In this blogpost I continue discussion around Industrial Connected Fleets from the M2M (machine-to-machine) point-of-view.
M2M and IoT. Can you do one without another?
M2M machine-to-machine refers to an environment where networked machines communicate with each other without human intervention.
Traffic control is one example of an M2M application. There multiple sensing devices collect traffic volume and speed data around the city and send the data to an application that controls the traffic lights. The intelligence of this application makes traffic more fluent and opens bottlenecks and helps traffic flow from city areas to another. No human intervention is needed.
Another example is the Auto industry, where cars can communicate with each other and with infrastructure around them. Cars create a network and enable the application to notify drivers about the road or weather conditions. Also in-car systems are using M2M for example rain detectors together with windshield wiper control.
There are lots of examples where M2M can be used. In addition to the above, it is worth mentioning the Smart Home and Office applications, where for example one device measures direct sunlight near the window and notifies the window blind controller to close the blinds when brightness threshold value is crossed. Another very interesting M2M areas are robotics and logistics.
M2M sounds a lot like IoT. What’s the difference? Difference is in network architecture. On M2M Internet connectivity is not a must. Devices and device networks can communicate without it. M2M is point-to-point communication and typically targets single devices to use short-range communication (wired or wireless). Whereas IoT enables devices to communicate with cloud platforms over the internet and gives cloud computing and networking capabilities. The data collected by IoT devices are typically shared with other functions, processes and digital services whereas M2M communication does not share the data.
I can say that IoT extends the capabilities of M2M.
Networking in M2M
M2M does not necessarily mean point-to-point communication. It can be point-to-multiple as well. Communication can be wired or wireless and network topology can be ring, mesh, star, line, tree, bus, or something else which serves the application best, as M2M systems are typically built to be task or device specific.
For distributed M2M networks there are a number of wireless technologies like Wifi, ZigBee, Bluetooth, BLE, 5G, WiMax. These can also be implemented in hardware products for M2M communication. Of course one option is to build a network with wired technology as well.
There are few very interesting protocols for M2M communication, which I go through at a high level. These are DDS, MQTT, CoAP and ZeroMQ.
The Data Distribution Service DDS is for real-time distributed applications. It is a decentralized publish/subscribe protocol without a broker. Data is organized to topics and each topic can be configured uniquely for required QoS. Topic describes the data and publishers and subscribers send and receive data only for the topics they are interested in. DDS supports automatic discovery for publishers and subscribers, which is amazing! This makes it easy to extend the system and add new devices automatically in plug-and-play fashion.
MQTT is a lightweight publish subscribe messaging protocol. This protocol relies on the broker to which publishers and subscribers connect to and all communication routes through the broker (Centralized). Messages are published to topics. Subscribers can decide which topic to listen to and receive the messages. Automatic discovery is not supported on MQTT.
CoAP (Constrained Application Protocol) is for low power electronic devices “nodes”. It uses an HTTP REST-like model where servers make resources available under URL. Clients can access resources using GET, PUT, POST and DELETE methods. CoAP is designed for use between devices on the same network, between devices and nodes on the Internet, and between devices on different networks both joined by an internet. It provides a way to discover node properties from the network.
ZeroMQ is a lightweight socket-like sender-to-receiver message queuing layer. It does not require a broker, instead devices can communicate directly with each other. Subscribers can connect to the publisher they need and start subscribing messages from their interest area. Subscriber can also be a publisher, which makes it possible to build complex topology as well. ZeroMq does not support Automatic discovery.
As you can see there is a variety of these protocols with features. Choose the right one based on your system requirements.
Make Fleet of Robots work together with AWS
DDS is great for distributed M2M networks. For robotics there is the open-source framework ROS (Robot Operating System). The version 2 (ROS2) is built on top of DDS. With the help of DDS, ROS nodes can communicate easily within one robot or between multiple robots. For example 3D visualization for distributed robotics systems is one of ROS enabled features.
I recommend you check AWS IoT RoboRunner service. It makes it easier to build and deploy applications that help fleets of robots work together. With the RoboRunner, you can connect your robots and work management systems. This enables you to orchestrate work across your operation through a single system view. Applications you build in AWS RoboMaker are based on ROS. With the RoboMaker you can simulate first without a need for real robotics hardware.
Our tips for you
It’s very clear that M2M communication brings advantages like:
- Minimum latency, higher throughput and lower energy consumption
- It is for mobile and fixed networks (indoors and outdoors)
- Smart device communication requires no human intervention
- Private networks brings extra security
And together with IoT, the advantages are at the next level.
Supercharge your system with a distributed M2M network and make it planet scaled with AWS IoT services. The technology is supporting very complex M2M networks where you can have distributed intelligence spread across tiny low power devices.
Check out our Connected Fleet Kickstart for boosting development for Fleet management and M2M: