This document provides an introduction to Internet of Things (IoT) concepts. It defines IoT as a network of physical devices connected via standard communication protocols. The document outlines key characteristics of IoT including connectivity, intelligence/identity, scalability, and security. It also describes the physical design of IoT including things/devices and common communication protocols. Finally, it discusses IoT communication models such as request-response, publish-subscribe, push-pull, and exclusive pair models.

1. Unit I
Introduction to Internet of Things
GVNSK Sravya
Assistant Professor,
Dept. of ECE
GNITS

2. Contents
• Definition and Characteristics of IoT,
• Physical Design of IoT-IoT Protocols,
• IoT Communication Models,
• IoT Communication APIs.
• IoT enabled Technologies: Wireless Sensor
Networks,
• Cloud Computing,
• Big data analytics,
• Communication protocols,
• Embedded Systems,
• IoT Levels and Templates.
• Domain Specific IoTs: Home, City, Environment,
• Energy, Retail, Logistics, Agriculture, Industry,
Health and Lifestyle.
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3. Definition of IoT
• A dynamic global network infrastructure with self-configuring
capabilities based on standard and interoperable communication
protocols where physical and virtual "things" have identities, physical
attributes, and virtual personalities and use intelligent interfaces, and are
seamlessly integrated into the information network, often communicate
data associated with users and their environment.
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4. Characteristics of IoT
• CONNECTIVITY-Things In IoT Should Be Connected To The
Infrastructure And Connectivity Is An Important Character/Requirement For
An IoT Infra.
• Anyone, Anywhere, Anytime – Connectivity Should Be Guaranteed In The
IoT Infra.
• Without Connection, Nothing Makes Sense! (I Say That, Things Are
Connected And They Need Connectivity)
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5. Characteristics of IoT
• INTELLIGENCE AND IDENTITY-The Extraction Of Knowledge
(I.E. What Is To Be Inferenced) From The Generated Data Is Very
Important.
• Sensors Generate Data, The Data Is To Be Interpreted Properly! Each
IoT Device Has An Unique Identity (Remember IP Address). This
Identity Is Helpful In Tracking The Equipment And At Times To Query
The Status.
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6. Characteristics of IoT
• Scalability–The Number Of Things (Devices) Getting Connected To IoT
Infra Is Getting Increased Day By Day. Hence, An IoT Setup Shall Be
• Capable To Handle The Massive Expansion. Also, The Data Generated
Shall Be Massive And It Should Be Handled Appropriately.
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7. Characteristics of IoT
• Dynamic And Self Adapting (Complexity) –The IoT Devices Should
Dynamically Adapt Itself To The Changing Contexts.
• AssumeA Camera Meant For Surveillance. It May Have To Work In Different
Conditions As Different Light Situations (Morning, Afternoon, Night)
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8. Characteristics of IoT
• Architecture –Architecture Cannot Be Homogeneous In Nature. It Should Be
Hybrid, Supporting Different Manufacturer's Product To Be In The Iot Network.
• Safety -Having Got All The Things Connected To Internet, The Personal Data (If
Sensitive) Is Under Threat. Hence, Securing The Data Is A Major Challenge . Not
Only Data Security, The Equipment Getting Involved In IoT Network Is Huge.
Hence, Persona Safety Is Also To Be Considered. Privacy With Protection!
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9. Physical and Logical Design of IoT
Physical Design of IoT system
• Refers to IoT Devices and IoT Protocols.
• Things are node device which have unique identities and can perform
remote sensing, actuating and monitoring capabilities.
• Communication established between things and cloud based server over
the Internet by various IoT protocols.
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10. Physical and Logical Design of IoT
Things
• Basically things refers to IoT Devices which have unique identities and can perform remote
sensing, actuating and monitoring capabilities.
• Things are main part of IoT Application.
• IoT Devices can be Sensing Devices, Smart Watches, Smart Electronics Appliances,
Wearable Sensors, Automobiles, and Industrial Machines.
• These devices generate data in some forms or the other which when processed by data
analytics systems leads to useful information to guide further actions locally or remotely.
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11. Physical and Logical Design of IoT
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12. IoT Protocols
• IoT refers to the interconnection via the internet of computing devices
embedded in every day objects, enabling them to send and receive the
data.
• It all starts with the sensors and ends with display or control of devices.
• So there are multiple protocols used in between.
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13. IoT Protocols
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14. Link Layer
• Protocols determine how data is physically sent over the networks
physical layer or medium.
• Local network connect to which host is attached.
• Hosts on the same link exchange data packets over the link layer using
link layer protocols.
• Link layer determines how packets are coded and signaled by the
hardware device over the medium to which the host is attached.
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15. IoT Protocols Link Layer
• 802.3 Ethernet
• 802.11 WiFi
• 802.16 WiMax
• 802.15.4 LRWPAN
• 2G/3G/4G/LTE
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16. Ethernet
• Data rates are provided from 10Gbits/s to 40Gbits/s and higher.
