How do you convert 250-microns to gsm?

This cannot be done unless you change the hardware itself. CDMA and GSM are two different technologies used by the carriers and it's a difference in the hardware that makes it not possible for you to...

It depends if the phone is compatible with a gsm network if so it has to be unlocked

How do you convert cellphone gsm frequency to another gsm frequency?"

You cannot convert GSM to cm since the first is a measure of planar density, with dimension [ML-2], whereas a centimetre is a linear measure with dimension [L]. However, you can turn GSM into grams...

Add 20 grams per square metre of the fabric. This could be in the form of embroidery, for example.