Jun 15, 2001 12:00 PM,

Spectrum Squeeze

BY Betsy Harter

As carriers fight for more spectrum, vendors push spectrum-optimization techniques.

Spectrum Shortage

According to Steve Berry, head of spectrum issues for CTIA (www.wowcom.com), additional spectrum is the “asphalt upon which the industry must run the wireless Internet.” However, the United States faces a double whammy, he said. Not only does the United States have half the available spectrum compared to other countries, it also has a spectrum cap of 45MHz per market, per carrier.

CTIA promotes a 2-step process to acquire more spectrum. The organization's short-term solution is to lift the 45MHz spectrum cap and to promote efficient use of that spectrum. Its long-term solution is to re-assign spectrum.

And not any old spectrum will do. Right now, the most coveted spectrum is in the 1.755GHz to 1.85GHz band, which is used by the Department of Defense (DoD; www.defenselink.mil), and the 2.5GHz to 2.69GHz band occupied by Instructional Television Fixed and MMDS services. Those who advocate taking over these bands say that because other countries use these bands, U.S. carriers will promote global harmonization by using these same bands. Although some carriers are considering the 700MHz band, used by TV stations, the United States would be the only country using this band for 3G services, Berry said.

Carriers are placing additional demands on the FCC and the National Telecommunications and Information Administration (NTIA) — the principal adviser to President Bush on telecom policy (www.ntia.doc.gov) — as well as the parties that currently hold the desired spectrum. Mark Tuller, Verizon (www.verizon.com) vice president and general counsel for legal and external affairs, said, “We want more spectrum that is clear, unencumbered, identified to be cleared in a particular time frame, and auctioned, so that we can build business plans around it.”

So far, the outlook for accessing any of the bands is grim. In April, the DoD reported that it would take as long as 2010 for non-space systems and beyond 2017 for legacy space systems to vacate its spectrum. Moreover, band-sharing is not an option, the DoD said, nor is relocation unless the wireless industry makes comparable spectrum available and foots the bill for moving costs, which could total $4.3 billion.

Similarly, the FCC (www.fcc.gov) reported that it could not find an alternative band for fixed wireless providers in the 2.5GHz to 2.69GHz spectrum. Band sharing, on the other hand, would cause interference with current providers.

Even though spectrum auctions generate billions of dollars from wireless carriers, current laws mandate that new spectrum occupants also must pay the costs for incumbents to move to new spectrum. Carriers advocate a change in the law, which would use the revenues generated from the auctions to pay for relocation.

“There is a phenomenal amount of money going into the treasury, with none of it coming back to benefit the companies that have, in fact, put this money into the industry,” said Brian Fontes, Cingular (www.cingular.com) vice president for federal relations.

Milton Brown, NTIA deputy chief counsel, said wireless carriers must recognize that current law clearly states that auction winners pay for relocation costs.

“We are moving forward with the law that is written,” he said.

Brown also emphasized that carriers must look beyond their desire for spectrum to the country's public-safety and national-security concerns.

“Everyone talks about other countries and how far behind we will be if we don't allocate this spectrum, but we don't have the same military that other countries have — we have a much bigger one,” he said. “You need to ask yourself: Are you willing to pay for it? And are you willing to wait for it?”

The Waiting Game

Whether or not carriers are willing to wait, it is almost certain that they will. In the meantime, there is a huge push from vendors to conserve current spectrum through efficient spectrum management.

“Are we willing to wait, and is the public willing to wait?” asked Leonhard Korowajczuk, CelPlan Technologies (www.celplan.com) president & CEO. “The public has been promised these new services, and how can we provide those services without new bands? I suggest we can squeeze a lot of traffic in existing spectrum. We need to optimize and deploy existing bands.”

Korowajczuk compares spectrum to space on a hard drive. Many years ago, people bought new hard drives with 10MB of space and thought they had enough space for the rest of their lives. Now, they have 100GB and are finding ways to use it up.

“Spectrum is very similar; it is very easy to use it,” he said. “We look at our hard drive and analyze it and see that there is a lot of wasted space. If we look at our past and the way that we have been using spectrum, we can do a much better job.”

CelPlan, which offers performance-analysis and -optimization tools and services, has found it can squeeze 50% to 100% more capacity from existing spectrum in some cases. For instance, CelPlan analyzes RF coverage, population, traffic handling, call quality and indoor coverage. It makes comparisons among these statistics, from which it makes recommendations for improvement in existing deployment, additional deployments and a solid evolution strategy.

“Any operator who does a good study or analysis can squeeze more spectrum, giving it enough today to transition to the new bands,” Korowajczuk said.

