The IoT technology stack could be split into Applications and Analysis, Services (including cloud), connectivity such as Internet Communication Protocols (e.g. TCP/IP, MQTT etc) as well as the term of "things". The latest include Robotics, Sensors, Metering technology, Smart technology (e.g. watches), Cameras, Mobile Phones and others.
As for the telecommunication part, I agree with all the aforementioned plus the fact of advanced radio techniques such as OFDM, Angle of Arrival Techniques in order to properly estimate the correct signal source as well as advanced software algorithms specialized for each application.