We gathered an assortment of portable wireless pagers, modems and cell phones from a range of service providers, took the devices to a variety of locations and tested them under real-world conditions. In the paging category, we tested GoAmerica's ARDIS-based service and the two-way RIM Inter@ctive Pager 850 from Research In Motion, the SkyTel two-way paging network using pagers from Motorola and Glenayre Technologies, and the BellSouth Mobitex network (also known as BellSouth Wireless Data, or BSWD) with the Palm VII. We also ran a Metricom Ricochet wireless modem through its paces and tested a data-capable CDMA (Code Division Multiple Access) cellular phone from Sprint PCS.

Other service providers and wireless devices are available, but ours is a representative sample. Although our primary focus was on the various network technologies you can use right now, in a real-world test it's impossible to separate the network from the device that accesses the network and from the service provider through which you purchase the device and service plan. We've examined all three components here.

Our Test Bed

Most of our testing took place in the Washington area, which has a fairly complete range of wireless services available. We tested in and around downtown D.C., in a suburban area of Maryland, and in various outlying areas, including rural southern Virginia outside the Richmond area, various highway locations and in downtown Baltimore. We also conducted some limited testing in Las Vegas and Los Angeles. The tests were real-world-based and as simple as could be designed because we were examining such a wide variety of networks, services, protocols and devices. We recorded the time it took to send a standard text message of known size over each device and repeated each trial a minimum of 10 times. We discarded the high and low values for each trial, along with any data points that were more than one standard deviation from the mean value.

Our standard test-file size was 5 KB--chosen because several of the paging networks or e-mail clients limit single messages to that size. We also tested larger file transfers (up to 45 KB) with the devices and services--CDMA, CDPD (Cellular Digital Packet Data) and Ricochet--that supported them.

Our test results cannot be considered scientific; throughput varies widely with all these devices depending on their physical location, proximity to the nearest transmitter or cell tower, RF (radio frequency) interference and environment, network traffic and other factors. But in a real-world sense, we obtained results in situations that should be comparable with the range of operational circumstances an average user might experience.

Who's Got the Standards?

The state of wireless infrastructure in the United States is a complete muddle. Competing standards have popped up like weeds and are growing just as haphazardly. In many cases, their underlying capabilities and technologies differ widely, yet they all want to fulfill the same goal--to get wireless data to and from your mobile workers.

Europe and most of Asia are a bit more civilized with respect to standards. GSM (Global System for Mobile Communications) is an international standard for cellular voice networks, and you can roam far and wide with a GSM phone. By comparison, what few GSM products are available in the United States actually operate on a different frequency range than overseas GSM networks. Nevertheless, a number of future technologies for wireless data are GSM-based, so GSM may be the dark horse in the U.S. wireless market. We could not test any devices that employ the U.S. variant (1900 MHz) of GSM because the local GSM provider, Omnipoint/VoiceStream Wireless, could not provide us with a working data-capable GSM handset.

The short-term solution to wireless interoperability woes in the United States may rely not upon standardization but on technological kludges. We are likely to see an increase in the number of multiband phones and devices sold--that is, devices that can operate on AMPS (Advanced Mobile Phone Service), CDMA, GSM/TDMA (Time Division Multiple Access) and perhaps other networks, depending on what's locally available. Such capability, along with the emergence of higher-level network-independent protocols--for example, WAP (Wireless Application Protocol) and WML (Wireless Markup Language)--may have to suffice until the next generation of wireless-data-enabled devices comes of age.

Think Globally, Deploy Locally

Large sections of the United States are bound to remain without mainstream wireless-data coverage for some time because their population densities are too low to justify the infrastructure costs. Sprint PCS boasts that its spectrum allocations let it cover the entire United States, but that's irrelevant unless someone at Sprint decides that the return on investment of such wide deployment justifies the expense of building the network out. The spectacular commercial failure of the Iridium network also indicates that low-population-density areas won't get salvation from LEO (low-Earth-orbit) satellite networks anytime soon, either.

