Chris,
This is another site you provided by you . Did you read the comments below by the engineer from Hutchisons Communications which has the largest CDMA system in the world with about 20,000 subscribers ?
Jim
CDMA Tries to Catch a Break
While technology trials lag, rival wireless
specs GSM and TDMA are flourishing
By Paul Rubin, Wireless Editor
(prubin@mcgraw-hill.com)
CDMA is fast reaching its moment of truth. The digital wireless transmission standard broke slowly from the starting
gate in the deployment race and now trails its main digital
rivals, GSM and TDMA, by a huge margin. Although several
cellular operators and PCS (personal communications
services) providers are now getting ready to roll out
CDMA-based networks, results from CDMA's first
commercial deployments are decidedly mixed. Meanwhile,
AirTouch Communications (San Francisco) missed its 1995
rollout date for a CDMA-based PCS network in Los Angeles
and is now noncommital about a delivery date (see "The Spin
on Ginn").
Backers of GSM (global system for mobile communication)
and its parent technology, TDMA (time-division multiple
access), believe they have the digital race already won. GSM
alone now has more than 15 million cellular and broadband
PCS users worldwide, proponents claim, while the number of
CDMA users is in the thousands.
So what happened? CDMA--code-division multiple
access--technology was supposed to deliver 20 times more
capacity than analog cellular networks (CDMA backers have
since lowered that capacity claim to a 10-fold advantage).
That extra capacity could be used not only to expand existing
cellular networks but also to deliver new services, such as
paging combined with voice service.
Even at the lower capacity claim, CDMA is more robust than
GSM and TDMA, which deliver three to six times the
capacity of analog cellular technologies. But recent
developments surrounding CDMA deployments have taken
some of the luster off those numbers.
Hutchison Telecommunications Ltd. (Hong Kong), which
deployed the world's first large-scale commercial CDMA
network, is giving the technology only a qualified endorsement.
Infrastructure costs are high and equipment choices are
limited, says Henry Wong, system engineering manager for
Hutchison.
Hutchison's CDMA system, which currently handles 1.3 times
the capacity of its analog network, will be loaded to five times
the capacity of the analog network by June, Wong says. He
adds that CDMA does a better job than analog technology in
reaching remote areas, but that indoor coverage is not much
better.
Dubious Achievement
In the United States, CDMA has finally made it to commercial
deployment-although on a very limited basis. Bell Atlantic
Nynex Mobile (Bedminster, N.J.) now operates a commercial
CDMA cellular network in Trenton, N.J. But the cellular
operator isn't disclosing any price information, and the service
is available only to 500 or 600 employees and to customers
with which the wireless service provider already has a working
relationship.
tele.com Home Page
This Month's Issue
The Business Angle
Technology Fare
The Supply Side
Soap Box
Getting to Know Us
Back Issues |
