The rumours are getting ever louder. The new version of iPhone is coming out and it has 3G capabilities.

Many have expressed their concerns that this will seriously affect the iPhone’s already relatively short battery life time. 3G chipsets certainly drain the batteries faster than 2 or 2.5G (i.e. GSM, GPRS and EDGE) chips. Most 3G handsets – regardless of the brand – have short battery life compared to their lower generation counterparts and most 3G handset owners are familiar with their radiating heat, especially during heavy data – or even just voice – usage.

There have been talks about new OLED displays which would decrease the battery usage by the other main power sucker – the display – and then leave some room for added power consumption from the 3G chipset. And obviously the new iPhone’s battery won’t be inferior to the current model’s.

Before the first version of the iPhone came out, I made a few predictions that turned out to be pretty accurate, so I’ll give it another shot: During a chat with my colleague – Chad Nordby – last week, we came across another method to dramatically increase the battery life: Turn 3G on only when high bandwidth is needed.

The phone would stay on the 2G network during normal operations. There is no need to drain the battery on UMTS (i.e. 3G) communications while idly waiting for a call. When the user activates the device, 3G could be turned on and ready for your high-speed browsing – very much the same way as is currently done for the WiFi capabilities. The same might also work for background communication – 3G could be turned on to fetch large payloads, such as a big email attachment, but minor status updates and mail checks could stay on the EDGE network.

The handover technology from 2G to 3G (or technically from GSM to UMTS) networks is already there and works quite well. When you’re drive out of 3G coverage, talking on the phone, even the phonecall is handed from one technology to another instantaneously without dropping the call.

So there’s nothing stopping them, and as such a small fraction of time is spent on usage of data services anyway (compared to idle time) this would fully address the battery concerns. So it is my prediction the new iPhone will work this way. Obviously any handset manufacturer could use this method, but Apple is probably the only one crazy enough to actually be thinking on these notes.

The sheep might catch on later 🙂