Concept, design, and prototype of shared base station supporting millimeter waves for 5G cellular networks

In the 5G cellular networks, micro-cells using mmW (millimeter Wave) bands will be densely deployed to enhance communication speed and capacity. On the other hand, mobile network operators are facing a significant challenge of how to realize ultra-dense micro-cell networks in a cost-effective manner. Recently, a new concept of network sharing toward multi-tenancy networks has been proposed and studied. In this concept, network resources including the BS (Base Station) are shared by multiple operators, resulting in significant cost reduction. In this respect, the shared BS needs to support several RATs (Radio Access Technologies) including mmW bands for providing a variety of communication systems. In this study, we prototype a shared BS supporting mmW bands based on the LTE system, by applying the frequency conversion technology to the off-the-shelf LTE eNB. This shared BS is mainly composed of an IF transceiver unit for the 4.5 GHz band and RF converter units for 28 GHz and 32 GHz bands. In addition, by applying the same architecture to the off-the-shelf UE, we successfully demonstrate the data transmission between the shared BS and the UE in 4.5 GHz, 28 GHz, and 32 GHz bands.