Modern Data Transmission Protocols for Precise Positioning

Improving access to precise positioning information by utilising modern data transmission protocols.

The Challenge

Real-time streaming of GNSS data and corrections via the Internet is one of the key enablers for precise positioning solutions. For more than a decade, NTRIP or Network Transport of RTCM (a standard) via Internet Protocol, has been the standard to disseminate GNSS data and corrections streams in real-time for accurate and precise positioning applications, as well as scientific and research communities. With technology advances in the hardware, software, and wireless communications, NTRIP faces several challenges that may limit the uptake and reduce the efficiency of precise positioning by modern mass-market applications. These include system hierarchy and scalability; operation efficiency and optimization; and protocol and software support. The objective of this scoping study is to review and evaluate modern data transmission protocols for improving access to real-time precise positioning information for modern mass-market applications.

Partners

The primary project partners were Geoscience Australia and Queensland University of Technology.

The Solution

This scoping study reviewed and evaluated seven modern IoT data protocols for GNSS data transmission, namely: HTTP, CoAP, MQTT, AMQP, Websocket, Kafka and 3GPP LTE Positioning Protocol (LPP). Protocol evaluations were based on the standards, academic literatures, and industry whitepapers over the past decade on various application scenarios, mostly related to IoT or smart applications (i.e. smart-city, smart farming, etc). The transmission protocols needed to satisfy the following requirements:

  • Utilise open standards.
  • Be interoperable with and supported by modern applications.
  • Have a highly scalable, reliable and secure system architecture.
  • Provide additional benefits to existing and future real-time GNSS applications through features such as buffering of data during telecommunication outages, interoperability with other systems, and reduction and optimisation of data transmission bandwidth.

MQTT scored highly in most areas, whereas HTTP/WebSocket lags others due to the request-response model designed for web applications. As NTRIP is based on HTTP for establishing the connection, it has similar characteristics and performance to HTTP. Overall, MQTT is considered the most flexible and versatile data communication protocol available to address future precise positioning requirements and is recommended for the future GNSS precise positioning sector. Furthermore, a hybrid solution that aggregates the strengths of multiple selected protocols may further improve the overall GNSS data transmission landscape.

Impact

Access to low latency, highly available GNSS data and correction streams in real-time is essential for modern precise positioning applications. This scoping study aimed to ensure that GNSS data streaming efforts meet the needs of modern users by recommending a protocol for future real-time GNSS data and correction streaming. The MQTT protocol or a hybrid solution will:

  • Improve efficiency and scalability needed to handle the expected volume of modern mass-market users.
  • Enable effective handling of the evolving GNSS data and correction message types and formats.
  • Provide the additional features needed to benefit CORS network operation and provide highly available and dependable services.

This project outlined several concepts to improve future precise positioning services. It is also necessary to continue this exploration and discussion with international GNSS communities. Potential future work includes:

  • The development, testing and demonstration of a proof of concept platform.
  • MQTT topic hierarchy design which is the key to incorporating the proposed benefits and will ensure interoperability among systems.
  • Development and demonstration of positioning tools integrating correction delivery through MQTT.
  • Alignment with the ACS software platform and the geodetic data interchange standards projects.
Project Summary

Download the final project summary here (PDF, 152KB)

Contact

To learn more, contact FrontierSI at contact@frontiersi.com.au or Positioning and Geodesy Technical Lead, Eldar Rubinov, at erubinov@frontiersi.com.au