For establishing a parent-child relationship between adjacent network nodes interconnected by a transmission medium, a handshaking circuit comprises a state detector for monitoring the transmission medium to detect predetermined first and second states and a contention that occurs when the predetermined...http://www.google.com.hk/patents/US6633577?utm_source=gb-gplus-share專利 US6633577 - Handshaking circuit for resolving contention on a transmission medium regardless of its length
