The next generation of mobile communications, also known as 5G, aims to address current and future IP-tsunami capacity problems while meeting the various service requirements. It is necessary to increase the network capacity and flexibility to meet the different Quality of Service (QoS) requirement of different services. The approach proposed by 5G NORMA project is to achieve the service flexibility by means of decomposition of mobile Network Functions (NFs) and to place them in different cloud data centres. The placement of NFs is done adaptively based on the service requirements. This whitepaper briefly present the concept of Software Define Mobile network Controller (SDM-C) in addition to a report on the proof-of-concept within the framework of the 5G NORMA project.