Updating old telephones
Keep your old SIM card somewhere safe — they are fragile!
Your phone must be unlocked to work with SIM cards on other networks.Some of the mentioned companies are searching for administrative assistant's.If you're like many people, your smartphone has become an external extension of your brain.Tip: Don't let your carrier talk you into purchasing or renting a SIM card for your destination country.You'll be able to get one much cheaper once you arrive in Asia.American CDMA cell phones operate on the 850 MHz and 1900 MHz frequency bands, while South Korean and Japanese phones use the 2100 MHz band. that are compatible with the GSM network are: T-Mobile and AT&T.
Your cell phone will have to be tri-band or quad-band to work abroad — check the phone's hardware specs. Customers with Sprint, Verizon Wireless, and other CDMA carriers typically aren't able to join the local cell networks in much of Asia aside.
If your phone is ever stolen, many providers will blacklist your phone so that it cannot be used, and a few may even be able to track it.
You should only have to unlock your cell phone once for international travel.
International roaming allows you to keep your number from home, however, you'll pay each time that someone calls you or vice versa.
Tip: When using a prepaid service in Asia, deactivate data roaming on your smartphone to avoid big, unexpected charges due to apps updating in the background.
In many Asian countries, mobile devices outnumber people! The most reliable way to find out if your mobile phone will work in Asia? While you've got them on the phone, you can find out about getting your smartphone "unlocked" to work on other networks, if it isn't already.