�ELECTRICAL AND ELECTRONICS ENGINEERING

IOT & ITS APPLICATIONS

(18EC743)

Module-I

Internet of Things

Introduction

• Internet of Things (IoT) comprises things that have unique identities and are connected to the internet.

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• Existing devises, such as networked computers or 4G enabled mobile phones already have some form of unique identities and are also connected to the internet, the focus on IoT in the configuration, control and networking via the internet of devices or things , that are traditionally not associated with the Internet. These include devices such as thermostats, utility meters, a blue tooth- connected headset, irrigation pumps and sensor or control circuits for an electric car’s engine.

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• Experts forecast that by the year 2020 there will be a total of 50 billion devices/ things connected to the internet.

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Introduction

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• The scope of IoT is not limited to just connected things(Devices, appliance, machines) to the Internet.

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• Applications on IoT networks extract and create information from lower level data by filtering, processing , categorizing, condensing and contextualizing the data.

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• 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.

Definition and characteristics of IoT:

Definition: 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 .

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Characteristics:

• 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.

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• Self – Configuring: IoT devices may have self-Configuring capability allowing a large number of devices to work together to provide certain functionality .

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• Interoperable communication protocols:

IoT Devices may support a number of interoperable communication protocols and can communicate with other devices and also with the infrastructure.

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• 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.

• 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.

Physical Design of IoT

• 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

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 , humidity, light intensity.

Physical Design of IoT

IoT Protocol

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1. Link Layer

• 802.3 Ethernet
• 802.1- WI-FI
• 802.16 wiMAX
• 802.15.4 LR-WPAN
• 2G/3G/4G-Mobile Communication

2. Network / internet layer :

3. Transport layer

4. Application layer

Physical Design of IoT

• IoT Protocol

1. 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. Host on the same link exchange data packets over the link layer using the link layer protocol.
• Link layer determines how the packets are coded and signaled by the hardware device over the medium to which the host is attached.

802.3 Ethernet:

802.3 is a collections 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.

IoT Protocol

802.11- WI-FI:

IEEE 802.11 is a collections 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 wirless broadband and Standards, including extensive descriptions for the link layer also called WiMAX. Wimax standard provides a data rates from 1.5 Mb/s to 1Gb/s

802.15.4 LR-WPAN:

IEEE 802.15.4 is a collections of standard for low rate wireless personal area network(LR-WPAN). Basis for high level communication protocols such as Zigbee. LR-WPAN standards provide data rates from 40 k b/ s.

2G/3G/4G-Mobile Communication 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.

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IoT Protocol

2. Network / Internet layer :

The network layer are responsible for sending of IP datagrams 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.

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.

IPv6: It is the newest versions of internet protocol and successor to IPv4. IPv6 uses 128 bit address schemes that are lost total of 2*128 are 3.4* 10 38 address.

6LoWPAN: IPv6 over low power wireless personal area networks brings IP protocol to the low power device which have limited processing capability it operate in the 2.4 GHz frequency range and provide the data transfer rate off to 50 kb/s.

IoT Protocol

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3. Transport layer :

The Transport layer protocols provides end-to-end message transfer capability independent of the underlying network. The message transfer capability can be set up on connections, either using handshake or without handshake acknowledgements. Provides functions such as error control , segmentation, flow control and congestion control.

TCP: Transmission Control Protocol used by web browsers(along with HTTP and HTTPS), email(along with SMTP, FTP). Connection oriented and stateless protocol.

• IP Protocol deals with sending packets, TCP ensures reliable transmission of protocols in order. Avoids n/w congestion and congestion collapse.

UDP: User Datagram Protocol is connectionless protocol. Useful in time sensitive applications, very small data units to exchange. Transaction oriented and stateless protocol. UDP does not provide guaranteed delivery, ordering of messages and duplicate eliminations.

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IoT Protocol

4. Application Layer:

Defines how the applications interface with lower layer protocols to send data over the n/w. Enables process-to-process communication using ports.

• HTTP:

Hyper Text Transfer Protocol that forms foundation of WWW. Follow request response model Stateless protocol.

• CoAP:

Constrained Application Protocol for machine-to-machine (M2M) applications with constrained devices, constrained environment and constrained n/w. Uses client server architecture.

• Web Socket:

Allows full duplex communication over a single socket connection.

• MQTT:

Message Queue Telemetry Transport is light weight messaging protocol based

on publish-subscribe model. Uses client server architecture. Well suited for constrained

environment.

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• XMPP:

Extensible Message and Presence Protocol for real time communication and streaming XML data between network entities. Support client-server and server-server communication.

• DDS:

Data Distribution Service is data centric middleware standards for device-to-device or machine-to-machine communication. Uses publish-subscribe model.

