diff --git a/TS-0041-oneM2M-SensorThings_interworking.md b/TS-0041-oneM2M-SensorThings_interworking.md
index a64dd604880e1ef7e6b945e4b2c3ed671e073d5a..2483fe6181ecc9000b1c0fe3261ca7d63a2bd3e5 100644
--- a/TS-0041-oneM2M-SensorThings_interworking.md
+++ b/TS-0041-oneM2M-SensorThings_interworking.md
@@ -167,7 +167,7 @@ The Sensing Entities data model and the purpose of data within the data model di
 
 Figure 6.0-1 shows an architecture approach for an Interworking Proxy Entity (IPE) between oneM2M and the OGC SensorThings API. The IPE is located between a oneM2M CSE and an OGC/SensorThings API (STA)-Server. 
 
-The basic interworking enables applications that are connected to an oneM2M-based system to get data from sensors that are connected to an OGC/STA server. Furthermore, an application that is connected to an OGC/STA server will be able to get data from sensors that are connected to an oneM2M-based system.
+The basic interworking enables applications that are connected to an oneM2M-based system to get data from sensors that are connected to an OGC/STA server. Furthermore, an application that is connected to an OGC/STA server will be able to get data from sensors that are connected to an oneM2M-based system. The communication flow of the IPE relies on HTTP and MQTT. The MQTT protocol enables publish-subscribe functionality for the OGC side, as specified in the MQTT extension of the SensorThings API <a href="#_ref_i.1">[i.1]</a>.
 
 ![Figure 6.0-1: IPE architecture overview](media/STA_oneM2M_architekturbild_01.svg)