BACK HAUL

(Note that this is sometimes spelled Backhaul)

For mobile phones in  a cellular systems making calls to land line phones at great distances, the wireless transmission through the air is generally a few miles or less to a base station.  The base station must connect by wires or by wireless switch to a local telephone switch to send the phone conversation onwards and into the regular wire telephone system.

The means by which information is carried from the base station to the central telephone switch is called back haul.  This term no doubt means that the system needs to haul back the phone conversation and data from the wireless network back to the wired network by some means.

Back haul is usually accomplished two ways.  Either a wire is used that can transfer high speed data, such as as T1, T3, E1 or ISDN cable, or the phone conversation and data can be sent back via a wireless point to point network.  Point to point networks normally use parabolic dishes that transmit voice and data in only a singular direction to another parabolic dish antenna, and also use microwave frequencies as a carrier for the voice and data.