Every cell phone tower includes scheduling software that decides how fast e-mails, videos, and photos flow to and from wireless gadgets. Today these schedulers are programmed, at least in part, to make sure that the most profitable Internet traffic moves along at a fast clip. But under forthcoming Federal Communications Commission (FCC) “Net neutrality” regulations, wireless carriers may have to more strongly consider something else: fairness.

“Sometimes these (wireless) schedulers are designed to maximize throughput, rather than fairness,” says Dipankar Raychaudhuri, director of the Winlab, a mobile Internet research lab at Rutgers University. “For example, you can maximize throughput to someone who has a strong signal–favoring one user who has a high signal over another who doesn’t–so that it leads to higher revenue.”

Last week, delivering on an Obama campaign promise, FCC Chairman Julius Genachowski announced in a speech that he would propose Net neutrality regulations. Such rules would promote the Internet as a level playing field, and prohibit service providers from slowing down or blocking access to websites or applications. The actual draft rules will be released next month, but Genachowski made it clear that both wired and wireless technologies are in the crosshairs. “It is essential that the Internet itself remain open, however users reach it,” he said, adding that “how the principles apply may differ depending on the access platform or technology.”

Ensuring Net neutrality across the airwaves will be more complex though. “I don’t have a position on Net neutrality,” Raychaudhuri adds, “but this would be quite an interesting technical problem to try and solve.”

The complexity of the situation is illustrated by a recent flare-up in the wireless space. The FCC is investigating a claim by Google that its Google Voice application was unfairly rejected from Apple’s iPhone App Store. AT&T, which provides iPhone service, shot back in a letter to the FCC that Google’s voice application blocks calls to some rural areas where it would be more expensive for Google to connect.

It’s not clear yet whether Google Voice–which bridges both Internet and landline connections–would be considered in violation of any existing regulation. Because while traditional phone companies are barred by regulation from blocking calls to far-flung exchanges, Internet telephony applications do not yet face such regulation.

As any cell phone user knows, quality of service depends on how close the nearest cell towers are, how many other people are using the network, and a host of other factors. Already, the number of iPhones in service is causing traffic congestion on AT&T’s network, and “this will happen to all of the operators as smart phones and data traffic grows very rapidly,” says Raychaudhuri.

Defining and regulating “fairness” as it pertains to wireless Internet traffic is inherently difficult, says Mung Chiang, a Princeton electrical engineering professor working on broadband access algorithms. “The notion of congestion–what is it, how often it happens, who is to blame–it’s much harder to define in wireless networks,” compared to landline Internet connections, he says. “Who is going to take the blame when somebody close to a tower transmits signals that may wipe out others, even if this person may not be downloading movies?”

However the FCC chooses to define Net neutrality, Chiang says the specter of regulation hangs heavy over wireless Internet businesses. “As with other industries, uncertainty is worse than anything,” he says. “Deploying towers, digging up roads, and standardizing new equipment is a very long-term, capital-intensive thing. If people don’t know what is going to happen until litigation sets precedents, that will be a big deterrent to capital expenditures, and that generally is a concern.”

The idea of Net neutrality itself is not new. In 2005 the FCC issued principles–but not formal regulations–saying consumers have a right to access legal Internet content and services of their choice. But the matter came to a head last year when Comcast started slowing some customers’ peer-to-peer traffic–that is, the bandwidth-slurping exchange of music and video directly between computer-users’ hard-drives. The FCC ruled that Comcast had to stop the practice. Comcast sued, challenging the FCC’s authority to act in the absence of formal regulations.

In response to the Genachowski speech, the wireless industry was quick to assert there is no problem to solve. AT&T suggested that the highly competitive wireless market–five carriers with more than 10 million customers and 10 carriers with four million or more–provides state-of-the-art service. “Today, American consumers enjoy the broadest array of innovative services and devices, the highest usage levels, the lowest prices, and the most competitive choices of any wireless market in the world,” a company statement said, adding that “we have never had concerns with disclosure or transparency regarding network management decisions so long as such requirements are reasonable.”

Such industry proclamations don’t mean that private interests can’t crowd out public ones, says John Palfrey, a Harvard Law School professor and co-director of the Berkman Center for Internet & Society. The risk, he adds, is that big media companies will seek to “solve the copyright debate through bandwidth shaping or other technical means,” or that ISPs will curtail certain kinds of speech, as is widely done in some other countries. “Without Net neutrality,” says Palfrey, “the most important public network in most people’s lives could become dominated by private interests. The parade of horribles that could occur is endless.”

Even Net neutrality advocates like Palfrey, however, concede that technology advances faster than government. “The trick will be to say ‘Can you draw those rules in such a way that will promote innovation over the medium to long term, not just the immediate term?’” he says. “Any regulation will need to be revised in five or ten years.”

Jon Crowcroft, a professor of Communications Systems at the University of Cambridge in the United Kingdom, fears that regulatory meddling will inevitably add costs. “I personally am disappointed that a regulatory agency wants to get in the loop. Generally regulations are needed when we have a market failure,” he says. “While today there are lots of anomalies, they are generally localized in geography and time, and generally drift toward a generally neutral network.”

He adds: “If someone has to put in extra technology to support existing customer base, it will increase the cost of your components, probably a lot. That would be a very negative effect.”