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In Network Computing's Real-World Labs® at Syracuse University, we put five wireless T1 products--Adtran Tracer, BreezeCom BreezeLink, Glenayre Western Multiplex (GWM) Lynx.sc, P-Com AirPro T1/E1 and Wave Wireless Speedcom T1/E1-- through a series of tests to assess their suitability for transporting both voice and data across metropolitan area networks.

Lynx.sc edged out P-Com AirPro T1 and Adtran Tracer for our Editor's Choice award; it was easy to install and performed flawlessly. GWM also provides the broadest line of single and multichannel T1 products at both 2.4 GHz and 5.8 GHz. In addition, AirPro earned our Best Value award. Besides the fact its $6,995 retail price was almost the lowest among the products we tested, P-Com is running a promotion through the end of 1999 offering a pair of radios, antennas and cabling for $6,995. That's value.

We tested the wireless devices in a hybrid voice-data network, passing data among Cisco routers and voice traffic across Nortel Meridian PBXes (see "How We Tested,"). All the products got the job done, though only the Lynx.sc provided 100 percent of the baseline throughput we were able to achieve with a hardwired connection between the ADC/Kentrox CSU/ DSUs we used on our test bed. Tracer fell just shy of 100 percent, while AirPro and Speedcom were also very close, achieving throughputs in excess of 98 percent. BreezeCom's BreezeLink did not fare quite so well. On the PBX side, all the products delivered clear voice communication.

Installing these products is not a job for amateurs (see "Installation Issues," page 90). Aiming antennas, particularly across distances of 20 miles or more, isn't easy; make sure that you install lightning arrestors and follow other safety precautions. Selecting the proper cables, antennas and output signal level requires knowledge of RF transmission characteristics, as well as the impact of weather conditions. With the exception of BreezeLink, all the products claim to support links of 10 miles or more with 99.999 percent availability (5.25 minutes of expected outage time per year). GWM claims to have hundreds of installations running at 50 miles or more.

On the whole, we were disappointed with the products' management capabilities. DIP switches are the primary means of configuration on some products. Even where software-based interfaces were available, they were often difficult to use. We were especially surprised to find that none of the products had native SNMP management support. Vendors pointed out that these devices are frequently not network accessible, as in the case of a cellular radio tower site, a common application for this technology. However, for point-to-point enterprise applications and within central-office hubs, IP network connections are almost always available. All the vendors acknowledged this as an important area for development in a changing market, where an increasing percentage of their customers are enterprise-oriented. Meantime, they recommend using dial-in or dial-out capabilities or SNMP proxy products that translate alarms sent through the serial port.