While GSM uses the information stored in a SIM card in order to work, CDMA, on the other hand, keeps the same type of information within the device itself.

All GSM phones and most iDEN phones require a SIM card to operate. There are certain types of phones (CDMA, TDMA, AMPS) that do not use a SIM. Instead, ...

Check out our guide for a closer look at the two popular wireless standards, CDMA and GSM. They're becoming a bit less relevant in the face of LTE, 4G, and 5G.

GSM: SIM CDMA: MEID, U-SIM. First, let’s get this out of the way: I’ve been using GSM and CDMA as blanket names for a set of standards that have changed over time.

Unlocking a GSM device allows you to use pay-as-you-go or prepaid SIM cards from other carriers. Prepaid accounts can work out cheaper than postpaid accounts because even though the per-minute ...

The long and contentious battle for the exact shape of the nano-SIM / Fourth Form Factor (4FF) technically came to a close on June 1st. However, the standards body behind the decision, the ETSI ...

While GSM phones enable you to remove the SIM card from one phone and insert it into another phone on the same carrier's network, you cannot always switch SIM cards between carriers, such as AT&T ...

When you insert the GSM SIM card, the BlackBerry will automatically enter Global Roaming Mode and search for a GSM signal. When you remove the SIM, the phone will search for a CDMA networks only. When ...

Having the Palm Pre on Sprint might be good for Americans driving their pick 'em up trucks down the CDMA data highway, but it doesn't do Europeans (or Palm's bottom line) any good over in the Old ...

By combining GSM SIM Toolkit and Class 2 SMS messages (the type sent to handsets where there's no user interaction required) the Gemalto "Facebook for SIM" doesn't require the handset to have a ...