GSM Cell Phones

Frequently Asked Questions


Global System for Mobile Communications (GSM) – Cell Phone Glossary

GSM is a digital cellular phone technology based on TDMA that is the predominant system Europe, the Middle East, Africa, Asia and in parts of America and Canada. First introduced in 1991, the GSM standard has been deployed at three different frequency bands: 900 MHz, 1800 MHz and 1900 MHz. GSM 1900 is primarily deployed in North America. Named after its frequency band around 900 MHz, GSM-900 has provided the basis for several other networks using GSM technology. GSM uses narrowband TDMA which allows eight simultaneous calls on the same radio frequency. Along with CDMA and TDMA it represents the second generation of wireless networks.
GSM phones require a small electronic chip, called a SIM card, to be inserted into a slot in the handset. This international SIM card is the “heart” of your phone – it contains your cell phone number, your phone book, and all of your registration information. Most companies with GSM service provide you access to over 320 GSM networks in over 140 countries.

GSM 900 – Cell Phone Glossary

The world’s most widely used digital network and now operating in over 100 countries around the world, particularly in Europe and Asia Pacific.

GSM 1800 – Cell Phone Glossary

Also known as DCS 1800 or PCN, GSM 1800 is a digital network working on a frequency of 1800 MHz. It is used in Europe, Asia-Pacific and Australia.

FAQ ON GSM Cell Phones


GSM 1900 – Cell Phone Glossary

Also known as PCS 1900, GSM 1900 is a digital network working on a frequency of 1900 MHz. It is used in the US and Canada and is scheduled for parts of Latin America and Africa.

What are Unlocked GSM Phones? Unlocked GSM phones are either a) phones which are directly from the manufacturer which were never locked, or b) phones from a carrier which have been modified to openly work on any network. What are the different frequencies of GSM that I need? Most of the world’s GSM networks operate at 900MHz and 1800MHz. However, in order to use the networks in the USA and Canada you will need a handset that is also capable of operating at the 1900MHz frequency. Most phones are now either “dual” “tri” or “quad band” (includes 850MHz) to serve most of the world. What are GSM and GPRS? GSM (Global System for Mobile Communications) has become the most successful global mobile technology for mobile phones and digital cellular networks with more than one billion subscribers. GPRS (General Packet Radio Service) brings the possibility of data services and applications based on Internet Protocol (IP) to GSM mobile networks. In current network implementations, GPRS data transfer speeds are between 30 to 40 Kbit/s. What do GSM and GPRS do? GSM is designed to deliver high-quality and secure mobile voice and data services to mobile users. Its success is based on its inherent support for roaming and interoperability across a number of different networks and across a number of different countries. GSM is available on multiple frequency bands globally and offers the widest selection of mobile services and mobile terminals currently available. GPRS enables fast connections through which information can be sent and received as the need arises, without having to wait for a dial-up modem to establish a connection. This is why GPRS devices are sometimes referred to be as being an ‘always online’ technology. And because pricing is often based on the amount of data transferred rather than the connection time, this has made GPRS applications such as email popular with small and large businesses around the world. Benefits of GSM & GPRS International standard – one and the same mobile phone works across continents International roaming capability for professionals travelling overseas Well established interoperability of GSM/GPRS devices and networks What is Bluetooth? Bluetooth is a specification for the use of low-power radio communications to wirelessly link phones, computers and other network devices over short distances. The name “Bluetooth” is borrowed from Harald Bluetooth, who was a king in Denmark more than 1,000 years ago. Bluetooth technology was designed primarily to support simple wireless networking of personal consumer devices and peripherals, including cell phones, PDAs, and wireless headsets. The wireless signals transmitted in Bluetooth reach over short distances, typically up to 30 feet (10 meters). Bluetooth devices generally communicate at less than 1 Mbps. Bluetooth networks feature a dynamic topology called a piconet or PAN. Piconets contain a minimum of two and a maximum of eight Bluetooth peer devices. Devices communicate using protocols that are part of the Bluetooth Specification. Although the Bluetooth standard utilizes the same 2.4 Ghz range as 802.11b and 802.11g, Bluetooth technology is not a suitable Wi-Fi replacement. Compared to Wi-Fi, Bluetooth networking is much slower, a bit more limited in range, and supports many fewer devices. As is true for Wi-Fi and other wireless technologies today, concerns with Bluetooth include security and interoperability with other networking standards. What is Java? Java is a software technology developed to provide a common base for running applications across a wide variety of computing platforms. It consists of a programming language and a run-time environment. Java applications can run on servers, personal computers, mobile phones and other devices. Because the capabilities of these computing platforms vary, Java has evolved into 3 editions: 1.) Java 2 Enterprise Edition (J2EE) – for high-end business machines 2.) Java 2 Standard Edition (J2SE) – for personal computers 3.) Java 2 Micro Edition (J2ME) – for smaller handheld devices such as mobile phones and PDAs The Mobile Information Device Profile (MIDP) is a key element of the J2ME, defining a platform for dynamic networked applications. Developers using MIDP can write applications once, then deploy them to a wide variety of mobile devices. MIDP has been widely adopted as the platform of choice for mobile applications. How does it work? Software written in Java is independent of operating systems, as the instructions are interpreted in the computer at the time when the software is run, not beforehand. Every computer or device that runs a Java application must have a Java Virtual Machine that adapts the application code for the specific device and before executing it. PLEASE NOTE: All of our Unlocked GSM Phones come from around the globe. As such, most carry an “International” warranty from the Manufacturer, which will be detailed within your product packaging, if appropriate. Only DOA (Dead on Arrival) Exchanges will be made for this product through the GSM Support Center. No returns are allowed otherwise. There are no exceptions.