Implementation of the MQTT Protocol

[andrasmarkus]

Building on the current functionality of the simulator, the goal is to model the operation of the MQTT protocol. The proposed functionalities are as follows:

MQTT Broker: Clients (publishers and subscribers) communicate through the broker. The broker is responsible for receiving messages from publishers and routing them to the appropriate subscribers based on the topic.

Topics: Topics are strings that define how messages are routed by the broker. The broker forwards messages to subscribers based on the topic.

QoS Levels: These levels define how the protocol handles message delivery:

• QoS 0: “At most once” - no acknowledgment from the broker.
• QoS 1: “At least once” - the message is acknowledged but may be delivered multiple times.
• QoS 2: “Exactly once” - ensures the message is delivered only once.