August 95

Problem/Situation: Fast accurate data transmission is needed for mobile government workers.

Solution: Wireless data communication methods are evolving, but must be evaluated carefully.

Vendors: Rysavy & Associates, ARDIS, RAM Mobile Data, AT&T;/McCaw, Ameritech, Bell Atlantic, Metricom Inc., Datacomm Research Co., LCC Inc.

Contacts: Ira Brodsky, Datacomm Research Co., 708/256-1763; James Kobielus, LCC Inc., 703/351-6666; Peter Rysavy, Rysavy & Associates, 206/517-5654.

By Tod Newcombe

Contributing Editor

Untethered computing has always appealed to the road warriors of today's Information Age. Already enamored by the cellular phone, mobile workers - and those who speak for them - have touted the potential benefits of instant data communications from a car, park bench or airport lounge. Several companies have poured millions of dollars into building wireless networks, hoping users would pull the plugs on their laptop modems and start transmitting data over the airwaves instead.

So far, it hasn't happened. The performance of wireless communications is achingly slow when compared to data communications via wired modems and land lines. Because of proprietary protocols, developing applications can be complex and costly. As a result, the total number of wireless users remains small, and few major organizations have adopted the technology.

But just as multimedia seemed to go nowhere until CD-ROM became inexpensive, wireless data communications appears poised to move forward, thanks, in part, to some faster, possibly less expensive technologies. "It's getting close to becoming an irresistible package, like the cellular phone," said Peter Rysavy, a consultant with Rysavy & Associates. "People who work in this industry can see it all coming together and at some point it's going to reach critical mass where the whole thing just explodes."

For state and local government, the changes could open the door to some innovative applications. Conventional thinking about wireless data communications in the public sector has usually restricted its use to law enforcement. Police, it was thought, would benefit the most from instant access to remote databases they could search to identify suspects and vehicles in the field.

But a host of government agencies, which also put workers in the field, could benefit from wireless communications as well. Still other agencies might want to rethink how they use their office workers and use some of them more productively in the field, communicating with the agency via laptops and wireless networks.

However, before agencies send out swarms of roaming workers equipped with personal digital assistants (PDA) and wireless modems, they must address a long list of issues. These range from coverage and costs to data rate performance and reengineering applications.


To transmit data over a wireless network, organizations currently have a couple of choices. One is to use the commercial radio data services provided by ARDIS and RAM Mobile Data. Both firms are fully deployed and provide their subscribers with the ability to transmit data while roaming throughout most of the United States.

ARDIS and RAM use a technology called packet radio, which broadcasts data in bursts or packets at transmission rates that range from 4.8K to 8K per second. (Higher transmission rates are possible in certain locations.) Both companies use a network of base stations to route messages along the shortest path and have proprietary protocols.

Another, more popular approach, according to Rysavy, is to purchase a cellular modem, plug it into a laptop, and send and receive data over the existing cellular phone network. Called circuit-switched cellular, the technology is relatively simple to use, although it requires a connection between the laptop, modem and cellular phone. Also, cellular subscribers are restricted in the ability to roam. Typically, they need additional accounts and phone numbers if they move between two or more cities.