6.2 Communication Flow

Figure 6.2-1 shows the oneM2M-to-OGC/STA direction. In order to transfer data from a oneM2M sensor to the OGC/STA server the IPE creates a <subscription> to the <container> resource in the CSE containing the desired data. Triggered by a sensor event a new <contentInstance> is added to the <container> by the <AE>. The IPE gets a <notification> containing the <contentInstance> resource. The IPE constructs an "Observation" creation request and copies the 'content' attribute of the <contentInstance> to the 'result' attribute of the "Observation" and sends it to a "Datastream" to be created as detailed in Section 6.3.1 at the OGC/STA server. The OGC/STA applcation gets the sensor data either by polling the OGC/STA server or subscribing to the corresponding "Datastream" at the MQTT broker of the OGC/STA server.

Figure 6.2-1: Communication oneM2M-to-OGC/STA direction

Figure 6.2-2 shows the OGC/STA-to-oneM2M direction. The IPE subscribes to the desired "Datastream" of the MQTT-Broker at the OGC/STA server. The OGC/STA server publishes a new "Observation" via the MQTT broker triggered by a OGC/STA sensor. The IPE creates a <contentInstance> in a container, to be created as detailed in Section 6.3.2 in the CSE and copies the 'result' attribute of the "Observation" to the 'content' attribute of the <contentInstance>. The oneM2M applcation gets the sensor data either by polling the CSE or subscribing to the desired <container> at the CSE.

Figure 6.2-2: Communication OGC/STA-to-oneM2M direction

The following text is to be used when appropriate: