Update 'doc/smart_home_technical_paper'

doc/smart_home_technical_paper

   A couple of market-leaders like eq-3, Amazon and Control4 have already established their own ecosystems with their own networking protocolls.
   Since the market is still growing, more companies join the smart home market with their own solutions and the vast variety of communication protocolls is ever growing.
   Existing community projects like FHEM, ioBroker and openHAB try to address this by providing a unified interface for a number of protocolls.
-  Because these projects either lack in usability (FHEM), require the knowledge of a specifiy programming language (openHAB) or lack customizability (ioBroker) we will describe in this paper a three-layered implementation of a highly customizable and easy to program solution.
+  Because these projects either lack in usability (FHEM), require the knowledge of a specifiy programming language (openHAB and Java) or lack customizability (ioBroker) we will describe in this paper a three-layered implementation of a highly customizable and easy to program solution.
   Section 2 covers the used hardware and communications design for the smart home environment. 
   The used software, why the software was used and how it works is described in section 3 and in section 3 
   Section 2 contains the outline of the setup used and we will describe the specific components and explain why they are used in Section 3
 
-2. THE GATEWAY's HARDWARE AND NETWORK COMMUNICATION
+2. THE GATEWAYs HARDWARE AND NETWORK COMMUNICATION
   A Raspberry Pi is used as the basis of the smart home gateway. 
   It provides a full linux installation with raspbian lite which is well equipped to run headless, has only basic applications preinstalled and uses few resources by passing on a graphical user interface.
   
   To communicate with commercial sensors the radio-tranciever HM-MOD-RPI-PCB from ELV is used.
   It provides an easy to use 868,3/869,525 MHz radio tranciever which connects to the raspberry pis GPIO-Pins
   
-3. THE SETUPS SOFTWARE
+3. THE SETUPs SOFTWARE
   [IMAGE]
   The smart home environment is comprised of three key layers: 
-  the logic-layer with node-red and node-red-dashboard implements the logic for the presencedetection and the graphical user interface.
-  node-red is used because it provides an easy-to-use flow-based programming interface.
-  data is represented by nodes 
-  mqtt is the protocol used in the networking-layer to relay data coming in from sensors to the logic-layer.
-  the interface-layer is used to connect 
+  the logic-layer uses node-red and node-red-dashboard to implement the smarthome logic and graphical user interface.
+  the networking-layer uses the protocol mqtt to use the raspberry pis wifi capabilities to communicate to wifi-sensors and to connect the third - interface - layer with the logic layer.
+  the interface-layer serves as the connection to proprietary sensors from companies like phillips and homematic.
+  It is comprised by software (homegear and piVCCU) which speak the vendor-specific protocols used by commercial sensors and actuators. 
+  The communication with the sensors is done via the 433MHz or 866MHz radio band