DDS Protocol in IoT: Features, Architecture, Working, and Applications 

The abbreviation DDS in the DDS protocol stands for Data Distribution Service protocol. Basically, it is an IoT protocol created by Object Management Group (OMG), purpose-built for M2M (i.e. Machine-to-Machine Communication). It ensures the exchange of data through a subscribe-publish model. Contrary to MQTT and CoAP protocols, DDS utilizes a brokerless architecture.  

It utilizes multicasting to make sure that Quality of Service (QoS) is in the high ranges for the applications. The protocol is known to be quite versatile, ideal for deployment on services starting from low-footprint embedded systems to cloud-driven environments.  Let us cover all the basics of the DDS protocol architecture and how it works. In this blog, we will take a closer look at the brokerless architecture that makes it efficient in the domain of the Internet of Things.  

What Is the DDS Protocol? 

DDS is an open standard mainly used for real-time applications. Primarily, it is an API standard and middleware protocol that focuses on enabling interoperable, high-performance, and scalable exchanges of data via the publish-subscribe pattern. It is the only open standard used for messaging that provides support to the unique needs of an enterprise and real-time systems. It supports all applications that require data exchanges in real-time such as defense, aerospace, simulation, air traffic control, and testing. It is a technology for software connectivity that ensures secure exchange of real-time data, rapid integration in industrial IoT, and modular application development.  

Architecture of the DDS Protocol 

The main architecture is explained via the following sections:  

Model: 

DDS is a middleware that makes network programming a lot simpler. It utilizes a pattern called publish-subscribe for sending and receiving information between the nodes. It transfers the data that nodes create to the subscribers who are interested in that particular topic. It manages transfer tasks like delivery, message addressing, and flow control. Every node can be a subscriber or a publisher, or both at the same time.  

Protocol: 

In the context of the Internet of Things, DDS employs a brokerless approach unlike CoAP and MQTT. Leveraging publish-subscribe methodology, it is mainly used for M2M communication. It utilizes multicasting to increase the QoS of the applications. The protocol is developed and managed by the Object Management Group. In the DDS protocol, there are two layers called: 

• DLRL. 

• DCPS.  

The term DCPS is a short form for Data-Centric Publish-Subscribe. It is a standard application programming interface for a topic-based, data-centric, and real-time subscribe/publish layer. The main purpose of this layer is to deliver data to the subscribers.  

The term DLRL is an abbreviation of the concept Data Local Reconstruction Layer. It is a standard Application Programming Interface for generating object views from topic collection. Its purpose is to ensure an interface for DCPS functionalities. This enables seamless sharing of distributed information among IoT-enabled devices.  

How It Works: 

• Data Distribution Service is a Global Data Space, which is fully distributed to prevent a central point of bottleneck and failure.  

• Applications can asynchronously and autonomously read and write data in GDS. 

• Since subscribers and publishers are discovered dynamically, they can become a part of GDS or leave it at any time.  

• The matching of subscriptions happens by considering all the topics, such as data type, name, etc.  

• Total subscriptions are matched dynamically, and the information flows from the publisher to subscribers.  

What Are the Applications of the DDS Protocol? 

RTPS packets and DDS are mainly utilized for mission-sensitive applications. In IoT, it tethers embedded systems and establishes a dependable communication layer between controllers, sensors, and actuators. Let us look at the main application of DDS in various industries: 

• Virtualization and Cloud: DDS in the areas of virtualization and data centers range from high-level utilization of software to low-level improvements. From handling machines and virtual units for effective exchange of data to how computing cores and VMs interact with one another. DDS is often the perfect choice for add-on or in-built capabilities for integration. Utilizing its multicasting capabilities, DDS can be leveraged across distributed networks to create the look of a uniform DDS-driven network.  

• Network and Telecommunication: In the sector of networks and telecommunication, the DDS protocol is used to enable and optimize communication between various network equipment, like optical transponders. These are the components that provide the basics of 5G mobile transport. Effective systems for establishing settings, tracking equipment, and implementing updates are also developed and distributed via DDS. The protocol is also being explored for SDN technologies to ensure integration in futuristic networking control planes.  

• Healthcare: DDS is utilized by healthcare stakeholders and organizations to enable interoperable connectivity of data for clinical systems and medical devices. Major applications in the healthcare sector include global healthcare institutions with real-time requirements, enabling medical devices for the safety of hospital patients, and the incorporation of clinical decision systems like medical tablets and computers. 

• Defense: The main use of DDS in the sector of defense includes weaponry and management, navigation systems, radar, and C&C systems. Renowned agencies like NASA utilize the DDS protocol in their launch control system. Mainly, NASA utilizes DDS in data acquisition and SCADA systems.  

• Energy: Climate change-related problems create the need for major evolutions and innovations due to widespread Industrial IIoT solutions. Areas of concern are being addressed with the help of existing technologies. Moreover, DDS is being implemented by both organizations and states for research and development. Essentially, DDS finds its use in applications like storage and management, power generation, and control and distribution.  

• Internet of Things: It ensures secure and reliable data exchanges between applications and devices in real-time. The importance of the DDS protocol in IoT makes it relevant for robotics, transportation, and industrial automation. DDS works on a publish-subscribe model where devices, i.e., publishers, share data related to any topic, and devices, i.e., subscribers, get the data they are interested in. DDS can facilitate V2I and V2V communication. Moreover, it can also help in collecting data from sensors fixed in safety systems and autonomous driving vehicles.   

Conclusion  

DDS is an open standard and middleware protocol as well as an API standard for scalable data exchange between devices in real-time. The DDS protocol is known for high QoS, broker-less architecture, publish-subscribe model, scalability, and real-time applications. The blog focuses on DDS and offers an overview of its fundamentals. For more information on IoT protocols, explore our website.  

Frequently Asked Questions 

Q. What Are IoT protocols? 

A- These protocols are the set of standardized rules and language that define how IoT devices, cloud platforms, and servers communicate with one another. Major IoT protocols include MQTT, CoAP, LoRaWAN, Wi-Fi, Zigbee, Bluetooth, etc.   

Q. Is It important to learn about the DDS protocol for IoT interview? 

A- The questions regarding DDS can be asked in an IoT interview. IoT interview questions basically cover all the fundamentals and real-life concepts.  

Q. In what programming language is DDS used as a standard messaging API for? 

A- DDS is mainly a standard application programming interface for the C++ coding language.  

Q. Are DDS and XMPP protocols related? 

A- Yes, both XMPP and DDS are related as they both support the publish/subscribe architecture. Moreover, both are used for real-time programs and applications. However, both have extremely different features and serve distinct purposes.  

Q. Are both SSH and DDS protocols used in the networked ecosystem? 

A- Yes, both are used in networked system. While DDS ensures reliable data exchange and real-time purposes, the SSH protocol in IoT prioritizes security in remote access.