Realistic Expectations
Of course, neither the systems we tested nor others available in the market can replace a 10-Gbps Ethernet link or other high-bandwidth fiber connection spanning multiple miles. And, enterprises must weigh environmental factors to determine whether a wireless link will provide enough reliability to supplant leased lines; see "So Near And Yet So Expensive" for a discussion of the trade-offs and the ROI picture. If analysis indicates that a leased line remain as a backup or alternate connectivity option, the ROI equation clearly changes.
Deploying a fixed wireless link between two campus buildings, where distances are short and line of sight is obvious, is something your IT staff can probably tackle working with your organization's physical plant department. However, outdoor installations aren't like setting up a WLAN: You must make sure antennas and radios are properly mounted and secured. Antennas must be aimed correctly or performance will drop dramatically. Proper grounding is crucial to ensure that your shiny new wireless antenna doesn't turn into a shiny new lightning rod--while posing serious risk to those in and around the building and opening your organization to liability. Fortunately, vendors provide clear instructions on how to properly ground their devices.
The radios we tested are clearly built for the great outdoors; they can run in temperatures from subzero to over 100 degrees and are sealed to work in 100 percent humidity. However, the power injectors, which are proprietary to each radio, are not as hardy. You'll need to build an enclosure, heated and cooled to prevent severe temperature extremes, or run the power injector inside.
We also recommend installing a UPS to keep your radios up and running during a power outage. If a UPS isn't in the budget, you could power radios with DC power and use a standard battery for backup power. After all, a backup link isn't much good if it goes down during every blackout.