Rather, it's the telephone companies that have a potentially significant advantage over smaller, data-only networks, such as Metricom, in the area of network build-out. The telcos moved from analog AMPS technology to digital technologies like CDMA and TDMA for reasons of economy and capacity. Because of the way these digital technologies split up one block of frequencies, cellular carriers can support a much larger number of subscribers per area than they could with analog technologies. Once converted to a digital infrastructure, the telcos can spread the cost of implementing data services over their millions of subscribers--in effect, using their existing base of voice customers to bootstrap their data offerings. By comparison, the data-only networks will have to rely on their ability to provide higher bandwidth to sell their services and will have to finance their infrastructure costs directly from their subscriber base.

Dedicated data services using wireless modems still offer greater bandwidth and thus flexibility for general Web browsing or deploying effective, usable corporate applications over wireless services. Sprint's CDMA data services, for instance, top out at 14.4 Kbps, while CDPD offers maximum throughputs of 19.2 Kbps, and Metricom Ricochet's first-generation data modems cruise along at a comparatively speedy 28.8 Kbps. The difference between 28.8 Kbps and 14.4 Kbps is the difference between usable but slow Web browsing and pure tedium. Bandwidths of 14.4 Kbps or even 9.6 Kbps can be suitable for use on cell-phone-sized devices, however, because their small screens and rudimentary keyboards tend to limit their primary uses to low-bandwidth transactional and point information, such as stock reports and movie listings.

Two-Way Paging: A New Face

The first type of wireless-data option we examined was the use of services based on two-way paging networks. For the most part, these are packet-switched networks that leverage dedicated, proprietary infrastructures originally built to support basic paging and short messaging. ARDIS, Mobitex and SkyTel are three of the most well-known wireless-data services, and all have many large-scale production systems deployed, especially in the areas of wide area fleet management and sales-force automation.

Paging services--the oldest and most well established of the wireless services--tend to be built on top of older technologies like X.25, but they do offer some services difficult or impossible to get elsewhere: guaranteed delivery and notification, built-in error correction and, in some cases, broadcast services. They also tend to have wide geographical coverage and good in-building penetration. The paging-based services suffer from some serious disadvantages over their competitors, however. None is IP-capable, and all were designed with low-bandwidth services in mind.

GoAmerica's ARDIS-based network services are provided by Motient Corp. through Motorola's DataTac service. Mobitex is offered by BellSouth. The SkyTel service is used by the Motorola PageWriter and Glenayre two-way pagers. All three of these services offer roughly similar throughput, and all are most well suited for bursty, short-message-based data, though clever system planners are stretching the definition of two-way-paging by offering real-time services, such as Palm's Palm.Net "Web clipping" service over Mobitex on the Palm VII (see "3Com's Palm Episode VII: Worth the Price of Admission?").

Analysis

Motient Corp. ARDIS
We started our testing with the ARDIS network. ARDIS' geographical coverage is widespread in the United States and roughly comparable with that of SkyTel, but not as extensive as Mobitex's coverage area. In testing with GoAmerica and the RIM 850 pager, throughput was generally quite good for short messages, averaging 4,390 bps. Network latency, however, varied widely even within a single test area, from almost nothing, yielding a transfer rate of more than 9,100 bps, to heavy latency, which dragged the rate down to less than 1,000 bps.

Flat-rate data pricing is available through GoAmerica at $59.95 per month. Such pricing is a must for any kind of large-scale wireless-data deployment, unless you want to pay through the nose.

Theoretically, the ARDIS network should provide good in-building penetration when you're near a transceiver tower. ARDIS' towers are in the center rather than on the perimeter of its RF cells, and it has wider channel spacing than Mobitex (25 KHz, compared with Mobitex's 12.5 KHz). However, Mobitex is building out new towers faster than ARDIS is, and we found that the Mobitex-based Palm VII gave the greatest range of geographical coverage and in-building penetration across our tests. ARDIS' coverage was surprisingly spotty, even within our suburban Maryland test location, and was frequently unavailable indoors (go to www.motient.com/find/ for ARDIS coverage areas).

As a specific device, however, the RIM 850 is one of the most well designed, most ergonomic two-way pagers we've seen: The tiny built-in Qwerty keyboard is usable for composing short messages, and the device isn't too large. The RIM 850's controls are well-placed, and the user interface is clean, making it easy to see why the RIM pagers consistently win raves from users. The battery life from the single AA battery, however, is poor compared with that of other two-way pagers.