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17. WiFi
• Collection of wireless LAN
• Data rates from 1Mb/s to 6.75Gb/s.
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18. WiMax
• Collection of wireless broadband standards.
• Data rates from 1.5Mb/s to 1Gb/s.
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19. LR-WPAN
• Collection of standards for low rate wireless personal area networks.
• Basics for high level communication protocols such as Zigbee.
• Data rates from 40Kb/s to 250Kb/s.
• Provides low cost and low speed communication for power constrained
devices.
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20. 2G/3G/4G- Mobile Communication
• Data rates from 9.6 Kb/s for 2G upto 100Mb/s for 4G.
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21. Network/Internet Layer
• Responsible for sending IP datagrams from source to destination
networks.
• Performs the host addressing and packet routing.
• Host identification is done using hierarchical IP addressing schemes such
as IPV4 or IPV6.
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22. Network/Internet Layer Protocols
IPV4
• Used to identify devices on a network using hierarchal addressing scheme.
• Uses 32 bit address schemes.
IPV6
• Uses 128 bit address schemes
6LoWPAN (IPV6 over Low Power Wireless Personal Area Network)
• Used for devices with limited processing capacity.
• Operates in 2.4 GHz.
• Date rates of 250kb/s.
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23. Transport Layer
• Provides end to end message transfer capabilities independent of the
underlying network.
• Message transfer capability can be setup on connections either using
handshakes (as in TCP) or without handshakes/acknowledgements (as in
UDP).
• It provides functions such as error control, segmentation, flow control and
congestion control.
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24. Transport Layer Protocols
TCP (Transmission Control Protocol)
• It is a connection oriented and stateful protocol
• While IP protocols deals with sending packets, TCP ensures reliable transmission of
packets in order.
• Also provides error detection capability so that duplicate packets can be discarded
and lost packets are retransmitted.
• Flow control capability of TCP ensures that rate at which sender send the data is not
too high for the receiver to process.
• The congestion control capability of TCP helps in avoiding network congestion and
congestion collapse which leads to degradation of network performance.
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25. Transport Layer Protocols
UDP (User Datagram Protocol)
• Unlike TCP it requires initial setup procedure, UDP is a connectionless
protocol.
• Useful for time sensitive applications that have very small data units to
exchange
• It is a transaction oriented and stateless protocol.
• Does not provide guaranteed delivery, ordering of messages and
duplicate elimination
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26. Application Layer
• It defines how the applications interface with the lower layer protocols to
send the data over the network.
• The application data is typically encoded by the application layer
protocol and encapsulated in transport layer protocol which provides
connection or transaction oriented communication over the network.
• It enables process to process connections using ports
• Port numbers are used for application addressing (eg. Port 80 for HTTP
port 22 for SSH etc.,)
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27. Application Layer Protocols
HTTP (Hypertext Transport Protocol)
• It forms the foundation of the World Wide Web (WWW)
• It includes commands such as GET, PUT, POST, DELETE, HEAD, TRACE,
OPTIONS etc.,
• It follows request response model where a client sends request to a server
using HTTP commands
• It is a stateless protocol and each HTTP request is independent of other
requests
• An HTTP client can be a browser or an application running on the client (eg.
Application running on an IoT device, mobile application or software)
• It uses URIs (Universal Resource Identifiers) to identify HTTP resources
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28. Application Layer Protocols
CoAP (Constrained Application Protocol)
• It is an application layer protocol for Machine to Machine applications,
meant for constrained environments with constrained devices and
networks
• Like HTTP, CoAP is a web transfer protocol and uses a request response
model, and it runs on UDP over TCP
• Uses a client server architecture where clients communicate with servers
using connectionless datagrams
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29. Application Layer Protocols
Web Sockets
• It allows full duplex communication over a single socket connection for
sending messages between client and server.
• It is based on TCP and allows streams of messages to be sent back and
forth between the client and server while keeping the TCP connection
open
• The client can be a browser, IoT device or mobile application
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30. Application Layer Protocols
MQTT (Message Queue Telemetry Transport)
• It is a light weight messaging protocol based on publish- subscribe
model.
• It uses a client server architecture where the client (an IoT device)
connects to a server (MQTT broker) and publishes messages to topics on
the server.
• The broker forwards the messages to the client to topics
• It is suited for constrained environments where the devices have limited
processing, memory resources and low network bandwidth.
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31. Application Layer Protocols
XMPP (Extensible Messaging and Presence Protocol)
• It is a protocol for real time communication and streaming XML data between
network entities.
• Provides wide range of applications including messaging, presence, data
syndication, gaming, multi party chat and voice/video calls.
• It allows sending small chunks of XML data from one network entity to
another in near real time.
• It is a decentralized protocol and uses client – server architecture.
• It supports both client to server and server to server communication paths.
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32. Application Layer Protocols
DDS (Data Distribution Service)
• It is a data centric middle ware software for device to device or M2M
communication.
• It uses a publish subscribe model where publishers (eg. Devices that
generate data) creates topic to which subscribers (eg. Devices that want
to consume data) can subscribe.
