10 Mar IoT Protocols – Your Must Read Guide to Master IoT Communication in 2025
2025’s Most Advanced IoT Protocols – The Complete List for Smarter Internet of Things Networks
IoT protocols are sets of instructions/rules for IoT devices to be able to send data over the internet. These IoT protocols are how both devices/gateways understand each other and are able to communicate. We can think of it as a common language understood on both sides. All industries are adopting IoT technology as they don’t want to stay behind in the fourth industrial revolution. But it’s not as simple as it sounds.
Selecting the right communication protocol is not an easy selection as it depends on the use case. It depends on power consumption, latency, security, and sometimes various tradeoffs. For example, between MQTT, CoAP, LoRaWAN, Zigbee, and NB-IoT, the choice can only be made after discussing bandwidth efficiency, network coverage, processing needs, and the use case. Understanding these differences will help you implement the right IoT solution. Before discussing the differences, first understand what Internet of Things protocols are.
What Are IoT Protocols?
IoT communication protocols are the rules and industry standards. They guide on how devices interact with each other over the cloud. These IoT protocols become mediums of data transmission across networks doesn’t matter which device manufacturer or platform. IoT communication protocols are designed to support machine-to-machine / M2M connections without a support team.
IoT technology is now in smart homes and healthcare to industrial automation and smart cities. generally, no two use cases are the same. Protocols must accommodate different power requirements, network ranges, and data transfer needs. It’s hard to select just one. The right protocol depends on the use case and that IoT systems remain efficient, scalable, and secure.
How are IoT Protocols different from Conventional Internet Protocols?
Traditional Internet protocols HTTP, FTP, and TCP/IP are for general web applications. They prioritize high-speed connection communication and are not suitable for low-power long ranges or big continuous data exchange. IoT protocols are specifically optimized for these unique requirements of IoT devices. Like many IoT devices operate on battery power and they may be put in areas with less constant internet connectivity. This means they need to be energy efficient and use the right communication protocols to send the data back whenever they get connected to the network.
IoT data transmission can be connection-oriented or connectionless communication. Connection-oriented protocols mean establishing a dedicated link before transferring data. This is how to ensure connection reliability with higher latency and energy use.
Whereas connectionless protocols send data without staying connected all the time. Engineers prefer this for faster and more efficient data transfer in real and resource-limited use cases. The table below compares these two approaches:
Connection-Oriented vs. Connectionless Communication
| Feature | Connection-Oriented (e.g., TCP) | Connectionless (e.g., UDP, CoAP) |
| IoT Protocols | TCP, MQTT (with QoS 1 & 2), AMQP | UDP, CoAP, MQTT (QoS 0), LoRaWAN |
| Setup | Requires a dedicated connection before data transfer. | Sends data without prior connection. |
| Reliability | Guaranteed delivery with error correction. | No guarantee; some data may be lost. |
| Latency | Higher; keeps the connection active. | Lower; data is sent instantly. |
| Overhead | Higher; keeps the connection active. | Low, reducing resource usage. |
| Energy Use | Higher; keeps connection active. | Lower; sends data intermittently. |
| Scalability | Limited for large networks. | Efficient for massive IoT deployments. |
| Use Cases | Higher; keeps the connection active. | Smart meters, environmental sensors. |
The Layered Architecture & the Basis of Data Transfer
IoT communication protocol follows a layered architecture model that helps understand how data moves across different protocols because it’s possible we want to send data to a device that is working on a different communication protocol currently. So understanding the network architecture comes in handy. Each layer in the architecture has a specific role. Layers ensure smooth information flow between devices/networks/gateways and applications. This setup helps IoT systems handle the sending of data, its processing, and user interaction efficiently.
When IoT devices exchange data, it goes through multiple layers before reaching its destination as mentioned previously. Each layer connects with the ones above and below it. The connection is a must for seamless communication while maintaining performance and security in complex IoT environments.
The infamous Layer Model for Data Transmission: The OSI Model
The OSI (Open Systems Interconnection) model is the most widely used framework for structuring IoT communication. We have read about it in high schools and universities time and again. It has seven layers. Each layer with a specific role in transmitting, processing, and managing data across an IoT network. Let’s discuss the layers first from a communication point of view.
- Physical Layer:
Physical layer is the lowest layer in the model. It is responsible for physically connecting devices and transmitting raw data as electrical, radio, or optical signals. In simplest words, wires!
