IoT Protocols: A comprehensive guide for enterprises

The Internet of Things (IoT) connects physical devices and enables data exchange over the Internet, and IoT protocols are responsible for the communication and data transfer between devices. As organizations need to understand the different technologies in order to choose the right solutions for their needs, our blog post is available to guide you through the main protocols and their IoT applications.

Definition and importance of IoT protocols

IoT protocols are a set of rules and standards that govern communication between devices on the Internet of Things (IoT). The main purpose of these technologies is to ensure smooth communication between different IoT devices, regardless of manufacturer or platform. They are the foundation of data transmission and are critical to the successful implementation of IoT projects. Without these proper protocols, IoT applications would not be able to communicate properly with each other.

Differences from conventional internet protocols

While traditional protocols such as HTTP and FTP were designed for Internet applications, IoT standards are specifically tailored to the needs of IoT devices. These include range, data volume, and energy efficiency. In practice, many IoT applications use conventional technologies because their performance is sufficient or because new protocols are still being developed.

Another difference is the type of communication. Traditional standards mainly use connection-oriented protocols such as TCP, however, IoT technologies support both connection-oriented and connectionless communication, allowing for flexible and adaptable data transfer in different IoT applications.

Connection-oriented protocols first establish an end-to-end connection between devices and then send the data to ensure that each device can send data without errors and in the correct order. On the other hand, connectionless data transfer communicates without such prior establishment of the end-to-end connection. These protocols are used when fast transmission is important and occasional data loss is acceptable.

Basics of data transfer: The layered architecture

IoT communication is based on a layered architecture that efficiently organizes data exchange across different protocols. Data exchange between devices goes through several layers from storage, to processing and to the user interface. Each layer is responsible for a specific task and communicates with the layers below and above it.

Well-known layer model for data transmission: OSI Model

The OSI (Open Systems Interconnection) model is the best known layer model and contains seven layers from bottom to top:

1. Physical layer: The lowest layer physically connects devices and transmits the bits via cable or mobile communications.
2. Data link layer: This layer ensures the error-free transmission of data packets via physical connections. This also includes controlled access to the transmission medium and error detection.
3. Network layer: This layer decides which path the data packets take through the network and is responsible for proper addressing.
4. Transport layer: This layer controls the transmission of data between end systems, ensuring reliable and orderly transmissions of data packets.
5. Session layer: This layer manages and synchronizes the dialog between the communication participants. It establishes, manages and terminates the sessions.
6. Presentation layer: This layer is responsible for translating data formats into a format that's understood by the application.
7. Application layer: The top layer represents the user application interface. This includes web access and email programs.

The actual data transmission is top-down, from the application layer to the physical layer. In general, each IoT protocol operates on a single layer. However, some standards communicate across multiple layers.

From three to five layers: Other layer models

Additionally, other layer models are also used. Some of them correspond to the OSI model, while others use different layers:

• Three-layer model: This layered architecture consists of the network access layer, the network layer and the application layer.
• Four-layer model: This model includes the network access layer, the network layer, the transport layer and the application layer. The TCP/IP model is the best known four-layer model and the basis of the commercial Internet.
• Five-layer model: This layered model consists of the physical layer, the data link layer, the network layer, the transport layer and the application layer.

IoT application layer protocols

The application layer is the top layer of the OSI model. At this level, the protocols execute the most data-intensive processes responsible for exchanging messages between end devices and software applications.

AMQP (Advanced Message Queuing Protocol)

AMQP is an open standard protocol used for message exchange and queue management. It provides reliable and orderly message delivery, supports a variety of communication patterns, and offers a high degree of interoperability. AMQP is widely implemented in the financial sector and in corporate communication.

HTTP (Hypertext Transfer Protocol)

HTTP is a widely used protocol for transferring Web pages and data over the Internet. This technology is easy to implement and leverages existing Web infrastructure. HTTP is often deployed in smart home systems that require integration with web services.

WebSocket

The WebSocket protocol provides low latency and efficient data transfer. It is ideal for real-time applications such as online games, financial trading platforms, and chat applications.

