CDMA2000, W-CDMA competing for IMT-2000
koreaherald.co.kr
The currently used personal mobile communication, called Personal
Communication Services, is similar in concept to IMT-2000. PCS is designed to
enable communication at anytime, anywhere and with anyone. If this is achieved,
then there is no real difference between PCS and IMT-2000, but this goal has not
been achieved as yet.
Trends in foreign countries Korea uses the IS-95A technology to provide voice
and low-speed data transmission services. But, to satisfy customers, Korea is
preparing to use IS-95B, a technology that offers faster data transmission and
clearer voice quality. This year, Korea will offer CDMA2000 and North American
styles of IMT-2000.
There are two main types of IMT-2000 technology, North America's IS-95
method and Europe's GSM method. Currently, Europe is trying to commercialize
W-CDMA, a GSM method, to service IMT-2000. In the future, it is expected that
the North America's CDMA2000 and Europe's W-CDMA technologies will
compete for the IMT-2000 market.
North American method has developed from IS-95A (14.4 Kbps) to IS-95B
(64 Kbps, 115 Kbps) to IS-95C (384 Kbps), an existing spectrum of IMT-2000
capable system. CDMA2000 (up to 2 Mbps) is a new IMT-2000 capable
spectrum.
European style has gone from GSM (9.6 Kbps) to GSM+ (57 Kbps for
HSCSD, 115 Kbps for GPRS) to GSM++ EDGE (384 Kbps), an existing
spectrum of IMT-2000 capable systems. It is going to W-CDMA (up to 2 Mbps),
a new IMT-2000 capable spectrum.
CDMA 2000 & W-CDMA There are several differences between the two
possible IMT-2000 technologies. If the two technologies are commercialized this
year, the compatibility problem must be considered. Two users with different
communication technologies must be able to communicate anywhere and anytime.
Comparing the two systems, chip rate of W-CDMA is 4.097 Mcps, faster than
3.686 Mcps of CDMA2000. In the light of operation mode, CDMA2000 is
synchronous, while W-CDMA is asynchronous. Network protocol of CDMA2000
is IS-41MAP, while that of W-CDMA is GSM-MAP. Vocodor of CDMA2000 is
variable rate, and that of W-CDMA fixed rate.
ServicesNetwork Service:
Since it is difficult to provide various services under the current low-speed
transmission, IMT-2000 supports the following various transmission speeds to
provide the services customer want.
- Teletex: The documentation containing teletex-coded information can be used
to exchange information among IMT-2000 customers.
- Videotex Service: Provides the search service for characters and images.
- Telefacsimile Service: Users can exchange coded information using the
automatic memory-to-memory method.
- Telephone Service: This public telephone service allows the customers to
exchange voice information in the communication mode.
- Program Voice Service: Allows the transmission of voice information to
IMT-2000 customers.
- Message Handling Service: Sends messages- International Paging Service:
Using the mobile satellite, IMT-2000 provides fiber-optic paging services, which is
better in quality than the current paging service.
- Point-to-Multipoint Communication Service: IMT-2000 provides the
point-to-multipoint services for distribution, group calling, and other applications.
- Video Phone Service for ISDN: Provides in real-time duplex communication
services which are mixtures of voice and image.
- Data Service: IMT-2000 provides synchronous and asynchronous data
services at 2Mbps speed.
- Program Image Service: Using network, IMT-2000 can transmit images.
Generally, the images that pass through IMT-2000 are compressed.
- Audiovisual Service: IMT-2000 allows simultaneous exchange of voice, data,
and images in more than two places to customers in real-time and in both-ways.
Mobile value-added service:
- Short Message Service: This is an asynchronous service that allows the
exchange of limited length messages between the storage system and the mobile
place and between two mobile places in real-time. IMT-2000 also provides the
point-to-point and point-to-multipoint services.
- Position Service: Provides the positions of the paging and paged party. To
protect the privacy of IMT-2000 customers, only the access-authorized
applications are included.
What's IMT-2000?IMT stands for the International Mobile Telecommunication
and the 2000 stands for the year of scheduled operation. It uses the world's unitary
frequency of 2GHz. It is the third-generation multimedia telecommunication service,
in which a single terminal can transmit voice, data, image and other multimedia data
to communicate anywhere in the world.
Service:
- Multimedia Communication: voice, data, and image- The International Roaming
Service: possible to communicate anywhere in the world with a single
terminalSystem:
- The goal is to integrate the wired and wireless communication networks using
the high-speed information communication network.
- Transmission Speed: 2 Mbps (inside building), 384 Kbps (walker), 144 Kbps
(moving vehicle)- Bandwidth: Total 230 MHz (1885~2025 MHz ?¥÷ 2110 ~ 2200
MHz)- WARC (World Administrative Radio Conference), an organization
managing the frequency policy, allocated it in 1992.
Features of IMT-2000IMT-2000 has a bandwidth of 5 MHz, considerably
wider than the current system's bandwidth of 1.25MHz. The World Administrative
Radio Conference, an organization managing the frequency policy, allocated the
total of 230 MHz (1885~2025MHz and 2110 ~ 2200MHz) in 1992.
As the bandwidth of IMT-2000 is increased to 5 MHz, it is possible to provide
various multimedia communications. IMT-2000 can support 2 Mbps of high-quality
multimedia services for people inside building where there is little movements, 384
Kbps high-speed data transmissions for people walking, and 144 Kbps for people
in moving vehicles.
Updated: 08/31/2000 |
