South Korean telecom companies look to continue their pioneer's role in applying up-to-date mobile technologies into practical use as they did with code division multiple access (CDMA). Korea has been faster than any other nations in the globe in jump-starting every commercial versions of CDMA, the offspring of U.S.-based Qualcomm. Thanks to the nimbleness led by Korea's foremost wireless carrier SK Telecom, the world's 10th-biggest economy has found a growth phase in the mobile telephony services and cell phone productions. With CDMA success under its belt, the country is once again at the forefront of deploying such next-generation techniques that evolved from CDMA as wideband CDMA (W-CDMA) and orthogonal frequency division multiplexing (OFDM). Customers use wireless local area network (LAN) services at a restaurant in Seoul. Korea already launched WCDMA in late 2003 and OFDM platform is also in brisk use here in the form of wireless local area network (WLAN), spearheaded by primary fixed-line telecom entity KT. The former state monopoly KT currently maintains roughly 14,000 hot spots, or WLANavailable areas, up to 40 percent of the world's total tally of 35,000. Also SK Telecom and KT plan to start made-in-Korea Interneton- the-go services called WiBro next year, also using OFDM, for the first time in history. Multiplexing Technologies There are a flurry of multiplexing technologies, the minimal must in order to enable millions of wireless phone calls with relatively narrow radio spectrum bandwidth. Because the spectrum is very limited resource, it is impossible for the government to allocate a wide range of it for wireless telephony services. To address challenges of processing numerous calls with a narrow frequency band came multiplexing techniques of combining a number of signals. Up until now, three major multiplexing methods have been developed . frequency division multiple access (FDMA), time division multiple access (TDMA) and CDMA. FDMA is the oldest and still most important way of enhancing the efficiency of radio frequencies by dividing them into pieces so that many concurrent users can share them. "It is like making lanes in expressway. By segregating traffic into a specific lane, the efficiency of frequency usage could rocket. FDMA is the most basic format used for all wireless technologies today," Dongwon Securities analyst Greg Roh said. Based on FDMA came two more advanced versions of TDMA and CDMA. After dividing given frequency into several lanes, TDMA split it again by dividing it into different time slots. By comparison, CDMA does not divide up the channel by time but instead encodes with data with a certain code that can be received by only a compatible receiver, or cell phone. "Let me take an example. There are four teams who want to use a meeting room. With TDMA, each of the four teams must share the room by turns while CDMA enables them to use the room without the constraint of time by speaking different languages," Samsung Electronics vice president Lee Kyung-ju said. FDMA is the most fundamental technology and all of latest formats like TDMA and CDMA also hinge on it. TDMA had emerged as a mainstream in the 1990s but CDMA stole the show in the 2000s. Next-generation solutions like WCDMA and OFDM is evolution of CDMA of which viability was on serious suspicion just a decade ago but Korea weeded off the concerns by successfully commercializing the formula. Deep Impact The world tilted into global standards for communications (GSM), which is based on TDMA in the mid 1990s but Korea selected CDMA as a single national standard in 1995. "It was a risk-ridden decision, which might have collapsed Korea's economy as a whole. But the perilous selection catapulted Korea to the world's telecom powerhouse in the end," Mertiz Securities economist Jeon Sangyong said. Spearheaded by SK Telecom, Korea kick-started every versions of CDMA for the first time in the world even faster than the U.S., the hometown of the thenunderdog technology. SK Telecom stunned the world by commercially kicking off CDMA services in 1996 and it continued to set the trend by embarking on advanced versions of CDMA2000 1x in 2000 and EV-DO (evolution data optimized) two years later. "SK Telecom proved CDMA is a competitive format against TDMA. In fact, the company is outright responsible for the current migration to W-CDMA and OFDM in the globe," Dongwon Securities' Roh said. "Without the vehement investment and resolution of SK Telecom, the world might tilt toward TDMA. SK Telecom and Korea changed the main development path of mobile technologies. SK Telecom really made a dent in the global wireless scene." Plus, SK Telecom jump-started WCDMA service late 2003, the thirdgeneration (3G) form of CDMA families, along with the nation's runner-up player KTF. W-CDMA promises hithertoimpossible features including fast vide conferencing and vide call offerings at an affordable price. SK Telecom also looks to sustain its tradition as an icebreaker by upgrading W-CDMA into high-speed data packet access (HSDPA) next year. Before commercializing HSDPA in a full-fledged manner, the outfit will give a glimpse of the services by test-running it during the Asia-Pacific Economic Cooperation Summit (APEC) slated for this November in Seoul. In adopting OFDM, which are regarded as the mainstream format of the future, Korea is also playing a major role. The country applied OFDM into two sectors of WLAN and WiBro, which provides folks outdoor connection to the high-speed, always-on Internet. KT launched OFDM-based WLAN early this month, which boasts of maximum speed of 54 megabits per second (Mbps), or about 20 times faster than current fixed-line hook-up. The services are available at universities, hotel lobbies and airport lounges, where are called as hot spots. According to the Wireless Broadband Alliance, the organization for the 28 countries that embrace WLAN, roughly 14,000 hot spots are existing in Korea among the world's total of 35,000. KT eyes to increase the number to 16,000 this year by introducing the Internet services at convenience stores, coffee shops and even pizza pubs. Another OFDM-capable services on the line is WiBro, the locally developed portable Internet that will be available next year by two licensees of SK Telecom and KT.