IoT ch1

IoT Communication Models

-Request-Response -Publish-Subscribe -Push-Pull -Exclusive-Pair

Link layer protocols for IoT:

802.3 - Ethernet 802.11 - WiFi 802.16 - WiMax. 802.15.4 - LR-WPAN 2G/ 3G/ 4G - Mobile Communication (cellular networks)

Embedded Systems

A computer system that has computer hardware and software embedded to perform specific tasks

What is 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

Controller Service

A native service that runs on the device and interacts with the web services Sends data from the device to the web service and receives commands back to control the device

Cloud Computing

A transformative computing paradigm that involves delivering applications and services over the Internet

IoT Protocols

Application layer HTTP, CoAp, Websocket ,XMPP ,DDS , MQTT, AMQP Transport layer TCP, UDP Network layer IPv4, IPv6, 6LoWPAN Link layer Ethernet, WiFi, LR-WPAN,WiiMax, LTE-cellular

Application Layer

Application layer protocols define how the applications interface with the lower layer protocols to send the data over the network The application data is encoded by the application layer protocol and encapsulated in the transport layer protocol which provides connection or transaction oriented communication over the network

Big Data Analytics

Big data is defined as collections of data sets whose volume, velocity or variety is so large that it is difficult to store, manage, process and analyze the data using traditional databases and data processing tools

Exclusive-Pair model

Client and server

Request-Response model

Client, Server and Resources Client: sends requests to the server Server: receives requests from client, process requests , looks up fetches resources, prepares response and sends response to client

IoT Level-1 System

Composed of a single device that performs sensing and actuation, stores data locally, performs analysis and hosts the application

IoT Level-3 System

Composed of a single node Data is stored and analyzed in the cloud and application is cloud-based

IoT Level-2 System

Composed of a single node that performs sensing and actuation and local analysis Data is stored in the cloud and application is usually cloud-based

IoT Level-5 System

Composed of multiple end nodes and one coordinator node End nodes perform sensing and actuation Coordinator node collects data from end nodes and sends them to cloud Data is stored and analyzed in the cloud and application is cloud-based

IoT Level-6 System

Composed of multiple independent end nodes that perform sensing and actuation and send data to the cloud Data is stored in the cloud and application is cloud-based The analytics component analyzes the data and stores the results in the cloud database The results are visualized with the cloud-based application The centralized controller is aware of the status of all end nodes and sends control commands to the nodes

IoT Level-4 System

Composed of multiple nodes that perform local analysis Data is stored in the cloud and application is cloud-based Local and cloud-based observer nodes are used to receive information collected from loT devices Observer nodes can process information and use it for various applications However, they do not perform any control functions

Physical Design of IoT:

Connectivity: USB host, Ethernet Processor: CPU Graphics: GPU Memory interfaces: NAND/NOR, DDR1,DDR2, DDR3 I/O interfaces: UART,SPI,I2C,CAN Storage interfaces: SD,MMC,SDIO Audio/Video interfaces: HDMI, 3.5mm audio, RCA video

How Push-Pull model Works?

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

The IoT is constructed from the following components:

Device Resources -Software Application Analysis Component Database Web Service Controller Service

Wireless Sensor Networks (WSNs)

Distributed devices with sensors which are used to monitor the environmental and physical conditions

Unique Identity:

Each IoT device has a unique identity and a unique identifier (such as an IP address or a URI) IoT systems may have intelligent interfaces that allow communication with users and the environmental contexts These interfaces allow users to query the devices, monitor their status, and control them remotely

How Exclusive-Pair model works?

Exclusive Pair is a bi-directional 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

IoT Level-5 System Example

Forest Fire Detection Multiple nodes placed in different locations for monitoring temperature, humidity, and CO2 levels in a forest The end nodes are equipped with various sensors (such as temperature, humidity and C02) The coordinator node collects the data from the end nodes and acts as a gateway that provides Internet connectivity to the loT system The controller service on the coordinator device sends the collected data to the cloud The data is stored in a cloud database The analysis of data is done in the computing cloud to aggregate the data and make predictions A cloud-based application is used for visualizing the data

IoT Level-1 System Example

Home Automation The system consists of a single node that controls lights and appliances in a home remotely The device interfaces with the lights and appliances using electronic relay switches The status information of each light or appliance is maintained in a local database REST services deployed locally allow retrieving and updating the state of each light or appliance in the status database The controller service continuously monitors the state of each light or appliance (by retrieving state from the database) and triggers the relay switches accordingly The application which is deployed locally has a user interface for controlling the lights or appliances Since the device is connected to the Internet, the application can be accessed remotely as well

An IoT device consists of several interfaces for connections to other devices

I/O interfaces for sensors Interfaces for Internet connectivity Memory and storage interfaces Audio/video interfaces

Network/Internet Layer Protocols for IoT:

IPv4: uses a 32-bit address (supports a total of 4,294,967,296 addresses) IPv6: uses a 128-bit address (supports a total of 3.4 x 1038 addresses) 6LoWPAN (IPv6 over Low power WPAN): Brings IP protocol to the low-power devices which have limited processing capability

Information

Information is inferred from data by filtering, processing, categorizing, condensing, and contextualizing data

Integrated into Information Network:

IoT devices are integrated into the information network so that they communicate with other systems IoT devices can be discovered in the network and have the capability to describe themselves to other devices or user applications Integration into the information network helps in making IoT systems "smarter" due to the collective intelligence of the individual devices in collaboration with the infrastructure

Interoperable Communication Protocols:

