What communication channel does the Huawei EM770 / EM770W (optional) support?
 
EM770:
GSM / EDGE:850 / 900 / 1800 / 1900
HSPA / UMTS:850 / 1900 / 2100

EM770W:
GSM / EDGE:850 / 900 / 1800 / 1900
HSPA / UMTS:850 / 900 / 1900 / 2100