By Tara Seals

I spent most of VON introducing and covering the wireless mobility education track and talking to people about 3G, 4G and related various and sundry topics. The biggest thing people wanted to talk about? Hold on to your hats: The iPhone has shown us that wireless data could clog networks.

Sure, I was tempted to say something mildly sarcastic like, “don’t tell me you left the ‘master of the obvious’ sash at home?” Instead, I checked my ingrained tendency towards snark in favor of seeing if I could learn something. AT&T Inc.’s well-documented congestion/slowdown woes provided a backdrop for panelists and attendees alike weighing the future of wireless. And it became apparent that there’s been a sea change in attitude when it comes to wireless data, mobile video, wireless VoIP, widgets. In short, iPhone-like things are ... kind of dangerous.

“Data usage is up but revenue remains flat,” said Bob Kersey, vice president of strategic marketing and business development. “Service providers don’t want to push tiered service plans. But free or really cheap comes with a big cost: congestion.” He noted the iPhone, natch, and raised the specter of the upcoming Apple tablet as a device that is about to push the issue to the max.

His comments pretty much summed up the thick air of ominous doom surrounding the wireless data explosion, which has gone from a “pure awesomeness” zeitgeist just a few months ... nay, weeks ago, to being seen as having the potential of sparking riots in the streets as the loading times for apps grind to a standstill.

Some got contrarian: “It’s clear that 3G is not the appropriate network for mobile VoIP,” said Mike Hollier, CTO at quality monitoring company Psytechnics. “Wi-Fi is the necessary medium.”

Some imparted fascinating knowledge: “Capacity issues are so great that some operators running multiple networks (e.g. TDM, MPLS, FTTx) are starting to use residential networks to backhaul data traffic to cell towers,” Scott Sumner told me. Scott’s the vice president of marketing at Accedian Networks, a packet performance assurance provider.

The resi fiber bandwidth loan is something he equated to a sprinkler not working, so you steal water out of your neighbor’s hose to water your lawn. And meanwhile, “the guy can’t take a shower.” In other words, sucks to be you, FTTx user.

And 4G? Let’s not even talk about it. “We’re all talking about 4G but we can’t even get 3G to work.” Sumner noted.

“We tend to forget the fact that it takes a lot of time to deploy a technology with sufficient density,” said Martin Suter, vice president of business development at service provider Wi-Fi company BelAir Networks. “For all the enthusiasm for LTE, the reality is that we’ll be living with 3G for a long time. Meanwhile we’re reaching critical mass in coverage and capacity – and what happens when 3G is embedded in gaming devices, cameras, music players?” He argued (unsurprisingly, given his business – but I think he’s right) that the breadth of bandwidth needed to support 3G applications and therefore large capacity is going to be a big windfall for Wi-Fi and/or femtocell vendors. Is it any wonder that AT&T mysteriously went from being rabidly anti the concept of free-Wi-Fi to “hey! We have free Wi-Fi!” – in the space of a few months?

The issue even trickled into my discussion with iotum CEO Alec Saunders (official shout-out: Alec is just a fabulous guy). iotum, a conferencing provider, offers Calliflower, a very cool service that wraps in functionality pulled from the social networking world, like sidebar chats and Twitter-like comment feeds. There’s also a Calliflower iPhone app, which Saunders was going to take me through until we hit a little snag: AT&T’s network. Saunders, roaming in from Canada, said he had found the iPhone service to be incredibly, unproductively slow as soon as he crossed the border. And after the Calliflower app took forever to load we decided to skip it, prompting a discussion of whether AT&T is possibly throttling roamed traffic from Rogers Wireless. I’m sure we’ll never know, but it seemed weird.

Anyway, it’s clear people are waking up to the fact that unmetered bandwidth and the mass migration to smartphones might be something more sinister than just an engine for subscriber growth. Sure, everyone knows backhaul and capacity need to be upgraded, but until this week the attitude I’ve heard is that carriers have it under control. But VON attendees didn’t seem so sure. They seemed to think the smartphone/wireless data enthusiasm on the part of operators is all a bit like fiddling while Rome burns because carriers aren’t at all ready.

And that might signal a new, more fearful, less irrationally exuberant attitude toward wireless data. There have been people raising the “red sky by morning” warning for a long time about congestion, but they’ve been somewhat relegated to the sidelines of conventional wisdom. Now, I’d keep an ear out for changes in operator messaging going forward. And get your willy-nilly wireless Internet surfing in now, because it could be the last hurrah for unmetered rate plans.