公开(公告)号：CA1141838A

公开(公告)日：1983-02-22

申请号：CA360342

申请日：1980-09-16

Applicant: IBM

Inventor： LEE ROBERT P ,  CLOSS FELIX H

IPC: H04L12/44 ,  H04L12/56 ,  H04B1/38 ,  H04B3/50

Abstract: METHOD AND MEANS FOR DEMAND ACCESSING AND BROADCAST TRANSMISSION AMONG PORTS IN A DISTRIBUTED STAR NETWORK A demand access broadcast transmission method and means capable of supporting random port access and any-to-any transmission at very high data rates. A communication medium formed from an inverted tree network of nodes and full duplex connecting links permits the establishment of a path lock up-link through the network from a demanding port to a root node on a first-come first-serve demand access basis with arbitration at each distinct tree node level. Broadcast transmission is perfected down-link over all fan-out paths from the root node. Collision is avoided by locking a path to a port and by limiting race conditions among active ports to only the leading edges of messages. Thus, relinquishment of a broadcast channel overlapped with retransmission of a message does not result in path seizure since the occurrence of message leading edges is the singular path connection invoking event. SA9-79-011