MQTT+: Enhanced Syntax and Broker Functionalities for Data Filtering, Processing and Aggregation

Dear all,

I would like to inform you of a paper recently published by my research group about MQTT+, an enhanced version of MQTT which provides data filtering, processing and aggregation at the broker.

Assuming a client publishing on the room1/temperature topic, MQTT+ allows a client to subscribe to advanced topics, such as:

Rule-based:  get notified only when temperature is greater than a certain value (e.g.,  $GT;value/room1/temperature)

Temporal aggregation: get notified on temporally aggregated values (e.g.,  $DAILYAVG/room1/temperature)

Spatial aggregation: aggregate values from different topics (e.g., $AVG/+/temperature)

Data processing: perform complex operations over data (e.g., $COUNTPEOPLE/image), assuming /image is a topic where images are published

MQTT+ allows also to combine the basic blocks together (e.g., getting the daily average only if it is greater than a certain value).

We believe that some of the functionalities we introduced are very useful in many occasions, and at the same time very simple to be implemented on a broker.  We have implemented all functionalities on the HiveMQ broker, but we are now porting
 everything to Mosquitto and will soon update the code online.

You can find an open version of the paper here: https://arxiv.org/pdf/1810.00773.pdf. I hope it can be a source of discussion, and any feedback is greatly appreciated. 

Best regards

Alessandro E. C. Redondi - PhD

Assistant Professor

Dipartimento di Elettronica, Informazione e Bioingegneria (DEIB)

Politecnico di Milano

Via Ponzio 34/5, 20133, Milano

ITALY

Tel: +39 02 2399 3403

http://home.deib.polimi.it/redondi/