Instant messaging between phones is hot, but text IM is already passé and the real interest at 3GSM is voice push-to-talk technology, mostly based on the IMS spec agreed this week by Nokia, Ericsson and Siemens.
Push-to-talk streams an audio message from your phone to someone on your buddy list over GPRS. Don't talk too loudly about the possibility of using it as a cheap way of making international voice calls, though - if you do, the software guys get edgy and start looking around to see if anyone from the networks is listening.
For a start, it is not a real-time service, says Kang Lee, founder, president and CEO of fastmobile, one of several companies working on push-to-talk software. "There's the transport delay from GPRS, and our servers add another 1.5 seconds delay," he says. "It's usable as a walkie-talkie but it's not a threat to voice revenues."
His company's fastchat software is for Symbian-based Nokia 7650 and 3650 handsets, with Ericsson P800-compatibility on the way. Rival developer Sonim has similar software for Microsoft-based smartphones.
Kang argues that fastchat is not a threat to MMS either, even though it also allows photos to be sent easily, whether it be to an MMS handset or to users on other IM systems such as MSN Messenger.
The technology is server-based, not peer-to-peer, and fastmobile is looking for iMode-style revenue sharing agreements with networks or service providers. The challenge will be to prevent the carriers from hedging it round with so many restrictions that it becomes impossible to sell. ®