Learning Center

Q: What is GSM?
A: Global System for Mobile Communication. Originally developed as a pan-European standard for digital mobile telephony, GSM has become the world’s most widely used mobile system. It is used on the 850 Mhz, 900 Mhz, 1800 Mhz and the 1900 Mhz frequencies.

Q: What are GSM bands 850/ 900/1800/1900?
A: GSM technology can work on up to 4 frequencies: 850 Mhz, 900 Mhz, 1800 Mhz, and 1900 Mhz. Some GSM phones support all the bands or frequencies, or just a couple. A dual band phone supports only two, usually 900/1900 or 850/1900. A Tri-Band phone supports three bands, either 850/1800/1900 or 900/1800/1900. A Quad-Band phone supports all GSM bands. Quad-Band phones are able to work with any and all GSM service providers. On the other hand, GSM service providers support just a subset of all the GSM bands available. Before buying a GSM phone, make sure the phone supports at least one of the bands that your GSM service provider supports. Example: AT&T, T-mobile, Einstein Wireless, Boost Mobile etc.

Q: What is a Sim Card?
A: A sim card is a small flat rectangle plastic that contains a microchip. This microchip is the heart of your phone that contains your phone number, your address book, and the necessary information for your phone to function. All sim cards look the same, but the microchip inside is different for every GSM service provider.

Q: What is an unlocked phone?
A: An unlocked phone is a phone that can work with any sim card and/or GSM service provider.

Q: What is a GSM service provider?
A: A GSM service provider, or “carrier”, is a certain company providing you with a working line and phone number. To do this, they will provide you with a sim card.

Q: What is GPRS?
A: General Packet Radio Service (GPRS) is a mobile data service available to users of GSM mobile phones. It is often described as "2.5G", that is, a technology between the second (2G) and third (3G) generations of mobile telephony. It provides moderate speed data transfer, by using unused TDMA channels in the GSM network.

Q: OEM Accessories vs. Aftermarket
A: OEM (original equipment manufactured) Accessories are the devices/accessories made by cell phone and PDA manufacturers. An important point many people are unaware of is the fact that OEM Accessories are mandated by international standards as part of the qualifications for ISO certifications. In most cases, if not all, the use of Aftermarket Accessories voids the manufacturer's warranty.