Add the backend infrastructure architeture with a hint document

Author: Karsten Reincke

NOTICE

@@ -9,4 +9,6 @@ Contributors:
 - Mark Düsener [], T-Systems International GmbH 
 - Karsten Reincke [kreincke], Deutsche Telekom AG
 - Thomas Klingbeil [tklingbeil], SAP SE
-- Eyk Kny [eykkny], SAP SE
+- Eyk Kny [eykkny], SAP SE
+- Steffen Grießhaber [], T-Systems International GmbH
+- Martin Mitev [], T-Systems International GmbH

backend-infrastructure-architecture.md

@@ -0,0 +1,9 @@
+# German Corona Warn App (CWA)
+## Backend Infrastructure Architecture Overview
+
+The file ``backend-infrastructure-architecture.pdf`` complements the “CWA Solution Architecture” document. It is intended as a technical overview document
+of Corona Warn App (CWA) and its underlaying infrastructure and network.
+
+This description of the **cwa backend infrastructure architecture** is not published as md file, because it is not intended to be developed together with the community. Whoever takes the sources and sets up his own 'corona warn app' may useanother backend structure. Nevertheless, it might be helpful to know how the currect project is implemented in a datacenter. Therefore, we publish this documen t as pdf file.
+
+