POI is the abbreviation of POINT OF INTERFACE, that is, a multi-system integration platform. It is mainly used for multi-band and multi-signal combination to achieve compatible coverage of multi-network signals. It realizes multi-system, multi-band signal transceiver and cable transmission: and is able to meet the versatile requirements of DTV, 2G,  3G, 4G,  5G (can support LTE MIMO) etc. The……