Unscrambling the wireless alphabet soup(continued)
By Aaron Tan, ZDNet Asia
Monday, June 19 2006 05:10 PM

losing their connections. There have been arguments that mobile WiMax might make 3G (Third-Generation) cellphone networks obsolete, but that remains to be seen.

Third-Generation (3G)
There are several 3G technology standards in the world, but the most common one used today is W-CDMA, or wideband code division multiple access. Developed by Japan's NTT DoCoMo, the standard was later included into the GSM family. It allows cellphone users to make video calls and watch streaming videos at speeds of up to 384Kbps (kilobits per second).

EV-DO, or 1x Evolution-Data Optimized, is the 3G technology used by CDMA operators in Korea, Japan and the United States, among other non-GSM service providers. It was developed by U.S.-based Qualcomm in 1999.

In a bid to be independent of Western technology, China, too, developed its own 3G standard called TD-SCDMA (time division-synchronous code division multiple access). In January this year, the Chinese government gave the thumbs up for its home-grown technology and declared it ready to be incorporated into cellphones. Lured by the world's largest cellphone market, foreign telecoms players such as Siemens are backing the 3G standard.

EDGE (Enhanced Data Rates for GSM Evolution)
Also known as 2.75G, the technology is a leg up over the older GPRS (general packet radio service) technology. It offers access speeds of up to 240Kbps, compared to about 80Kbps for GPRS.

Some operators, such as Hong Kong's Peoples, have found the technology good enough to provide data services similarly available on 3G networks.

Other operators in the region with EDGE networks include Smart in the Philippines, DiGi and Maxis in Malaysia, DTAC in Thailand and AirTel in India.

HSDPA (high speed downlink packet access)
Touted as the successor of 3G, this technology is an upgrade of W-CDMA networks, where access speeds can be boosted to about 1.4Mbps. In the Asia-Pacific region, China, South Korea, Japan, Philippines, Singapore, Taiwan and Australia, are among the countries which plan to roll out HSDPA networks, or are in the midst of doing so.

Hardware makers such as Intel, Lenovo and Samsung have already committed to developing HSDPA-enabled devices. WiMax connectivity, however, will only be commercially available in portable devices in 2009.