Understanding Machine-to-Machine (M2M) Communication

M2M (Machine-to-Machine) communications enable devices and machines to communicate and exchange data without human intervention. Various standards and protocols facilitate M2M communication, such as MQTT, CoAP, LwM2M, HTTP, DDS, Zigbee, and Z-Wave.

M2M architecture is designed in such a way that its capabilities can be used for remote monitoring, predictive maintenance, automation, environmental monitoring, asset tracking, and more.

M2M System Architecture

Following are the elements of an M2M system. Let’s understand the functions or working of these M2M system architecture components.

• Things/Devices: These are equipped with communication capabilities to interact with other components of the M2M system. They can range from simple sensors and actuators to complex machines that can collect data or perform specific tasks.
• Connectivity: Devices require connectivity to communicate with each other and exchange data. The communication technologies can be wired or wireless, including cellular networks (2G, 3G, 4G, or 5G), Wi-Fi, Ethernet, Zigbee, LoRaWAN, or satellite.
• Network Infrastructure: This facilitates communication between devices and servers or cloud platforms. It also includes switches, routers (or access points), base stations, and other networking equipment that ensures data transmission and routing.
• Gateway: In some M2M systems, a gateway is needed as an intermediary between devices and servers/cloud. It can perform functions such as data pre-processing, protocol translation, or security functions. It also enables devices having different protocols to communicate with each other.
• Cloud Platform or Central Server: This serves as a central repository to collect data, process it (if required), and store it. It may host applications and services for specific actions or analysis. The cloud platform includes databases where data is stored for analysis, reporting, and retrieval.
• Analytics and Other Apps: These help in analyzing the data and processing it to derive insights and generate reports. They are also used to trigger actions based on analysis.
• User Interface: This can be in the form of mobile apps or web portals. They allow end-users or admins to monitor and control devices and check the overall system remotely.

The generic architecture of M2M can also be categorized into four phases as shown in the image above. It consists of collection of the data, transmission of the data through the communication medium/network, assessment of the data collected, and response to the machine based on the assessment.

Example:

Let’s take the example of a smart meter to understand the M2M concept. The smart meter records the electricity rate, which will be communicated to the software application over some medium using the internet. This application processes the data sent by the smart meter and decides whether the consumer device can be switched on at this time or at a later stage to conserve energy. Hence, the smart electricity meter here acts as an interface between both the consumer and the electric company to save energy and money.

M2M systems support a mechanism to manage and interact with multiple M2M Applications. The M2M system Architecture consists of the following:

• M2M Applications
• M2M Transport network, which covers Access network, core network (CN), and M2M service capabilities.

The architecture is divided into M2M Device domain and a Network and applications domain.

M2M Capabilities

The following capabilities of M2M have the potential to revolutionize various industries and applications. Some key M2M capabilities are as follows:

• Remote monitoring
• Data collection and analysis
• Automation of various processes and tasks
• Remote control and management of devices and systems
• Smart grids and energy management to allow real-time monitoring and control of energy
• Predictive maintenance
• Asset tracking
• Environmental monitoring
• Healthcare and telemedicine
• Smart home and IoT applications

M2M Applications

Cellular-based M2M solutions provide easier installation and provisioning, targeted mainly for short-term deployments. M2M communication could be carried over mobile networks such as GSM-GPRS, CDMA EVDO networks, 4G LTE, etc.

In M2M communication, the role of the mobile network is largely confined to serving as a transport network. M2M devices vary from highly mobile vehicles communicating in real-time, to im-mobile meter-reading appliances that send small amounts of data at random instants. It covers the communications between the M2M Gateway(s) and M2M application(s), e.g., xDSL, LTE, WiMAX, and WLAN.

Cellular M2M is widely adopted in energy, transport, real estate, and agriculture sectors.

As mentioned previously, a smart meter utilizes energy efficiently and hence brings down CO2 emissions. Hence, M2M helps in lowering the effect of global warming. In the transport sector, M2M helps by providing information regarding the best-optimized routes to trucks, ships, trains, and planes so that wastage of fuel can be avoided. This also helps reduce CO2 emissions by cutting the distance of the travel.

M2M helps in building and home management by conserving energy for various systems viz. cooling, lighting, heating, ventilation, and other electronic appliances. It also provides security for the home or building owner with the M2M compliant security-enabled devices.

In the agriculture sector, M2M provides solutions to monitor cattle health and grazing style, soil monitoring, smart farming, and smart watering. This helps grow a large amount of crops with fewer resources and hence saves money for the farmers.

M2M Protocols

M2M (Machine-to-Machine) Communication relies on various standards and protocols to ensure interoperability and efficient data exchange between devices and systems. Some of these key standards are described below.

• MQTT (Message Queuing Telemetry Transport): It is a publish-subscribe messaging protocol designed for IoT and M2M applications. It operates on a broker-based architecture, which allows devices to publish messages to a central server (i.e., broker), which later distributes those messages to other devices (subscribers) as per their requests.
• CoAP (Constrained Application Protocol): It is designed for M2M communication in constrained environments such as low-power devices and networks. It is based on REST architecture.
• LwM2M (Lightweight M2M): It is a protocol developed by the Open Mobile Alliance (OMA) for M2M communication in IoT devices. It is used to manage and control devices remotely. It can be used for firmware updates, monitoring, and configurations of devices.
• HTTP (Hypertext Transfer Protocol): It is widely used for web communication. It is used when interacting with web-based services and APIs.
• DDS (Data Distribution Service): It is a standard for real-time data distribution.
• AMQP (Advanced Message Queuing Protocol): It is a messaging protocol that allows reliable message delivery between devices and systems.
• Zigbee: Low-power wireless standard that works in mesh topology. It is defined in IEEE 802.15.4 standard. It is used in home automation and industrial settings for M2M communication.
• Z-wave: It is another wireless communication standard used in smart home automation and other M2M applications.
• 3GPP: It defines various cellular standards which include GSM, LTE, and 5G, etc. These standards are often used for M2M communication.
• OPC UA: It is a machine-to-machine communication protocol used in industrial automation to enable interoperability and data exchange between different machines and systems.

There are several more M2M standards and protocols which include Modbus, CAN, Thread, Bluetooth, LoRaWAN, Sigfox, AMT, XMPP etc.

M2M References

• Standard - ETSI TS 102 689: Machine to Machine Communications (M2M); M2M service requirements
• Standard - ETSI TS 102 690: Machine to Machine Communications (M2M); M2M functional architecture

These documents can be downloaded from the website: https://www.etsi.org/Website/Technologies/M2M.aspx

Conclusion

M2M communication offers increased efficiency and improved user experiences. M2M protocols offer unique capabilities such as MQTT/CoAP are used for lightweight messaging, LwM2M for remote device management, DDS for real-time data distribution, HTTP for web-based interactions, etc. The Zigbee and Z-Wave are used for low-power wireless connections.