The GoAmerica service was easy to set up, GoAmerica's technical staff was competent and responsive, and the provider's pricing plan was reasonable and included unlimited data usage. If the RIM 850 had an IrDA (Infrared Data Association) port, and if the ARDIS coverage had been more consistent geographically, it would have been one of our favorite combinations of service and device. The inconsistent results, however, make it more difficult to recommend. GoAmerica does offer the RIM 950 pager, which is identical to the 850, but uses the Mobitex network. In light of our test results, this might be a more attractive option.

Service: GoAmerica, (888) 462-4600, (201) 966-1717, www.goamerica.com.

Device: RIM Inter@ctive Pager 850, Research In Motion, (519) 888-7465, www.rim.net.

BellSouth Mobitex/BellSouth Wireless Data
We tested Mobitex/BSWD services via a Palm VII device, which offers a wide variety of data services over the Mobitex network, via a convenient and compact two-way radio built into the product. The Palm.Net service provides access to those specific Web sites for which a small client application, called a PQA (Palm Query Application) has been written and installed on the Palm VII, so open Web browsing isn't an option. Until recently, Palm didn't offer an unlimited data version of its service, and heavy data users could easily spend a mint once they'd burned through their prepaid data allotment. Now that an unlimited-use option is available (priced at a reasonable $44.99 per month), Palm.Net service is much more palatable.

Mobitex's biggest problem, however, is shared by the other paging networks: It lacks IP support. This shortfall makes it difficult to set up corporate users to receive e-mail and use corporate applications over the Palm VII. E-mail, for instance, is available only via the iMessenger service, which comes with the Palm VII; regular POP3-based e-mail must be forwarded from an existing POP3 account to the user's Palm.Net mailbox.

Some third-party services, such as ThinAirApps' ThinAirMail and Corsoft's iPopper, will poll your POP3 or IMAP account and give you access via Palm VII. It is also possible to host corporate applications and data via Palm.Net, and some organizations are using Palm VIIs to provide mobile users with access to corporate data. Again, however, the lack of native IP complicates things.

In our field tests with 5-KB files, data transfer with the Palm VII using the Palm.Net service over Mobitex averaged a fairly poky 2,000 bps, with surprisingly little variation based on location, from Maryland to Virginia to Las Vegas. Geographical coverage, however, was the best we found with any device (see www.bellsouthwd.com/cov/coverage.html for coverage areas). Mobitex provided the best in-building penetration as well, offering coverage with our Palm VII when ARDIS, SkyTel and even CDMA cellular signals were blocked.

Palm.Net offers relatively secure data encryption, combining Mobitex's built-in proprietary network security with Certicom's Elliptic Curve Cryptography, along with SSL (Secure Sockets Layer) on the Palm.Net back end. While Mobitex supports notification services, the Palm VII doesn't have any "standby" mode for the radio, so pager-like message notification is unavailable with this device.

The Palm VII really pushes the envelope of paging network-based services, coming as close as possible to general-purpose data connectivity over Mobitex. However, the lack of IP support will make enterprise IT system deployments difficult, and the throughput is nothing to write home about. Still, at the moment, the combination of low price point and extensive geographical coverage makes the Palm VII one of the more attractive options to investigate, and in our tests it was the strongest of the three paging-based services.

Services: Mobitex/BellSouth Wireless Data, BellSouth, (800) 726-3210, (732) 602-5500, www.bellsouthwd.com; Palm.Net, Palm, (800) 881-7256, (408) 326-9000, www.palm.net.

Device: Palm VII, Palm, www.palm.com/products/palmvii/index.

MCI WorldCom SkyTel
Both the Glenayre AccessLink II and the Motorola PageWriter 2000X, which use the SkyTel two-way paging service and ReFlex 50 protocol, showed slow real-world transfer rates of 840 bps to 1,940 bps with our 5-KB test file, averaging 1,573 bps. Latency was a major issue with this relatively low bandwidth, however. Many trials aborted because the message was queued for later transmission--presumably because of network traffic or coverage issues. Overall geographic coverage was midway between that of ARDIS and Mobitex, with coverage widely available throughout the D.C. metro area and Baltimore, but not in the more rural areas we tested. (Visit the SkyTel Web site for an interactive coverage map of this service.)

