Samsung SCH-R910 exclusively design to be works under CDMA 800 / 1900 for 2G and for 3G it works with CDMA200 1xEV-DO. And it been named as 4G Smartphone because it supports with LTE 1700 / 2100 MHz. For EVDO it can be used up to 3.1 Mbps and for LTE up to 12 Mbps. This Handset also known as Samsung Galaxy Indulge and sometimes also named as Samsung Forte. Because it not a GSM Gadget, you will never able to use on any GSM Networks, and it been exclusively designed for MetroPCS Carrier (LTE Data Networks Provider). Note: LTE abbreviation of Long Term Evolution.
Little note about the availability of User Manual of Galaxy Indulge: Even though this smartphone officially released on February 2011, the Online Manual PDF of the phone still did not available until we got it at this week (April 2011, Despite of the date that mentioned on the User Manual Download Page of Indulge 4G SCH R910 was also said in February 23, 2011, but it is the fact that we could download or find the PDF File until this week, indeed we already check it over and over again).