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IoT technologies and protocols

Get started in the world and technology of IoT. This guide will give you a strong foundation in IoT protocols and technology to help you make the right choices for your project.

A guide to IoT technologies and protocols

The Internet of Things is a convergence of embedded systems, wireless sensor networks, control systems, and automation that makes connected industrial manufacturing factories, intelligent retail, next-generation healthcare, smart homes and cities, and wearable devices possible. IoT technologies empower you to transform your business with data-driven insights, improved operational processes, new lines of business, and more efficient use of materials.

The technology of IoT continues to expand, with countless service providers, a variety of platforms, and millions of new devices emerging every year, leaving developers with many decisions to make before entering the IoT ecosystem.

This guide is designed to help you understand common IoT protocols, power, and connectivity requirements. If you’re looking for a more basic introduction to IoT technology, check out the What is IoT? and IoT cybersecurity web guides.

IoT technology ecosystem

The IoT technology ecosystem is composed of the following layers: devices, data, connectivity, and technology users.

Device layer

The combination of sensors, actuators, hardware, software, connectivity, and gateways that constitute a device that connects and interacts with a network.

Data layer

The data that’s collected, processed, sent, stored, analyzed, presented, and used in business contexts.

Business layer

The business functions of IoT technology, including the management of billing and data marketplaces.

User layer

The people who interact with IoT devices and technologies.

Learn more about how to properly connect devices when you build with Azure IoT Hub.

The IoT technology stack part 1:

IoT devices

IoT devices vary widely but tend to share these common concepts and vocabulary. You can also learn more about the varieties of devices that utilize IoT technology in this IoT device catalog.


Actuators perform physical actions when their control centers gives instructions, usually in response to changes identified by sensors. They’re a type of transducer.

Embedded systems

Embedded systems are microprocessor-based or microcontroller-based systems that manage a specific function within a larger system. They include both hardware and software components such as Azure RTOS.

Intelligent devices

Devices that have the ability to compute. They often include a microcontroller and may utilize services such as Azure IoT Edge to best deploy certain workloads across devices.

Microcontroller unit (MCU)

These small computers are embedded on microchips and contain CPUs, RAM, and ROM. Although they contain the elements needed to execute simple tasks, microcontrollers are more limited in power than microprocessors.

Microprocessor unit (MPU)

MPUs perform the functions of CPUs on single or multiple integrated circuits. Although microprocessors require peripherals to complete tasks, they greatly reduce processing costs because they only contain a CPU.

Non-computing devices

Devices that only connect and transmit data and do not have the ability to compute.


In general terms, transducers are devices that convert one form of energy into another. In IoT devices, this includes the internal sensors and actuators that transmit data as the devices engage with their environment.


Sensors detect changes in their environments and create electrical impulses to communicate. Sensors commonly detect environmental shifts like changes in temperature, chemicals, and physical position and are a type of transducer.

The IoT technology stack part 2:

IoT protocols and connectivity

Connecting IoT devices

A major aspect of planning an IoT technology project is to determine the devices’ IoT protocols—in other words, how the devices connect and communicate. In the IoT technology stack, devices connect either through gateways or built-in functionality.

What are IoT gateways?

Gateways are part of the technology of IoT that can be used to help connect IoT devices to the cloud. Though not all IoT devices require a gateway, they can be used to establish device-to-device communication or connect devices that are not IP based and can’t connect to the cloud directly. Data collected from IoT devices moves through a gateway, gets preprocessed at the edge, and then gets sent to the cloud.

Using IoT gateways can lower latency and reduce transmission sizes. Having gateways as part of your IoT protocols also lets you connect devices without direct internet access and provide an additional layer of security by protecting data moving in both directions.

How do I connect IoT devices to the network?

The type of connectivity you utilize as part of your IoT protocol depends on the device, its function, and its users. Typically, the distance that the data must travel—either short-range or long-range—determines the type of IoT connectivity needed.

Types of IoT networks

Low-power, short-range networks

Low-power, short range networks are well-suited for homes, offices, and other small environments. They tend to only need small batteries and are usually inexpensive to operate.

Common examples:


Good for high-speed data transfer, Bluetooth sends both voice and data signals up to 10 meters.


A set of communication protocols for communication between two electronic devices over a distance of 4 cm (1 ⁄2 in) or less. NFC offers a low-speed connection with simple setup that can be used to bootstrap more-capable wireless connections.


The low cost of operating Wi-Fi makes it a standard across homes and offices. However, it may not be the right choice for all scenarios because of its limited range and 24/7 energy consumption.


A mesh network using low-energy radio waves to communicate from appliance to appliance.


An IEEE 802.15.4-based specification for a suite of high-level communication protocols used to create personal area networks with small, low-power digital radios.

Low-power, wide-area networks (LPWAN)

LPWANs enable communication across a minimum of 500 meters, require minimal power, and are used for a majority of IoT devices. Common examples of LPWANs are:


High capacity and low latency, these networks are a great choice for IoT scenarios that require real-time information or updates.

