… CDPD: the age of discovery

Mobile Phone News,  Dec 6, 1993  

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The deployment of CDPD equipment is not an exact science, and MOBILE PHONE NEWS Senior Editor Andrea Knotts Bona discovered that no one manufacturer can supply a complete data system from software to hardware. The growing need for wireless data systems integrators is apparent as CDPD deployment becomes a reality. "There is a lot of integration involved in CDPD," said Barbara Mierisch, AT&T spokeswoman.

AT&T recently introduced a series of new CDPD products to support the 1.0 specification as defined by the CDPD consortium tasked with writing a cellular data protocol. AT&T's family of products includes the mobile data base station (MDBS) and the mobile data intermediary system (MDIS). Additionally, the company provides the integration, installation and support services required to apply the products to a carrier's existing cellular network.

Mierisch explains the MDBS is analogous to the cellular network's mobile base station and the MDIS is similar to the cellular switch and controller, A MDBS handles such tasks as sending and receiving data packets to and from the modems of various subscribers using the data services.

"We design the network architecture and manage the system development and testing as well as look at product quality," said Bob Sellinger, AT&T Network Systems PCS director. "Our CDPD system is designed to work with any system and will have tremendous power with our Autoplex cellular network system."

AT&T's products were designed and developed in cooperation with San Diego-based Pacific Communications Services Inc. (PCSI) and Denver-based-Evolving Systems Inc. We announced in August we were adding a CDPD system to our wireless data product line.

The most expedient way to pull together all the necessary equipment was to use other vendors products," said Mierisch. AT&T chose PCSI and ESI because of their existing products and early developmental work with CDPD.

AT&T's CDPD overlay equipment uses "the most open protocols architecture as possible," said Mierisch. With its CDPD equipment overlay, AT&T can provide a carrier with data services no matter which vendor's switching equipment the carrier uses. However, AT&T's CDPD equipment coupled with AT&T network switching equipment provides many advantages, said Sellinger.

"There is the opportunity to reuse some of the voice equipment if an Autoplex series 2 switch is in place because the Autoplex series 2 uses linear amplifiers," Sellinger said. "CDPD is a growth option for Autoplex switching equipment."

Although the price to deploy CDPD equipment remains configuration dependent--a complete CDPD overlay's typical ballpark cost per cell, including a pro-rated portion of MDIS and software, would be somewhere around $50.000 to $75,000 per cell. This figure represents about 1/10 of the corresponding voice equipment cost per cell site. If a carrier does not have an Autoplex system--separate amplifiers would need to be added at a price of $2,000 to $3,000 per-sector per-cell.

"We are the only vendor with patented linear amplifier," Sellinger said. Customers with Autoplex series 2 equipment are at an advantage, because the switch will do double duty. With the coming of CDPD this is where the Autoplex can come into place, they can see the power work for them, Mierisch said.

"We are up to the equipment supply challenge," said Sellinger. However, there is the issue of separating CDPD network deployment fact from fiction. Only six mobile data handheld products were working on the test system at the recent Comdex exhibition in Las Vegas--predominantly the Thinkpad 750s were used, said Sellinger. Carriers participating in demonstrations included GTE, Bell Atlantic Mobile Systems and McCaw.

Initially, major CDPD deployment will be in the major cities, but the lowly interstates will need to be covered, said Sellinger. Cellular carriers' CDPD deployment has been following Sellinger's deployment assessment. Initially, McCaw will deploy CDPD in six major metro areas, GTE in three markets, BAM in two, and PacTel's President Lee Franklin said the carrier would to expand CDPD into most of its other markets by the end of 1994.

COPYRIGHT 1993 Access Intelligence, LLC
COPYRIGHT 2008 Gale, Cengage Learning