|
|
|
Public Address System (PAS) |
The Public Address System at each place could be required for announcements in Railways. The PAS nodes at each station transmit the information over to the transmission network over an Ethernet link.
Since the transmission to the PAS nodes is required only in bursts, the Ethernet data from the PAS can be multiplexed over at each node for network efficiency. The data for the PAS nodes can be differentiated based on the MAC address or the VLAN identifier. The intermediate SDH nodes can be equipped with Ethernet switching capability that could allocate a VC-12 to PAS systems at all stations. The edge node could multiplex the Ethernet data and hand it over a Fast Ethernet link to the PAS controller.
|
|
