MQTT-Topic Naming Criteria of Open Data for Smart Cities

Nowadays, the need of sharing of dynamic open data to improve the cities intelligence are increased significantly. To share these data, MQTT, the lightweight messaging publish/subscribe protocol is one of most popular protocols. The sharing of data via MQTT includes two components; topic and message where the topic element is used to define which the subscriber are received which data, meanwhile the data are presented in the message element. However, There are none of criteria or standard of topic naming to share the open data via MQTT. It makes the sharing of open data is too difficult with MQTT protocol. In this work, we propose MQTT-Topic Naming Criteria of Open Data for Smart Cities (MTNC) to be the criteria of topic naming for the open data of any city. The proposed criteria used in both processes; publishing and subscription of MQTT messages. Then, we evaluate the impact of MTNC on the data selecting and searching of the subscribers who not know the MTNC. The results show that topic naming with MTNC is more effective than the topic naming without MTNC in selecting and searching topics of the subscribers. The average numbers of the subscribers can found their needed data when they select the data from the list of topics are 7/10 and 3/10 time with and without MTNC respectively. Moreover, the experimental results show that the most keywords that the subscribers often use in their topic searching are the objective of data presented in MTNC.