IoT devices can communicate with other devices and also with the infrastructure

Dynamic & Self-Adapting:

IoT devices can dynamically adapt with the changing contexts and take actions based on their operating conditions, user's context, or sensed environment For example: surveillance cameras can switch from lower resolution to higher resolution modes when any motion is detected and alert nearby cameras to do the same

Self-Configuring:

IoT devices can work together to provide certain functionality These devices have the ability to configure themselves, setup the networking, and fetch latest software upgrades with minimal human intervention

Knowledge

Knowledge is inferred from information by organizing and structuring information and is put into action to achieve specific objectives

Link Layer

Link layer protocols determine how the data is physically sent over the network's physical layer or medium The scope of the link layer is the local network connection to which the host is attached Hosts on the same link exchange data packets over the link layer using link layer protocols

IoT Level-4 System Example

Noise Monitoring The system consists of multiple nodes placed in different locations for monitoring noise levels in an area The nodes are independent of each other and equipped with sound sensors Each node runs its own controller service that sends the data to the cloud The data is stored in a cloud database Analysis of data (collected from several nodes) is done in the cloud A cloud-based application is used for visualizing the aggregated data

Transport Layer

Provide end-to-end message transfer capability independent of the underlying network Message transfer capability can be set up on connections, either using handshakes (TCP) or without handshakes/acknowledgements (UDP)

Publish-Subscribe model

Publisher, Broker and consumer-n Publisher: sends messages to the topics Broker: categorizes different topic to suite different consumers

Push-Pull model

Publisher, Queues and Consumer-n Publisher send topics to the queues Messages pushed to queues Then Messages are pulled from the queues to be sent to the consumers

How Publish-Subscribe model works?

Publishers are the source of data Publishers send the data 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

IoT Communication APIs

REST-based communication API WebSocket-based communication API

Data

Raw and unprocessed data obtained from IoT devices or systems

Network/Internet Layer

Responsible for sending IP datagrams from source network to destination network Performs the host addressing and packet routing

IoT Level-2 System Example

Smart Irrigation The system consists of a single node that monitors the soil moisture level and controls the irrigation system The device used in this system collects soil moisture data from sensors The controller service continuously monitors the moisture levels If the moisture level drops below a threshold, the irrigation system is turned on For controlling the irrigation system actuators (like solenoid valves) can be used The controller also sends the moisture data to the computing cloud A cloud-based REST web service is used for storing and retrieving moisture data from the cloud database A cloud-based application is used for visualizing the moisture levels over a period of time, which can help in making decisions about irrigation schedules

How Request-Response model works

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

IoT Level-3 System Example

Tracking Package Handling The system consists of a single node (for a package) that monitors the vibration levels for a package being shipped The device in this system uses accelerometer and gyroscope sensors for monitoring vibration levels The controller service sends the sensor data to the cloud in real-time using a WebSocket service The data is stored in the cloud and also visualized using a cloud-based application The analysis components in the cloud can trigger alerts if the vibration levels become greater than a threshold Moreover, cloud based applications can subscribe to the sensor data feeds for viewing the real-time data

IoT Level-6 System Example

Weather Monitoring The system consists of multiple nodes placed in different locations for monitoring temperature, humidity and pressure in an area End nodes are equipped with various sensors (such as temperature, pressure, and humidity) End nodes send the data to the cloud in real-time Data is stored in a cloud database Data analysis is done in the cloud to aggregate the data and make predictions A cloud-based application is used for visualizing the data

IoT is enabled by several technologies

Wireless Sensor Networks Cloud computing Big Data analytics Embedded systems Security protocols and architectures Communication protocols Web services Mobile Internet Semantic search engines

Web services serve as

a link between the IoT device, application, database and analysis components

Software components on the IoT device is for

accessing, processing, and storing sensor information, or controlling actuators connected to the device

In Push-Pull model Queues

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 at which the consumers pull data

When the broker receives data for a topic from the publisher, it sends the data to

all the subscribed consumers

IoT applications provides

an interface that the users can use to control and monitor various aspects of the IoT system Applications allow users to view the system status and view the processed data

Analysis Component Responsible for

analyzing the IoT data and generate results in a form easy users to understand Analysis of IoT data can be performed either locally or in the cloud Analyzed results are stored locally or in the cloud

Consumers subscribe to the topics which are managed by the

broker

Publishers are not aware of the

consumers

Datagrams

contain the source and destination addresses which are used to route them across multiple networks

Big data analytics involves several steps

data cleansing, data munging (or wrangling), data processing and visualization

Queues help in

decoupling the messaging between the producers and consumers

Web services can be

either implemented as REST service or WebSocket service

The transport layer provides functions such as

error control, segmentation, flow control and congestion control

Port numbers used

for application addressing (for example port 80 for HTTP and port 22 for SSH)

IoT Level-2 System Suitable for

for solutions where the data involved is big, however, the primary analysis requirement is not computationally intensive and can be done locally itself

Data of the IoT database can be stored

locally or in the cloud and stores the data generated by the IoT device

IoT Level-1 System Suitable for

modeling low-cost and low-complexity solutions where the data involved is not big and the analysis requirements are not computationally intensive

IoT Level-5 System Suitable for

solutions based on WSNs, in which the data involved is big and the analysis requirements are computationally intensive

IoT Level-4 System Suitable for

solutions where multiple nodes are required, the data involved is big and the analysis requirements are computationally intensive

Host identification is done

using hierarchical IP addressing schemes such as IPv4 or IPv6