UNIT-I

Introduction to IoT
It has been anticipated that very soon all the different things that are going that we are
seeing around us and that we have around us are all going to be internet worked. They
are all going to be interconnected. So, at present what we enjoy as services, as internet
based services is basically a connection of different computers and computing
devices. So, basically this capital I internet that all of us use is basically a global
network or an internet work of different computers and computing devices.what
internet of things says is that the scope of this internet is going to be expanded. So, it
is going to be expanded beyond computing and computer devices being connected. It
is going to interconnect different things that physical objects that we see around us,
the different objects such as the lighting system in a room, the lights, the fans, the air
conditioners and anything and everything including things such as the toothbrush, the
microwave oven, the refrigerator and so on. Not only in our homes, but also in our
businesses such as internet working different machines, internet working different
equipments. The scope of IoT is not limited to just connected things(Devices,
appliance, machines) to the Internet.  Applications on IoT networks extract and
create information from lower level data by filtering, processing , categorizing,
condensing and ontextualizing the data. The information obtained is then organized
and structured to infer knowledge about the system and or its user, its environment
and its operations and progress towards its objectives, allowing a smarter
performance.

Internet of Things:
A dynamic global network infrastructure with self – configuring based on standard
and interoperable communication protocols where physical and virtual “things” have
identified, physical attributes, and virtual personalities and use intelligent interfaces,
often communicate data associated with users and their environment.
1.2 Characteristics 

1. Dynamic and self-Adapting: IoT devices and systems may have the capability to
dynamically adapt with the changing contexts and take actions based on their
operating condition.Ex: Surveillance cameras can adapt their modes based on
whether it is day or night. 
2. Self – Configuring: IoT devices may have self-Configuring capability allowing a
large number of devices to work together to provide certain functionality .
3. Interoperable communication protocols: IoT Devices may support a number of
interoperable communication protocols and can communicate with other devices and
also with the infrastructure. 
4. Unique Identity: Each IoT devices has a unique identity and a unique
identifier.IPaddress, URI).IoT systems may have intelligent interfaces which adapt
based on the context, allow communication with users and the environment contexts.
5. Integrated into information network: IoT devices are usually integrated into the
information network that allows them to communicate and exchange data with other
devices and systems.
1.3 Physical Design of IoT
1.3.1 Things of IoT :
The “Things” in IoT usually refers to IoT devices which have unique identities and
can perform remote sensing, Actuating and monitoring capabilities. IoT devices can
exchange data with other connected devices and applications (directly or indirectly),
or collect data from other devices and process the data locally or send the data to
centralized servers or cloud based applications backends for processing the data or
from some task locally and other task within the IoT infrastructure, based on
temporal and space constraints. An IoT device may consist of several interfaces
connections to other devices, both wired and wireless. These include
I) IoT interfaces for sensors
II) interfaces for internet connectivity
III) memory and storage interfaces
IV) audio video interfaces.
An IoT Device can collect various types of data from the the onboard or attached
sensors, such as temperature e , humidity, light intensity. IoT devices can also be
varied types, for instance, wearable sensors, smart watches, LED light automobiles
and industrial machines.
1.4 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 function blocks are described as follows

 Devices: An IoT system comprises of the devices that provide sensing, actuation,
monitoring and control function
Communication: communication block handle the communication systems
 Services : An IoT system uses various types of IoT services, such as services for
devices monitoring ,device control services ,data publishing services and services
for devices discovery.
 Management: Functional blocks provide various functions to govern the IoT
system
 Security: Security functional block security IoT system and by providing
functions such as application authorization message and content integrity and
data security.
 Application: IoT application provides and interface that the user can used 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 to data.

