Alternative name for overhead line, typically for data link between buildings
Although not entirely correct, the term "catenary" is often used in connection with this sort of installation - probably more for the sake of having something to call it other than just "overhead wire". The name "catenary" actually comes from the mathematical equation that describes the curve formed by a chain or cable suspended by its two ends in a gravitational field and is derived from the hyperbolic cosine function (see Wikipedia for a longer description that is somewhat off-topic for this site). For engineering purposes, it allows you to calculate the load on the fixings at the two ends and the expected "droop" in the cable in between.

Sometimes, the use is more specific, such as this paragraph from a press release issued by Network Rail in the UK:


  Generally, most types of railway overhead line equipment have overhead
  conductors with a copper contact wire suspended from a catenary wire
  by 'droppers' or 'drop wires.'


But the term is often applied to anything strung between points such as catenary bridges or walkways.