5G IoT

Although not yet available, 5G IoT networks are expected to enable further innovations in IoT by providing much faster download speeds and connectivity to many more devices in a given area.


These LTE-based networks are the lowest cost option. They lay the groundwork for Cat-M, a technology that will replace 2G.


This standard for cellular IoT will eventually replace 3G. Cat-1 networks are easy to set up and offer a great solution for applications requiring a voice or browser interface.


Long-range wide-area networks (LoRaWANs) connect mobile, secure, bi-directional battery-operated devices.

LTE Cat-M1

These networks are fully compatible with LTE networks. They optimize cost and power in a second generation of LTE chips designed specifically for IoT applications.

Narrowband or NB-IoT/Cat-M2

NB-IoT/Cat-M2 uses direct-sequence spread spectrum (DSSS) modulation to send data directly to the server, eliminating the need for a gateway. Although NB-IoT networks cost more to set up, not requiring a gateway makes them less expensive to run.


This global IoT network provider offers wireless networks to connect low-power objects that emit continuous data.

IoT protocols: How IoT devices communicate with the network

IoT devices communicate using IoT protocols. Internet protocol (IP) is a set of rules that dictates how data gets sent to the internet. IoT protocols ensure that information from one device or sensor gets read and understood by another device, a gateway, a service. Different IoT protocols have been designed and optimized for different scenarios and usage. Given the diverse array of IoT devices available, using the right protocol in the right context is important.

What IoT protocol is right for me?

The type of IoT protocol you’ll need depends on the system architecture layer that the data will travel in. The Open Systems Interconnection (OSI) model provides a map of the various layers that send and receive data. Each IoT protocol in the IoT system architecture enables device-to-device, device-to-gateway, gateway-to-data center, or gateway-to-cloud communication, as well as communication between data centers.

Application layer

The application layer serves as the interface between the user and the device within a given IoT protocol.

Advanced Message Queuing Protocol (AMQP)

A software layer that creates interoperability between messaging middleware. It helps a range of systems and applications work together, creating standardized messaging on an industrial scale.

Constrained Application Protocol (CoAP)

A constrained-bandwidth and constrained-network protocol designed for devices with limited capacity to connect in machine-to-machine communication. CoAP is also a document-transfer protocol that runs over User Datagram Protocol (UDP).

Data Distribution Service (DDS)

A versatile peer-to-peer communication protocol that does everything from running tiny devices to connecting high-performance networks. DDS streamlines deployment, increases reliability, and reduces complexity.

Message Queue Telemetry Transport (MQTT)

A messaging protocol designed for lightweight machine-to-machine communication and primarily used for low-bandwidth connections to remote locations. MQTT uses a publisher-subscriber pattern and is ideal for small devices that require efficient bandwidth and battery use.

Transport layer

In any IoT protocol, the transport layer enables and safeguards the communication of the data as it travels between layers.

Transmission Control Protocol (TCP)

The dominant protocol for a majority of internet connectivity. It offers host-to-host communication, breaking large sets of data into individual packets and resending and reassembling packets as needed.

User Datagram Protocol (UDP)

A communications protocol that enables process-to-process communication and runs on top of IP. UDP improves data transfer rates over TCP and best suits applications that require lossless data transmissions.

Network layer

The network layer of an IoT protocol helps individual devices communicate with the router.


Many IoT protocols utilize IPv4, while more recent executions use IPv6. This recent update to IP routes traffic across the internet and identifies and locates devices on the network.


This IoT protocol works best with low-power devices that have limited processing capabilities.

Data link layer

The data layer is the part of an IoT protocol that transfers data within the system architecture, identifying and correcting errors found in the physical layer.

IEEE 802.15.4

A radio standard for low-powered wireless connection. It’s used with Zigbee, 6LoWPAN, and other standards to build wireless embedded networks.


Low-power wide-area networks (LPWAN) networks enable communication across distances of 500 meters to over 10km in some places. LoRaWAN is an example of LPWAN that’s optimized for low power consumption.

Physical layer

The physical layer is the communication channel between devices within a specific environment.

Bluetooth Low Energy (BLE)

BLE dramatically reduces power consumption and cost and maintains a similar connectivity range as classic Bluetooth. BLE works natively across mobile operating systems and is fast becoming a favorite for consumer electronics due to its low cost and long battery life.


This wired connection is a less expensive option that provides fast data connection and low latency.

Long-term evolution (LTE)

A wireless broadband communication standard for mobile devices and data terminals. LTE increases the capacity and speed of wireless networks and supports multicast and broadcast streams.

Near field communication (NFC)

A set of communication protocols using electromagnetic fields that allows two devices to communicate from within four centimeters of each other. NFC-enabled devices function as identity keycards and are commonly used for contactless mobile payments, ticketing, and smart cards.

Power Line Communication (PLC)

A communication technology that enables the sending and receiving of data over existing power cables. This allows you to both power and control an IoT device through the same cable.

Radio frequency identification (RFID)

RFID uses electromagnetic fields to track otherwise unpowered electronic tags. Compatible hardware supplies power and communicate with these tags, reading their information for identification and authentication.