- Data Link Layer:
Data Link layer ensures error-free data transmission over a physical medium. It also manages device addresses and network access.
- Network Layer:
Network layer determines the best path for data packets. It makes sure data packets reach the correct destination within the network.
- Transport Layer:
Transmission layer controls the end-to-end transmission of data. Its responsibility is that packets are delivered in order and without errors.
- Session Layer:
Session layer manages communication sessions. This means ensuring that devices can start, maintain, and end data exchanges.
- Presentation Layer:
Presentation layer translates data into a standardized format. This layer makes sure different devices/applications understand and process the information.
- Application Layer:
Application layer is the highest layer. It is responsible for user interaction and application-specific functions. It includes web services, messaging, cloud integration, etc.
Is a 7-layer OSI Model a Necessity?
No, we use simplified layer models in IoT applications as well. We don’t always need the complexity of the 7-layer OSI Model. We sometimes drop/merge a few layers as well. This reduces complexity by grouping multiple OSI layers into fewer categories.
- Three-Layer Model:
It includes the network access layer, network layer, and application layer. It’s a basic structure for lightweight IoT systems.
- Four-Layer Model:
It consists of the network access layer, network layer, transport layer, and application layer. Its best-known example is the TCP/IP model. Itis the foundation of the modern Internet!
- Five-Layer Model:
If we extend the TCP/IP model by adding a physical layer and data link layer then we get a five-layer model. It provides greater detail in data transmission processes.
Key Application Layer Protocols in IoT
IoT Application Layer Protocols
The application layer is the top layer of the IoT protocol communication model as discussed before. It is responsible for exchanging messages between devices/gateways, and cloud services. The application layer ensures that data can be processed and acted upon by end applications. This layer plays a crucial role in IoT device interoperability. It allows different platforms and manufacturers to communicate efficiently over the Internet.
Application layer protocols are designed to meet specific IoT requirements. If we want low power consumption or lightweight messaging, and secure data exchange. It all depends on the application and the client’s requirements. Some standard IoT protocols are:
AMQP Advanced Message Queuing Protocol
AMQP is the standard for messaging communication. It provides reliable message delivery. It also supports queue management and ensures interoperability across platforms. We use AMQP widely nowadays in financial transactions, enterprise systems, and industrial IoT. It is THE protocol for secure and ordered message exchange.
HTTP Hypertext Transfer Protocol
Who doesn’t know HTTP? It is the most adopted protocol for web-based communication. It is also used in smart home devices, mobile apps, web apps, cloud services, etc. It’s not a complex protocol. We can use existing web infrastructure and make straightforward integration but HTTP can be resource-intensive. It is not very recommended for low-power IoT devices.
WebSockets
If you want real-time communication then WebSocket it is. They allow low-latency, full-duplex communication. They are ideal for financial trading platforms, online gaming, and live data streaming. Sockets allow devices to maintain an active connection. They reduce the need for continuous polling. Real-time means real-time like a WhatsApp message.
LwM2M Lightweight Machine-to-Machine Protocol
LwM2M is a lightweight and resource-efficient protocol. It was specially designed for remote management of devices over the internet. With LwM2M, we can configure devices, update their firmware, and monitor them with less bandwidth usage. We commonly see LwM2M in smart metering and industrial IoT systems.
XMPP Extensible Messaging and Presence Protocol
XMPP is a messaging protocol. It was originally developed for instant messaging and online presence management. It supports secure and scalable communication, it is one of the suitable protocols for chat applications, social networks, and IoT messaging frameworks. XMPP is particularly useful in device-to-device links within IoT systems.
SMS/SMPP Short Message Service / Short Message Peer-to-Peer
SMS and SMPP enable IoT communication over cellular networks, making them useful for fleet management, telematics, and remote monitoring. These protocols offer global coverage and function without requiring an active internet connection, making them reliable for critical IoT applications.
USSD Unstructured Supplementary Service Data
USSD is a real-time communication protocol for mobile network services (our mobile sims for example). It does not require an internet connection. It is ideal for secure transactions, remote authentication, and IoT applications in areas with limited connection.
SSI Simple Sensor Interface
SSI is a lightweight protocol for real-time “sensor data transmission”. It provides direct communication between sensors and control systems. It is ideal for industrial automation, process monitoring, and smart manufacturing.
