Signs say more existing fiber needs to come online and demand might soar in the next few years.\nThe "fiber glut" that has been widely blamed for a weak long-haul telecom equipment and services market still exists in most areas, but there are signs that more existing fiber needs to come online and demand might soar in the next few years.Carriers and industry analysts say they're confident there is plenty of fiber in the ground after the building boom of the late 1990s. However, the oversupply is bigger in some areas than others, and carriers might have to light up more fiber pairs now in the ground to meet growing demand.Unfortunately, most companies can't tap into that bargain, long-haul capacity without going through the local loop. For them, the cost of WAN services usually is dominated by the price of the last-mile connection provided by a former regional Bell operating company, says Dave Passmore, an analyst at Burton Group. Only 10% of business locations have fiber going to them, he says."They're having to buy network services that require the last-mile connection, and so they're still being held hostage by the [incumbent local exchange companies]," he says. "They're not in a position to take advantage of this glut of fiber in the core."Meanwhile, there are indications that the recent deep slump in spending on equipment to light up that fiber might be ending. Within a few years, new ways of organizing and using IT resources might change the picture dramatically, experts say.The market for wavelength-division multiplexing (WDM) equipment to light up long-haul fiber plummeted from $5.1 billion in 2000 to $376 million last year and an estimated $269 million this year, according to RHK analyst Ron Kline. But RHK expects revenue to pick up next year and increase slowly to $307 million by 2007. Growth from spending by carriers that are responding to demand will drive that recovery, Kline says."They will be very targeted deployments. It won't be a mass build like we've seen in the past," Kline says.One possible source of that growth is\u00a0Verizon, which plans to light up long-haul fiber across the U.S. as it further develops its long-distance voice and data business, says Ells Edwards, a spokesman for Verizon. Most of that will be fiber it leases from existing long-haul providers.AT&T\u00a0is expanding its network outside the U.S. to meet demand for data services by multinational companies, says Dave Johnson, an AT&T spokesman. That network, which mostly has capacity leased from other carriers, serves 120 cities.But long-haul fiber is abundant in most places. AT&T is probably far from exhausting the capacity of networks on its international routes, Johnson says. The same is true of AT&T's U.S. network, where the company has no major expansions in the works.As an example of overcapacity, of the long-haul fiber that goes through Chicago, last year only 3.9% was lit, according to TeleGeography. Of the lit capacity, only 2.7% was dedicated to IP bandwidth and probably less than 1% was dedicated to voice and other types of networking, says TeleGeography analyst Alan Mauldin. The rest of the lit capacity was not deployed. It's unlikely all of that is being held back by carriers as inventory or by corporations as back-up capacity, he adds.Not all routes are as wide-open. TeleChoice said in July 2001 that it had found the supply of already lit fiber near a critical point on 14 of the 22 intercity routes it studied in the U.S. On those routes, 70% or more of the lit fiber was in use, a threshold at which carriers usually expand capacity.Based on one growth scenario TeleChoice studied that year, on half of the 22 routes, all the lit and dark fiber would have been used up by 2006. Growth didn't happen at anywhere near that rate, says Russ McGuire, who was lead analyst on that report and is now an independent consultant at Seek First Networks.As more organizations start to use grid and on-demand computing and to virtualize their processing power and data storage, demand for long-haul capacity could grow dramatically, says Frank Dzubeck, president of consultancy Communications Network Architects.Grid computing brings together the resources of one or multiple organizations to solve computing problems. On-demand computing lets a company turn on capacity on the spot based on how much power is needed. By 2005 or 2006, those could become "virtual" resources that might come from just about anywhere and use long-haul capacity along the way, Dzubeck says. To be useful, grid and on-demand computing eventually will require at least 100M bit\/sec of capacity, he says.By that time, more consumers will use broadband and will take advantage of more bandwidth-hungry applications, he adds. Networked remote sensors also will start to consume bandwidth.Lawson is a correspondent with IDG News Service's San Francisco bureau.