Protocols and Standards Behind IoT: CoAP, BLE, MQTT, DDS

IoT is so much more than just a huge mesh of connected devices or simple automation; it's potentially driving markets and changing a number of industries worldwide. Now, the overwhelming number of physical objects and devices are capable of collecting, storing, processing, automating, and conveying end-to-end information to applications, servers, and other objects. They include medicine, transportation, automotive, manufacturing, retail, security, and other numerous industries.

As we already know, an IoT device is designed in such a way that it can efficiently function and enable the live exchange of data online with other connected communication networks. While developing an IoT system is as easy as ABC, with a vast spectrum of communication and messaging protocols available, choosing the right one to make a connection possible might be difficult.

The decision to selecting the ideal protocol for your IoT product depends on various factors of your device, including the architecture, layer, type, and functionality. Each connectivity protocol comes with its own set of positives and negatives. To help you make the right decision, we've analyzed the four dominant, widely-used IoT protocol options for IoT apps. Let's have a look at each of them in greater detail.

#1: Bluetooth

Bluetooth is one of the most extensively used short-range wireless communication protocols for various consumer and computing products. The communication technology is expected to take the IoT architecture to the next level and become the key for various wearable and wireless devices. The new Bluetooth Low Energy (BLE) protocol or also called Bluetooth Smart is a modified version offering a similar range to the traditional Bluetooth while reducing data rates and power consumption. Eddystone is a protocol specification used to define the message format of BLE for propinquity beacon interactions. This protocol is going to structure the underlying base for most IoT devices and to all market innovations since it's flexible and scalable.

#2: Constrained Application Protocol (CoAP)

A standard IoT architecture consists of a software system, application layer, communication, and hardware, with CoAP acting as the application protocol layer. The IETF Constrained RESTful Environments (CoRE) developed an Internet utility and productivity protocol for constrained internet devices. This lightweight analog is designed to work with restricted nodes and networks by enabling them to connect to the IoT with low availability and bandwidth.

CoAP acts as a kind of HTTP that uses RESTful architecture to create a communication bridge between the IoT and various component-level elements and equipment such as actuators and sensors. Even in poor network quality, the CoAP enables devices to send data reliably and maintain a small distant communication successfully. One of the best aspects of CoAP is that it allows you to choose a data model of your choice. Similar to HTTP, it involves a variety of payloads and can be integrated with different data formats, including CBOR, JSON, XML, and so on.

From a developer's point of view, getting a value from a sensor is much similar to obtaining data from a web API. When a client sends a request to access resources through the usage of methods like PUT, GET, POST, and DELETE, the server responds and makes resources available at a Uniform Resource Identifier (URI).

#3: Message Queue Telemetry Transport (MQTT)

MQTT is one of the most dominating machine-to-machine (M2M) protocols based on the publish/subscribe message model. This message protocol uses TCP/IP layer for connections with remote locations and also for sending dependable and secure streams of information. Transferring data flows from sensors allows this message protocol to connect the gadget and its networks with the middleware standard (dealer) and different packages.

As far as its mechanism is concerned, the MQTT message protocol comprises three primary components to standardize its functionality: Subscriber; Publisher; and Broker.

• Publisher: collects the information generated by the writer and transfers it to subscribers by the means of the usage of the broker component.
• Broker/Dealer: checks the authorization of publishers and subscribers to ensure security.

This protocol is mainly useful when there's a need for monitoring and handling huge ecosystems of small devices via the internet. The classic examples are underwater lines, parking sensors, and power grids.

Pros:

• Lightweight and works extremely well for constrained networks
• Flexibility and freedom to choose Quality of Services with underlying network infrastructure and other given functionality
• Developed, standardized, and defined by OASIS Technical Committee
• Quick to set up and easy to implement

Cons:

• High power usage due to the TCP-based connection
• Short of encryption

#4. Data Distribution Service (DDS)

Designed and summarized by Object Management Group (OMG), Data Distribution Service (DDS) is a competent IoT protocol for scalable, real-time M2M communication. The protocol has been built and implemented to last for decades. This protocol leverages multicasting techniques in the transmission of data and high-quality QoS in the small memory footprint devices and to applications. It employs Data-Centric Public-Subscribe (DCPS) layer to directly communicate the information from publishers to subscribers and deliver reliable, scalable performance in embedded systems.

Since this message model has databus that directly connects subscribers and producers, it doesn't require a broker carrier to convey any sort of information. In addition to that, the DDS standard makes use of Data-Local Reconstruction Layer (DLRL) to provide a functional, powerful interface to carry out submit-subscriber functionalities. DDS successfully authorizes the allotment of distributed data amongst varied platforms and IoT enabled systems, ranging from real-time objects to cloud platforms. DDS is designed in such a way that it utilizes minimal resources, not only on the device but also on the network.

Conclusion

When it comes to selecting an IoT communication protocol for your project, there's no one-stop solution. While one protocol offers a disciplined plan to monitor as well as secure billions of interconnected devices and nodes, another one will be better at supporting green bandwidth usage and lowering power requirements while covering a whole host of industries and new IoT use cases. In the end, your decision to choosing the best communication protocol for IoT-based systems depends on your individual requirements and business needs, so think and pick accordingly.