Kumu Networks, a wireless startup which claims to have eliminated self-interference from Wi-Fi radios, announced today that it had raised another $25 million in venture capital funding from Cisco, Verizon, Deutsche Telekom and Swisscom. Founded in 2011 by a group of academics from Stanford, Kumu says that its full-duplex wireless technology allows radios to both transmit and receive on the same frequency by canceling out the self-interference noise that usually occurs when transmitting – in essence, the radio can’t hear itself transmit.