Aside from the speed problems, the second drawback to the SkyTel pagers is the cost of their service plans, which are more oriented to short alphanumeric messages than any kind of large-scale wireless-data connectivity, such as e-mail or corporate data. The PageWriter 2000X, already an expensive unit at $450, comes with a service plan priced at $34.95 for 1,400 messages of 10 characters apiece (14,000 characters total), with additional data at 10 cents per 10 characters. Clearly, this plan is not remotely sufficient for even a few average-sized e-mail messages. SkyTel has a similar plan for the Glenayre: $285 for the pager, and then $25 per month for 1,000 10-character messages, with the same 10 cents per 10 characters for usage over the allotment. If you use one of the SkyTel units for even 10 or 20 1-KB e-mail messages, you'll be facing incredible monthly bills.

The Motorola PageWriter pager is a large clamshell unit, but includes a mini-Qwerty keyboard for message composition on its approximately half-PDA (personal digital assistant)-sized screen, along with built-in PIM (personal information manager) applications, such as scheduling, calendar, notepad and the InfoBeam application, which gets information such as weather and stock reports. Its built-in rechargeable battery lasted for several weeks of occasional use, as did the single AA battery of the Glenayre pager. The Glenayre unit, however, deserves recognition for being the smallest two-way pager we've seen and for having the cleanest, easiest-to-use interface--impressive for a device with only three buttons (one of which is a four-way toggle switch) and a four-line display. AccessLink II's navigation, with just a few simple controls, is easier than PageWriter's with a full keyboard. Both devices have built-in IrDA ports that greatly increase their functionality when used in conjunction with a PDA or laptop.

In fact, despite the shortcomings we found with the SkyTel network, the built-in IrDA capability of the Glenayre AccessLink II and Motorola PageWriter pagers let them perform double duty as a kind of wireless e-mail and data gateway for a PDA, which we found extremely useful. The PDA--we used a Palm V and Handspring's Visor--wirelessly sent a request for data, such as weather, travel or stock information, or an outgoing e-mail message, to the pager over infrared, and the pager sent that request over the air. When requested data came back, it was beamed wirelessly from the pager back to the PDA for viewing. The built-in IrDA capability, used in conjunction with software such as JP Systems' InfoBeam and BeamLink on the PDA, makes it possible to take a first step toward the Holy Grail of device convergence and seamless multidevice interoperability.

Service: SkyTel, MCI WorldCom, (800) 395-5304, www.skytel.com.

Devices: Glenayre AccessLink II, Glenayre, www.glenayre.com.
Visor, Handspring, (888) 565-9393, www.handspring.com.
Motorola PageWriter 2000X two-way pager, Motorola, www.motorola.com.
Palm V, Palm, www.palm.com/products/vseries.html.

Wireless Modems: The Fastest--For Now
Wireless modems offer dedicated data services, usually faster than paging-based or digital-cellular hybrids, and they are IP-capable. Right now, the two primary forms are CDPD modems and Metricom's Ricochet modems. Wireless modems using CDPD or Metricom's network can serve as modem substitutes but generally will not offer voice or paging services. Geographical coverage is not as extensive as Mobitex's, for instance, but if these options are available in your area, they may provide the best combination of throughput and price for general-purpose data use.

One of the most intriguing wireless options is the Ricochet modem offered by Metricom, which won a finalist spot in our Well-Connected Awards this year in the Best Mobile Computing Technology category. Metricom started out by supplying vertical-market radio systems to do remote usage monitoring for water meters and the like, and then moved into the horizontal wireless-data market. On the plus side, Metricom has complete control over its custom network, which was designed from the ground up for data.

The first-generation Ricochet modems act as AT-compatible modem substitutes, using a standard serial port for connectivity. With a data rate of up to 28.8 Kbps, the Ricochet data throughput blows away all the other options we tested here for raw speed.

Metricom's infrastructure is clever and unique: Self-contained "pole-top" microcell transceivers are slung underneath light poles about every half mile in metropolitan areas and receive their power from the pole. The packet-switched Ricochet system operates in the unlicensed 902- to 928-MHz range and uses an FHSS (frequency-hopping spread-spectrum) approach, which, along with the transceiver placement, results in a robust data infrastructure. Operating the modem while at highway speeds is possible, and handoffs between microcells worked seamlessly in our testing as well. This is a low-power solution, which gives the wireless modems a battery life of around six hours.

