Slow to pick up 3G signal

[Moccasin]

I'm loving my 5s however both I and a friend seem to find that it is slow too pick up a 3G signal even in the centre of the city.

Until last weekend I assumed it was a fault with the O2 network, however I was in London and showing my mother how to use my iPhone 4 which she has inherited. Both phones were side by side and the 4 was showing 3G while the 5s was still on GPRS.

Is this a fault with the carrier settings? iOS7? (my iPhone 4 is still on iOS 6). I can't imagine that it is a fault with the phone as it would be odd that we both had the same fault.

Any help appreciated.

 

[digitalfailure]

I'm also with O2 and have noticed this on my 5s when compared to previous performance of my 4s in the same area.

I find I have to click airplane mode on and off and the phone miraculously connects to 3G then.

O2 say it's not a fault on their network.