1 : try and remember what 4G actually is. 100bps download at high mobility [say a car / train] and 1Gbps low mobility [walking talking].
2 : True 4g is an all IP backbone.
3 : There are no 4g networks anywhere and it is recognised generally that it will be 2013 before there are any.
4 : the 5Mhz item is a bit of a red herring : you only *need* the 20mhz blocks if you are to provide the "up to 1Gbps" download speeds.
5 : When was the UK at the cutting edge of telecomms : suppliers are either Swedish, French, Finnish or Chinese. Marconi was the last UK supplier and they took the smorgesboord five or six years ago.
Conclusion : it will be a decade before anybody, anywhere in the world gets anywhere need there 4g specs [100bps / 1Gbps] so, in my very humble opinion, OfCom are pretty much spot on in taking the careful, do it properly approach.
Look at Scandinavia and 3g. They did a technology / beauty contest back in '99 and ended up with 3g pretty much everywhere, which is used. We did that stupid £20billion auction, which resulted in a slow roll out and the end result is faster Twitter.
Maybe take a step back, look at what 4g /could/ do, make some technical requirements of the NetOp's, [based on download / uplopad speed, capaicty and converage in town and out of town etc] divvy up the bandwidth properly and have in integrated approach to mobile…..
Sorry, that sounds like planning and this is Blighty. Would never happen.....