The tertiary cabling connects the floor distributor( EV) in a star configuration with the subscriber connection boxes at the workplace. The length of the route between the floor distributor and the telecommunications outlets is specified in the cabling standards as max. 90 m.
Normally, symmetrical copper cables are laid in the tertiary area. If this area is wired with optical fibers to implement fiber to the desk( FTTD), a link attenuation of 2.2 dB can be assumed for determining the attenuation budget. This value applies to both single- mode and multimode fibers and takes into account one splice and one connector at each end of the cable. In the secondary area, hybrid cables and high-pair cables may also be used if they meet the performance requirements.