Naming scheme for the most important trans-atlantic cable systems. The systems range from the coaxial cables TAT-1 to TAT-7 up to TAT-14, which is due to enter service late 2000. Most TATs run from the US or Canadian east coast to the west coast of Britain or Northern Germany. The fiber optic TAT-8 to TAT 12/13 are in active service today.
While the earlier systems had one single back-up fibre pair, the TAT-12 and TAT-13 is considered together as a completely backed up system, with four pairs of a capacity of 5 Gbps each.
Comparatively, TAT-8 was only 2*280 Mbps + 1 one back-up channel. This capacity was originally intended to last until the year 2000, but was filled in 1990, six times faster than expected. Thereby TAT-9,10 and 11 came in quick succession during 1992 and '93.
When TAT-14 arrives, it will have a fully redundant capacity of 4*160 Gbps.
Other variations of TAT is the PTAT, the Private TransAtlantic cable system, operated and financed by a private group consisting of Cable & Wireless, Mercury and Sprint. CANTAT-3 runs out of Nova Scotia via Iceland to Northern England, Denmark and Germany and it's mainly owned by TeleGlobe Canada.