09. December 2024, 14:00 until 15:00

PhD defense Jürgen Fredriksson

Other

MQTT, a suitable protocol for GNSS data transmission

Currently, the common ways to distribute Global Navigation Satellite System (GNSS) data from a reference station, a so called CORS, are the protocols Networked Transport of RTCM via Internet Protocol (Ntrip) and Transmission Control Protocol (TCP). Using TCP will be the adequate choice if the GNSS data source and their consumers are in the same Local Area Network (LAN). If data should be provided over the internet, the Wide Area Network (WAN), Ntrip will be the better choice. This protocol has simple security features such as authentication and authorization of connected clients and has been considered as the quasi-standard for GNSS data transmission for decades. As a matter of fact Ntrip version 1.0 respectively, version 2.0 are further abstractions over Hypertext Transfer Protocol (HTTP), version 0.9 respectively, version 1.1 which need a special client which is able to handle this protocol. Furthermore, its main design focuses on transmitting documents like websites instead of continuously streamed binary data. Using a protocol that is more suitable for Machine to Machine (M2M) transmission will improve the provision of GNSS data over the network. Message Queuing Telemetry Transport (MQTT) or Advanced Message Queuing Protocol (AMQP) are open and reliable protocols that meet this requirement. They have some advantages over Ntrip like a smaller header, delivery guarantees and a security layer to data transmission. Compared to Ntrip and due to its short header and high throughput, especially MQTT will reduce hardware resources to transfer the same amount of data and make it also more energy efficient. This thesis will mainly focus on the implementation and evaluation of a prototype to compare MQTT and Ntrip from four points of view: the latency of the delivered GNSS data, the system resources used for transmission, the position accuracy and fixing time of a connected GNSS receiver and the data transfer rate. Therefore, a suitable test scenario must be designed and implemented. In summary, the thesis deals with the question if MQTT is a suitable choice for the efficient distribution of GNSS data from one end point to one or many others.

Calendar entry

Event location

FH HS 7, yellow area, 2nd floor
1040 Wien
Wiedner Hauptstraße 8

 

Organiser

TU Wien

 

Public

Yes

 

Entrance fee

No

 

Registration required

No