至於GSM可用的前提有2個：
(1) Unlocked
(2) triband or quadband (Chinese and US GSM frequencies are different)
http://www.worldtimezone.com/gsm.html (3G for data only)
(1) Unlocked
(2) triband or quadband (Chinese and US GSM frequencies are different)
http://www.worldtimezone.com/gsm.html (3G for data only)
| U S A | 1900 | 850 | 3G 850/1900, 3G 1700/2100 | Sprint 4G LTE; Sprint Clearwire WiMAX; MetroPCS 4G LTE; Verizon USA 4G; T-Mobile 4G; AT&T 4G (HSPA+ and LTE) |
| China | 900 | 3G 2100 | |||
| China, Hong Kong (SAR) | 900 | 1800 | 3G 2100 | ||
| China, Macau (SAR) | 900 | 1800 | 3G 2100 |