1.5 Sensing
A device that provides a usable output in response to a specified measurement.
The sensor attains a physical parameter and converts it into a signal suitable for
processing (e.g. electrical, mechanical, optical) the characteristics of any device or
material to detect the presence of a particular physical quantity.
Sensor Classification :Passive & ActiveAnalog & digitalScalar & vectorPassive
Sensor –Can not independently sense the input. Ex- Accelerometer, soil
moisture, water level and temperature sensors.Active Sensor – Independently
sense the input. Example- Radar, sounder and laser altimeter sensors.Analog

Sensor – The response or output of the sensor is some continuous function of

its input parameter. Ex- Temperature sensor, LDR, analog pressure sensor and
analog hall effect.Digital sensor –Response in binary nature. Design to
overcome the disadvantages of analog sensors. Along with the analog sensor, it
also comprises extra electronics for bit conversion. Example – Passive infrared
(PIR) sensor and digital temperature sensor(DS1620).Scalar sensor – Detects
the input parameter only based on its magnitude. The answer for the sensor is a
function of magnitude of some input parameter. Not affected by the direction
of input parameters.Example – temperature, gas, strain, color and smoke
sensor. Vector sensor –The response of the sensor depends on the magnitude of
the direction and orientation of input parameter. Example – Accelerometer,
gyroscope, magnetic field and motion detector sensors.
1.6Actuation
An IoT device is made up of a Physical object (“thing”), Controller
(“brain”),Sensors ,Actuators, Networks (Internet). An actuator is a machine
component or system that moves or controls the mechanism of the system.
Types of Actuators :
1. Hydraulic Actuators –
A hydraulic actuator uses hydraulic power to perform a mechanical operation. They
are actuated by a cylinder or fluid motor.
2. Pneumatic Actuators –
A pneumatic actuator uses energy formed by vacuum or compressed air at high
pressure to convert into either linear or rotary motion
3. Electrical Actuators –
An electric actuator uses electrical energy, is usually actuated by a motor that
converts electrical energy into mechanical torque.
4. Mechanical Actuators –
A mechanical actuator executes movement by converting rotary motion into linear
motion.
5. Thermal/Magnetic Actuators –
These are actuated by thermal or mechanical energy. Shape Memory Alloys
(SMAs) or Magnetic Shape ‐Memory Alloys (MSMAs) are used by these actuators.

1.7 Basics of Networking

 Network: A network is a collection of computers and devices that are connected
together to enable communication and data exchange.
 Nodes: Nodes are devices that are connected to a network. These can include
computers, Servers, Printers, Routers, Switches, and other devices.
 Protocol: A protocol is a set of rules and standards that govern how data is
transmitted over a network. Examples of protocols include TCP/IP, HTTP,
and FTP.
 Topology: Network topology refers to the physical and logical arrangement of
nodes on a network. The common network topologies include bus, star, ring,
mesh, and tree.
 Service Provider Networks: These types of Networks give permission to take
Network Capacity and Functionality on lease from the Provider. Service
Provider Networks include Wireless Communications, Data Carriers, etc.
 IP Address: An IP address is a unique numerical identifier that is assigned to
every device on a network. IP addresses are used to identify devices and enable
communication between them.
 DNS: The Domain Name System (DNS) is a protocol that is used to translate
human-readable domain names (such as www.google.com) into IP addresses that
computers can understand.
Types of Computer Networks
Computer networks are divided into different categories:
Based on the communication medium
 Wired Network: It uses cables to connect devices, such as laptops or desktop PCs,
to the Internet or another network. The different types of cables used in computer
networks include coaxial, fiber optic, Unshielded Twisted Pair (UTP), Shielded
Twisted Pair (STP) cable, etc.
 Wireless Network: Computer networks that are not connected by any kind of
cables are called wireless networks. These networks establish use Radio Frequency
(RF) connections between nodes in the network. Examples include laptops with
WLAN cards and TV remotes.
 There are three types of deployment to create a wireless network,
namely centralized deployment, converged deployment, and cloud-
based deployment.
Based on Geographical Area
 Local Area Network (LAN): It is a set of computers connected in a small
geographical or physical area such as a building, office, or college. LANs are
usually privately owned and managed.
 Metropolitan Area Network (MAN): It is a larger version of LAN that spans
over a bigger geographical area such as a town or a city. It can be used for
connecting various offices of the same organization that are spread over a city.
 Wide Area Network (WAN): WAN is the largest network that spans countries,
continents, or the globe. For example, the Internet is the largest WAN that connects
billions of computers worldwide.
 Virtual Private Network (VPN): It is a secure, point-to-point connection between
two network endpoints. It extends a private network across a public network,
allowing users to exchange data across shared or public networks as if their
systems were directly connected to the private network.
 A VPN creates an encrypted channel that keeps identity, credentials, and data
exchanged inaccessible to hackers.

