AppleInsider says Nokia Siemens have a new "Network Controlled Fast Dormancy technology", which reduce power consumption on mobile phones & increases battery life significantly - and IOS4.2 takes advantage.
So is Nokia Siemens equipment behind any of our networks here in Australia?
Several networks operated by Huawei, Nokia-Siemens and Ericsson have been upgraded this year with enhanced fast dormancy.
Huawei does Optus's 900MHz 3G network
Ericsson does Vodafone's 900MHz 3G and Telstra's 850MHz 3G networks.
Nokia Siemens does Vodafone's 850MHz " iPhone only" metro network
Nokia Siemens also does the Vodafone-Optus 2100 MHz metro network
I would say Vodafone's metro 850mhz is most likely to have it already, but I wouldn't be surprised if Telstra and the Huawei parts (900MHz) of Optus' network have it already or very shortly.
This feature is designed to address a major issue that the iPhone causes with mobile networks. Expect all of our networks to have this enabled very soon.