IOT Unit I - iot notes unit1 PDF

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Name of the Teacher: Geetanjali yatnalkar

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Class: TYIT

Subject: Internet of Things

Paper: USIT502

Internet Of Things UNIT I Iot-An Overview Designed principles for connected devices • Internet Principles •

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Chapter 1 The Internet of Things: An Overview Embedded system

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

Embedded System is one that has computer hardware with software embedded in it as one of its important components.



An embedded system is a special-purpose computer system designed to perform one or a few dedicated / Specific functions

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Embedded system is any device that includes a programmable computer but is not itself a general-purpose computer.

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An application specific electronic sub-system which is completely encapsulated by the main system it belongs to

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Components of Embedded System • CPU (Microcontroller) • Firmware (Embedded software) • Memory (RAM , ROM) • FPGA / ASIC • Sensors (Temperature , pressure etc) • Actuators(Relays , Drivers etc) • ADC and DAC • User interface • Backup and Safety • External Environment

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Future – Embedded System •

Internet of Things

• Cyber Physical System • Intelligent System • Wireless Sensor Networks • Mechatronics • Automobiles • Aerospace • Networking • Digital Signal Processing

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Internet of Things Definition 1 The Internet of Things, also called The Internet of Objects -wireless network between objects, usually the network will be wireless and selfconfiguring, such as household appliances. 2 By embedding short-range mobile transceivers into a wide array of additional gadgets and everyday items, enabling new forms of communication between people and things, and between things themselves Physical object +

Controllers Sensors, actuators +

Internet =

Internet of Things

Q May2019- Define and explain Internet of Things. 7

IoT means a “Smart World”

How IOT works https://youtu.be/Q3ur8 wzzhBU

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Contd..

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

IoT means “from anytime, anyplace connectivity for anyone, and for anything”.

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With continuous advancements in sensor and networking technology, the Internet of Things (IoT) is taking shape as an everpresent always-on global computing network

Future of IOT

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Flavour of IOT Vision

Things like wearable watches,alarm clocks,home devices etc.become smart and function like living entities.  By sensing,communicating through embedded devices 



Interacts with remote objects –servers,clouds applications,services or persons through internet

Ex, Smart watch,smart bus,smart home,smart umbrellaThe alarm rings-you see that its 5 min later than usual wake up time The clock has checked train time online and your train is delayed,so lets you sleep in a little longer



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Enchanted object 

Embedding ordinary things with extraordinary power

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Enchanted object are based on everday technologies but with magical features and added capabilities

It implies intelligence greater than strictly necessary to carry out taskfor which they are designed. Q.Dec 2018 “Any sufficiently advanced technology is indistinguishable From magic”Discuss

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https://youtu.be/VFW25-jJ3L8

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

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https://youtu.be/6UgM9-JCfUw smart home

Who is making Internet of Things 

Person/artist-



Designer/engineer-

Designer can make ugly prototype into things of beauty, more sophisticated product Engineer required –solve technical challenges  

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Software developer Hacker

Chapter 2 Design principles for connected devices 

Calm and ambient technology-Mark Weiser at Xerox PARC in 1990

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Ubiquitous or ubicomp-ambient computing- something acting in background

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Calm –don’t demand for attention but provides useful information

to attract the attention Live wire-First IOT device created by Natalie Jermijenko- Xerox PARC also known as Dangling string Noisy side effects leads to a better technology. Q.Dec 2018 Explain Calm and ambient technology using example of ‘live wire’. 16

Q.May 2019 Write a note on Calm and Ambient Technology

Magic as Metaphor 

Metaphore of IOT object-How IOT (smart) objects are not different from a magic

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Metaphores are the key of IOT

1.Acceptance from society- ex. Windows vista,window 8,Motorola phone,pager devices 2. Portable internet terminalStretch normal boundaries of a product too far with advance technology 3.Ambient Devices-Enchanted object Ex.Smart umbrella 4. IOT as a Global Neural Network Focuses on alternate capacities for data processing and physical action 17

Normalcy field 

Technology Blogger- V.Rao

We lives in past and don’t see the present Q. Dec 2018-What is “manufactured normalcy field”? Explain

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Privacy and Keeping secrets 

Balance security and trust carefully

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Keeping secrets

“Don’t share more than you need to provide the service” 

Confidential data

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Prove identity and verify messages

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Encryption

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Secure data access

Q. May 2019 Discuss the issue of Privacy in IOT

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Whose Data is it Anyway? 

