@@ -189,13 +189,13 @@ The IPE shall map the 'result' attribute of an OGC/STA 'Observation' to the 'con
## 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 OGC/STA the IPE creates a <subscription> to the <container> resource in the CSE containing the desired data. Triggert by a sensor event a new <contentInstance> is added to the <container> by the <AE>. The IPE gets a <notification> message 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 the OGC/STA server. The OGC / STA applcation gets the sensor data either by polling the OGC / STA server or subscribing to the regarded "Datastream" at the MQTT broker of the OGC / STA server.
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 regarded "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. OGC/STA does not provide a publish/subscribe mechanism on HTTP protocol level, but OGC allows an optional MQTT extension for STA services <ahref="#_ref_i.1">[i.1]</a>. The IPE subscribes to the MQTT-Broker of the OGC/STA server. The OGC/STA server publishes its new "Observation" via the MQTT broker. The IPE creates a <contentInstance>using a HTTP request and copies the 'result' attribute of the "Observation" to the 'content' attribute of the <contentInstance>.
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 triggert by a Sensor Thing API 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.
