IOT NOTES BASED ON THE ENGINEERING ACADEMICS
- 1. Module 1: Introduction to IoT • Introduction to IoT ‐ Defining IoT, ‐ Characteristics of IoT, ‐ Physical design of IoT, ‐ Logical design of IoT, ‐ Functional blocks of IoT, ‐ Brief review of applications of IoT. • Smart Object ‐ Definition, ‐ Characteristics and Trends • Self-learning Topics: Hardware and software development tools for - Arduino, NodeMCU, ESP32, Raspberry Pi, for implementing internet of things, SimulatorsCircuit.io, Eagle, Tinkercad PMModak SSPMCOE 1
- 2. 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 environments. PMModak SSPMCOE 2
- 3. Characteristics of IoT 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. IP address, 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. PMModak SSPMCOE 3
- 4. Physical Design 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 application back-ends for processing the data, or ‐ Perform some tasks locally and other tasks within the IoT infrastructure, based on temporal and space constraints (s (i.e. Memory, processing calibrators, communication latencies and speed and deadlines). PMModak SSPMCOE 4
- 5. Generic block diagram of an IoT Device • An IoT device may consist of several interfaces for connections to other devices, both wired and wireless. • I/O interfaces for sensors • Interfaces for Internet connectivity • Memory and storage interfaces • Audio/video interfaces. PMModak SSPMCOE 5
- 6. Physical Design of IoT: IoT Protocols PMModak SSPMCOE 6
- 7. 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. IoT Protocols: Link Layer PMModak SSPMCOE 7
- 8. • 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. • 802.1- WI-FI: IEEE 802.3 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 from 1.5 Mb/s to 1Gb/s the recent update provides data rates of hundred megabits per second for mobile station. • 802.15.4 LR-WPAN: IEEE 802.1 5.4 is a collections of standard for low rate wireless personal area network(LRWPAN).These standard 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. IoT Protocols: Link Layer PMModak SSPMCOE 8
- 9. • 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. • 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 232 address. As more and more devices got connected to the internet. The IPv4 has succeeded by IPv6. ‐ IPv6: It is the newest versions of internet protocol and successor to IPv4. IPv6 uses 128 bit address schemes that are lost total of 2128 are 3.4* 1038 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 Protocols: Network / internet layer PMModak SSPMCOE 9
- 10. IoT Protocols: 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 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 .The flow control capability ensures that the rate at which the sender since the data is now to too to high for the receiver to process. • UDP: User Datagram Protocol 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. PMModak SSPMCOE 10
- 11. IoT Protocols: Application layer • Application layer protocol define 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. • Application layer protocol enable process-to-process connection using ports. • Protocols: HTTP, COAP, Websocket, MQTT, XMPP, DDS, AMQP PMModak SSPMCOE 11
- 12. IoT Protocols: Application layer 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 other request 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, however it runs on the top of the UDP instead of TCP CoAP uses a client –server architecture where client communicate with server using connectionless datagrams. • It is designed to easily interface with HTTP. Like HTTP, CoAP supports method such as GET, PUT, DELETE . PMModak SSPMCOE 12
- 13. IoT Protocols: Application layer WebSocket: • WebSocket protocol allows full duplex communication over a single socket connections for sending message between client and server. • 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 MQTT is well suited for constrained and environments where devices have limited processing and memory resources and the network bandwidth is low. PMModak SSPMCOE 13
- 14. IoT Protocols: Application layer 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. XMPP supports both client to server and server – client communication path. DDS: Data distribution service is the date centric middleware standard for device-to- device or 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 to exchange which then distribute message copies to queues. PMModak SSPMCOE 14
- 15. Logical Design of IoT • Logical design of an IoT system refers to an abstract representation of the entities and processes without going into the low-level specifics of the implementation. • An IoT system comprises of a number of functional blocks that provide the system the capabilities for identification, sensing, actuation, communication, and management. PMModak SSPMCOE 15
- 16. The functional blocks • 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 device monitoring ,device control services ,data publishing services and services for device 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. PMModak SSPMCOE 16
- 17. Applications of IoT 1) Home 2) Cities 3) Environment 4) Energy 5) Retail 6) Logistics 7) Agriculture 8) Industry 9) Health & Life Style PMModak SSPMCOE 17
- 18. IoT communication model • Request Response Communications Model • Publish – Subscribe Communication Model • Push Pull Communication Model • Exclusive Pair Communication Model PMModak SSPMCOE 18
- 19. Request-Response communication model • Request-Response is a 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 representations, prepares the response, and then sends the response to the client. PMModak SSPMCOE 19
- 20. Publish-Subscribe communication model • 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 receives data for a topic from the publisher, it sends the data to all the subscribed consumers. PMModak SSPMCOE 20
- 21. Push-Pull communication model • 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 consumers pull data. PMModak SSPMCOE 21
- 22. Exclusive Pair communication model • Exclusive Pair is a bidirectional, fully duplex communication model that uses a persistent connection between the client and server. • Once the 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. PMModak SSPMCOE 22
- 23. IoT communication APIs • REST- based communication API: • WebSocket based communication API: PMModak SSPMCOE 23