Other vendors also are singing to the same tune, noted Gray Hancock, Current Analysis (www.currentanalysis.com) analyst. “There are quite a few start-up companies with a value proposition to maximize efficient use of spectrum, as well as do it cost-effectively,” he said.

MDiversity, for example, claims that carriers using its technology can do one of four things: double capacity, double data throughput, increase coverage by up to four times or reduce mobile power by up to 90%. Bill Howe, mDiversity president & CEO (www.mdiversity.com), said the company's proprietary Multi-Link Networking technology effectively routes traffic to the best base station instantaneously. Doing so allows each handset to capture the strongest signal without doing the full handoff that systems require today. MDiversity's network software senses and monitors various signal strengths, and the algorithms route the call to the best link. It determines the best link through a variety of parameters, including a combination of signal quality and signal strength. Then, it sends the call to another site where there is a clearer signal.

Schema (www.schema.com) advocates a different sort of spectrum optimization: telecom resource management. The combination of an optimization engine and data-mining platform enables carriers to leverage information sources that they normally do not consider, such as billing data, and translates the data to optimize the network.

Using its Falcom Spectrum Optimizer, the company recently proved in a market trial that carriers can increase network capacity by more than a third — the equivalent of adding several hundred thousand new subscribers to the network — without additional cell sites or base stations, said Yuval Davidor, Schema founder. During this trial, Schema enhanced the network by maximizing wireless resources and enabling capacity growth. It eliminated major inefficiencies, reduced dropped calls by 10%, decreased blocked calls by 30%, diminished handoff failure by 47% and lessened bit error rate by 20%.

Schema got its start by using its technology to solve complex problems in other industries. It has applied its solutions to wireless and has since improved capacity, QoS and capital efficiency for carriers such as Verizon Wireless, Cellcom Greenbay (www.cellcom.com), Cellcom Israel (www.cellcom.co.il) and Motorola's Pelephone (www.pelephone.co.il).

Vendors Push Smart Antennas

Smart-antenna companies are pushing spectrum-management solutions, as well. Greg Oslan, Wireless Online (www.wireless-online.com) president & CEO, said until now, carriers have used the “brute-force method” to manage spectrum, meaning they either add more sites or sector their sites to reuse frequencies.

“They are hitting the wall in the ability to add more sites or sector further because interference is becoming too great,” he said. “To the degree that you are able to reduce interference — even a small amount — you are able to offer much more capacity on a given site in a network, broader coverage, reduced costs and improved quality.”

Through its internal and customer field trials, Wireless Online has proved a 60% reduction in interference by refocusing RF energy into very narrow beams on particular subscribers or groups of subscribers.

“Because the energy is concentrated, it goes further, and because it is narrow, it doesn't interfere with other things,” he said. “We take many of those narrow beams and focus them on many subscribers at the same time so you get redundancy in the communications links to multiple subscribers and better quality in the link.”

Wireless Online has wide-scale, narrowband-data deployments in the United States and Latin America with SkyTel (www.skytel.com), WorldCom (www.worldcom.com), Arch Wireless (www.arch.com) and WebLink Wireless (www.weblinkwireless.com).

Similarly, Metawave's smart antennas are reducing interference levels, said Bob Hunsberger, Metawave (www.metawave.com) chairman & CEO.

“Typical cell-site traffic is unbalanced; one of three sectors is more heavily loaded than others. As traffic rises at a busy hour, it blocks or denies calls even though there is unused space in the other sectors,” he said. “Our smart antennas and software change the shape, size and orientation to reform antenna patterns to better balance the loads.”

CDMA, GSM, analog and 3G carriers can use Metawave's SpotLight smart antennas to analyze their cell sites, see where loads are unbalanced and decide how traffic ought to be divided to balance loads. Some carriers analyze the patterns every few weeks or months. Others choose add-on components that will detect changing traffic patterns throughout the day, then adjust the loads.

Efficient Management Not Enough

Although carriers acknowledge the possibilities of more efficient spectrum management, they claim that the need for more spectrum is unavoidable in the long run.

Verizon's Tuller said CDMA technology is 10 times more efficient than competing technologies and allows 3G services to be deployed in current spectrum. By using CDMA, Verizon is being as efficient as possible.

“But voice is growing; data is starting to be rolled out,” he said. “The current allocations we are operating with will not support the wireless industry over the long term. We estimate that by 2004 to 2005, we'll need significant allocations of new spectrum. We are not going to meet that need simply by squeezing more people onto the spectrum we already have got or increasing the technological flexibility of our usage in that spectrum.”

Once new spectrum is allocated; however, it must be used efficiently, Korowajczuk reiterated. “We need to conserve spectrum the way we need to conserve fossil energies. This is a finite resource,” he said.