Active switching star node and network of stations interconnected by such a star node

Abstract

In a network a star node (SN) interconnects a plurality of stations (ST–ST). The star node (SN) has interfaces (I–I), each having a connection terminal (BP) for connecting a selected one of the stations to the star node (SN) and each interface receives at a connection terminal (BP) a signal from the station associated with that interface and forwards the received signal to the connection terminal (BP) of the other interfaces. The star node (SN) further has a common terminal (RT) and each interface has a receiver (CMP) coupled to the connection terminal (BP) for receiving the signal from the associated station, a transmitter (TR) coupled to the connection terminal (BP), a first activity detector (A) for generating a first activity signal (AS) in response to signal transitions at an input (CIP) of the receiver (CMP), a second activity detector (A) for generating a second activity signal (AS) in response to signal transitions at the common terminal (RT), a first switch (SW) for disabling signal transfer from the receiver (CMP) to the common terminal (RT) in response to the second activity signal (AS), and a second switch (SW) for disabling signal transfer from the common terminal (RT) to the transmitter (TR) in response to the first activity signal (AS). The structure of the interface allows easy expansion of the number of interfaces within the star node (SN) and a data protocol without a preamble.