TSD-2000-1-1 OPTICAL FIBRE CABLING: LAN APPLICATION SUPPORT GUIDE Issue 5
The conventional way of designing optical fibre cabling has been to ensure that the optical loss budget of the cabling is conformant with the optical power budget of the equipment to be connected to it. The actual loss of the cabling, verified during post-installation testing, is required to be conformant with its optical loss budget.
This approach to the design and implementation of optical fibre cabling was described in BS 7718 (1996). Since that time the ways in which the capacity of optical fibres, both single mode and multimode, is used have changed radically. For local area network (LAN) telecommunications the data rates have increased dramatically and are still doing so. As part of that process we have moved from loss-limited, or attenuation-limited, applications such as Token Ring and FDDI to bandwidth-limited applications such as 1000BASE-SX/LX and 10 Gigabit Ethernet. This evolution has brought with it new design rules and enhanced performance options for multimode optical fibre cabling together with an increased emphasis on singlemode technology.
The object of this LAN Application Support Guide is to provide the reader with an understanding of both the “old” and “new” design issues. For new installations, the key issues addressed are:
– the specification of optical fibre performance;
– the selection of optical fibre type;
– the design of optical fibre cabling channels.