1.8 Communication Protocols:

Link Layer: Link Layer protocols determine how the data is physically sent over the
networks physical layer or medium(example copper wire, electrical cable, or radio
wave). The Scope of The Link Layer is the Last Local Network connections to which
host is attached.
 802.3 Ethernet: 802.3 is a collection of wired Ethernet standards for the link
layer. For example 802.3 10BASE5 Ethernet that uses coaxial cable as a shared
medium, 802.3.i is standard for 10 BASET Ethernet over copper twisted pair
connection, Standards provide data rates from 10 Mb/s to 40 gigabits per second
and the higher. The shared medium in Ethernet can be a coaxial cable , twisted
pair wire or and Optical fiber. Shared medium carries the communication for all
the devices on the network.
 802.1- WI-FI: IEEE 802.3 is a collection of wireless Local area network.
(WLAN) communication standards, including extensive descriptions of the link
layer. For example 802.11a operate in the 5 GHz band, 802.11b and 802.11g
operate in the 2.4 GHz band. 802.11ac operates in the 5G hertz band.
 802.16 wiMAX: IEEE 802.16 is a collection of wireless broadband and
Standards, including extensive descriptions for the link layer also called WiMAX
wimax standard provides a data rates from from 1.5 Mb/s to 1Gb/s the recent
update provides data rates of hundred megabits per second for mobile stations.
 802.15.4 LR-WPAN: IEEE 802.1 5.4 is a collection of standards for low-rate
wireless personal area network(LRWPAN).These standards form the basis of
specifications for high level communication Zigbee. LR-WPAN standards
provide data rates from 40 k b/ s. These standards provide low cost and low-speed
communications for power constrained devices. 2G / 3G / 4G mobile
communications: These are the different generations of mobile communication
standards including second generation (2G including GSM and CDMA). 3rd
Generation (3G including UMTS and CDMA2000) and 4th generation 4G
including LTE.
Network / internet layer : The network layer is responsible for sending of IP data
grams from the source network to the destination network. This layer performs the
host addressing and packet routing. The datagrams contains a source and destination
address which are used to route them from the source to the destination across
multiple networks. Host Identification is done using the hierarchy IP addressing
schemes such as ipv4 or IPv6.
 IPV4: Internet protocol versions for open parents close (IPV4) is there most
deployed internet protocol that is used to identify the device is on a network using
a hierarchy latest schemes. It uses 32 bit addresses scheme that allows total of 2 32
address. As more and more devices got connected to the internet. The Ipv4 has
succeeded by IPv6.
 IPv6: It is the newest version of the internet protocol and the successor to IPv4.
IPv6 uses 128 bit address schemes that are lost total of 2128 are 3.4* 10 38 address.
 6LoWPAN: IPv6 over low-power wireless personal area networks brings IP
protocol to the low power device which has limited processing capability it
operate in the 2.4 GHz frequency range and provide the data transfer rate off to
50 kb/s.
Transport layer : The Transport layer protocols provide end-to-end message transfer
capability independent of the underlying network. The message transfer capability can
be set up on connections, either using handshakes or without handshake
acknowledgements. It Provides functions such as error control , segmentation, flow
control and congestion control. 
 TCP: Transmission control protocol is the most widely used to transport layer
protocol that is used by the web browsers along with HTTP , HTTPS application
layer protocols, email program (SMTP application layer protocol) and file
transfer protocol. TCP is a connection Oriented and stateful protocol while IP
protocol deals with sending packets, TCP ensures reliable transmissions of
packets in order. TCP also provide error deduction capability so that duplicate
packets can be discarded and low packets are retransmitted .
 UDP: unlike TCP, which requires carrying out an initial setup procedure, UDP is
a connection less protocol. UDP is useful for time sensitive application they have
very small data units to exchange and do not want the overhead of connection
setup. UDP is a transactions oriented and stateless protocol. UDP does not
provide guaranteed delivery, ordering of messages and duplicate eliminations.
Application layer : Application layer protocol defines how the application interfaces
with the lower layer protocols to send the data over the network. Data are typically in
files, is encoded by the application layer protocol and encapsulated in the transport
layer protocol .The Application layer protocol enables process-to-process connection