In our tests, a 5-KB test file was sent over the Ricochet network at an average speed of 6,140 bps. However, most of the slower-than-expected throughput was because of network overhead involved with making the TCP/IP connection to the SMTP server.

Test files between 20 KB and 35 KB averaged 12,994 bps, and our 46-KB test file showed a mean sustained throughput of 17,944 bps. No other solution came close to this level of speed. In addition, connection to the network was routinely fast and reliable, with dropped connections almost nonexistent, unlike CDPD.

Metricom's bad news is its geographic coverage, which has been limited to a handful of areas--primarily Washington metro and suburbs, Seattle, the San Francisco Bay area and New York (complete coverage maps are available at the Ricochet Web site).

Within the D.C. area, for instance, coverage is excellent, and the cost can't be beat--$29.99 per month for unlimited data and Internet access, including an e-mail account (though as a standard wireless modem, Ricochet allows easy access to any POP3 account via its service).

Metricom is getting ready to roll out a new 128-Kbps wireless service to 46 cities starting this summer (coverage maps for the initial 21-city rollouts can be found at www.ricochet. net/about_us/coverage_maps/index.html). The service was not available in time for our tests. If it delivers, Metricom will provide the first high-speed, wide area wireless coverage with a high degree of availability.

Service: Ricochet, Metricom, (800) GO-WIRELESS, (408) 399-8200, www.ricochet.net.

Devices: Ricochet Original Modem, Ricochet SE Modem, Metricom, (800) GO-WIRELESS, (408) 399-8200, www.ricochet.net.

Cellular Digital Packet Data
CDPD is a dedicated data service that offers a theoretically good combination of speed, availability and standards-based operation. CDPD modems are available not only for Palm PDAs, but for laptops and desktops. This technology leverages the unused portion of AMPS cellular circuits, so voice and data can share the same networks. As a result, it should be possible to get wireless coverage anywhere you can get cellular service.

But it's not that simple. When AMPS networks become congested, they lack the capacity to share with data circuits. And because special equipment has to be installed for the data capability, CDPD coverage, though fairly extensive, is not nearly as ubiquitous as basic analog voice service or even some of the paging networks. (For a comparison of nationwide CDPD coverage versus Mobitex coverage, see www.mobitex.org/resources/uscompare.html.)

Several vendors offer CDPD services, particularly over AT&T's Wireless IP network, and some organizations--notably utility companies and public-safety operations--are using CDPD data access. Mass-market penetration, however, has been relatively low so far, though pricing is good to excellent. GoAmerica offers a $59.95 unlimited usage plan and a special $49.95 plan for the Novatel Wireless Minstrel III, and Bell Atlantic offers a regional CDPD plan for $24.95 for unlimited e-mail access--the least expensive unlimited usage data plan we've seen.

According to coverage maps (for East Coast CDPD coverage see www.bam.com/wireless/necstmap.htm; for nationwide CDPD coverage see www.goamerica.net/html/networks/CDPD/maps/ ), CDPD looks like a strong contender, but in our real-world tests it didn't fulfill its promise. We tested CDPD service with a Novatel Wireless Minstrel III modem for a Palm IIIx, along with GoAmerica's service. This service was not nearly as robust as the others we tried. When a connection could be established, the data rate was quite acceptable (CDPD raw data rates top out at either 19.2 Kbps or 9.6 Kbps, depending on the coverage in your area). Our 5-KB test file produced data rates averaging 2,891 bps, and our 46-KB file delivered 3,140 bps. Those results are better than those of most other services, but at times we had difficulty getting and keeping a connection.

The Minstrel III provides an excellent and comprehensive set of built-in diagnostics for checking your connection, but too often, we experienced problems. The device would register a "network busy" message, then take one to three minutes to find and register with the network or drop the connection. In-building penetration and geographic coverage were poorer than with CDMA or most of the paging services we tested.

