access other services provided by the communication network. The application layer
provides services like, naming (presentation), message formatting, email, authentication etc,
to the users.
Different protocols at transport layer are:
HTTP (Hyper Text Transfer Protocol)
– Uses TCP, Stateless, Request-Response Model
CoAP (Constrained Application Protocol)
– Uses UDP, Request-Response Model
MQTT (Message Queue Telemetry Transport)
– Follows publish-subscribe model
– No security
– Used with low power devices
XMPP (Extensible Messaging and Presence Protocol)
– Real-time communication, For sending XML data
AMQP (Advanced Message Queuing Protocol)
– Supports both point-to-point and publisher-subscriber models
– High performance and secure protocol
– Uses TCP
WebSocket
– Full-duplex connection over a single socket connection
– Uses TCP
 DDS (Data Distribution Service)
– Middleware standard, Reliable than MQTT
– Follows publish-subscribe model
– Uses UDP

Difference between COAP and MQTT protocols:

Basis of COAP MQTT

Constrained Application Message Queuing Telemetry

Abbreviation
Protocol Transport

Communication It uses Request-Response

It uses Publish-Subscribe model
Type model.

Transport layer This mainly uses User This mainly uses Transmission
protocol Datagram protocol (UDP) Control protocol (TCP)

Header size It has 4 bytes sized header It has 2 bytes sized header

No it does not uses REST

RESTful based Yes it uses REST principles
principles

Logical Design of IoT

Logical design of IoT system refers to an abstract representation of the entities & processes
without going into the low-level specifies of the implementation.
For understanding Logical Design of IoT, let us describes below terms.
▪ Functional Blocks of IoT
▪ Communication Models of IoT
▪ Communication APIs of IoT

Functional Blocks of IoT

An IoT system comprises of a number of functional blocks that provide the system the
capabilities for identification, sensing, actuation, communication and management.
The functional blocks are-
➢ Device
o Devices are used to provide sensing actuation and monitoring control functions
that collect the data from the outer environment. The device block interacts with
the communication block.
➢ Communication
o The communication block contains different protocols (wired or wireless)
through which the data moves from devices to Internet and from Internet to
devices. The services block acts as a middleware which can provide services like
device identification, device discovery, or data processing and analysis.
➢ Services
o This functional block provides some services like monitoring and controlling a
device and publishing and deleting the data and restore the system.
➢ Management
o The management block allows us to manage the other blocks like device, services,
communication, application, and security.
➢ Security
o This block is used to secure an IoT system using some functions like authorization,
data security, authentication, 2 step verification, etc.
➢ Application
o The users of an IoT application interacts with the application block. It provides
user interface with which the user can access the data sent by the sensors,
perform operations on that like aggregation, simplification, etc. and visualize that
data.
o The application interface can also provide control functions for controlling the
sensors, actuators or functionality of the application.
Communication Models of IoT
IoT consist of smart devices that communicate with each other. It enables these devices to
collect and exchange data.
There are 4 communication models as described below-
Request-Response Model
Request-response model is communication model in which the client sends requests to the
server and the server responds to the requests. When the server receives a request, it decides
how to respond, lookup the resources, fetches the data, prepares the response, and then sends
the response to the client.
HTTP works as a request-response protocol between a client and server.
Request-Response is a stateless communication model and each request-response pair is
independent of others.

Publish-Subscribe Model
Publish-Subscribe is a communication model that involves publishers, brokers and
consumers. Publishers are the source of data. Publishers send the data to the topics which are
managed by the broker. Publishers are not aware of the consumers. Consumers subscribe to the
topics which are managed by the broker. When the broker receive data for a topic from the
publisher, it sends the data to all the subscribed consumers.
Push-Pull Model
Push-Pull is a communication model in which the producers push the data to the queues and the
consumers pull the data from the Queues. Producers do not need to be aware of the consumers.
Queues also act as a buffer which helps in situations when there is a mismatch between the rate
at which the producers push data and the rate at which the consumer pull the data.

Exclusive Pair Model

Exclusive Pair is a bidirectional, full duplex communication model that uses a persistent
connection between the client and server. Connection is setup and it remains open until the client
sends a request to close the connection. Client and server can send messages to each other after
connection setup. Exclusive pair is stateful communication model and the server is aware of all
the open connections.
Communication APIs of IoT
Application Programming Interface (API) is a software interface that allows two applications to
interact with each other without any user intervention.
Generally, we used Two APIs For IoT Communication. These IoT Communication APIs are:
➢ REST-based Communication APIs
➢ WebSocket-based Communication APIs

REST (Representational State Transfer)

REST is an architectural style for designing networked applications. It uses standard HTTP
methods (GET, POST, PUT, DELETE, etc.) and relies on stateless, client-server communication.
• REST is suited for stateless, request-response type interactions commonly used in CRUD
operations.

WebSocket
WebSocket is a communication protocol that provides full-duplex communication channels over
a single TCP connection. Unlike HTTP, WebSocket allows for continuous two-way communication
between the client and server.
• WebSocket is ideal for real-time, full-duplex communication where persistent
connections and low latency are required.