using ports.
 HTTP: Hypertext transfer protocol is the application layer protocol that forms
the foundations of world wide web http includes, ,commands such as GET, PUT,
POST, DELETE, HEAD, TRACE, OPTIONS etc. The protocol follows a
request-response model where are client sends request to server using the http,
commands. HTTP is a stateless protocol and each HTTP request is independent
father request and the HTTP client can be a browser or an application running on
the client example and application running on an IoT device ,mobile mobile
applications or other software.
 CoAP: Constrained application protocol is an application layer protocol for
machine to machine application M2M meant for constrained environment with
constrained devices and constrained networks. Like http CoAP is a web transfer
protocol and uses a request- response model, CoAP uses a client –server
architecture where client communicate with server using connectionless data
grams.It is designed to easily interface with http like http,CoAP supports method
such as GET, PUT, DELETE .
 Websocket:Websocket protocol allows full duplex communication over a single
socket connection for sending messages between client and server. The
websocket 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, a mobile application and IoT device
 MQTT :Message Queue Telemetry Transport it is a lightweight message
protocol based on public -subscribe model. MQTT uses a client server
Architecture by the clients such as an IoT device connect to the server also called
the MQTT broker and publishers message to topic on the server. The broker
forward the message to the clients subscribed to topic .
 XMPP: Extensible Messaging and Presence Protocol it is a protocol for real-time
communication and streaming XML data between network entities XMPP powers
wide range of applications including messaging, presence, data syndication,
gaming multiparty chat and voice / voice calls. XMPP Allows sending small
chunks of XML data from one network entity to another in real time.
 DDS: Data distribution service is the date centric middleware standard for
deviceto-device machine to machine communication DDS uses a publish
subscribe model where publisher example device that generate data create topics
to which subscribers per can subscribe publisher is an object responsible for data
distributions and the subscriber responsible for receiving published data. DDS
provide quality of service (QoS) control and configurable reliability
 AMQP: Advanced Message Queuing protocols. it is an open application layer
protocol for business messaging. AMQP support point to point and publish -
subscribe model routing and queuing. AMQP broker receive message from
publishers example devices or applications that generate data and about them
over connections to consumers publishers publish the message
1.8 Sensor Networks.
A sensor network is a group of sensors where each sensor monitors data in a
different location and sends that data to a central location for storage, viewing, and
analysis.There are many applications for sensor networks, from monitoring a single
home, to the surveillance of a large city, to earthquake detection for the whole world.

Home security

The primary goal of a home security sensor network is to detect an intruder. Many
different types of sensors can help collect data towards that goal, such as magnetic
open sensors on doors and windows, acoustic-based glass break sensors, security
cameras, and motion detectors.All of the sensors send their data to a central system,
which typically stores the data for a period of time and gives the homeowners a way
to view it. More sophisticated system can analyze the data and send an alert to the
homeowners when it sees enough evidence of an intrusion.
Environmental monitoring

Researchers, farmers, and governments need to monitor aspects of the natural

environment such as air pollution, water quality, soil conditions, and weather metrics.
The traditional approach to monitoring is to collect a sample, bring it back to a lab,
analyze it, and record the results. Needless to say, that approach is slow and
dependent on human labor, so traditional monitoring doesn't produce a lot of data.A
more automated and scalable approach is to use a sensor network. Sensors can be
distributed across an area, collect the environmental data, and send it back to a central
server for processing.

Municipal surveillance

In a city, crime can happen anywhere, and with modern transportation, criminals can
come from anywhere to commit crime in a city. Police officers can't be everywhere at
once, so how can they track down the criminals that commit crimes? One approach is
a network of surveillance cameras throughout the city, all linked together and sending
video back to the police station.