CoAP Constrained Application Protocol
CoAP is specifically designed for low-power, resource-constrained IoT devices. It follows a RESTful architecture. It can be easily integrated with existing web services. CoAP is widely used in smart cities, smart homes, and sensor networks. If you need low bandwidth and energy efficiency then CoAP is for you.
DDS Data Distribution Service
DDS is also a real-time data exchange protocol but we use it in high-performance IoT applications. It is an upgraded version of the previously mentioned real-time protocols. We see DDS in aerospace, defense, and industrial automation. Its use case is low-latency, reliable data transmission.
MQTT Message Queuing Telemetry Transport
MQTT is one of the most widely adopted IoT protocol for messaging. It was designed for low-bandwidth, power-efficient communication. It operates on a publish-subscribe model. And it is highly scalable. MQTT is extensively used in home automation, health monitoring, and industrial IoT.
Which IoT Application Layer Protocol should we choose in 2025?
The right IoT protocol for application layer depends on your specific use case. It depends on your device constraints, network conditions, and performance requirements. Different applications demand different levels of power efficiency, data reliability, latency, and scalability. It’s not a one-protocol-fits-all situation.
1. If Your IoT Devices Are Low-Power and Resource-Constrained
We recommend: CoAP, MQTT, LwM2M
- Best for battery-operated sensors, smart meters, smart watches, etc.
- Designed for low bandwidth, minimal processing power, and energy efficiency.
- CoAP is lightweight and integrates well with web services.
- MQTT with QoS settings ensures reliable message delivery.
- LwM2M provides remote device management and configuration.
Use Cases:
- Smart home automation (e.g., motion sensors, temperature sensors).
- Environmental monitoring (e.g., air quality sensors, weather stations).
- Wearables and health trackers.
2. If Your IoT System Requires Reliable Message Delivery
We recommend: MQTT, AMQP, DDS
- Best for applications where message loss is unacceptable.
- MQTT supports three Quality of Service levels and ensures messages are delivered at least once, exactly once, or at most once.
- AMQP provides message queuing, acknowledgment, and guaranteed delivery. It is best for financial and enterprise applications.
- DDS is used in real-time, safety-critical applications in autonomous systems and industrial automation.
Use Cases:
- Industrial automation and predictive maintenance.
- Healthcare applications (e.g., remote patient monitoring).
- Smart grid and energy management (e.g., power grid monitoring).
3. If You Need Real-Time, Low-Latency Communication
We recommend: WebSocket, DDS, XMPP
- Best for applications that require instant data exchange without delays.
- WebSockets are for bi-directional, real-time communication for web and cloud IoT applications.
- DDS are high-performance, low-latency data transfer protocols for mission-critical systems.
- XMPP supports real-time messaging and presence management. It is ideal for instant communication between devices.
Use Cases:
- Connected vehicles and autonomous systems.
- Stock trading platforms and financial services.
- Smart transportation and traffic monitoring.
4. If Your IoT Devices Need to Integrate with Web Services
We recommend: HTTP, WebSocket, CoAP
- Best for applications that require seamless interaction with cloud platforms, APIs, and web applications.
- HTTP is widely supported but can be resource-intensive for low-power devices.
- WebSocket enables persistent connections for real-time data streaming.
- CoAP is a more lightweight alternative to HTTP, designed for low-power IoT devices.
Use Cases:
- Smart home systems with mobile app control.
- Cloud-based IoT dashboards and analytics.
- Remote monitoring applications with web access.
5. If Your IoT Deployment Relies on Cellular Networks
We recommend: MQTT, SMS/SMPP, USSD
- Best for wide-area, mobile IoT applications where Wi-Fi or LPWAN is not available.
- MQTT works well over cellular networks with low bandwidth.
- SMS/SMPP and USSD allow devices to communicate via mobile networks without requiring an internet connection.
Use Cases:
- Fleet management and asset tracking.
- Smart agriculture and remote monitoring.
- Emergency alert systems and public safety IoT.
Final Thoughts:
We repeatedly mention time and again that the right IoT protocol for the application layer depends on your use case and requirements. We shortlisted a few use cases and IoT protocols for you based on key factors:
✔ Power Consumption
✔ Reliability & Message Delivery
✔ Real-Time Communication
✔ Web Integration
✔ Cellular IoT
If you still need help to understand your requirements or your IoT ecosystems then let us know. We will optimize efficiency, reduce costs, and ensure seamless data exchange across your IoT ecosystem.
