Frequently Asked Questions

What Is GSM?
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.

Which Carriers Use GSM Phones?
In the United States, Cingular Wireless, AT&T and T-Mobile are the major GSM networks. Outside of the US, most other countries, especially in Europe and parts of Asia, exclusively use GSM phones.

The following is a full list of GSM Carriers in the United States:

AT&T
Cellular One
Centennial Wireless
Cingular
CorrComm
EDGE Wireless
Einstein PCS
Immix Wireless
NPI Wireless
Simmetry Communications
Speak Out Wireless
T-Mobile
Viaero Wireless
iWireless

All Phones from Cellular Express will Work with AT&T, Cingular, T-Mobile, Cellular One and Rogers!

What are Unlocked GSM Phones?
An Unlocked GSM phone is not locked to a particular carrier and will work with virtually any GSM service provider in the world. All you have to do to set up an Unlocked phone with your current service is simply insert your SIM card into the back of the phone. Most of the phones sold by Cellular Express are Unlocked and are guaranteed to work with Cingular, AT&T and T-Mobile in the United States along with many other carriers internationally.

How do I set my new phone up with my current service?
Setting up an Unlocked phone with your existing service and phone number is easy. All you have to do is remove the SIM card from the back of your old phone and insert it into the back of your new GSM Unlocked phone and your service, phone number and contacts will be automatically copied to the new phone and you should be able to make and receive calls immediately.

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 traveling 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.