Whose data is being gathered?

Ex. Camera deployed in an advertising hoarding Adam Greenfield- “Data subjects”

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Web thinking for connected Devices 

Job Postel’s law

Be careful when designing or building anything which is interacting with other services ,specially when you aren’t building the components with which your system interacts

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Small pieces ,loosely joined

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Design thing/piece well which will not depend too much on tight integration with separate components it uses

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Generalised system

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Reuse and repurpose to add new capabilities

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Use existing standards and protocols

First class citizens on the Internet 

An extension of the concept of loose coupling is to strive to make your devices first-class citizens on the Internet.

Where possible, use the same protocols and conventions that the rest of the Internet uses. If not, find the solution Ex. Wireless Application Protocol (WAP) for mobile handset

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Graceful Degradation 

Endpoints with a massively disparate and diverse range of capabilities.

Hence building services which can be used by all of them a nearly impossible task. However, a number of design patterns have evolved to solve the problem 

Backward compatibility



The HTML format does this by stating that any client should ignore any tags (the text inside the ) that it doesn’t understand, so newer versions can add new tags without breaking older



Graceful degradation –

Degrade levels in device/system-Better than nothing 24

AFFORDANCES in IOT 

Strong clues to the operations of things

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Affordances provide strong clues to the operations of things.

“ Knobs are for turning. Slots are for inserting things into. Balls are for throwing or bouncing.” Know just by looking: no picture, label. Complex things may require explanation, but simple things should not. When simple things need pictures, labels, or instructions, the design has failed. —The Design of Everyday Things, MIT Press, 1998 

Enhance existing affordances

Ex. Use USB connector than round connector 25

Chapter 3 Internet Principles Overview 

Origin of Internet late 1960 and early 1970s’

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Advanced Research Project Agency Network’(ARPANET) The first workable prototype of the Internet

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Global interconnected network

Internet communication

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Internet /Internetworking Protocol (IP) 

IP- Transmission mechanism used by TCP/IP protocols

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IP transports data in packets called Datagrams

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No error checking or tracking and no facility to reorder datagrams at destination Still IP provides basic transmission functions

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IP protocol suite

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IP protocol suite TCP/IP 

Network model consist of layers. Each layer –specific functionality Within layers –protocols to implement specific task

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

Protocols- set of rules or language like packet format, type and size

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Layer is a collection of protocols

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TCP simplest transport protocol on the Internet

Contd.. 

TCP is built on top of the basic IP protocol and adds sequence numbers, acknowledgements, and retransmissions.

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Link layer manage the transfer of bits of information across a network link.

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Internet Layer IP

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Transport Layer-TCP-UDP More sophisticated control of the messages passed. Delivers message from a process to another process

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Application layer -contains the protocols that deal with fetching web pages, sending emails, and Internet telephony

UDP –User Datagram Protocol

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No handshake or retransmission occurs, nor is there any delay to wait for messages in sequence.

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The lack of overhead, however, makes UDP useful for applications such as streaming data, which can cope with minor errors but doesn’t like delays. Voice over IP (VoIP)—computer-based telephony, such as Skype

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UDP is also the transport for, DNS and DHCP which relate to discovery and resolution of devices on the network

IP addresses

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

IP addresses are numbers.

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In (IPv4), almost 4.3 billion IP addresses are possible— 4,294,967,296 to be precise, or 232

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IP addresses as four 8-bit numbers separated by dots (from 0.0.0.0 to 255.255.255.255

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8.8.8.x — One of several IP ranges assigned to Google.

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192.168.x.x — A range assigned for private networks. Your home or office network router may well assign IP addresses in this range. 10.x.x.x — Another private range.

Domain Name System (DNS) 

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(DNS) helps to navigate the Internet

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Phonebook of Internet- google.com, bbc.co.uk, makeinindia.com

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14 generic domain.

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Domain transfers information to individual machine or services

Static and Dynamic IP address 

Static IP address doesn't change

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Assigned by ISP

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Ranges of different sizes

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Class A — From 0.x.x.x Class B — From 128.0.x.x Class C — From 192.0.0.x

Dynamic IP address

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A dynamic IP address is an IP address that changes from time to time

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IP address from the network itself using the Dynamic Host Configuration Protocol (DHCP)

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It is a temporary “lease” which is selected dynamically according to which addresses are currently available

Differences Between Static and Dynamic IP address

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The static IP is fixed which means it could not be changed until the user wants to change it. Conversely, the Dynamic IP changes frequently and each time the user connects to a network.