LwM2M (Lightweight Machine-to-Machine)

The LwM2M protocol is specifically designed to manage IoT devices. It's resource-efficient and enables efficient remote configuration and monitoring of energy and utility applications.

XMPP (Extensible Messaging and Presence Protocol)

The Extensible Messaging and Presence Protocol is a messaging and presence management technology. Presence management allows communication partners to indicate their availability in a messenger. XMPP is flexible, secure, widely deployed, and extensible. The protocol is commonly used for chat applications and social networks, as well as for device communication in IoT networks.

SMS/SMPP (Short Message Service/Short Message Peer-to-Peer)

The SMS protocol is well known for sending short messages over cellular networks. SMPP is the standard for exchanging SMS messages between Short Message Service centers and external messaging servers. Both technologies are reliable and widely deployed as they enable communication between IoT devices over cellular networks. The technologies are also widely used in telematics and fleet management.

USSD (Unstructured Supplementary Service Data)

The USSD standard is a protocol for communication between mobile devices and application servers of mobile network operators. It’s fast, promotes secure real-time communication,does not require a permanent Internet connection and does not store messages. The IoT protocol is also used for mobile payments.

SSI (Simple Sensor Interface)

SSI technology is a simple communication protocol for real-time data transfer between sensors and computers. SSI is easy to implement and supports direct connection of sensors and control systems. This IoT protocol is often used in industrial applications that require efficient transmission of sensor data.

CoAP (Constrained Application Protocol)

CoAP is designed specifically for locally constrained devices and networks. It's lightweight, efficient, reliable, and can be integrated with existing web services. The IoT protocol is ideal for smart city and smart home systems, which are typically limited to a specific area and require resource-efficient technology.

DDS (Data Distribution Service)

The DDS technology is a protocol for reliable real-time data exchange between IoT devices. This standard is often used for safety-critical applications in aerospace, defense and industrial automation.

MQTT (Message Queuing Telemetry Transport)

MQTT is a reliable message delivery protocol. It's easy to implement and suitable for IoT devices with limited bandwidth and power. MQTT technology is widely used in home automation, health monitoring, and industrial monitoring.

Transport layer protocols for IoT technologies

The transport layer is the fourth layer in the OSI model and ensures the reliable transmission of data between end systems. Protocols in this layer control the flow of data and assure that data packets arrive correctly and in the right order.

TCP (Transmission Control Protocol)

The TCP standard is a connection-oriented protocol. It uses acknowledgment messages to guarantee that data packets arrive in the correct order and without loss. The protocol is primarily used in industrial automation, healthcare, and safety-critical applications. Data integrity, which refers to the correctness, completeness, and security of data, is critical in these IoT areas.

UDP (User Datagram Protocol)

UDP is a connectionless protocol that sends data packets directly to the recipient without first establishing a connection. The technology provides low latency and fast data transmission, whilst also being used for non-critical applications such as streaming videos and Voice over Internet Protocol (VoIP), where occasional downtime does not necessarily affect data integrity.

IoT network layer standards

The network layer is the third layer of the OSI model. It is responsible for forwarding data packets between different networks. The appropriate protocols decide which route the data packets take to reach their destination efficiently.

IP (Internet Protocol)

IP is a widely used protocol for addressing and routing data packets on the Internet. It's flexible and compatible with almost any type of network and device. The IP standard is implemented in nearly all IoT applications, including smart homes, wearables, and industrial automation.

6LoWPAN (IPv6 over Low-Power Wireless Personal Area Networks)

The 6LoWPAN protocol promotes efficient use of bandwidth and power. It is specifically designed for low-power wireless networks and enables the seamless integration of small IoT devices into the Internet with minimal power consumption. The technology is widely adopted for smart cities, home automation and industrial sensor networks where energy efficiency and low cost of ownership are critical.

IoT protocols in the data link layer

The data link layer is the second layer of the OSI model. Technologies in this layer maintain the error-free transmission of data between two directly connected devices.

IEEE Standards

The Institute of Electrical and Electronics Engineers (IEEE) develops and maintains several standards for data transmission. They are robust, compatible with many types of networks, and interoperable across devices and vendors. One such protocol is IEEE 802.15.4, the basic standard for ZigBee, an energy-efficient IoT protocol for low-power devices, and other wireless networks. IEEE 802.15.4 is primarily used in home automation, industrial monitoring and sensor networks.