CDPD is an IP-native service, so if coverage is clean in the areas where users will be traveling, as with the Ricochet, the Minstrel III modem could give mobile workers access to corporate applications and data over the Internet. In cases during our testing where coverage was strong, access to the Web via a PalmOS browser, such as ProxiWeb, was a piece of cake, as was pulling mail off POP3 accounts. CDPD has many advantages on paper, but in practice, it was not as reliable as we would have liked.

Service: GoAmerica (888) 462-4600, (201) 996-1717, www.goamerica.com.

Device: Minstrel III, Novatel Wireless, (888) 262-9172, www.novatelwireless.com or sales@novatelwireless.com.

Wireless Phones: Dial-a-Data
No test of wireless data devices and services would be complete without a data-enabled digital phone service, such as Sprint PCS.

Today's digital-based phones offer generally much higher throughput than analog connections, but currently at a cost in geographic coverage and in-building penetration. And even when used with a digital data-capable network, such as the Sprint CDMA network we tested, raw throughput will be no better than 14.4 Kbps, and often much worse. Nevertheless, if your mobile workers are in an area with Wireless Web service from Sprint PCS or other digital data network coverage, it's hard to beat the combination of a digital data-capable phone and a mobile-computing device for convenience and portability.

Samsung Electronics Co.'s Samsung SCH-8500 is a dual-band CDMA/analog phone with a Phone.com "microbrowser" installed, letting users browse Web sites that have an HDML (Handheld Devices Markup Language)-formatted version available. The SCH-8500 is not currently WAP- or WML-capable. HDML-formatted sites include the large news and transaction-oriented sites, such as CNN, Amazon.com and Bloomberg. While these features offer some level of utility, the real interest for us was the device's functionality as a data modem. In this mode, with the optional data-link cable, the SCH-8500 provided data rates over Sprint's CDMA network that were a consistent 1,400 bps to 1,600 bps for our 5-KB test file, rising to an average of 2,065 bps for our 46-KB file.

Data connectivity to the Samsung phone is provided via a data cable that sells for $100 and is rather clunky to use. A few phones, such as the Nokia 8210 GSM cell phone, have a built-in IrDA port. Until the Bluetooth standard comes along (see "The Future Of Wireless," IrDA connectivity is the only way to avoid lugging a box of overpriced, custom cables.

The Sprint PCS CDMA Wireless Web network is circuit-switched and provides a generally stable connection, assuming you're in a coverage area. And coverage is impressive, with service available in 330 major markets and more than 400 cities nationwide (for coverage maps, see s3.sprintpcs.com/learn/coverage_intro.asp).

In our tests, Sprint's coverage was better than that of CDPD, but not quite as good as the Mobitex coverage, especially in the rural Virginia test areas. Nationwide, coverage is good and getting better as Sprint builds more CDMA cells. In-building penetration was mixed and has a lot to do with how close you are to any cell tower. For instance, our suburban Maryland test location provided consistent connectivity inside and out, while a location closer to the center of D.C. fell back to analog (non-data-capable) mode as soon as we went inside.

CDMA-based data pricing is clearly problematic. Sprint PCS offers a wide range of service plans, but in each you purchase a set number of minutes and pay per minute thereafter. Technically, Wireless Web access--that is, data--is a $10 per month add-on, but with various promotional plans available, it may be attainable as a no-cost option. For roughly the same price as an unlimited usage plan from GoAmerica, $44.99 to $69.99, for example, you'll get only 300 to 700 minutes of airtime, with additional voice or data priced from 25 cents to 35 cents per minute. Even 30 minutes of data use per day gobbles up 900 minutes per month. If your mobile users make frequent use of data services, the current Sprint PCS plans will cost you a steep premium over unlimited-use CDPD, Ricochet or GoAmerica's ARDIS and Mobitex-based services.

Sprint offers 15 phones that are data-enabled and/or provide basic browser functionality. A PC Card for pure data access should be available soon, but one of the advantages of using the phone as a data device is that it can serve as a voice handset as well. In addition, like the Ricochet, but unlike the Minstrel CDPD modem or any of the pager-based solutions, the data-capable phone gives no problems in dialing directly into a modem pool or remote-access server. This handy capability increases your deployment options.

What About WAP?

