Lets be clear 3 do not use o2s network for their 4G. There have been talks about a merger with 3 and o2 but that's not in place right now.
EE are part of a network called MBNL which is a joint venture between EE and 3. This DOES NOT mean that EE and 3 have the same reception, they do not. It simply means that 3 often put their transmitters on the same physical mast that EE will also use. Often EE will be 10 metres higher up on that mast, with 4 transmitters pointing in all directions whereas 3 will be 10 metres lower, with just the 1 transmitter on that mast. ALSO you often find that EE have an output power of 30+ db whereas 3 are only outputting at 18db. So generally this is why EE has better coverage than 3. YES sharing same physical masts. Very different setups. It can work the other way around ofcourse.
Also plenty of orange sites do not have a 3 transmitter on them.
In terms of the o2 and 3 merger, that would be complicated as o2 and vodafone are in a joint venture called Cornerstone. This is where o2 and vodafone share masts like EE and 3 do.
So having an agreement for 3 to merge with o2 would confuse the MBNL and cornerstone relationships and is unlikely.
Hope I helped
Edited by ukhardy07 (Tue 23-Sep-14 13:11:06)