Deloitte took its annual look at what the next year holds for carriers, and came up with one definitive point: It’s going to be a rough one.

Unsurprisingly, the top issue at the core of the research firm’s grim prediction is the ongoing capacity crunch. The amount of traffic running on carriers’ networks is expected to rise considerably over the next year, putting carriers in what Deloitte delicately refers to as a “difficult predicament.”   

Essentially, carriers have to figure out some way to meet a tidal wave of demand for mobile data. Practices like data caps and traffic management are likely to come across as heavy-handed to subscribers accustomed to unlimited data plans. Fourth-generation technologies have yet to be deployed, and spending money right now to reinforce their network will likely do little in the short term to satisfy customers.

As Deloitte researchers put it, “if carriers improve mobile bandwidth capacity by an arbitrary X percent, consumers are likely to consume at least two times as much data. In other words, in 2010, any sensible increase in network capacity will probably be more than fully utilized by ‘data-gulping consumers,’ leaving carriers poorer and customers just as unhappy as before.” 

So what’s to be done? Get as far away from all-you-can-eat plans as possible. 

Unlimited plans distance customers from the correlation between the amount of data they use and the amount they pay for it. The problem is a familiar one to AT&T: The carrier says 3 percent of its smartphone users are responsible for 40 percent of traffic. AT&T’s bandwidth hogs are getting more than their fair share out of unlimited plans while degrading service for other customers.

Deloitte recommends that carriers look to Internet service providers for a more sustainable model. “There is a strong need for more rational pricing, especially in the mobile market,” says Deloitte. 

The unlikely savior in this network traffic mess could be net neutrality legislation. To quote Deloitte, “Although carriers have feared that net neutrality rules would force them to provide services that don’t make sense economically, the reality may be that the new rules will make it easier for them to shift customers off the unmetered broadband plans that appear to be breaking their networks.”

That development, if it occurs, could cause a major shift in carriers’ views of net neutrality. 

Deloitte made a smattering of other predictions in its annual report, which drew on input from 7,000 partners and senior professionals around the world. 

Among the firm’s other insights were several items on mobile search. The company says mobile search will be strategically important, if financially insignificant. Over the next year, mobile search providers could end up spending billions of dollars to favorably position their companies to exploit future income streams. 

Deloitte predicted competition in the mobile search arena to be “fierce in 2010 and for years to come,” with OEMs and operators “likely to have a powerful influence on the outcome.” 

Mobile VoIP also landed a prominent spot in Deloitte’s 2010 list, with the research firm predicting that “users and usage of mobile [VoIP] should start to evolve from niche to mainstream… Rising adoption of these services could cause a fundamental shift in expectations of what mobile voice can and should do.”

The report also looked into green networks, expectations of the enterprise space and the length of contracts.

Deloitte’s expectations are predicated upon the direction of the global economy. It’s not yet clear if the end of stimulus funding will plunge the country back into a recession, or how fast the economy may improve. 

“…The adoption of mobile broadband is accelerating – too quickly, perhaps – despite uncertain economic times,” said Jolyon Barker, Deloitte’s global manager of technology, media and telecommunications, in a preface to the report. “As a result, the entire telecom industry, from equipment makers and carriers to consumers and even regulators, is trying to cope.”