3G (Third Generation)

3G mobile communication standards and technologies enables communication using voice, text, images and video. 3G is the third generation of mobile communications technology. Analog cellular was the first generation, digital PCS was the second.

3G promises increased bandwidth, up to 384 Kbps when a device is stationary or moving at pedestrian speed, 128 Kbps in a car, and 2 Mbps in fixed applications.

GPRS, EDGE, WCDMA and UMTS are the technologies leading up to 3G. The new EDGE air interface has been developed specifically to meet the bandwidth needs of 3G.

CSD is the usual form of data transmission through circuit switching. Just as with audio transmission on land line based phones, charges are based on the time spent using it.

Maximum transfer rates vary between 9.6kbps and 14.4kbps depending on the mobile phone handset and theservice provider in use. HSCSD (High Speed Circuit Switched Data) is similar to CSD but with an enhanced maximum transfer rate of 43.2kbps.

Dual Band is a digital cellular technology. Dual Band capability gives you the ability to make and receive mobile phone calls from around the world.

The majority of GSM mobile phones available today are dual band enabled, meaning they are capable of using both the GSM 900 and GSM 1800 bands prevalent in Europe, Africa and Asia.

EDGE is an acronym for Enhanced Data GSM Evolution. It is a faster version of GSM wireless service, up to 384 Kbps. It will achieve the delivery of advanced mobile services such as the downloading of video and music clips, full multimedia messaging, high-speed colour Internet access and e-mail on the move.

The new EDGE air interface has been developed specifically to meet the bandwidth needs of 3G.

Short for Enhanced Global System for Mobile Communications, its an expansion on one of the leading digital cellular systems.

The EGSM operating frequency extends to 10MHz lower than the GSM 900 band. This means if the operator has access to the bandwidth, it can expand the network capacity. The mobile phones must also support the lower bandwidth to make use of the expansion.

GPRS (General Packet Radio Service) will mean being continuously connected to networks and be able to access information and entertainment services as and when you wish. You will only be charged for data received or transmitted and not for simply being connected as is currently the case with CSD (Circuit Switched Data). It is the perfect compliment to technologies such as MMS.

GPRS makes use of packet switching technology. By way of data transfer it can use multiple time slots for optimal performance instead of single time slots. Data is transmitted in short bursts across an IP network providing fast transmission speeds.

Short for Global System for Mobile Communications, one of the leading digital cellular systems. GSM uses narrow band TDMA, which allows eight simultaneous calls on the same radio frequency. GSM was built based on the TDMA protocol and is very popular in Europe and Asia.

GSM was first introduced in 1991. As of the end of 1997, GSM service was available in more than 100 countries and has become the standard in Europe and Asia.

GSM phones usually don't offer an analog capacity which would enable them to be used to make calls when the user is out of a digital cellular area. CDMA and TDMA cell phones usually do include analog capability, however GSM phones provide other advantages over CDMA and TDMA - such as tri-band phones (operate on the 900, 1800 and 1900 frequency bands).

Second generation GSM provides a short messaging service, SMS, that enables text messages up to 160 characters in length to be sent to and from a GSM phone. This will eventually be superseded by MMS as part of the new third generation GSM technology known as 3G.

Some GSM phones are locked when purchased in an attempt to avoid the customer moving to a different network. This has given rise to GSM 'Unlocking'.

In an attempt to stop customers moving to other networks (with a GSM phone that may have been sold to the customer at a loss by that network) some networks 'lock' mobile phones so that they cannot be used in other networks.

There are methods of removing this 'lock' however so that it can be used if the customer decides to move to another network. Unlocking software can be obtained which can be downloaded and used to unlock the mobile phone.

It is also possible to buy dual SIM covers for certain phones. These dual SIM covers can provide many advantages. For example you could use two networks on one phone, have one contract and one pay as you go account on the same phone, add a SIM card for use in another country or even have a separate number for business and another for personal use.

Short for High Speed Circuit Switched Data, HSCSD is an enhancement of CSD services of all current GSM networks. Access to data services is 3 times faster at a speed of up to 28.8 kbps. In many networks upgrades will mean that rates of up to 43.2 kbps are achievable meaning faster transmission of MMS and email and quicker access to other online services.

HSCSD uses multiple channels to reach these higher data transfer rates.

The Subscriber Identity Module (SIM) smart card contains user account information. Any GSM phone becomes immediately programmed after plugging in the SIM card, thus allowing GSM phones to be easily rented or borrowed. SIM cards can be programmed to display custom menus for personalized services.

TDMA is one of the most common digital communication technologies. It divides a sequence of conversations into packets of data according to time. It is offered in several bandwidths, typically 800 MHz and 1900 MHz and requires a TDMA phone.

Along with GSM TDMA offers slower data bandwidth for wireless data connection (typically 9.6 Kbps) while CDMA usually allows for 14.4 Kbps.

Tri-band is a digital cellular technology. Tri-band capability gives you the ability to make and receive mobile phone calls from around the world. A number of GSM phones, such as Nokia 6310i, are compatible with all 3 GSM frequencies: GSM 900 and 1800 bands (prevalent in Europe, Africa and Asia) and North-America's GSM 1900 band.

Yet others, such as the Nokia 6650, can make use of WCDMA networks as well as GSM networks.

UMTS is the European third generation (3G) wireless standard. According to the GSM association, UMTS will offer a wide range of voice, data and multimedia services. Data rates will reach from 114 to 2000 Kbps (or 2 Mbps) depending on whether the user is stationary or in motion.

Video pictures, real time video transmission, online entertainment, shopping, banking and enhanced web access are some of the things that should be possible.

Virtual networks do not have their own infrastructure of radio transmitter equipment thus the term 'virtual network'. Instead they use the radio transmitter systems of one of the UK's four mobile phone networks (O2, T-Mobile, Orange and Vodafone) and re-brand the air time under their own name. Virgin Mobile uses the T-Mobile network of radio transmitters to provide their mobile service for example.

Fresh (Carphonewarehouse), Virgin Mobile and FT Mobile are all examples of virtual networks currently operating in the UK with many more likely to follow such as the larger supermarket chains. This will open up the mobile communications market to more competition which, in the long, run can only be a good thing for the consumer.

WAP is short for Wireless Application Protocol which is a secure specification which enables users to receive information almost instantaneously. WAP allows users of hand held devices such as phones, mobiles phones, communicators and two way radios to access information very quickly.

WAP devices with a display unit such as a mobile phone can use an inbuilt browser called a micro browser to access WAP enabled web content via their phone. The browser is designed to take the limited memory of the mobile device into consideration and uses the WML language, specially designed for small screens and one-naf navigation. It also supports WMLScript which is similar to JavaScript but again is designed to make the most of the limited memory available within the mobile device.