"Long-distance networking over copper cabling (which we define here as between 300m to 2,000m) surpasses the traditional Ethernet limitation of 100 metres. Doing this requires special adaptors such as LONGSPAN devices which can deliver full-speed 100BaseTX Ethernet at distances up to 820m over Cat6 cable, with or without POE. Longer distances up to 1400m can be achieved over RG11 coax, at the same speeds, with HIGHWIRE Longstar, which is especially useful in the train and rail industry, as coax is very a good medium for noise and interference suppression. If no POE is required, HIGHWIRE Longstar can operate up to 4,200m at 10Mbps (10BaseTX) and auto-adapts. Veracity also offers LIGHTSPAN, a more traditional Ethernet over fibre media converter, which can reach 2,000m with multi-mode cable at 100BaseFX and is especially immune to electromagnetic interference, although does not deliver POE."