Generations Wireless Technology- THIRD GENERATION TECHNOLOGY
(3G – 3.75G)
3G is the third generation of mobile phone standards and technology, superseding 2G, and preceding 4G. It is based on the International Telecommunication Union (ITU) family of standards under the International Mobile Telecommunications programme, IMT-2000. 3G technologies enable network operators to offer users a wider range of more advanced services while achieving greater network capacity through improved spectral efficiency. Services include widearea wireless voice telephony, video calls, and broadband wireless data, all in a mobile environment. Additional features also include HSPA data transmission capabilities able to deliver speeds up to 14.4Mbit/s on the downlink and 5.8Mbit/s on the uplink. Spectral efficiency or spectrum efficiency refers to the amount of information that can be transmitted over a given bandwidth in a specific digital communication system. … High-Speed Packet Access (HSPA) is a collection of mobile telephony protocols that extend and improve the performance of existing UMTS protocols.
Unlike research 802.11 (common names Wi-Fi or WLAN) networks, 3G networks are wide area cellular telephone networks which evolved to incorporate high-speed internet access and video telephony. research 802.11 networks are short range, high-bandwidth networks primarily developed for data. Wi-Fi is the common name for a popular wireless technology used in home networks, mobile phones, video games and more. The notebook is connected to the wireless access point using a PC card wireless card. A videophone is a telephone which is capable of both audio and video duplex transmission.
3G technologies make use of TDMA and CDMA. 3G (Third Generation Technology) technologies make use of value added services like mobile television, GPS (global positioning system) and video conferencing. The basic feature of 3G Technology is fast data transfer rates. 3G technology is much flexible, because it is able to support the 5 major radio technologies. These radio technologies operate under CDMA, TDMA and FDMA.CDMA holds for IMT-DS (direct spread), IMT-MC (multi carrier). TDMA accounts for IMTTC (time code), IMT-SC (single carrier). FDMA has only one radio interface known as IMT-FC or frequency code. Third generation technology is really affordable due to the agreement of industry. This agreement took pace in order to increase its adoption by the users. 3G system is compatible to work with the 2G technologies. The aim of the 3G is to allow for more coverage and growth with minimum investment.
There are many 3G technologies as W-CDMA,
GSM EDGE, UMTS, DECT, WiMax and CDMA
2000.Enhanced data rates for GSM evolution or
EDGE is termed to as a backward digital
technology, because it can operate with older
devices.
3G has the following enhancements over 2.5G and previous networks: Enhanced audio and video streaming; Several Times higher data speed; Video-conferencing support; Web and WAP browsing at higher speeds;
IPTV (TV through the Internet) support.
5.1) 3.5G – HSDPA (High-Speed
Downlink Packet Access)
High-Speed Downlink Packet Access(HSDPA) is a
mobile telephony protocol, also called 3.5G (or
“3½G”), which provides a smooth evolutionary path
for UMTS-based 3G networks allowing for higher
data transfer speeds.
HSDPA is a packet-based data service in W-CDMA downlink with data transmission up to 8-10 Mbit/s (and 20 Mbit/s for MIMO systems) over a 5MHz bandwidth in WCDMA downlink. HSDPA implementations includes Adaptive Modulation and Coding (AMC), Multiple-Input Multiple-Output (MIMO), Hybrid Automatic Request (HARQ), fast cell search, and advanced receiver design. 5.2.) 3.75G – HSUPA (High-Speed Uplink Packet Access)International Journal of Computer Applications (0975 – 8887) Volume 5– No.4, August 2010 30 The 3.75G refer to the technologies beyond the well defined 3G wireless/mobile technologies. High Speed Uplink Packet Access (HSUPA) is a UMTS / WCDMA uplink evolution technology. The HSUPA mobile telecommunications technology is directly related to HSDPA and the two are complimentary to one another. HSUPA will enhance advanced person-to-person data applications with higher and symmetric data rates, like mobile e-mail and real-time person-toperson gaming. Traditional business applications along with many consumer applications will benefit from enhanced uplink speed. HSUPA will initially boost the UMTS / WCDMA uplink up to 1.4Mbps and in later releases up to 5.8Mbps.