AvMap Geosat 6 series - Manual (Page 111)

AvMap - 111
Trouble Shooting
6.18 With which mobile phone carriers does
Geosat 6’s phone work? (only for GSM models)
Geosat 6 GSM models are compatible with GSM SIM
cards. The SIM card can be of any carrier as log as it
is a GSM type (not UMTS).
Geosat 6 is not compatible with UMTS SIM cards. It is
suggested to request to your mobile phone operator
for a GSM SIM “BIS” which means a twin of your card
with the same telephone number, so you can keep
one in your mobile phone and one in Geosat 6 in
order to use it for hand free calls in your car.