How can I force my iPhone 5s to use fast 4G over strong 3G signal?

[lockei]

I've recently upgraded to try out 4G as an alternative to poor broadband signal at home as my primary data/internet provider.  Issue is that 2G & 3G signal is also bad, so we have a sure signal to boost the 3G signal.  My iPhone 5s jumps on to the 3G signal in preference to the much faster 4G signal.  Can I force the phone to use (fast) 4G in preference to (strong) 3G?  And, before anyone suggests it, I need to leave the sure signal switched on as not all handsets have switched to 4G.  Thanks

[jeffkinn · Accepted solution]

Degister your number from the sure signal is the first thing to say.

[lockei]

Thanks for the suggestion to de-register from the SureSignal.  My number was the owner of the SS, so it wouldn't let me de-register.  However, I've managed to create a dummy account for one of the other registered users and transfered ownership accross to that account, which then enabled me to de-register from the SS.  A bit painful, but it's worked.  Thank you.