OL4.FEB–Pacific Communication Sciences, Inc.–RP
CDPD: The future of cellular data communications?
The scramble to participate in the growing market for wireless communications is underway. Vendors are offering a multitude of products and solutions. Proponents of one such solution, Cellular Digital Packet Data (CDPD) technology, believe that it will soon make affordable high-speed wireless data communication a routine occurrence.
CDPD is being offered as a cost-effective solution for two-way wireless data communications for laptops and personal digital assistants (PDAs). Unlike digital cellular solutions that would require the construction of a whole new digital infrastructure, CDPD technology uses the analog cellular networks already in place in the U.S.and Canada.
The technology takes advantage of the “idle” time that occurs during normal transmission across cellular telephone channels. This idle time–which is typically more than 30% of the air time–takes place between telephone call segments resulting from telephones moving from one cell to another.
CDPD technology detects and uses this wasted time by packaging data in small packets and sending it in short bursts during the idle periods. If both data and voice try to use the same frequency at the same time, voice is given priority. Since the packet data includes retries, no data is lost.
To implement CDPD, existing cell sites require a small amount of additional equipment. According to some estimates, the incremental cost is less than 10% of the cost of acquiring and outfitting a cell site. This allows CDPD to be priced at levels below competing wireless data services.
Among the first CDPD products to be announced is a CDPD communications system for use with IBM-compatible mobile computers. The unit, called the Ubiquity 2000 from Pacific Communication Sciences, Inc. (San Diego), is a self-powered cellular system that provides CDPD, circuit-switched cellular data, cellular voice, cellular fax, wireline data, wireline fax, and wireline voice.
Other features of the product include easy attachment to portable computers and “antenna diversity,” which neutralizes the common problem in wireless communications of small, local areas of poor signal strength. The Ubiquity 2000 costs $1,595 and will be available in the first quarter. For more information, contact Donald Burtis of Pacific Communication Sciences, Inc., at 619-535-9500 or .
–Richard Pell Jr.
CAPTIONS:
to be written to fit by Rich Pell.
CAPTIONS:
The Ubiquity 2000 is a CDPD communications system for use with portable IBM-compatible PCs.
DIAGRAM:
CDPD technology takes advantage of the “idle” time that is characteristic of transmission across cellular telephone channels.
GRAPH:
According to some forecasts, CDPD may be available to as many as 85% of metropolitan area cellular subscribers within three years.
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