Differentiate between REST and WebSocket based communication APIs

REST WebSocket

Stateless Stateful

Follow Request-Response model for

Follow Full duplex Communication
Communication
Each request involves setting up a new TCP
Single TCP Connection
Connection

Header Overhead No Header Overhead

Not Suitable for Real Time Application Suitable for Real Time Application

Cloud Computing
Cloud Computing means storing and accessing the data and programs on remote servers that
are hosted on the internet instead of the computer’s hard drive or local server. Cloud computing
is also referred to as Internet-based computing, it is a technology where the resource is provided
as a service through the Internet to the user. The data that is stored can be files, images,
documents, or any other storable document.
The following are some of the Operations that can be performed with Cloud Computing
• Storage, backup, and recovery of data
• Delivery of software on demand
• Development of new applications and services
• Streaming videos and audio

Types of cloud computing deployment models:

Public cloud

A Public Cloud is Cloud Computing in which the infrastructure and services are owned and
operated by a third-party provider and made available to the public over the internet. The
public can access and use shared resources, such as servers, storage, and applications and the
main thing is you pay for what you used. Examples of public cloud providers – are Amazon Web
Services (AWS), Microsoft Azure, and Google Cloud Platform (GCP).

Private cloud
A Private Cloud is a cloud computing environment in which the infrastructure and services are
owned and operated by a single organization, for example, a company or government, and it is
accessed by only authorized users within that organization. Private Cloud organizations have
their own data center. Private cloud provides a higher level of security. Examples – HPE, Dell,
VMware, etc.
Hybrid cloud

A hybrid cloud is a combination of both public and private cloud environments that allows
organizations to take advantage of the benefits of both types of clouds. It manages traffic levels
during peak usage periods. It can provide greater flexibility, scalability, and cost-effectiveness
than using a single cloud environment. Examples – IBM, Data Core Software, Rackspace, Threat
Stack etc.

Cloud Service Models:

Infrastructure as a service (IaaS)

Infrastructure as a service (IaaS) offers on-demand access to IT infrastructure services,
including compute, storage, networking, and virtualization. It provides the highest level of
control over your IT resources and most closely resembles traditional on-premises IT resources.

Platform as a service (PaaS)

Platform as a service (PaaS) offers all the hardware and software resources needed for cloud
application development. With PaaS, companies can focus fully on application development
without the burden of managing and maintaining the underlying infrastructure.

Software as a service (SaaS)

Software as a service (SaaS) delivers a full application stack as a service, from underlying
infrastructure to maintenance and updates to the app software itself. A SaaS solution is often an
end-user application, where both the service and the infrastructure is managed and maintained
by the cloud service provider.
Fog Computing

Fog computing in IoT is a decentralized computing model that brings computation and data
storage closer to the edge of the network. In other words, fog computing moves processing
power and data storage away from centralized server farms and into local networks where IoT
devices are located.

Edge Computing

A distributed computing model, processes data and applications at the edge of the network,
close to the data source. By contrast, in the traditional centralized model of cloud computing,
data and applications are stored in a central location and accessed over the network.

Big Data Analytics

Big data analytics refers to the systematic processing and analysis of large amounts of data and
complex data sets, known as big data, to extract valuable insights. Big data analytics allows for
the uncovering of trends, patterns and correlations in large amounts of raw data to help
analysts make data-informed decisions. This process allows organizations to leverage the
exponentially growing data generated from diverse sources, including (IoT) sensors, social
media, financial transactions and smart devices to derive actionable intelligence through
advanced analytic techniques.
Chapter 1: MCQ’s

1. What is the primary purpose of IoT?

a) To connect humans with each other
b) To connect physical objects and devices to the internet
c) To create virtual reality environments
d) To improve social media interactions

2. Which of the following statements best describes IoT?

a) A network of interconnected humans sharing data
b) A system of mechanical and digital machines without unique identifiers
c) A network of physical objects or 'things' with unique identifiers capable of
transferring data over a network
d) A network exclusively designed for computer-to-computer interaction

3. What are the characteristics of IoT devices?

a) They must be capable of complex computations
b) They must have a unique identification, capture data autonomously, and operate
at low power
c) They must have internet access at all times
d) They must have high physical strength and durability

4. Which of the following is not a building block of an IoT system?

a) Sensors
b) Processors
c) Displays
d) Gateway
 5. Which technology enables devices to communicate wirelessly over short distances by
using radio waves?
a) RFID
b) Bluetooth
c) Wi-Fi
d) Ethernet

6. What is the main purpose of using BLE (Bluetooth Low Energy) in IoT devices?
a) To achieve long-range communication
b) To provide high data rates
c) To reduce power consumption
d) To enable wired communication

7. Which technology uses light to transmit data and is considered faster than Wi-Fi?
a) RFID
b) NFC
c) Li-Fi
d) BLE

8. What is the primary function of a gateway in an IoT system?

a) To process data collected from sensors
b) To provide network connectivity to IoT devices
c) To store data in the cloud
d) To analyze data and make decisions autonomously
9. Which protocol is commonly used in LPWAN (Low-Power Wide Area Network)
applications for long-range communication with low power consumption?
a) Zigbee
b) Wi-Fi Direct
c) LoRaWAN
d) Bluetooth

10. Which level of IoT architecture involves multiple nodes, independent sensors, and
cloud-based data analysis?
a) Level 1
b) Level 3
c) Level 4
d) Level 6

Answers:

1. b) To connect physical objects and devices to the internet

2. c) A network of physical objects or 'things' with unique identifiers capable of
transferring data over a network
3. b) They must have a unique identification, capture data autonomously, and operate at
low power
4. c) Displays
5. b) Bluetooth
6. c) To reduce power consumption
7. c) Li-Fi
8. b) To provide network connectivity to IoT devices
9. c) LoRaWAN
10. c) Level 4