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Static IP is configured by the ISP (Internet Service Provider) while dynamic IP can be configured using DHCP.

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The associated risk of website hacking is large in static IP address as it is always constant. As against, there is low risk regarding dynamic IP address.

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When the device is configured with static IP address, it can be tracked. Whereas in case of dynamic IP address the tracking of the device is difficult as the IP address is always changing.

IPV6 

To overcome shortage of IPV4 address IPV6 is designed

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IPV6 -128 bits or 16 bytes long, specifies colon hex notation

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Example of IPv6-- FE80:CD00:0000:0CDE:1257:0000:211E:729C

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IPv6 address is split into two parts, a network and a node component.

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The network component - first 64 bits of the address and is used for routing.

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The node component - later 64 bits and is used to identify the address of the interface,derived from the physical, or MAC, address using the IEEE’s EUI-64 format.

IPv6 and Powering Devices

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Explosion in the number of Internet of Things devices will almost certainly need IPv6 in the future. But we also have to consider the power consumption of all these devices.

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vision of 6LoWPAN, an IETF working group proposing solutions for “IPv6 over Low power Wireless Personal Area Networks”, using technologies such as IEEE 802.15.4.

MAC address- Media Access Control.

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MAC address - the final address on a physical envelope

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used to differentiate different machines on the same physical network so that they can exchange packets.

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It is a 48-bit number, usually written as six groups of hexadecimal digits, separated by colons—for example: 01:23:45:67:89:ab

TCP and UDP Ports

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

The most common transport protocols that use port numbers are the TCP and UDP

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A port number is always associated with an IP address of a host and the type of transport protocol used for communication.

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AN EXAMPLE: HTTP PORTS

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When browser requests an HTTP page, it usually sends that request to port 80. The web server is “listening” to that port and therefore replies to it.

Contd… If HTTP message to a different port, one of several things will happen:  

“RST” packet (a control sequence resetting the TCP/IP connection) Firewall lets the request simply hang instead of replying

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“restricted ports”.

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Garbage response

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Ports 0–1023 are “well-known ports”, and only a system process or an administrator can connect to them.

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Ports 1024–49151 are “registered”, so that common applications can have a usual port number. However, most services are able to bind any port number in this range.

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Other Common Ports OTHER COMMON PORTS ◾ 80 HTTP ◾ 8080 HTTP (for testing servers) ◾ 443 HTTPS ◾ 22 SSH (Secure Shell) ◾ 23 Telnet ◾ 25 SMTP (outbound email) ◾ 110 POP3 (inbound email) ◾ 220 IMAP (inbound email) All of these services are in fact application layer protocols.

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Application layer protocols HTTP The HyperText Transfer Protocol,

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most widely used Application layer protocol in the world today.

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Purpose - provide a lightweight protocol for the retrieval of HyperText Markup Language (HTML) and other documents from Web sites throughout the Internet.

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Each time you open a Web browser to surf the Internet, you are using HTTP over TCP/IP.

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Used to not only fetch hypertext documents, but also images and videos or to post content to servers,

HTTPS: ENCRYPTED

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

In HTTP if the conversation happened in binary, an attacker could write a tool to translate the format into something readable, the conversation isn’t encrypted.

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The HTTPS protocol is just a mix-up of plain old HTTP over the Secure Socket Layer (SSL) protocol.

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An HTTPS server port (usually 443)

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HTTPS established an encrypted link between the browser and the web server using the Secure Socket Layer (SSL) or Transport Layer Security (TLS) protocols. TLS is the new version of SSL.

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The https is essentially http over SSL. SSL establishes an encrypted link using an SSL certificate which is also known as a digital certificate.

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Contd.. 

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It is a protocol for securing the communication between two systems e.g. the browser and the web server.

http

https

Transfers data in hypertext (structured text) format

Transfers data in encrypted format

Uses port 80 by default

Uses port 443 by default

Not secure

Secured using SSL technology

Starts with http://

Starts with https://

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http://zai.lecturer.pens.ac.id/Kuliah/Komunikasi%20Data/Buku%20Re ferensi/Data%20Communications%20and%20Networking%20By%20B ehrouzThatttnk you%20A.Forouzan.pdf

Thank you 48

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