@BEGIN_FILE_ID.DIZUMF: CDPD New Standards for Cellular Data @END_FILE_ID.DIZ /|___ ___ ____________ / | | \/ \ _____/ / | | |\/ __) _/ ! | \/ | |Z! \________|__ ||___|__ | <===PRESENTS===\|=======\|=======> CELLULAR COMMUNICATIONS FOR VOICE & DATA A new cellular technology in the works, called cellular digital packet data, or CDPD, promises at last to make mobile computing a completely wireless affair. Currently, cellular telephones and networks let us make phone calls wherever we happen to be, but if we try to send a spreadsheet file, search our office database, or log into CompuServe through cellular connections, we're asking for trouble. For these tasks, you must hook up you laptop computer to a standard telephone line. But CDPD aims to change that. CDPD'S ADVANTAGE CDPD brings the magic of packet switching to the cellular network, combining the virtues of both. By using cellular channels, CDPD takes advantage of the extremely wide coverage of the cellular network. But because CDPD uses a form of packet switching, it sends data more cheaply and more reliably than traditional cellular connections, which were designed for carrying voice. Because packet switching doesn't require making and sustaining a two-way cellular connection or "circuit," users are charged for packets or kilobytes of data sent, rather than for the time they occupy a cellular channel. The packet-switching approach is also cheaper because transmission time is shorter-the modem has to correct fewer errors. Cellular connections are susceptible to interference, but by routing small packets of data over open cellular channels-the packets hop from channel to channel in order to give voice calls priority-CDPD makes more efficient use of cellular channels. Of course, whether carriers pass on this savings to users depends on how hard they're competing. Anyone who uses RadioMail or another wireless e-mail or paging service, which rely on the Ardis and RAM Mobile Data packet radio networks, knows how reliable packet switching is. These networks deliver wireless e-mail and other short data messages, for service personnel, rental car companies, and delivery services-without a hitch. What does CDPD have that these networks don't? For starters, CDPD is a newer technology and can transfer data at 19.6kbps;many of the Ardis and RAM Mobile networks use older technology-fast enough to deliver short messages reliably, but way too slow for long ones. Both Ardis and RAM have been busy upgrading their key metropolitan networks from 4800 to 19.6kbps. But while many of their key networks now offer 19.6kbps speed, Ardis and RAM simply can't match the coverage the cellular-based CDPD provides. Cellular phone service is offered in many more area than wireless e-mail. This market reality also means that CDPD has much stronger backing. While packet radio is championed by only two major vendors, a number of heavyweights are behind CDPD. Not only is it being jointly developed by a number of cellular carriers, but it's also got the backing of major hardware manufactures and software developers. Apple and IBM, as well as Lotus, Novell, and Microsoft, are among the companies now developing CDPD products. The cellular carriers behind CDPD include AirTouch Cellular Data (formerly PacTel Cellular), Ameritech Cellular, Bell Atlantic Mobile, Contel Cellular, GTE Personal Communications Services, McCaw Cellular Communications, NYNEX Mobile Communications and southwestern Bell Mobile Systems. Most carriers are working feverishly to offer CDPD service in the near future. AirTouch plans to offer CDPD coverage in all its market areas, including the Bay Area, by the end of 1995. NYNEX Mobile has already begun installing CDPD in New York City, and plans to cover the entire New York boroughts network area by the end of this year. And Bell Atlantic Mobile has already introduced commercial CDPD service in Washington D.C., Baltimore, and Pittsburgh EASY FOR USERS CDPD is fairly painless for users to adopt. You won't need special hardware of software to use CDPD-simply equip your mobile computer with a CDPD modem and you're ready to hook up. Because CDPD supports standard network protocols (it's based on TCP/IP, the protocol on which the Internet operates), it is essentially and extension of the wired data networks we currently use, such as our office networks, commercial online services, and the Internet. CDPD will be completely transparent to network operating systems, operating systems, and applications software. To your office LAN, whenever your remote laptop is turned on, its CDPD modem will appear as just another network interface card-as if your laptop were on a workstation on the next desktop. Because of its standard protocol, CDPD bridges cellular and standard telephone networks. This means that wired devices can connect with wireless ones, and vice versa. Only your wireless remote computer needs a CDPD modem-the office desktop can reach it through the standard modem you're already using. In fact, a CDPD transmission often travels part of its journey via wire-whether it finds its way to a wired or wireless machine remains transparent to the users. How much will CDPD cost? Bell Atlantic's AirBridge packet system, for example, offers a sliding scale based on usage. For infrequent users, the monthly minimum is $15, with charges of $.0058 per packet and $.58 per kilobyte during peak period (8 a.m. to 4 p.m.). For heavy users, the monthly minimum is $120, with charges of only $.0017 per packet and $.17 per kilobyte. Under both plans, prices are 50 percent lower during off peak times. There is a one time activation fee of $50 and a monthly port connection of $40 for 9.6kbps and $50 for 56kbps (excluding leased telephone company lines). Even now-prices will surely fall over time-CDPD is not expensive by cellular standards. You probably won't be using CCDP to surf the 'Net real soon. By the end of next year, your company might be using CDPD for e-mail, paging, or short messaging. CDPD will first compete with the packet radio networks in these markets. There's still a way to go before CDPD will be honed for heavier data networking, so we can't be certain that CDPD will ultimately be the wireless medium of choice. But right now, CDPD looks to be the most open and flexible form of wireless data communications, as well as the one with the widest coverage. Where to buy: AirTouch Cellular (510) 988-4400 Bell Atlantic Mobile (908) 306-7500 NYNEX Mobile Communications (914) 365-7200 SPRINT Cellular (312) 399-5153 BROUGHT 2 U BY The P/\NTHER *END*