IoT Architecture and Sensors Overview

IoT Architecture

• IoT architecture consists of devices, network connectivity, and cloud technology enabling communication between devices.
• This architecture consists of three layers: Perception, Network, and Application.
• The Perception layer is responsible for collecting data from sensors and devices.
• The Network layer facilitates connectivity and communication between devices.
• The Application layer provides the user interface and processes the collected data.

Sensors

• Sensors are inexpensive devices with sensing elements that collect data about physical properties and changes in the environment.
• They can be active or passive, depending on whether they generate their own energy or rely on external sources.
• Sensors can be intrusive or non-intrusive, depending on their placement within an object or the environment.
• The perception layer uses various technologies including RFID, GPS, WSN, and NFC to capture data from sensors.

Bluetooth Low Energy (BLE)

• Bluetooth Low Energy (BLE) is a low-power version of Bluetooth used in various IoT applications.
• BLE has low latency, low cost, multi-vendor interoperability, and easy application development.
• It operates in the 2.4 GHz frequency band and defines PHY and MAC layers for wireless networks.
• It features three unidirectional advertising channels.

Zigbee Module

• Zigbee modules are low-power wireless devices used for creating personal area networks.
• These modules are popular in applications like home automation, medical device data collection, and low-power, low-bandwidth needs.

Zigbee Network Architecture

• The Zigbee network architecture consists of four layers: Application, Network, MAC, and Physical.
• The Application layer is the highest layer and is responsible for manufacturer-defined applications.
• The Network layer manages mesh networking and acts as an interface between the MAC and Application layers.
• The MAC layer manages network discovery and handles PAN ID.
• The Physical layer controls the Zigbee radio, converting data packets into bits for transmission and vice versa.

Radio Frequency IDentification (RFID)

• RFID is a wireless communication technology used to automatically identify and track objects using electromagnetic fields.
• RFID tags consist of a microchip and an antenna, transmitting data to a reader.
• Readers send radio waves and receive signals from tags via antennas.
• Passive RFID tags are powered by the reader's waves, while active tags have their own power source.

Data Flow in RFID

• Readers emit radio waves that are received by tags.
• Tags transmit stored data back to the reader.
• Readers process the data and forward it to a computer system for further processing.

WiFi

• WiFi, or Wireless Fidelity, is a technology that enables electronic devices to connect to a wireless LAN using the IEEE 802.11 standards.
• Devices like smartphones, laptops, and tablets can connect to the internet or communicate wirelessly within a specific area.

6LoWPAN

• 6LoWPAN stands for "IPv6 over Low-Power Wireless Personal Area Networks."
• It is a network protocol that enables small, low-power devices to communicate over IP networks using IPv6 over IEEE 802.15.4 networks.
• This protocol facilitates IoT connectivity by enabling resource-constrained devices to connect to IP-based networks.

6LoWPAN Packet Transmission

• 6LoWPAN encapsulates IPv6 packets into smaller frames for transmission over low-power wireless networks.
• Header compression reduces packet size, enabling small, low-power devices to send and receive data.

6LoWPAN Motivation

• Sensors transmit small amounts of data compared to devices like smartphones and PCs.
• Sensors often have limited wireless connectivity capabilities.
• Using IPv6 instead of proprietary protocols offers interoperability and leverages existing internet protocols.

6LoWPAN Network Architecture

• The Access Point (AP) acts as an IPv6 router, handling the uplink to the Internet.
• Multiple devices, such as PCs and servers, can connect to the AP.
• An edge router connects the 6LoWPAN network to the IPv6 network.

Constrained Application Protocol (CoAP)

• CoAP is an application layer protocol designed for resource-constrained devices in the IoT.
• It uses UDP for communication, providing a lightweight alternative to TCP.
• CoAP follows the REST (Representational State Transfer) architecture, similar to HTTP.
• Resources are identified by URIs, and standard methods like GET, POST, PUT, and DELETE are used to interact with them.

CoAP Message Exchange

• CoAP operates over UDP, making it suitable for unreliable networks.
• It uses a two-layer messaging model: fixed-length header followed by options and payload.
• The message type is determined by the client request (CON, NON, ACK, or RST).

Extensive Messaging Presence Protocol (XMPP)

• XMPP enables the transfer of XML elements over networks.
• It is widely used for instant messaging and is an open-source protocol.
• XMPP's architecture is based on a client-server model, where clients cannot communicate directly but need an intermediate server for communication.

This quiz explores the fundamental aspects of IoT architecture, including its three layers: Perception, Network, and Application. It also delves into the role of sensors in data collection and the various technologies utilized within the perception layer. Test your knowledge on these essential components of the Internet of Things.