Fixed Wireless And Broadband: What they mean to you

What do you want? Speed. How do you get it? Any way you can. Enter fixed wireless into the broadband fray.

Internet access providers used to be one-technology animals. DSL was available from one carrier, cable from another. Now, say analysts like Andy Fuertes of Allied Business Intelligence, "Carriers want subscribers and will use whatever technology they can to get them." Instead of differentiating themselves by using the moment's prevailing technology, they differentiate themselves by offering a smorgasbord of choices. And with fixed wireless, the menu has expanded.

Fixed wireless describes a variety of radio wave-based technologies that offer different benefits for different services. What they have in common is a base station they use to send and receive data over radio waves within a specific geographical area. Consumers attach a wireless modem to either an individual computer or LAN to make the connection. The modem can be used not only for general point-to-multi- point networks, but also for point-to-point connections.

"Given the demand for bandwidth by companies and individuals, service pro-providers want a number of different technologies," says Troy Trenchard, director of marketing for fixed wireless at Cisco Systems Inc. "In a lot of places, fiber doesn't reach the majority of customers who have come to need a lot of bandwidth. DSL hasn't deployed as fast as people expected and cable only reaches a certain population--suburban and rural neighborhoods--not business districts. So we have service provider customers looking to fixed wireless to get in faster and reach places the other technologies can't reach, and some include it as part of a multiple strategy."

Multiple Choice

The fixed wireless technologies most often referred to are Multi-channel Multi-point Distribution Service (MMDS) and Local Multi-point Distribution Service (LMDS). MMDS has a narrower spectrum, offering speeds of up to 10 Mbps downstream and 32 Kbps upstream,but because it operates in the 2 Gigahertz (GHz) range, explains Fuertes, it is less expensive and not as susceptible to interference by trees and rain. Consequently, it's the technology being employed by Sprint and others for residential and small-business use.

"We recently bought six MMDS companies, which has given us access to 30 million households in the 90 top markets in the United States," says Robert Hoskins, Sprint's director of media relations. Sprint has integrated these into one company, Sprint Broadband Wireless Group, and recently initiated a nationwide launch in Phoenix, Ariz.

"MMDS has a range of up to 35 miles, and can reach about 90 percent of the people in the metroplex, more than DSL or cable can provide," Hoskins notes.

LMDS, on the other hand, with only a two- to three-mile radius coverage area and a susceptibility to blockage by foliage, is better suited for dense urban settings and a commercial core of subscribers. Ranging from 28 GHz to the 38 GHz bandwidth,primarily licensed by the FCC to Winstar Communications and Advanced Radio Telecommunications,LMDS offers much higher data speeds of 250 Mbps.

As of the end of 1999, Winstar had building-access rights in 8,000 of the largest buildings in the United States, and is adding them at a pace of more than 1,500 per quarter, says Bill Vogel, Winstar's senior vice president for strategic planning. That access means having the right to go to the roof, install a radio, do the inside fiber wiring and put the equipment in the basement.

Vogel points to FCC numbers that show that even with 750,000 office buildings in the United States, only 10,000 have fiber connections today. "So the fiber business model has already played out in terms of the number of physical buildings they will reach," says Vogel. Installing fiber in cities involves a long process that includes securing permits, negotiating legal rights of way and building access, not to mention the actual trenching of the streets to lay the fiber, he adds.

The FCC also has set aside wireless frequencies in a band called the Unlicensed National Information Infrastructure. The idea is to create a frequency band that allows some experimental use of the airwaves without the expense of buying them or applying for licenses, with the potential result of smaller ISPs and communications companies being able to enter this very competitive high-speed broadband segment at a much lower cost.

Ghost Busting

One issue for fixed wireless is signal interference, known in the industry as "multipath interference." This happens when wireless communications systems experience echoes at certain frequencies from secondary signals that bounce from buildings or other obstacles just after the original signal is received.

Cisco decided to address head-on the ghosting problem in the MMDS space by purchasing Clarity Wireless, a company that developed a technology called vector orthogonal frequency division multiplexing, (VOFDM) which converts the potentially interfering ghosting echoes into intentional signal paths.

"VOFDM allows us to take reflected or time-delayed signals that would have created reception problems and allow it instead to have stronger signals," says Trenchard. "It basically reassembles the signals for a better connection."

Part Of The Mosaic

Compared to the roll-out problems cable and DSL have experienced, industry experts look at fixed wireless as a faster, less expensive way to generate high-speed connectivity. "There are lots of deployment problems with DSL, such as cross-talk, outdated equipment in the network and multiple providers trying to co-locate central offices," says Christopher Whitely, project manager for The Insight Research Corp. "Fixed wireless doesn't have any of those problems."

But even fixed wireless advocates view it as part of a mosaic of services used to keep their networks seamless. Winstar, for instance, also has invested in more conventional network equipment to meet the needs of customers who may have branches outside their fixed wireless service. "We're a hybrid player," acknowledges Vogel.

"The heart of the problem for fixed wireless providers is that they have to deal with technology problems like line-of-sight, shadowing and rainfall," says Whitely. "And they have to change the perception of many people in the industry, as well as customers, who associate a wireless technology with unreliability."

Fuertes cites the installed base already won by DSL and cable. "Cable modems passed 30 million homes and DSL has relatively easy access to about 50 percent of phone lines," he says. "Fixed wireless won't overtake them."

Craig Wigginton, a Deloitte & Touche partner in the Technology & Communications Group in New York, describes fixed wireless as a viable alternative in the marketplace, based on specific target markets. "In a majority of these cases, the target is densely populated metropolitan areas," he says. "It's more efficient to wire up a full building and put transmitters and hubs in place, than a small building with fewer business customers and less usage. Fixed wireless works in densely populated areas because it's conceivably a lot quicker to put up than to hook up hard wire and to selectively target your marketplace."

But, he notes, "with a wireless system you need to own the spectrum, and that's been selling at a premium of late. And you still have to wire up the building. The only thing that gets bypassed is the last mile."