Sony has confirmed that that 3G connectivity will be an optional extra included only in some models of the Next Generation Portable.
"The first thing to clarify, which I'm not sure the presentation did a perfect job of doing today, is that all of the devices will have wi-fi capability; a separate SKU will have 3G," SCEE president and CEO Andrew House told Eurogamer.
"So the user gets a choice. Wi-fi is available wherever, which clearly is the most important aspect of connectivity and that connected experience. 3G will be a subset of that."
Sony is currently in talks with mobile operators about 3G partnerships, though it has confirmed that the service will incur some sort of charge for the user.
Added House: "You'll hear more from us around that aspect of the strategy as we get closer to launch."
As for what 3G connectivity could offer, House talked up the possibility of "asynchronous" gaming, much as is seen with turn-taking iPhone titles like Words With Friends.
"One area that I'm particularly excited about is the idea of asynchronous gaming," he explained.
"The game experience is existing either on a PS3 or on your NGP, and then the 3G ability is the real-time. You know, 'You're under attack, you've got to go do something' messaging, just keeping that link with you, which clearly is not very heavy in terms of data traffic, but creates a whole different sense to the experience."