LPWAN (Low Power Wide Area Network)

LPWAN technology includes several protocols such as LoRaWAN and NB-IoT. The LoRaWAN standard supports data transmission over long distances, while NB-IoT is ideal for low-power devices. Not only do LPWANs offer both long range and energy efficiency, they also connect devices over long distances and extend their battery life. Applications include smart cities, agriculture, environmental monitoring and logistics.

Physical layer standards for IoT communications

The physical layer is the lowest layer of the OSI model. Protocols at this level govern the transmission of bits over a transmission medium, such as copper wire, fiber optic cable, or radio waves.

Bluetooth/BLE (Bluetooth Low Energy)

Bluetooth is a wireless technology for short-range data transmission. BLE is the low-power version of Bluetooth and is ideal for battery-powered devices. Both protocols are inexpensive and simple options for data transmission. Wearables, smart home devices, and healthcare applications often use Bluetooth and BLE.

Ethernet

Ethernet technology is a common standard for wired networks. As an IoT protocol, Ethernet provides robust and fast data transmission, ideal for Industry 4.0 and smart buildings where high bandwidth is required.

Wireless technologies: 2G, GPRS/Edge, 3G, 4G/LTE and 5G

Mobile communication standards enable wireless communication over long distances. LTE and 5G provide high data rates and low latency, whereas in contrast, 2G, GPRS and 3G have lower performance but are widely used. IoT applications include smart cities, autonomous driving and mobile IoT devices.

NFC (Near Field Communication)

The NFC protocol supports wireless communication over very short distances, typically a few centimeters. NFC is easy to use, offers fast transmission, and does not require device pairing like Bluetooth. The technology is used in contactless payment systems and for exchanging information between devices.

PLC (Powerline Communication)

The PLC standard uses existing power lines for data transmission, which provides a cost-effective networking solution without the need for additional wiring. PLC is ideal for in-building data transmission and is often used for smart home and building automation applications.

LoRaWAN (Long Range Wide Area Network)

The LPWAN protocol LoRaWAN is a wireless technology for long-range communicationstransmitting data over long distances with low power consumption. It's ideal for battery-powered devices over large areas, such as in agriculture.

Sigfox

The Sigfox wireless networking protocol is optimized for low data rates and long ranges. Sigfox is energy efficient, cost effective and easy to deploy. Asset tracking and smart metering applications use the technology.

Neocortec

The Neocortec standard is a robust and scalable solution for connecting many IoT devices. It enables flexible and energy-efficient communication for Industry 4.0 and smart buildings.

Weightless

The Weightless IoT protocol is suitable for wireless communication over long distances at low data rates. It's for applications that have occasional data transmission requirements, such as smart metering or asset tracking.

RFID (Radio Frequency Identification)

RFID technology uses radio waves to identify and track objects. It is fast, robust, contactless and can be applied in a variety of environments, including logistics, inventory management and access control systems.

Wi-Fi

Widespread Wi-Fi technology creates locally restricted networks. It's easy to deploy, compatible with many devices and applications, and provides fast data transmission. Smart homes, office buildings, and public hotspots all use Wi-Fi.

Z-Wave

The Z-Wave protocol is designed for home automation. It's energy efficient, easy to install, and supports a high level of interoperability between devices from different manufacturers. Z-Wave is primarily used in smart home applications such as lighting, security, and monitoring systems.

ZigBee

ZigBee technology is a low-power IoT protocol. It's ideal for battery-operated devices in smart home, industrial automation and healthcare applications.

Other protocols for IoT technologies

There are also a few more industry-specific IoT protocols and a number of security protocols. Specialized protocols for IoT applications are tailored to the needs and requirements of different industries. These protocols offer benefits that traditional protocols cannot, such as improved efficiency, security, and reliability.

Most IoT protocols already have built-in security in the form of end-to-end encryption. Where devices do not have encryption, IoT security protocols are used to ensure secure data transmission through authorized devices.