Wi-Fi/802.11 is a standard in homes and offices. Although it’s an inexpensive option, it may not suit all scenarios due to its limited range and 24/7 energy consumption.


A mesh network using low-energy radio waves to communicate from appliance to appliance.


An IEEE 802.15.4-based specification for a suite of high-level communication protocols used to create personal area networks with small, low-power digital radios.

The IoT technology stack part 3:

IoT platforms

IoT platforms make it easy to build and launch your IoT projects by providing a single service that manages your deployment, devices, and data. IoT platforms manage hardware and software protocols, offer security and authentication, and provide user interfaces.

The exact definition of an IoT platform varies because more than 400 service providers offer features that range from software and hardware to SDKs and APIs. However, most IoT platforms include:

  • An IoT cloud gateway
  • Authentication, device management, and APIs
  • Cloud infrastructure
  • Third-party app integrations

Managed services

IoT managed services help businesses proactively operate and maintain their IoT ecosystem. A variety of IoT managed services, such as Azure IoT Hub, are available to help streamline and support the process of building, deploying, managing, and monitoring your IoT project.

IoT applications of current technologies

AI and IoT

IoT systems gather such massive amounts of data that it’s often necessary to use AI and machine learning to sort and analyze that data so that you can detect patterns and take action on insights. For example, AI can analyze data gathered from manufacturing equipment and predict the need for maintenance, reducing costs and downtime from unexpected breakdowns.

Blockchain and IoT

Currently, there is no way to confirm that data from IoT has not been manipulated before it gets sold or shared. The blockchain and IoT work together to break down data siloes and foster trust so that data can be verified, traced, and relied upon.

Kubernetes and IoT

With a zero-downtime deployment model, Kubernetes helps IoT projects stay updated in real-time without impacting users. Kubernetes scales easily and efficiently using cloud resources, providing a common platform for deployment to the edge.

Open source and IoT

Open source technologies are accelerating IoT, allowing developers to use the tools of their choice on IoT technology applications.

Quantum computing and IoT

The significant amount of data generated by IoT naturally lends itself to quantum computing’s ability to speed through heavy computation. Additionally, quantum cryptography helps add a level of security that’s required but currently hindered by the low computational power inherent to most IoT devices.

Serverless and IoT

Serverless computing enables developers to build applications faster by eliminating the need for them to manage infrastructure. With serverless applications, the cloud service provider automatically provisions, scales, and manages the infrastructure required to run the code. With the variable traffic of IoT projects, serverless provides a cost-effective way to scale dynamically.

Virtual reality and IoT

Used together, virtual reality and IoT can help you to visualize complex systems and make real-time decisions. For example, using a form of virtual reality called augmented reality (also known as mixed reality) you can display important IoT data as graphics on top of real-world objects (such as your IoT devices) or workspaces. This combination of virtual reality and IoT has inspired technological advancements in industries like healthcare, field service, transportation, and manufacturing.

Digital Twins and IoT

Testing your systems before execution can be a dramatic cost- and time-saving measure. Digital Twins takes data from multiple IoT devices and integrates it with data from other sources to offer a visualization of how the system will interact with devices, people and spaces.

IoT data and analytics

IoT technologies produce such high volumes of data that specialized processes and tools are needed to turn the data into actionable insights. Common IoT technology applications and challenges:

Application: Predictive maintenance

IoT machine learning models designed and trained to identify signals in historical data can be used to identify the same trends in current data. This lets users automate preventative service requests and order new parts ahead of time so that they’re always available when needed.

Application: Real-time decisions

A variety of IoT analytics services are available, designed for end-to-end real-time reporting, including:

  • High-volume data storage using formats that analytics tools can query.
  • High-volume data stream processing to filter and aggregate data before analysis gets performed.
  • Low-latency analysis turnaround using real-time analytics tools that report and visualize data.
  • Real-time data intake using message brokers.

Challenge: Data storage

Large data collection leads to large data storage needs. Several data store services are available, varying in capabilities like organizational structures, authentication protocols, and size limits.

Challenge: Data processing

The volume of data collected through IoT presents challenges for cleaning, processing, and interpreting at speed. Edge computing addresses these challenges by shifting most data processing from a centralized system to the edge of the network, closer to the devices that need the data. However, decentralizing data processing introduces new challenges, including the reliability and scalability of edge devices and the security of the data in transit.

IoT security, safety, and privacy

IoT security and privacy are critical considerations in any IoT project. Although the technology of IoT can transform your business operations, IoT devices can pose threats if not properly secured. Cyberattacks can compromise data, ruin equipment, and even inflict harm.

Strong IoT cybersecurity, such as Azure Sphere, reaches beyond standard confidentiality measures to include threat modeling. Understanding the different ways attackers might compromise your system is first the step toward preventing attacks.

When planning and developing your IoT security system, it’s important to choose the right solution for every step of your platform and system, from OT to IT. Software solutions such as Azure Defender, give you the protection you need throughout your given system.

Resources to get started

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