For general-purpose use, WAP isn't really here yet. We attempted to get one of the early WAP-ready phones from Nokia to test for this article, but it wasn't ready for release. Server-side WAP gateways are available; Nokia has a solid WAP server with an e-mail gateway that can serve mail to WAP clients from corporate Microsoft Exchange, IMAP4, POP3 and Lotus Notes servers, as well as provide a cookie proxy (WAP doesn't support client-side cookies). Widespread availability of WAP-capable phones, however, is still just over the horizon.

And while WAP has promise as a network-neutral mechanism for presenting information over small wireless devices, despite all the hype, it's not a panacea. Vendors are salivating over the prospect of hundreds of millions of potential wireless service customers using wireless-data-enabled cell phones, but as a prospective technology for your mobile work force, WAP devices may be only a small part of your solution.

On the other hand, if you offer content or do business over the Web, it would be foolish to ignore the huge market of cell-phone users with WAP-enabled browsers soon to appear on the market, and it's not too difficult to offer your Web-based information in a WML- or HDML-based form.

Service: Sprint PCS Wireless Web, Sprint, (800) 480-4727, www.sprintpcs.com.

Device: Samsung SCH-8500 CSMA phone with connection kit, Samsung Electronics Co.

Send your comments on this article to Richard Hoffman at rhoffman@nwc.com.

