A method is disclosed for facilitating a user activity related to a call. The method is implemented by a transmitter for a multi-user MIMO system having NT transmit antennas and\u2211k=1K\u2062\u2062NRkreceive antennas associated with K receivers respectively associated with the K users. The photopolymerizing lithographic plate excellent in its sensitivity as compared with the conventional one can be obtained. According to the embodiments of the present invention, the load between networks in an overlap area may be balanced. The furniture leg is suitable for tables of any kind, chairs, organ benches and the like. The process includes formation of a lactam which is reduced to the hexitol.