Fixed Wireless Struggles for Success

The majority of today's most popular fixed-wireless systems eschew FCC licensing in favor of unlicensed frequencies, usually in the 2.4-GHz ISM or 5-GHz UNII bands. The end result has been

Dave Molta

June 11, 2004

3 Min Read
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Fixed microwave wireless systems have been around for a long time. Inthe BF days -- that's before fiber -- microwave radios represented themost cost-effective physical medium for delivering information over longdistances. Towers were constructed in suburban and rural areas, carryinganalog voice calls over the wireless equivalent of T1 lines. Then, inthe 1980s, a company called Microwave Bypass Systems teamed up with somehospitals and universities in the Boston area to deliver higher speedEthernet traffic over the airwaves. In those early days of the Internet,that was quite a feat.

Early fixed-wireless systems usually ran over licensed spectrum,requiring organizations to navigate FCC bureaucracy. The majority oftoday's most popular systems eschew FCC licensing in favor of unlicensedfrequencies, usually in the 2.4-GHz ISM (Industrial, Scientific andMedical) or 5-GHz UNII (Unlicensed National Information Infrastructure)bands. The end result has been a free-for-all of sorts. WISPs (WirelessInternet Service Providers) have capitalized on low-cost wirelesschipsets and related electronics to deliver last-mile access solutionsat prices that substantially undercut traditional wireline carriers.

This all works amazingly well in moderately populated areas that areoften underserved by traditional providers. But for large metropolitanareas, it's become cause for concern. Without coordination, it's justtoo easy for your link to step all over mine, diminishing performanceor, in the worst case, taking it out altogether.

It's this state of affairs that has the industry looking in multipledirections for solutions. While it's difficult to imagine the FCCplaying a proactive role in eliminating the possibility of interference-- after all, that's the beauty of unlicensed bands -- it is conceivablethat governmental entities could emerge to both encourage responsibleuse and resolve disputes. Many governmental entities, ranging from waterauthorities to sewage districts, have been created to address a specificproblem. But with government action comes more regulation, higher pricesfor consumers and greater obstacles to market penetration.

The alternative is a form of voluntary corporate regulation instigatedby the companies whose livelihood is at stake. California is nowemploying just such a strategy, having established two new BANC(Broadband Access Network Coordination) groups that serve Los Angelesand San Diego, two of the densest broadband wireless markets. Instigatedby NextWeb, which bills itself as the nation's largest fixed-wirelessInternet service provider, the BANCs are loosely formed regulatorybodies that focus on proactive strategies for diminishing the likelihoodof interference. It's an interesting approach that will probably buy theindustry some time. But it's unlikely it will be enough to guard againstproblems.Eventually, governmental authorities, at either the local or thenational level, will need to step in and develop more regulation. Whilethe rules defining the legal use of unlicensed spectrum were created tominimize the detrimental effects of interference, nobody could haveprojected that the technology would be so widely adopted. And the truthis, we haven't seen nothing yet. With licensed spectrum being auctionedoff to service providers for billions of dollars, it doesn't take agenius to predict that some pretty heavy action will take place in theunlicensed bands.

If the usage of this spectrum were limited to fixed-wirelessapplications, which often use highly directional, narrow-beam wirelesslinks, industry self-regulation might be feasible. But it won't be longbefore the hotspots at Starbucks and McDonald's morph into broaderhotzones, which cover square miles rather than square feet. In fact, theCity of Auckland, New Zealand, just this week announced the deploymentof a wireless zone covering its central business district. The emergenceof mesh routing technology is making it increasingly easy to deploy suchsystems. But without adequate safeguards to protect the integrity ofspectrum, it's tantamount to building your dream lakefront retirementhome on a piece of choice frontage you don't own.

-- Dave Molta, [email protected]

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