Sometimes when you insert certain network inside your double SIM Android smartphone,
you will notice that EDGE will be displayed on one of the SIM;

this simply means that it is on 2G, this is because 3G is enabled
only on one SIM at a time especially on Tecno smartphones,
so in other to enable 3G on any SIM you wish to use,
you have to set it up manually, while 3G is enabled on one SIM 2G
will automatically be enabled on the other SIM,...http://www.jindublog.com/2014/01/how-to-switch-between-3g-and-2g-on.html