"I can shed some light on your photograph of the pole with unknown network. What you are looking at here is a pair of 'cell enhancers'.  The top two antennae (rectangular box type things) are directional and are pointing to the 'donor' cell.  The lower two antennas are shrouded Yagi type antennas and are what are known as the 'mobile facing' antennas.  A cell enhancer is basically a bi-directional amplifier, in which the down link and uplink signals are separated into their two frequency bands, amplified and re-radiated.  This gives in-fill coverage where the donor cell has a hole in its coverage, such as in a dip along a main road.  I guess that the pole you show has two enhancers, with one looking one way along a road and the other covering the opposite direction.  Each enhancer requires one donor-facing antenna and one mobile-facing antenna.

This type of installation is used quite a lot by Orange, but I couldn't confirm that this particular installation is theirs.

The rectangular antennas are known as tri-corner antennas and are made by Andrews (from USA, under their rural telephony product range) and the Yagi antennas are almost certainly made by Jaybeam Antennas."

Another visitor writes:

"It is indeed a Andrews antenna/DICE cell enhancer" and explains that they're also used to enhance in-building coverage.

Mike says: Thanks very much... the mystery is solved!
 

Original photo by Gordon Crosby (with kind permission).