Video chat is shaping up to be one of the hot applications for the very latest smartphones, but it could present a new set of challenges for mobile operators and application providers.

A new breed of smartphones -- such as the High Tech Computer Corp. (HTC) (Taiwan: 2498) EVO and Apple Inc. (Nasdaq: AAPL)'s iPhone 4 -- with cameras on the front of the device make it easy to see the person you're talking to, and vice versa. (See Apple Unveils the iPhone 4 and Sprint's EVO Launch Creates Buzz & Mixed Crowds.)

Even if devices that can better support video applications are starting to arrive, however, it is not at all clear that 3G networks -- or the application providers -- can support live video over their systems.

Apple is restricting the use of its FaceTime video call application for the new iPhone to WiFi connections for the rest of 2010. "We need to work a little bit with the carriers," CEO Steve Jobs said at the WWDC launch of the new iPhone today.

The company that developed the video chat application for Sprint's EVO phone, Qik, had to take their client down for the time being after demand overwhelmed its servers, following the EVO launch on Friday.

"We are seeing some unprecedented number of new users joining and Qikking," the company wrote on its corporate blog. "It truly is beyond what we had imagined."

Qik is promising to fix its issues as soon as possible. Even so, some Twitter Inc. users that did get to try it described it as horrible, although others appear happy with the overall video service.

The real-time nature of two-way video chat and its strain on both the uplink and downlink of the 3G wireless connection is what makes this traffic particularly hard to deal with. Operators can't do some of the caching and buffering tricks they do with video downloads on a live two-way call.

The one-two punch of live video applications becoming more popular and more smartphones coming from HTC and others with front-mounted cameras means that video chat is likely to be an issue throughout 2010 for operators and developers.

"It has the carriers scared witless," says Raymond Pasquale, managing director of business development at Westford, Mass.-based mobile multimedia optimization company, Aylus Networks Inc.

He says that -- using technology like that offered by Aylus -- carriers can ease their pain by reducing the size of video streams or even refusing to complete video connections if the bandwidth is not available. Pasquale says that Aylus's gear is in tests with six carriers at the moment for video and audio applications.

Nonetheless, for the time being, Apple and its operator partners are not risking two-way video chat on 3G.

— Dan Jones, Site Editor, Light Reading Mobile