• AMQP: Advanced Message Queuing Protocol is open application layer protocol for business messaging. Supports both point-to-point and publish-subscribe model.

LOGICAL DESIGN of IoT

Logical design of an IoT system refers to an abstract representation of the entities and process without going into low level specification of the implementations .

1) IoT Functional Blocks

2) IoT Communication Models

3) IoT Comm APIs

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1) IoT Functional Blocks: Provide the system the capabilities for identification, sensing, actuation, communication and management.

• Device: An IoT system comprises of devices that provide sensing, actuation, monitoring and control functions.
• Communication: the communication block handles the communication for IoT system.
• Services: An Iot system uses various types of IOT services such as services for device monitoring, device control services, data publishing services and services for device discovery.
• Management: Provides various functions to govern the IoT system.
• Security: Secures IoT system and providing functions such as authentication, authorization, message and context integrity and data security.
• Application: IoT application provide an interface that the users can use to control and monitor various aspects of IoT system.

2) IoT Communication Models:

a) Request-Response

b) Publish- Subscibe

c)Push-Pull

d) Exclusive Pair

1. Request-Response Model:

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Request response: Request-response is a Communications model in which the client sends request to the server and the server responds to the requests. when the server receives a request it decides how to respond, if it shows the data retrieved resources definitions for the response , and then send the response to the client. Access to response model is a stateless communication model and each request response per is independent of others the crime and server interactions in the request response model.

• Examples:
• When you send a spreadsheet to the printer,your spreadsheet program is the client.
• When you want to watch that youtube video on your smart phone, your web browser (or) youtube app is the client, requesting the video over that gaint of networks, the internet youtube webserver receives the request and responds by serving the video page to you. along with the other millions of video pages going to other millions of viewers world wide.

2) Publish-Subscibe Model:

• Involves publishers, brokers and consumers. Publishers are source of data. Publishers send 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 receives data for a topic from the publisher, it sends the data to all the subscribed consumers.

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• Examples: letters, emails

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3) Push-Pull Model:

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• Push pull is communication model in which the data producers push the data to queues and the consumers pull the data from the queues.

• Queues help in decoupling the messaging between the Producers and Consumers .

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• It also act as a buffer which helps in situations when there is a mismatch between the rate at which the produces push data and the rate at which the consumers pull the data

Examples:

• when we visit a website we saw a number of posts that published in a queue and according to our require ments we click on a post and start reading it.
• Lectures
• Email updates
• Voice mails
• Reports
• Contracts
• Documents
• Other examples are letters, voice mails, Meetings, workshops, video conferencing, training.

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Exclusive pair:

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• It is a bidirectional fully duplex communication model that uses a persistent connection between the client and server.

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• Here first set up a connection between the client and server and remains open until the client sends a close connection request the server.

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3) IoT Communication APIs:

a) REST based communication APIs(Request- Response Based Model)

b) Web Socket based Communication APIs(Exclusive Pair Based Model)

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1. REST based communication APIs:

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• Representational State Transfer(REST) is a set of

architectural principles by which we can design web services and web APIs that focus on a system resources and how resource states are addressed and transferred.

• The REST architectural constraints apply to the components, connectors and data elements. Fig. shows communication between client server with REST APIs.

Client-Server: The principle behind client-server constraint is the separation of concerns Separation allows client and server to be independently developed and updated.

Stateless: Each request from client to server must contain all the info. Necessary to understand the request, and cannot take advantage of any stored context on the server.

Cache-able: Cache constraint requires that the data within a response to a request be implicitly or explicitly labeled as cache-able or non-cacheable. If a response is cache-able, then a client cache is given the right to reuse that response data for later, equivalent requests.

Layered System: constraints the behavior of components such that each component cannot see beyond the immediate layer with which they are interacting.

User Interface: constraint requires that the method of communication between a client and a server must be uniform.

Code on Demand: Servers can provide executable code or scripts for clients to execute in their context. This constraint is the only one that is optional.

b) Web Socket Based Communication APIs:

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• Web Socket APIs allow bi-directional, full duplex communication between clients and servers.

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• Web Socket APIs follow the exclusive pair communication model.

IOT ENABLING TECHNOLOGIES:

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1)Wireless Sensor Network(WSN):

Comprises of distributed devices with sensors which are used to monitor the environmental and physical conditions. Zigbee is one of the most popular wireless technologies used by WSNs. WSNs used in IoT systems are described as follows:

• Weather Monitoring System: In which nodes collect temp, humidity and other data, which is aggregated and analyzed.
• Indoor air quality monitoring systems: to collect data on the indoor air quality and concentration of various gases.
• Soil Moisture Monitoring Systems: to monitor soil moisture at various locations.
• Surveillance Systems: Use WSNs for collecting surveillance data(motion data detection).
• Smart Grids : Use WSNs for monitoring grids at various points.
• Structural Health Monitoring Systems:

Use WSNs to monitor the health of structures(building, bridges) by collecting vibrations from sensor nodes deployed at various points in the structure.

