2. 1. Definition and characteristics of IoT
2. Design of IOT: Physical design of IOT
3. Logical Design of IOT- Functional Blocks
4. communication models
5. communication APIs
6. IOT enabling Technologies- Wireless Sensor Networks
7. Cloud computing
8. big data analytics
9. embedded systems
10. IOT Levels and deployment templates
Contents of UNIT – 1st 2
Definition and characteristics of IoT
Definition : The internet of things, or IoT, is a 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.
Characteristics of IoT :
Connectivity empowers Internet of Things by bringing together everyday objects. Connectivity of these
objects is pivotal because simple object level interactions contribute towards collective intelligence in IoT
network. It enables network accessibility and compatibility in the things. With this connectivity, new market
opportunities for Internet of things can be created by the networking of smart things and applications.
IoT comes with the combination of algorithms and computation, software & hardware that makes it smart.
Ambient intelligence in IoT enhances its capabilities which facilitate the things to respond in an intelligent way
to a particular situation and supports them in carrying out specific tasks. In spite of all the popularity of smart
technologies, intelligence in IoT is only concerned as means of interaction between devices, while user and
device interaction is achieved by standard input methods and graphical user interface.
The number of devices that need to be managed and that communicate with each other will be much larger
than the devices connected to the current Internet. The management of data generated from these devices and
their interpretation for application purposes becomes more critical. Gartner (2015) confirms the enormous
scale of IoT in the estimated report where it stated that 5.5 million new things will get connected every day
and 6.4 billion connected things will be in use worldwide in 2016, which is up by 30 percent from 2015. The
report also forecasts that the number of connected devices will reach 20.8 billion by 2020.
The primary activity of Internet of Things is to collect data from its environment, this is achieved with the
dynamic changes that take place around the devices. The state of these devices change dynamically,
example sleeping and waking up, connected and/or disconnected as well as the context of devices including
temperature, location and speed. In addition to the state of the device, the number of devices also changes
dynamically with a person, place and time.
Heterogeneity in Internet of Things as one of the key characteristics. Devices in IoT are based on different
hardware platforms and networks and can interact with other devices or service platforms through different
networks. IoT architecture should support direct network connectivity between heterogeneous networks. The
key design requirements for heterogeneous things and their environments in IoT are scalabilities, modularity,
extensibility and interoperability.
IoT wouldn’t be possible without sensors which will detect or measure any changes in the environment to
generate data that can report on their status or even interact with the environment. Sensing technologies
provide the means to create capabilities that reflect a true awareness of the physical world and the people in it.
The sensing information is simply the analogue input from the physical world, but it can provide the rich
understanding of our complex world.
IoT devices are naturally vulnerable to security threats. As we gain efficiencies, novel
experiences, and other benefits from the IoT, it would be a mistake to forget about
security concerns associated with it. There is a high level of transparency and privacy
issues with IoT. It is important to secure the endpoints, the networks, and the data that
is transferred across all of it means creating a security paradigm.
Design of IOT: Physical design of IOT
Physical Design of IoT 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.
The IoT architecture is multi-layered with delicate components intricately connected
to each other. It starts with sensors, which are the source of data being
collected. Sensors pass data onto an adjacent edge device, which converts
data into readable digital values and stores these temporarily.
Physical Design of IoT
Basically Things refers to IoT Devices which have unique identities and can perform
remote sensing, actuating and monitoring capabilities. Things are is main part of IoT
Application. IoT Devices can be various type, 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.
IoT protcols help to establish Communication between IoT Device (Node Device) and
Cloud based Server over the Internet. It help to sent commands to IoT Device and
received data from an IoT device over the Internet. An image is given below. By this
image you can understand which protocols used.
Link layer protocols determine how data is physically sent over the network’s physical
layer or medium (Coxial calbe or other or radio wave). This Layer determines how the
packets are coded and signaled by the hardware device over the medium to which the host
is attached (eg. coxial cable).
Example of Link Layer Protocol:
• 802.11 – WiFi
• 802.16 – Wi-Max
• 802.15.4 -LR-WPAN
• 2G/3G/4G- Mobile Communication
Responsible for sending of IP datagrams from the source network to the destination
network. Network layer performs the host addressing and packet routing. We used IPv4
and IPv6 for Host identification. IPv4 and IPv6 are hierarchical IP addressing schemes.
Example of Network Layer
This layer provides functions such as error control, segmentation, flow control and
congestion control. So this layer protocols provide end-to-end message transfer capability
independent of the underlying network.
Example of Transport Layer:
Application layer protocols define how the applications interface with the lower layer protocols
to send over the network.
Example of Application Layer
Logical Design of IoT | IoT Communication Models & APIs
Logical Design of IoT
In this slide we discuss Logical design of Internet of things. 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, we
describes given below terms.
