In this paper we report on a wireless Ethernet link over 60GHz mmWave, which is a full-duplex wireless link in the same frequency channel. To provide a dense wireless network, beam forming with a phased-array transceiver is a key technology for frequency reuse. We introduced a particle swarm optimization algorithm for beam forming with effective interference cancellation in each field. This method works independent of the transceiver arrangement and is free from device-specific variability and non-linearity. We prototyped the wireless Ethernet link system and achieved a BER less than 1.0E-11 at a 3m distance. We were able to prove its feasibility at system-level application.