Industry-specific application protocols for the Internet of Things

Important specialized standards for IoT applications include:

LTE-M (Long Term Evolution for Machines)

Designed for IoT devices, the LTE-M cellular standard provides low latency and high data rates. LTE-M also enables reliable communications and supports mobile IoT applications such as autonomous driving. This technology is used in logistics, fleet management and telematics.

NB-IoT (Narrowband IoT)

As a low-power wide area network (LPWAN), NB-IoT is optimized for low-power devices. The protocol offers long battery life and high network coverage in buildings and remote areas. NB-IoT is suitable for smart metering, environmental monitoring and smart cities.

MIoTy

Another LPWAN protocol designed for robustness and scalability, is MIoTy. It transmits large amounts of data with low power and offers high immunity to interference and easy integration into existing systems. The protocol standard is used in data-intensive and large-scale industrial applications, smart cities and agriculture.

5G IoT

5G IoT is a dedicated 5G network technology for IoT applications. It offers extremely high data rates, low latency and connects a wide range of devices. The standard supports real-time applications such as autonomous driving and industrial automation.

OCPP (Open Charge Point Protocol)

The Open Charge Point Protocol is an open communication protocol for electric vehicle and smart grid charging infrastructure. The technology enables interoperability between different charging providers and supports the integration of energy management systems.

IEC 62056

IEC 62056 is the standard protocol for smart meter data transmission. It is a reliable and standardized method for remote monitoring of energy meters.

OBD2/CAN-BUS

OBD2 (On-Board Diagnostics) and CAN-BUS (Controller Area Network) are vehicle diagnostic and communication protocols. Both technologies provide a standardized interface for diagnosing and monitoring vehicle data for intelligent fleet management.

OPC UA (Open Platform Communications Unified Architecture)

OPC UA is used in Industry 4.0 as a standardized protocol for secure data exchange between machines and systems. The technology provides interoperability, scalability, and a high level of security for industrial applications.

Wireless M-Bus

Wireless M-Bus enables reliable, secure and energy-efficient communication of measurement data over long distances. The IoT protocol is used in energy, water and smart metering.

IoT security protocols: Protecting connected devices

Important security standards for IoT devices include:

IPSec (Internet Protocol Security)

This protocol is responsible for secure communications over the Internet Protocol. IPSec provides a high level of security through encryption and authentication to protect data in transit and prevent unauthorized access. IPSec is commonly used in virtual private networks (VPNs) and Internet of Things (IoT) applications that require secure data transmission over the Internet.

OpenVPN

Open source software uses SSL/TLS for key distribution, supports multiple encryption algorithms, and can be protected by firewalls. OpenVPN supports secure remote connectivity for IoT devices that need to connect over public networks.

TLS (Transport Layer Security)

The TLS protocol encrypts data and provides integrity protection during data transmission. It's a good solution for securing communication channels and protecting sensitive data. TLS is widely used for web services, email, and messaging.

Choosing the right IoT protocols

Selecting the right IoT protocols is critical to the success of an IoT project. Companies need to consider several factors to assure that the protocols are appropriate for their application.

Important criteria include bandwidth requirements, latency requirements, range, energy efficiency, and the number of devices to be connected. The protocols selected may need to be compatible with existing systems and devices to facilitate integration and operation. Some protocols are also less expensive to implement and operate than others.

By carefully analyzing these factors, organizations can select the IoT protocols that meet their specific needs.

FAQ: Frequently asked questions about IoT protocols

What are IoT protocols? IoT protocols are standards that allow communication between IoT devices. They ensure a reliable and secure data transmission.

How do IoT devices communicate with each other? IoT devices communicate using a layered architecture, of which there are several models.

What are the different layers of IoT communication? The different layers include: Physical layer, data link layer, network layer, transport layer and application layer. Each layer is assigned to different IoT protocols with specific tasks.

Which protocol is used to connect all devices in the IoT? There is no universal protocol that connects all IoT devices. Specific protocols are used depending on the application and requirements, such as MQTT, CoAP or HTTP.

How many types of IoT communication are there? There are two main types of IoT communication: connection-oriented and connectionless communication.