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2) Cloud Computing:

Services are offered to users in different forms.

• Infrastructure-as-a-service(IaaS):provides users the ability to provision computing and storage resources. These resources are provided to the users as a virtual machine instances and virtual storage.

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• Platform-as-a-Service(PaaS): provides users the ability to develop and deploy application in cloud using the development tools, APIs, software libraries and services provided by the cloud service provider.

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• Software-as-a-Service(SaaS): provides the user a complete software application or the user interface to the application itself.

3) Big Data Analytics: Big data is defined as collections of data set whose volume, velocity in terms of its temporal variations )or variety, is so large that it is difficult to store, manage, process and analyze the data using traditional database and data processing tools.

Some examples of big data generated by IoT are Sensor data generated by IoT systems.

• Machine sensor data collected from sensors established in industrial and energy systems.
• Health and fitness data generated IoT devices.
• Data generated by IoT systems for location and tracking vehicles.
• Data generated by retail inventory monitoring systems.

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4) Communication Protocols:

• form the back-bone of IoT systems and enable network connectivity and coupling to applications.

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• Allow devices to exchange data over network.

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• Define the exchange formats, data encoding addressing schemes for device and routing of packets from source to destination.

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• It includes sequence control, flow control and retransmission of lost packets.

5) Embedded Systems: is a computer system that has computer hardware and software embedded to perform specific tasks. Embedded System range from low cost miniaturized devices such as digital watches to devices such as digital cameras,Point of sale terminals, vending machines, appliances etc.

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IoT levels and Deployment Templates

In this section we define various levels of IoT systems with increasing completely. IoT system comprises of the following components:

1. Device : An IoT device allow identification, remote sensing, actuating and remote monitoring capabilities.

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2. Resources : Resources are software components on the device for accessing and storing information for controlling actuator connected to the device also include software components that enable network access for the device .

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3. Controller service: Controller Service is a native service that runs on the device and interact with the web services. Controller service sends data from the device to the web service receive command from the application from controlling the device.

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4. Data base: Data base can be either local or in the cloud and stores the data generated by the IoT device.

5. Web service: Serve as a link between the device, application database and analysis components. Web Services can be implemented using HTTP and REST principles or using website protocol.

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Analysis component: The analysis component is responsible for analyzing the IoT data and generate results in the form which are easy for the user to understand. Analysis of IoT data can be performed either locally or in the cloud. Analyzed results are stored in the local or cloud database.

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Application: IoT applications provide an interface that the user can use to control and monitor various aspects of the IoT system. Applications also allow user to view the system status and view the processed data.

1. IoT Level1:
1. System has a single node that performs sensing and/or actuation, stores data, performs analysis and host the application as shown in fig.
2. Suitable for modeling low cost and low complexity solutions where the data involved is not big and analysis �requirement are not computationally intensive.
3. Example of Level 1 IoT system for home automation.

2) IoT Level2:

• It has a single node that performs sensing and/or actuating and local analysis as shown in fig.
• Data is stored in cloud and application is usually cloud based.
• Level2 IoT systems are suitable for solutions where data are involved is big, however the primary analysis requirement is not computationally intensive and can be done locally itself.
• Example of Level2 IoT system for Smart Irrigation.

IoT Level3:

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• System has a single node. Data is stored and analyzed in the cloud application is cloud based as shown in fig.
• Level3 IoT systems are suitable for solutions where the data involved is big and analysis requirements are computationally intensive.
• An example of IoT level3 system for tracking package handling.

4) IoT Level4:

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• System has multiple nodes that perform local analysis. Data is stored in the cloud and application is cloud based as shown in fig.
• Level4 contains local and cloud based observer nodes which can subscribe to and receive information collected in the cloud from IoT devices.
• An example of a Level4 IoT system for Noise Monitoring.

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IoT Level5:

• System has multiple end nodes and one coordinator node as shown in fig.
• The end nodes that perform sensing and/or actuation. Coordinator node collects data from the end nodes and sends to the cloud.Data is stored and analyzed in the cloud and application is cloud based. Level5 IoT systems are suitable for solution based on wireless .
• sensor network, in which data involved is big and analysis requirements are computationally intensive.
• An example of Level5 system for Forest Fire Detection.

6) IoT Level6:

• System has multiple independent end nodes that perform sensing and/or actuation and sensed data to the cloud.
• Data is stored in the cloud and application is cloud based as shown in fig.
• The analytics component analyses the data and stores the result in the cloud data base. The results are visualized with cloud based application.
• The centralized controller is aware of the status of all the end nodes and sends control commands to nodes.
• An example of a Level6 IoT for Weather Monitoring System.