•IoT Functional Blocks
•IoT Communication Models
•IoT Communication APIs
17. 17IoT Functional Blocks
An IoT system comprises of a number of functional blocks that provide the system the
capabilities for identification, sensing, actuation, communication and management.
functional blocks are:
Device: An IoT system comprises of devices that provide sensing, actuation, monitoring
and control functions.
Communication: Handles the communication for the IoT system.
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.
19. 19IoT Communication Models
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, fetches the data, retrieves resource representation, prepares the
response, and then sends the response to the client. Request-response is a stateless
communication model and each request-response pair is independent of others.
HTTP works as a request-response protocol between a client and server. A web browser
may be the client, and an application on a computer that hosts a web site may be the server.
Example: A client (browser) submits an HTTP request to the server; then the server returns
a response to the client. The response contains status information about the request and
may also contain the requested content.
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
Push-Pull is a communication model in which the data producers push the data to queues
and the consumers Pull the data from the Queues. Producers do not need to be aware of the
consumers. Queues help in decoupling the messaging between the Producers and
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 rate at which the consumer
Exclusive Pair Model
Exclusive Pair is a bidirectional, fully duplex communication model that uses a persistent
connection between the client and server. Connection is setup 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.
IoT Communication APIs
Generally we used Two APIs For IoT Communication.
These IoT Communication APIs are:
•REST-based Communication APIs
•WebSocket-based Communication APIs
REST-based Communication APIs: Representational state transfer (REST) is a set of
architectural principles by which you can design Web services the Web APIs that focus
on systems’s resources and how resource states are addressed and transferred.
REST APIs that follow the request response communication model, the rest
architectural constraint apply to the components,
connector and data elements, within a distributed hypermedia system.
The rest architectural constraint are as follows:
Client-server – The principle behind the client-server constraint is the separation of concerns.
for example clients should not be concerned with the storage of data which is concern of the
serve. Similarly the server should not be concerned about the user interface, which is concern
of the clien. Separation allows client and server to be independently developed and updated.
Stateless – Each request from client to server must contain all the information necessary to
understand the request, and cannot take advantage of any stored context on the server. The
session state is kept entirely on the client.
Cache-able – Cache constraints requires that the data within a response to a request be
implicitly or explicitly leveled as cache-able or non cache-able. If a response is cache-able,
then a client cache is given the right to reuse that repsonse data for later, equivalent requests.
caching can partially or completely eliminate some instructions and improve efficiency and
Layered system – layered system constraints, constrains the behavior of components such
that each component cannot see beyond the immediate layer with they are interacting. For
example, the client cannot tell whether it is connected directly to the end server or two an
intermediaryalong the way. System scalability can be improved by allowing intermediaries to
respond to requests instead of the end server, without the client having to do anything
A RESTful web service is a ” Web API ” implemented using HTTP and REST principles.
REST is most popular IoT Communication APIs.
WebSocket based communication API
Websocket APIs allow bi-directional, full duplex communication between clients and
servers. Websocket APIs follow the exclusive pair communication model. Unlike request-
response model such as REST, the WebSocket APIs allow full duplex communication and
do not require new coonection to be setup for each message to be sent.
Websocket communication begins with a connection setup request sent by the client to the
server. The request (called websocket handshake) is sent over HTTP and the server
interprets it is an upgrade request. If the server supports websocket protocol, the server
responds to the websocket handshake response. After the connection setup client and server
can send data/mesages to each other in full duplex mode.
Websocket API reduce the network traffic and letency as there is no overhead for connection
setup and termination requests for each message. Websocket suitable for IoT applications
that have low latency or high throughput requirements. So Web socket is most suitable IoT
Communication APIs for IoT System.
30. 30Wireless Sensor Network
•Distributed Devices with sensors used to monitor the
environmental and physicalconditions
•It is a network formed by large no. of sensor nodes to detect
light, heat , pressure ect. i.e. used to monitor environmental and
•Each node can have several sensors attached to it.
• Each node can also acts as a routers
• Coordinator collects data from all nodes
•Coordinator acts as gateway that
connects WSN to the internet.
31. 31Examples ofWSNs
• Indoor Air Quality Monitoringsystem
• Weather Monitoring System
• Soil Moisture Monitoring System
• Survelliance Systems
• Health Monitoring Systems
WSNs are enabled by wireless communication protocols such as IEEE802.15.4
Zigbee is one of the most popular wireless technology used by WSNs.
Zigbee specifications are based on IEEE802.15.4 which is used for low powered
Data rate: up to 250KBps. Range: upto 100 Meters
• Deliver applications and services over internet
Provides computing, networking and storage resources on demand
Cloud Computing is a way of making use of virtual computer world wide using
the same personalized experience.
Types of Cloud computing services
1. IaaS(Infrastructure as a Service),
2. PaaS(Platform as a Service and
3. SaaS(Software as a Services)
local storage computing
•Saas : Clients can access and use
software at remote location using a web
Ex: Google documents
• Paas : Clients can install, build and modify or
Ex: App cloud, Google App Engine
IaaS: Clients can use storage to install and manage operating systems
and any desired applications.( i.e Virtual machines + virtual storage)
Ex: Web Hosting.