- 24. REST-based Communication APIs • Representational State Transfer (REST) is a set of architectural principles by which you can design web services and web APIs that focus on a system’s resources and how resource states are addressed and transferred. • REST APIs follow the request- response communication model. • The REST architectural constraints apply to the components, connectors, and data elements, within a distributed hypermedia system. PMModak SSPMCOE 24
- 25. WebSocket-based Communication APIs • WebSocket APIs allow bi- directional, full duplex communication between clients and servers. • WebSocket APIs follow the exclusive pair communication model PMModak SSPMCOE 25
- 26. Smart Objects: Introduction • Smart objects are, quite simply, the building blocks of IoT. • They are what transform everyday objects into a network of intelligent objects that are able to learn from and interact with their environment in a meaningful way. • The real power of smart objects in IoT comes from being networked together rather than being isolated as standalone objects. • This ability to communicate over a network has a multiplicative effect and allows for very sophisticated correlation and interaction between disparate smart objects. • Example ‐ If a sensor is a standalone device that simply measures the humidity of the soil, it is interesting and useful, but it isn’t revolutionary. If that same sensor is connected as part of an intelligent network that is able to coordinate intelligently with actuators to trigger irrigation systems as needed based on those sensor readings, we have something far more powerful. ‐ Extending that even further, imagine that the coordinated sensor/actuator set is intelligently interconnected with other sensor/actuator sets to further coordinate fertilization, pest control, and so on—and even communicate with an intelligent backend to calculate crop yield potential. ‐ This now starts to look like a complete system that begins to unlock the power of IoT and provides the intelligent automation we have come to expect from such a revolutionary technology. PMModak SSPMCOE 26
- 27. Smart Objects: A Definition • A Definition Historically, the definition of a smart object has been a bit nebulous because of the different interpretations of the term by varying sources. • To add to the overall confusion, the term smart object, despite some semantic differences, is often used interchangeably with terms such as smart sensor, smart device, IoT device, intelligent device, thing, smart thing, intelligent node, intelligent thing, ubiquitous thing, and intelligent product. • In order to clarify some of this confusion, A smart object, is a device that has, at a minimum, the following four defining characteristics. PMModak SSPMCOE 27
- 28. Smart Objects: A Definition • Defining characteristics 1. Processing unit: - A smart object has some type of processing unit for acquiring data, processing and analyzing sensing information received by the sensor(s), coordinating control signals to any actuators, and controlling a variety of functions on the smart object, including the communication and power systems. - The specific type of processing unit that is used can vary greatly, depending on the specific processing needs of different applications. - The most common is a microcontroller because of its small form factor, flexibility, programming simplicity, ubiquity, low power consumption, and low cost. PMModak SSPMCOE 28
- 29. Smart Objects: A Definition Defining characteristics 2. Sensor(s) and/or actuator(s): - A smart object is capable of interacting with the physical world through sensors and actuators. - A sensor learns and measures its environment, whereas an actuator is able to produce some change in the physical world. - A smart object does not need to contain both sensors and actuators. In fact, a smart object can contain one or multiple sensors and/or actuators, depending upon the application. PMModak SSPMCOE 29
- 30. Smart Objects: A Definition Defining characteristics 3. Communication device: - The communication unit is responsible for connecting a smart object with other smart objects and the outside world (via the network). - Communication devices for smart objects can be either wired or wireless. - In IoT networks smart objects are wirelessly interconnected for a number of reasons, including cost, limited infrastructure availability, and ease of deployment. - There are myriad different communication protocols for smart objects. PMModak SSPMCOE 30
- 31. Smart Objects: A Definition Defining characteristics 4. Power source: - Smart objects have components that need to be powered. - The most significant power consumption usually comes from the communication unit of a smart object. But the other three smart object building blocks, the power requirements vary greatly from application to application. - Typically, smart objects are limited in power, are deployed for a very long time, and are not easily accessible. - This combination, especially when the smart object relies on battery power, implies that power efficiency, judicious power management, sleep modes, ultra-low power consumption hardware, and so on are critical design elements. - For long-term deployments where smart objects are, for all practical purposes, inaccessible, power is commonly obtained from scavenger sources (solar, piezoelectric, and so on) or is obtained in a hybridized manner, also tapping into infrastructure power. PMModak SSPMCOE 31
- 32. Characteristics of a Smart Object PMModak SSPMCOE 32
- 33. Trends in Smart Objects • Size is decreasing: There is a clear trend of ever-decreasing size. Some smart objects are so small they are not even visible to the naked eye. This reduced size makes smart objects easier to embed in everyday objects. • Power consumption is decreasing: The different hardware components of a smart object continually consume less power. This is especially true for sensors, many of which are completely passive. Some battery powered sensors last 10 or more years without battery replacement. • Processing power is increasing: Processors are continually getting more powerful and smaller. This is a key advancement for smart objects, as they become increasingly complex and connected. • Communication capabilities are improving: It’s no big surprise that wireless speeds are continually increasing, but they are also increasing in range. IoT is driving the development of more and more specialized communication protocols covering a greater diversity of use cases and environments. • Communication is being increasingly standardized: There is a strong push in the industry to develop open standards for IoT communication protocols. In addition, there are more and more open source efforts to advance IoT. PMModak SSPMCOE 33