IoT Systems Fundamentals Quiz

Internet of Things (IoT)

• IoT is a network of physical objects embedded with electronics, software, sensors, and connectivity
• IoT enables these objects to collect and exchange data
• IoT is an ecosystem of connected physical objects accessible via the internet
• IoT allows remote sensing and control across existing network infrastructure
• IoT leads to better integration between physical and computer-based systems which in turn improves efficiency, accuracy, and economic benefit

Characteristics of IoT

• Connectivity: IoT devices need to be connected to an infrastructure. Without connectivity, they are useless.
• Intelligence: Extracting knowledge from generated data, properly interpreting sensor data is key
• Scalability: The number of connected IoT devices increases constantly. The system must be able to handle massive growth.

Unique Identity

• Each IoT device has a unique IP address for tracking and querying its status

Dynamic and Self-Adapting

• IoT devices should adapt to changing environments; for example, a surveillance camera needs to function in different light conditions (morning, afternoon, night).

Architecture

• IoT architecture needs to be heterogeneous to support different product manufacturers
• A heterogeneous architecture is needed to support different product manufacturers working with the IoT

Safety

• The interconnected nature of IoT devices poses security risks. Data can be tampered with if proper safety measures are not in place

Physical and Logical Design of IoT

• Physical Design: Detailed, graphical, specific solutions outlining assembly/configuration
• Logical Design: High-level, textual or graphical with no detail; focuses on design factors (risks, requirements, constraints, assumptions)

Physical Design of IoT

• A physical design describes individual devices and their protocols forming a functional IoT-ecosystem
• Devices such as sensors, actuators, and their connections are described.

Things/Devices in IoT

• Things/devices in an IoT system build connections, process data, provide interfaces, storage and graphical interfaces
• An analytical system uses the data from devices to improve the system

IoT Protocols

• Protocols establish communication between node devices and servers over the internet to send commands and receive data.
• These protocols operate on network layers (application, transport, network and link layer).

Application Layer Protocols

• Protocols define how data is sent over network using application interface
• Protocols include HTTP, WebSocket, XMPP, MQTT, DDS, and AMQP.

HTTP (Hypertext Transfer Protocol)

• A protocol used for communication between web browsers and servers for transmitting media documents
• It's a stateless protocol, where the server does not retain data between requests.

WebSocket

• Enables two-way communication between a client (e.g., web browser) and a host that can run on untrusted code in a controlled environment.

MQTT (Message Queuing Telemetry Transport)

• A machine-to-machine protocol based on publish/subscribe
• Uses a central broker to route messages from publishers to subscribers

Transport Layer

• Controls data segment flow and handles error control
• Provides end-to-end message transfer independent of underlying network
• Protocols include TCP and UDP.

TCP (Transmission Control Protocol)

• Defines how to establish and maintain network communication in proper manner using internet protocol; used in WWW, Email, Streaming media

UDP (User Datagram Protocol)

• A connectionless protocol; does not require a connection to transfer data, used in DNS Queries, Online Gaming

Network Layer

• Sends datagrams from one network to another
• Uses IPv4 and IPv6 for host identification
• IPv4 is a 32-bit protocol address assigned to devices on a network; Used to identify host and location
• IPv6 is a successor to IPv4, using 128-bit addresses to overcome limitations of older standard.

Link Layer

• Determines how data packets are coded and signaled.
• Defines technologies and protocols primarily used in LANs.
• Two important aspects of link layer are Ethernet and WiFi

Network Protocol Layers

(Layered model showing order of operations in network communication)

Logical Design of IoT

• A logical design for an IoT system focuses on the structural arrangement of components (computers, sensors, and actuators) to fulfill a specific function
• It doesn't delve into low-level programming specifics

Device

• Components of IoT systems that provide sensing, actuation, monitoring and control functions
• Sensors collect data from the surroundings, actuators affect physical processes
• An entry point or gateway for input to the IoT system

Communication

• Processes are in charge of handling communications amongst IoT-system devices

Service

• Provides various functions for device monitoring, device control, data publishing, and device discovery

Management

• Block in charge for overseeing overall operation of IoT system, configuration, firmware updates, and system monitoring

Security

• Takes care of functionalities like authentication, authorization, message and content integrity, data security

Application

• Interface for users to control and monitor various aspects using processed data
• Can provide function/service insights. For example, analyze energy usage in a building or adjust greenhouse temperature

IoT Functional Block Advantages

• Scalability: Easily add new components as needed to adapt to changes in business or technological needs
• Interoperability: Products from multiple suppliers integrate seamlessly, reducing integration costs
• Modularity: Components are interchangeable, adaptable, and easily swapped.
• Flexibility: Flexible deployment choices- on-premise, cloud or hybrid

IoT Communication Models

• Request-response: Client requests data from server, server returns a response
• Publisher-subscriber: Publishers send data to a topic managed by a broker, which routes data to subscribers, without requiring the publisher to know about the subscribers.
• Push-pull: Publishers push data into queues and consumers pull data out of those queues, acting as a buffer for communication timing mismatches.
• Exclusive Pair: Bi-directional communication between client and server; connection established and remains open until closure request.

IoT Communication APIs

• REST (Representational State Transfer): A set of architectural principles for designing web services and web APIs that focuses on resources and how their states are addressed/transferred
• Follows request-response communication model for components, connectors and data in a distributed hypermedia system
• Web Socket: Allows bidirectional, full-duplex communication between clients and servers. Does not require a new connection for each communication
  • Useful for low-latency/high-throughput applications

IoT Enabling Technologies

• Wireless Sensor Networks (WSN): Distributed devices with sensors for environmental or physical condition monitoring
• Cloud Computing: Accessing applications and resources over the internet from remote locations
• IaaS: Infrastructure as a service, providing access to servers, storage, and networking resources. (e.g., web hosting, virtual machines)
• PaaS: Platform as a service, providing a platform to develop, run, and manage web applications. (e.g., App Cloud, Google app engine)
• SaaS: Software as a service, delivery of applications over the internet (e.g., Google Docs, Gmail)
• Big Data Analytics: Method for studying massive volumes of data from various sources (e.g., social media, sensor data, transactions)
• Communication Protocols: The backbone allowing network connectivity and linking applications (e.g., data encoding, addressing schemes)
• Embedded Systems: Combination of hardware and software for specific tasks like collecting data and sending it to the internet (e.g., digital cameras, industrial robots, wireless routers,)

IoT Levels and Deployment Templates

• Level 1: Single node (device) performing sensing/actuation, data analysis, and application hosting.
• Level 2: Single node (device) for sensing/actuation and local analysis; data and applications established in cloud.
• Level 3: Single node; data and applications in the cloud and suitable for big data, computationally intensive analysis
• Level 4: Multiple nodes performing local analysis; a cloud-based application- and-database system
• Level 5: Multiple end nodes and one coordinator node; data to the cloud via a coordinator node and suitable for big data, computations intensive applications
• Level 6: Multiple independent nodes, cloud-based analytics components, and central control; used in sensing-and-actuation applications that require cloud storage and analysis.