• Publisher is an object responsible data distribution and the subscriber is
responsible for receiving published data.
• It provides Quality of Service Control (QoS) and configurable reliability
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33. Application Layer Protocols
AMQP (Advanced Message Queuing Protocol)
• It is an open application protocol for business messaging
• It supports both point to point and Publisher/subscriber models, routing and queuing
• It receives messages from publishers(devices or applications that generate data) and
route them over connections to consumers(applications that process data)
• Publishers publish the messages to exchanges which then distribute message copies
to queues
• Messages are either delivered by the broker to the consumers which have subscribed
to the queues or the consumer can pull the messages from the queues.
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34. Physical and Logical Design of IoT
Logical Design of IoT system
• Refers to an abstract representation of the entities & processes without going into the low-
level specification of the implementation.
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35. Physical and Logical Design of IoT
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Logical Design of IoT
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36. Physical and Logical Design of IoT
• An IoT system comprises of a number of functional blocks that provide
the system capabilities for identification, sensing, actuation,
communication and management.
• Functional blocks are:
i. Device: An IoT system comprises of devices that provide sensing,
actuation, monitoring and control functions.
ii. Communication: Handles the communication for the IoT system.
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37. Physical and Logical design of IoT
• Services: services for device monitoring, device control service, data publishing
services and services for device discovery.
• Management: this blocks provides various functions to govern the IoT system.
• Security: this block secures the IoT system and by providing functions such as
authentication , authorization, message and content integrity, and data security.
• Application: This is an interface that the users can use to control and monitor
various aspects of the IoT system. Application also allow users to view the system
status and view or analyze the processed data.
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38. IoT Communication Models
• What is communication in IoT ?
• How is communication done in IoT ?
• Why communication is essential in IoT ?
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39. IoT Communication Models
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• Request and Response Model
Request
Response
Fig 1:Request-Response Communication Model
Client –Send
request to
server
Server Resources
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40. IoT Communication Models
Publish-Subscribe Model
Send messages to topic
Fig2:Publish-Subscribe model
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Publisher
Subscriber 1
Subscriber 2
Subscriber 3
Topic A
Topic B
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41. IoT Communication Models
Publish-Subscribe Model
Send messages to topic
Fig2:Publish-Subscribe model
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Publisher
Subscriber 1
Subscriber 2
Subscriber 3
Topic A
Topic B
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42. IoT Communication Models
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Push-Pull Model
Message Message buffered in queue Message pulled from queue
Message Published from queue
Fig3:Push-Pull Model
Publisher Consumer
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43. IoT Communication Models
Exclusive Pair Model
Request to setup connect
Response accepting request
Message from client to server
Message from server to client
Connection close request
Connection close response
Fig4:Exclusive Pair Model
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Client Server
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44. IoT Levels
• An IoT system comprises of the following components
i. Device
ii. Resources
iii. Controller service
iv. Database
v. Web service
vi. Analysis Component
vii. Application
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45. IoT Levels
• Device: An IoT device allows identification, remote sensing, actuating and remote monitoring
capabilities. You learned about various examples of IoT devices in section
• Resource: Resources are software components on the IoT device for accessing, processing, and
storing sensor information, or controlling actuators connected to the device. Resources also include the
software components that enable network access for the device.
• Controller Service: Controller service is a native service that runs on the device and interacts with the
web services. Controller service sends data from the device to the web service and receives commands
from the application (via web services) for controlling the device.
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46. IoT Levels
• Database: Database can be either local or in the cloud and stores the data generated by the IoT device.
• Web Service: Web services serve as a link between the IoT device, application, database and analysis
components. Web service can be either implemented using HTTP and REST principles (REST service)
or using WebSocket protocol (WebSocket service).
• Analysis Component: The Analysis Component is responsible for analyzing the IoT data and
generate results in a form which are easy for the user to understand.
• Application: IoT applications provide an interface that the users can use to control and monitor
various aspects of the IoT system. Applications also allow users to view the system
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47. IoT Levels
IoT level 1:
• Single node/device
• Sensing/actuation
• Stores data, reforms ,analysis, not big, low complexity
• Example: Home automation
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48. IoT Levels
IoT level 2:
• Single node/actuation
• Data is stored in cloud
• Data is big
• Example: Smart irrigation
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49. IoT Levels
IoT Level 3:
• Single node
• Data is stored and analyzed – cloud based
• Data involved is big and analysis requirements computationally
intensive.
• Example: Tracking package handling
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50. IoT Levels
IoT level 4:
• Multiple nodes
• Data is stored in cloud
• Local and cloud based observer nodes
• Data involving is big
• Analysis requirements are computationally intensive.
• Example: Noise monitoring – with sound sensor ,nodes are independent
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51. IoT Levels
IoT Level 5:
• Multiple end nodes
• Coordinator node
• Coordinator node collects data from the entry and send to the cloud
• Data is stored and analyzed in the cloud and applications is cloud
based
• Example : Forest fire detection (temperature, humidity and carbon
dioxide levels )
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