3G

3G

3G or 3rd generation mobile telecommunications is a generation of standards for mobile phones and mobile telecommunication services fulfilling the International Mobile Telecommunications-2000 (IMT-2000) specifications by the International Telecommunication Union.

Time line in using 3G

GPRS

GPRS operates at much higher speeds than cur rent  networks,  providing advantages  from a software perspective. Wireless middleware currently is required to enable slow speed mobile clients to work with fast networks for applications such as e−mail, databases, groupware, or Internet access. With GPRS, wireless middleware will probably be unnecessary, making it easier to deploy wireless solutions.

EDGE

            Beyond GPRS, EDGE takes the cellular community one step closer to UMTS. It provides higher data rates than GPRS and introduces a new modulation scheme called 8−Phase Shift Keying (PSK). The TDMA community also adopted EDGE for their migration to UMTS. The data rates allocated for EDGE are started at 384 Kbps and above as a second stage to GPRS. EDGE uses the same modulation techniques as many of our existing TDMA infrastructures using Gaussian Minimum Shift Keying (GMSK) 8−PSK. Moreover EDGE uses a combination of FDMA and TDMA as the multiple access control methods.

WHY EDGE?

            EDGE is a new modulation scheme that is more bandwidth efficient than the GMSK modulation scheme used in the GSM standard. It provides a promising migration strategy for HSCSD and GPRS. The technology defines a new physical layer: 8−PSK modulation, instead of GMSK. 8−PSK enables each pulse to carry 3 bits of information versus the GMSK 1−bit−per−pulse rate. Therefore, EDGE has the potential to increase the data rate of existing GSM systems by a factor of three.

            EDGE retains other existing GSM parameters, including a frame length, eight time slots per frame, and a 270.833 kHz symbol rate. The GSM 200 kHz channel spacing is also maintained in EDGE, enabling the use of existing spectrum bands. This fact is likely to encourage deployment of EDGE technology on a global scale.

UMTS

            UMTS is a modular concept that takes full advantage of the trend of converging existing and future information networks, devices, and services, and the potential synergies that can be derived from such convergence. UMTS will move mobile communications forward from where we are today into the 3G services and will deliver speech, data, pictures, graphics, video communication, and other wideband information direct to people on the move. UMTS is one of the major new 3G mobile communications systems being developed within the framework, which has been defined by the ITU and is known as IMT−2000.

WCDMA

            WCDMA is an ITU standard derived from CDMA and is officially known as IMT−2000 direct spread. WCDMA is a 3G mobile wireless technology offering much higher data speeds to mobile and portable wireless devices than commonly offered in today's market.

            WCDMA can support mobile/portable voice, images, data, and video communications at up to 2 Mbps (local area access) or 384 Kbps (wide area access). The input signals are digitized and transmitted in coded, spread−spectrum mode over a broad range of frequencies. A 5 MHz wide carrier is used compared with a 200 kHz wide carrier for narrowband CDMA.

Applications of 3G

Online e−mail

Access to the World Wide Web

Enhanced short message services

Wireless imaging with instant photos or graphics

Video services

Document/information sharing

Surveillance

Voice messaging via Internet

Broadcasting