The most visible application for point-to-point fixed wireless is cellular backhaul. As mobile system operators push coverage beyond their metropolitan cores, unlicensed fixed wireless provides the most flexible and cost-effective means of providing connections from outlying cell towers back to mobile switching centers. Not surprisingly, many fixed wireless systems are designed to emulate T1 connections. Even in newer products geared toward enterprise LAN interconnections, it's common for vendors to supply both Ethernet and T1 interfaces. That's a big convenience when you have a combination of LAN interconnection and PBX or videoconference applications.
Three key point-to-point fixed wireless markets are education, health care and government. Universities, which are known for expanding their footprints into locations adjacent to their campuses, often use short-range fixed wireless to provide services to locations where conduit and fiber don't exist and the costs to deploy fiber would be high. Similar situations exist in large and expanding health-care complexes. Government and corporate applications tend to be more MAN-oriented, with typical link lengths of 5 miles or more.
Fixed wireless is also popular for providing temporary network connections, particularly when disaster strikes. Much has been written about the role fixed wireless played in restoring communication services to lower Manhattan following the terrorist attacks on the World Trade Center. Indirectly related to those applications are installations where fixed wireless is installed in conjunction with terrestrial links as a redundancy mechanism to ensure high availability.
Cost vs. Benefit
We'll admit that, as appealing as fixed wireless is, guided media--most often fiber--is almost always a better solution in terms of raw performance and reliability. But many times it's difficult or impossible to get fiber to a facility, either across the street or across town. That's when most organizations turn to leased-line services, usually T1 or T3 links.
A recent study by Proxim Corp. of 18 urban and suburban areas in the Eastern, Midwestern and Western United States showed that the nationwide monthly average cost of a T1 local loop circuit is $382, while a T3 circuit runs $3,550 (see "Make Your Case: Determining Real ROI"). At those prices, many fixed wireless offerings can pay for themselves in less than one year. That's the kind of compelling ROI that makes bean-counters sit up and take notice.