Locked phone means that you have to use GSM phone on certain network, not others. If you put in SIM from other companies, the phone can't operate. To unlock, means you can use other companies' SIM and hence networks.
To unlock a phone totally, you need to find local store for $10. After unlock, this GSM phone is as an open phone, you can pop in any SIM card to use it. If you travel back to China, you can use that unlocked phone in English version, or ask some local store to change to Chinese version for 40RMB. That chinese version phone can be used in US as well.
BUT, you can't unlock a phone in China and use in US.
Ask carrier to unlock may only be temporary, and many times asking you to mail it back for 3 days. Just find that local cell phone repair store and 10 bucks!
I don't understand why you need a SIM reader. Are you planning to unlock yourself? Find on eBay for tool kit then!
To unlock a phone totally, you need to find local store for $10. After unlock, this GSM phone is as an open phone, you can pop in any SIM card to use it. If you travel back to China, you can use that unlocked phone in English version, or ask some local store to change to Chinese version for 40RMB. That chinese version phone can be used in US as well.
BUT, you can't unlock a phone in China and use in US.
Ask carrier to unlock may only be temporary, and many times asking you to mail it back for 3 days. Just find that local cell phone repair store and 10 bucks!
I don't understand why you need a SIM reader. Are you planning to unlock yourself? Find on eBay for tool kit then!