scope:

This standard applies to all station LANs supporting Operational Telecommunications systems and station assets used by London Underground.

For the purpose of this standard a Station Asset Communications Network (SACN) is a Local Area Network (LAN) that interconnects all operational station assets and provides connectivity to other networks e.g. service control centres or the BTP. A SACN can be wireless or wired, utilising copper and fibre optic cabling. Where Wireless Networks are used, they shall comply with the requirements of S1144 Wireless Communications Systems.

This standard describes the communications infrastructure necessary to convey station control and monitoring data reliably, it does not prescribe what the data represents.

For the services considered within the SACN, only layers 1 through to 4 of the OSI model are considered in this standard. These layers support the services necessary for the reliable transfer and routing of data via a network, however the specification, content or use of the data is not defined in this standard.

The SACN shall link all station assets to provide control, performance and condition monitoring using a network based on open standards. The network provides the underlying services necessary for the reliable transport of information, but does not prescribe the specific data, codes or both that would be conveyed.

Purpose

The purpose of this standard is to define the requirements for Station Asset Communications Networks, suitable for the control and monitoring of assets within the locale of a station.