This morning we had our GB service, where the the talks were themed around the idea of a mobile phone. One of the talks was titled "What network are you on?" and started by talking about some of the mobile phone networks and about how mobiles connect to their network through aerials on masts. We then heard about how there would normally be several aerials at the top of a phone mast and several huts at the bottom (one for each network). So I learnt all sorts about phone masts today, and might have to google a bit now to find out more.