Executive Summary Wireless Solutions For wireless data, the word of the day is compromise. The assortment of technologies is bewildering, and vendors will tell you that you can have it all--anywhere, anytime, seamlessly. But the truth is, geography will determine what services you can deploy. In and around major metropolitan areas, the selections are plentiful and inexpensive, ranging from two-way paging services, to data piggybacked over cellular phone networks, to dedicated data-only wireless networks. In rural areas, away from population concentrations, your data options are slim to none and likely to remain so for the near term. CDMA (Code Division Multiple Access) data from a digital cellular carrier will probably provide the biggest footprint for usage, but may seem painfully slow. Choosing two-way packet-switched paging services, such as Mobitex and ARDIS, will gain you coverage and in-building penetration, but at the potential cost of high latency, low speed and lack of access to native IP-based services. The IP-based CDPD (Cellular Digital Packet Data) was balky in our tests, but fairly speedy when we got a good connection. Metricom's Ricochet network is fast, IP-based and inexpensive, but available only in a few metropolitan areas. As for future technologies, WAP (Wireless Application Protocol)-enabled phones will be limited by small screens and minimal data-entry options. However, the sheer volume of cellular customers will drive that market. Metricom promises a 128-Kbps wireless service this year in 46 markets, and other high-speed data networks are about a year away. Wireless: A Glossary of Terms AMPS (Advanced Mobile Phone Service): This basic analog cellular service in the United States and South America typically operates at 800 MHz and uses FDMA transmission technology. With AMPS, when one person grabs a segment of frequency for a call, nobody else within the cell can use it. Digital cellular technologies offer ways for carriers to allow more calls in a cell, using the same amount of bandwidth. CDMA (Code Division Multiple Access): The dominant PCS standard in the United States, this spread-spectrum technology, developed by Qualcomm, lets multiple callers share a segment of frequencies. CDPD (Cellular Digital Packet Data): This packet-based technology allows either 9.6-Kbps or 19.2-Kbps data rates over standard analog channels in the 800- to 900-MHz range, by finding and employing unused channels. AT&T's Wireless IP is an example of a CDPD-based service. FDMA (Frequency Division Multiple Access): Used in the AMPS system, FDMA is a method of coordinating radio traffic to prevent interference between users sharing a set of frequencies. Only one subscriber can access a given frequency at one time. GSM (Global System for Mobile Communications): A variant of TDMA, GSM is the closest to a worldwide standard for cellular service. A single-frequency GSM cellular handset may work compatibly in Europe, Asia, India and Africa--though not in the United States. PCS (Personal Communications Service): PCS refers to the three predominant digital cellular technologies operating in the 1.9-GHz band in the United States: CDMA, GSM and TDMA, all of which can allow data to be sent over cellular networks. TDMA (Time Division Multiple Access): TDMA is a method of dividing a single analog channel into a number of time slots and assigning each user a distinct time slot within a given channel. This lets more users (usually three) access a channel at one time without interference. TDMA is one of the standard digital cellular technologies, along with CDMA. GSM is a variant. WAP (Wireless Application Protocol): This network-neutral protocol is used for sending data to and from WAP-capable devices, such as cellular phone handsets. For explanations of more wireless terms, see www.wirelessdata.org/primer/terms.asp. The Future of Wireless Future capacity always affects current purchasing decisions. Here's a peek at the road map for wireless. WAP (Wireless Application Protocol): In the short term, WAP will be a dominant standard for data-enabled phones. Network-neutral WAP gateways should work over most current mainstream networks, and the huge potential market for data-enabled cell phones will drive WAP products and tools. However, applications that use more than minimal data will likely find the small form factor of most WAP-enabled devices to be constraining. GPRS (General Packet Radio Service), EDGE (Enhanced Data Rates for Global Evolution): These services will provide some interim solutions between the current patchwork digital data mechanisms and the third-generation systems being considered and planned for long-term implementation. GPRS' theoretical maximum data rate is about 171 Kbps when all available slices of bandwidth are used simultaneously, and EDGE's is similar. Interoperability is still a big issue, as is existing telco investment in current, incompatible technologies. For instance, many third-generation systems are CDMA-based for the most part. EDGE is GSM/TDMA-based, as is GPRS. Telcos that use existing non-GSM infrastructures will need to be convinced that migrating to EDGE- or GPRS-based solutions is in their long-term interest. For the foreseeable future, then, the patchwork state of wireless data is likely to continue. PANs (Bluetooth Personal Area Networks): Although this is not a wide area technology, the Bluetooth standard for PANs will make a significant impact in the wireless world, if it can move from a standard to an implementation. Intended primarily as a way to wirelessly connect disparate devices over distances shorter than 10 meters, Bluetooth could be the remedy for the inconvenience of having to connect everything with convoluted cabling, especially mobile/portable devices. With a bandwidth of 700 Kbps to 1 Mbps, a Bluetooth transceiver can be carried in a user's pocket, and can wirelessly transfer data to and from PDAs (personal digital assistants), laptops, printers and other Bluetooth devices on or around a mobile user. One thing all these new technologies have in common is that they're packet-switched and IP-capable. Circuit-switched networking for data and non-IP-based paging networks, such as ARDIS and Mobitex, while they have served well in particular applications, are not going to be economically viable technologies for high-speed general-purpose wireless data. Look for technologies such as the packet-switched GPRS to be enabled over even traditionally circuit-switched networks, such as GSM. Going Wireless in Public Wireless LAN technology as a broadband access medium is an attractive option for business travelers and other mobile professionals. New services are being rolled out at airports, conference and convention centers, and hotels worldwide. This build-out is in its early phases, but the appeal of untethered, multimegabit Internet access is compelling, and with prices for wireless infrastructure gear falling rapidly, the economics are starting to make sense. While you may now commonly plug your notebook computers into telephone data ports in conference and convention centers, imagine turning on your notebook in the public areas and gaining broadband access to your VPN (virtual private network) without ever plugging in. At your hotel, you may even be able to head to the pool and geek out, if you think you're buff enough to wear a swimsuit and an IBM ThinkPad in the same chair. Likewise, the airport--a frustrating location for any frequent traveler--is in the crosshairs of several new wireless access firms. This stuff is getting deployed, and fast. As of June 4, MobileStar Network Corp. (www.mobilestar.com) has support in 24 states, 19 airports (most in American Airlines terminals and Admiral's Clubs) and about 100 hotels around the country. Priced at roughly $10 per use or billed monthly ($30 to $40 per month, depending on your usage plan), this service is based on the 802.11 FHSS (frequency-hopping spread-spectrum) system. Wayport (www.wayport.com) offers a similar service built around the higher-performance 11-Mbps 802.11b DSSS (direct-sequence spread-spectrum) wireless standard. Although Wayport trails MobileStar in PoPs (points of presence), its build-out plans are impressive. Service is available in the Austin and Dallas/Fort Worth, Texas, airports and a number of large hotels in those metropolitan areas. Wayport recently announced a partnership with Wyndham International, a Dallas-based hotel company that plans to deploy Wayport's service this year in nearly 200 properties and 50,000 rooms in the United States, the Caribbean and Canada. Wayport is also targeting conference centers and other airports across the country. -- Joel Conover