34. 34Big DataAnalytics
• Collection of data whose volume, velocity or variety is too
large and difficult to store, manage, process and analyze
the data using traditional databases.
Big data Analytics involves
Data munging (Data
Replacing Converting data
from one format
35. 35Embedded Systems
• A microcontroller-based, software-driven, reliable, real- time control system, designed to
perform a specific task..
• It can be thought of as a computer hardware system having software embedded
•An embedded system can be either an independent system or a part of a large system.
36. 36Key Components
•Microprocessor or micro controller
•Memory (RAM, ROM ect.)
•Storage ( Flash Memory)
•Networking units(Ethernet, Wifi adaptors )
•I/O units ( Keyboard, display ect)
Some Embedded systems have
•DSP(Digital Signal Processor)
•App Specific Processor
•Embedded systems run embedded OS
Ex: RTOS(Real Time OS)(like symbian, Vxworks , Windows
embedded compact ect.)
37. IoT Levels and Deployment Templates
An IoT system comprises the following components:
Device, Resource, Controller Service, Database, Web service,Analysis
An IoT device allows identiﬁcation, remote sensing,
• Software components on the IoT device for
-accessing, processing and storing sensor information,
-controlling actuators connected to the device.
- enabling network access for the device.
• Controller service is a native service that runs on the device and interacts
with the web services.
•It sends data from the device to the web service and receives commands
from the application (via web services) for controlling thedevice.
Component and Application.
•Database can be either local or in the cloud and stores the data generated by the IoT device.
•Web services serve as a link between the IoT device, application, database and analysis
•It can be implemented using HTTP and REST principles (REST
service) or using the WebSocket protocol (WebSocketservice).
•Analysis Component is responsible for analyzing the IoT data and
generating results in a form that is easy for the user to understand.
•IoT applications provide an interfacethatthe users canuse to control and monitor
various aspects of the IoTsystem.
•Applications also allow users to view the system status and the processed data.
39. IoT Level-1
A level-1 IoT system has a single
node/device that performs sensing and/or
actuation, stores data, performs analysis
and hosts the application.
Level-1 IoT systems are suitable for
modelling low- cost and low-complexity
solutions where the data involved is not big
and the analysis requirements are not
41. IoT Level-2
•A level-2 IoT system has a single node that performs
sensing and/or actuation and local analysis.
Data is stored in the cloud and the
application is usually cloud-based.
•Level-2 IoT systems are suitable for solutions where the
data involved is big; however, the primary analysis
requirement is not computationally intensive and can be
43. IoT Level-3
A level-3 IoT system has a single node. Data is stored
and analyzed in the cloud and the application is
Level-3 IoT systems are suitable for solutions where
the data involved is big and the analysis
requirements are computationally intensive.
44. IoT – Level 3 Example: Tracking Package Handling
Sensors used Accelrometer
sense movement or vibrations
Gives orientation info
Websocket service is used because sensor data can be sent in real time.
45. IoT Level-4
A level-4 IoT system has multiple nodes
that perform local analysis. Data is stored
in the cloud and the application is cloud-
Level-4 contains local and cloud- based
observer nodes which can subscribe and
receive information collected in the cloud
from IoT devices.
Level-4 IoT systems are suitable for
solutions where multiple nodes are
required, the data involved is big and the
analysis requirements are
46. IoT – Level 4 Example: NoiseMonitoring
Sound Sensors are used
47. IoT Level-5
•A level-5 IoT system has multiple
end nodes and one coordinator
•The end nodes perform sensing
•The coordinator node collects data
from the end nodes and sends it to
•Data is stored and analyzed in the
cloud and the application is cloud-
Level-5 IoT systems are suitable for solutions based on wireless sensor
networks, in which the data involved is big and the analysis requirements
are computationally intensive.
48. IoT – Level 5 Example: Forest FireDetection
Detect forest fire in early stages to take action while the fire is still
Sensors measure the temperature, smoke, weather, slope of the earth,
wind speed, speed of fire spread, flame length
49. IoT Level-6
•A level-6 IoT system has multiple independent end
nodes that perform sensing and/or actuation and send
data to the cloud.
•Data is stored in the cloud and the application is
•The analytics component analyzes the data and
stores the results in the cloud database.
•The results are visualized with the cloud-based
•The centralized controller is aware of the status of
all the end nodes and sends control commands to
50. IoT – Level 6 Example: Weather MonitoringSystem
Wind speed and direction
Temperature (air, water, soil)
Snow depth Barometric pressure
51. IoT Issues and Challenges
• Cyber Attacks, Data Theft
• Controlling access and ownership of data.
• Integration Inflexibility
Legality and Rights
• Data Protection laws be followed, Data Retention and destruction
Economy and Development
• Investment Incentives, Technical Skill Requirement