I'd like to purchase a Samsung Galaxy S-5 (32GB) from Korea and use it in the USA. I use Straight Talk with an AT&T SIM. Also, if I purchase a Korean S5, can anyone provide guidance on how to get around the region lock (if there is one this phone)? Thanks.
First, get to know the bands that AT&T supports. There are several models in Korea. Most popular ones are the 900S, 900K and 900L.
SM-G900S
Secondary Cellular Networks:LTE2100 (B1), LTE850 (B5), LTE1800 (B3), LTE2600 (B7)
Cellular Networks:GSM900, GSM1800, GSM1900, UMTS850 (B5), UMTS1900 (B2), UMTS2100 (B1)
Cellular Data Links:GPRS, EDGE, UMTS, HSDPA, HSUPA, HSPA+
SM-G900K
Secondary Cellular Networks:LTE700 (B17), LTE1800 (B3), LTE2600 (B7), LTE900 (B8)
Cellular Networks:GSM900, GSM1800, GSM1900, UMTS850 (B5), UMTS1900 (B2), UMTS2100 (B1)
Cellular Data Links:GPRS, EDGE, UMTS, HSDPA, HSUPA, HSPA+
SM-G900L
Secondary Cellular Networks:LTE2100 (B1), LTE850 (B5), LTE1800 (B3), LTE2600 (B7)
Cellular Networks:GSM900, GSM1800, GSM1900, UMTS850 (B5), UMTS1900 (B2), UMTS2100 (B1)
Cellular Data Links:GPRS, EDGE, UMTS, HSDPA, HSUPA, HSPA+
Hope this helps