The first wave: As traditional wireless operators continue to mull wireless local loop options, several broadband hopefuls are ready to make a go of it

In all but the least developed areas of the world, the concept of wireless local loop is still far from specific. It exists in many different but still theoretical forms-some depicting fixed wireless access as a last-mile bypass option and others suggesting the replacement of traditional wireline services with full-mobility wireless alternatives.

Differences also abound in the types of services WLL networks are supposed to transport. To some, WLL means broadband, a term that is itself somewhat ambiguous but generally refers to high-speed data transport. Others see the architecture as the ideal platform for carrying residential and business voice traffic, opening landline networks to shoulder high-speed data.

While specific definitions of WLL gradually take form, however, several companies-most of which defy traditional telecom categorization-are ramping up the first generation of fixed wireless networks in the U.S.

Air assault Call them the pioneers of the aired-out loop. They are companies such as Teligent, WinStar Communications, Advanced Radio Telecom and Teleport subsidiary BizTel Communications, all of which are preparing to-or already-offer high-speed transport services over broadband wireless networks in major urban markets across the country. The mission of most of them is to enter those regions with a high-bandwidth, bundled service offering comparable with or better than landline offerings in quality, cost and customer care.

"Low cost and simplicity in an integrated package are the differentiations," says Robert Stewart, vice president at Teligent.

These operators are a new breed, better characterized as wireless competitive local exchange carriers than the cellular and PCS carriers that fit the traditional wireless model. They essentially beat the rest of the telecom industry to the wireless punch by realizing early that fairly simple and easily deployable digital microwave technologies were well-suited for transport between end customers and the public network.

For example, Teligent is designing its network using a point-to-multipoint digital microwave transmission platform that uses Class 5 switches (Figure 1). The company originally had planned to use the 18 GHz band, but a spectrum dispute with satellite hopeful Teledesic prompted the FCC to move Teligent to 24 GHz and give it an additional chunk of spectrum.

Teligent intends to target business customers housed in office buildings and corporate campuses-locations that can be served with unobtrusive, inexpensive rooftop antenna equipment that transmits back to central communications nodes that are also rooftop-mounted. Those nodes connect to switches that facilitate transport to local, long-distance or Internet pipes.

Teligent made a move that could launch it ahead of its broadband wireless peers when it recently announced the first successful test call on a point-to-multipoint architecture, which refers to the ability to serve multiple customer buildings from a single, centrally located base station. The company plans to have point-to-multipoint systems-which are generally considered economically superior to and more manageable than point-to-point systems-in place when it begins launching the first of its markets later this year.

"We're going to do some detailed configuration work to see how we can get the most out of the equipment," Stewart says.

WinStar is testing a point-to-multipoint system in Florida, but the carrier's currently operational markets use point-to-point systems. WinStar plans to migrate to point-to-multipoint in its 38 GHz markets to gain advantages in how it can divvy up slices of bandwidth to different customers in a market.

"It allows you some intelligent applications in terms of allocating bandwidth that you don't have today," says Doug Morgan, vice president of marketing at WinStar.

The big buildup For all these companies, the simplicity of implementing the broadband wireless technology means economical deployment, quick time to market, fast transmission speeds, dynamic bandwidth allocation and high capacity. But like any new operators, they face a long and often difficult construction effort.

Broadband wireless providers' main concern is gaining access to rooftops to locate their hubs and getting into the buildings to tap into the lucrative customer opportunities inside. Most carriers are building in an incremental manner, locating hubs where they have lined up customers or have the best chances of doing so.

"We are not going to warehouse roof rights," Stewart says. "We want to get them and use them."

Roof rights and zoning issues were concerns that formerly plagued wireless companies seeking permission to construct new facilities in crowded metropolitan areas. But Morgan of WinStar believes that the success of broadband wireless access technologies has muted some of those issues and shown building landlords in particular the advantages they can glean from cooperating with the construction.

"We've been doing this long enough that we're delivering the right kind of value proposition to building owners," says Morgan. "They really do show this as a building amenity."

Even before broadband wireless hopefuls can enter the building to connect to their spectrum, however, they must lay out the expansive wireline portions of their networks.

"There's more work to be done before you get to that point," Stewart says. "There's a lot more infrastructure work to be done."

Selling the goods As they continue with their network buildout efforts, broadband wireless operators also must grapple with the question of what types of services they can and want to support. Most have moved from a carrier's carrier approach to a direct marketing effort that is particularly focused on small and medium-sized business customers. Some of these companies plan to offer bundled packages-local, long-distance and data offerings-and some are pursuing a more focused approach.

"The big opportunity here is Internet access," says Ira Brodsky, president of Datacomm Research. "People want faster access, and it doesn't look like the incumbents are moving that quickly, given how slowly the [Bell companies] and other LECs have rolled out ISDN."

Advanced Radio Telecom, another 38 GHz hopeful, apparently heard that data call from potential customers. Earlier this month, the company announced that it would devote its efforts to building networks to carry data services almost exclusively.

"We had primarily supplied links before in providing carrier connections to buildings," says William Maxwell, executive vice president of strategic planning, marketing and sales at ART. "Now we've gone to a very data-centric approach."

ART's voice efforts will be limited to voice over IP, Maxwell says. "We will support voice, but really over a packet network," he says. "We really believe the world is going data, and data is digital."

The competition these companies face is likely to come primarily from fiber-based CLEC networks and increasingly from incumbent carriers upgrading their copper plant with digital subscriber line (DSL) technology. Still, most broadband wireless carriers view DSL as a long time out and their own approach as ready-made.

"We think that technology will come; we're just not sure when," says Teligent's Stewart. "The [Bell companies] have been talking about ISDN for a long time. That was the first 'copper renaissance.'"

"It's not a threat at all in our minds-it's complementary," says ART's Maxwell. "We're going into buildings with a pipe in the sky, but we'll certainly use DSL in buildings."

Although some networks are operational, all the companies pursuing broadband wireless strategies are still in the early stages of buildout, development and improvement.

But these companies have already demonstrated the efficacy of the wireless approach, and their example is likely to validate future efforts to tap into lucrative service niches by wireless means.