MQTT vs DDS in IoT | Difference between MQTT and DDS

This page compates MQTT vs DDS protocol used IoT. It mentions difference between MQTT and DDS (Data Distribution Service) w.r.t. architecture, requirements, complexity etc.

MQTT Protocol

Broker based MQTT protocol

The figure-1 depicts MQTT protocol architecture. Following are the features of MQTT protocol:
• It consists of three components viz. publishers, broker and subscribers.
• It is based on publish/subscribe architecture.
• Publishers are like sensors or IoT devices which send their data or change in some information to the broker as per topic.
• Subscribers are like applications which subscribed with broker to receive change in parameters of a certain topic or sensory data.
• Refer MQTT vs HTTP>> for core features of MQTT protocol.

Refer MQTT Protocol>> for more information.

DDS Protocol

Following are the features of DDS protocol.
• It is broker less protocol used mainly for M2M and IoT applications.
• It is session layer protocol.
• Instead of broker, it uses data writers and data readers.
• Like MQTT, it is also publish/subscribe protocol without broker.
• It has 23 QoS levels which include security, priority, reliability, urgency, durability etc.
• Let us see working of DDS protocol. Publisher distributes the sensory data to be delivered. Data writer part interacts with the publisher and takes of any changes to be sent to subscribers. Data readers read the published data and deliver to subscribers. Subscribers need to subscribe for the topic which is nothing but sensory data.

Following table mentions comparison between MQTT and DDS protocols.

Features MQTT DDS
Full Form Message Queue Telemetry Transport Data Distribution Service
Architecture Centralized, all communications route through the broker. Decentralized, peer to peer communication.
Transport layer protocol TCP UDP
Admin needed Yes, Broker is required to be installed, all the clients configured with server or broker address No, automatic discovery (i.e. plug and play), self forming, self healing
message rate few messages/second per device upto 10000s messages/second per device
Service interruptions They are tolerable in MQTT network. They are potentially calamitous in DDS architecture.

IoT Wireless Technologies

WLAN    ➤THREAD    ➤EnOcean    ➤LoRa    ➤SIGFOX    ➤WHDI   
Zigbee   ➤6LoWPAN   ➤Zigbee RF4CE   ➤Z-Wave   ➤NFC   ➤RFID   ➤INSTEON  

What is difference between

Difference between OSI and TCPIP layers  Difference between TCP UDP  FTP vs HTTP   FTP vs SMTP   FTP vs TFTP   ARP vs RARP   NAT vs PAT   RIP vs OSPF  SLIP vs PPP  IMAP4 vs POP3  IPV4 vs IPV6 

RF and Wireless Terminologies