Unleashing Unlicensed Communications By Bill Frezza   Three times Apple Computer has pleaded its case before the FCC, seeking a spectral homeland for unlicensed wireless data products that would support communications over longer distances than are practical under the Industrial, Scientific & Medical (ISM) band spread-spectrum regulations. The quest began in 1991 as an effort to support untethered connectivity for nomadic devices, motivated by new vistas being opened up by Apple's Newton. It has since evolved into a determined push to assure inexpensive Internet access for the poster children of the Information Age--namely, rural-area schools, hospitals and libraries. Through it all, the core of Apple's vision has been to set aside a slice of spectrum to catalyze the emergence of self-organizing wireless webs, otherwise known as community networks. These would be constructed entirely on an ad hoc basis by and for end users. Community networks would not require billions in up-front infrastructure investment by network operators granted exclusive geographic franchises, hence there would be no usage charges. The simple idea behind Apple's push is that users should be able to buy gizmos with antennas on them, plug them in and immediately begin communicating with anyone within range--even over distances of several miles. After six long years of lobbying, and a string of bitter defeats along the way (see "Hip Checking at 2 GHz," at techweb.cmp.com/ nc/603/603frezza.html), it looks like Apple has finally come home with the prize. FCC Report and Order 96-102 Dubbing it the Unlicensed National Information Infrastructure (U-NII) band, a recently issued FCC Report and Order opened up a hefty 300 MHz of bandwidth to all comers, with an unusually small number of strings attached (see www.fcc.gov). To put things in perspective, this is 2.5 times the total bandwidth allocated to Personal Communication Services (PC S), which brought in over 20 billion dollars at auction. That this much spectrum could be doled out for nothing is a fairly strong indication that spectrum scarcity is largely a political illusion--a fact likely to come back to haunt those deep-pocket real estate speculators who thought they were buying the last vacant lots in town. This seemingly inconsistent approach to spectrum management has kindled an interesting debate among advocates of spectrum privatization, not to mention continued wailing by die-hard statists who still believe the airwaves belong to "the people." Anyone complaining that this is a spectrum giveaway should note that the U-NII frequencies were not handed over for the exclusive use of any established business interest, as i s being contemplated with UHF spectrum for high-definition television. Unreconstructed socialists can think of the U-NII band as a wireless commune to be shared for the common good--a public park amid the hustle and bustle of the digital city. Rugged frontiersmen are no doubt eyeing this turf as if it were virgin prairie waiting for the arrival of homesteaders. Either way, the entrepreneurial opportunities are of a totally different nature than those afforded by the PCS auctions, where only companies with world-class investment bankers could play. As a result, the potential benefits to the aforementioned poster children--a relatively unattractive market in its own right--could be substantial. Using wireless to satisfy the needs of the clamoring information have-nots, thereby keeping their paws out of the Universal Service slush fund, could prove to be the best way to nip the creation of new multibillion-dollar info-entitlements in the bud. The rules and regulations handed down by the FCC are surprisingly simple. Three 100-MHz wide bands were each designated with a different maximum-allowable transmit power. These are 5.15 to 5.25 GHz with a maximum power of 200-milliwatt EIRP, 5.25 to 5.35 GHz with a maximum power of 1-watt EIRP, and 5.725 to 5.825 GHz with a maxim um power of a quite respectable 4-watt EIRP. (EIRP stands for Effective Isotropic Radiated Power, which means that antenna gain is included.) By comparison, your portable cellular phone typically transmits at 600 milliwatts or less. There is no explicit spreading requirement as there is in the ISM band spread-spectrum regulations, some of which overlap these same frequencies. But the rules do set a peak power-density limit that calls for a proportionate decrease in transmit power if the emissions bandwidth is reduced below 20 MHz. This is intended to discourage narrowband applications (for example, long-range walkie-talkies). Amazingly enough, neither a modulation scheme, a channelization plan nor a spectrum etiquette is mandated, all of which are traditional ways to assure equitable spectrum sharing. In an unprecedented burst of laissez-faire enthusiasm, the FCC left it entirely up to the market to work things out.

The Networkologist by Patricia Schnaidt Corporate View by Brian Walsh In the Middle by Bruce Robertson On The Wire by Bill Alderson and J. Scott Haugahl Updated March 25, 1997