From DDI website: The site has a series of frames describing CDMAone which can be viewed by clicking on Next.
ddi.co.jp
DDI and IDO Set to Introduce
CDMA
In March 1997, DDI Corp. and IDO Corp. announced
that they planned to jointly introduce a code division
multiple access (CDMA) digital cellular system
nationwide. It is the latest digital cellular technology
and is gaining wide acceptance throughout the world,
as the communications environment becomes
increasingly globalized and seamless in terms of
technology, systems and businesses. In addition to
providing voice communications, cellular phones using
state-of-the-art systems technology will act as
sophisticated information terminals, transmitting and
receiving multimedia information and images. The new
service will initially provide 14.4kbps data
communications transmission speed, and 64 kbps data
transmission speed will be added in 1999. In line with
its philosophy of promoting global standardization and
the development of a communications environment
which allows people to communicate anywhere,
anytime, with anyone, DDI views the introduction of
state-of-the-art CDMA technology as the next step in
increasing customer convenience, service and mobility
in an advanced digital format, while remaining
compatible with the analog systems in current use.
EMeeting User Demand
The Ministry of Posts and Telecommunications
forecasts that the number of subscribers to cellular
systems will increase to about 45 million by the spring
of 2001. New users are putting growing pressure on the
current spectrum, and the TACS and PDC systems have
nearly reached their capacity limits, so there is a
pressing need to effect improvements to support
increased user traffic through the introduction of
high-speed services which make the most effective use
of the new 1.25 MHz bandwidth. Otherwise, it will
become impossible to handle the onslaught of new
subscribers expected around 1998 in cities such as
Tokyo and Osaka. This is why DDI and IDO are
moving rapidly to introduce the CDMA digital cellular
system and services. DDI will be the first company in
Japan to introduce cdmaOneTM, in July of 1998 in
Kansai, Kyushu and Okinawa, while IDO will start
cdmaOneTM services in the spring of 1999.
ENumerous Advantages with CDMA Technology
CDMA is a modulation and multiple access scheme
based on spread spectrum communications technology.
In addition to solving the immediate capacity concerns
of the rapidly growing cellular market, it also answers
industry's long-term need for affordable, efficient
mobile communications systems and services.
Compared to FDMA and TDMA technology, CDMA
features more spectrum-efficient, economical, quality
mobile digital cellular capabilities. |
