Using SDN as a key enabler for co-primary spectrum sharing

Over the past years the mobile traffic demands and the number of the connected devices have been constantly increasing thus indicating that in the near future the current spectrum usage models may fail to cover user needs. At the same time, spectrum scarcity over several Mobile Network Operators (MNOs) leads to inefficient spectrum usage. Co-primary spectrum sharing is a scheme for trading resources among MNOs, enabling flexible spectrum usage, which is arising as a possible solution to spectrum scarcity. However, up to now the schemes for co-primary shared access are hard to be implemented. The recently introduced concept of Software Defined Networking (SDN) gives the flexibility to MNOs' network configuration and, therefore, is arising as an enabler for efficiently handling spectrum trading. In this paper we present a complete functional architecture aiming at enabling co-primary spectrum sharing among MNOs. We, furthermore, propose a scheme for implementing the introduced architectural scheme, coupled with fully described information flows among the (SDN) network entities. Such solution enables the concurrent reconfiguration (when required) for both core and access network nodes, based on the spectrum trading process.