Nokia Siemens: iOS 4.2 Includes Fast Dormancy

Apple’s iOS 4.2.1 update for the iPhone apparently includes an undocumented feature that helps improve battery life, according to Nokia Siemens. The feature, called Network Controlled Fast Dormancy, improves how the iPhone communicates with cell carrier networks and offers improved battery life in the process.

iOS 4.2: Fast Dormancy ready

While Apple hasn’t confirmed that it’s using Network Controlled Fast Dormancy, Nokia Siemens is in a good position to determine whether or not the feature is in place since it created the technology. “Basically, the technology makes the network and the handset work together to create the best conditions for smartphones to work quickly, yet have a long battery life and minimize network congestion,” Mobile Broadband team member Leslie Shannon said on the company’s blog.

Nokia Siemens network tests showed that iPhones running iOS 4.2 are taking advantage of the feature, and as a result, at least some iPhone users should be seeing an increase in battery life.

Network Controlled Fast Dormancy works by putting mobile phones in an intermediate state between idle and active that lets devices wake for activity quickly, and doesn’t have to send as many signals to check for new data. “The new Apple software release supports this way of working on networks that have the technology implemented,” Ms. Shannon said.

The change is good news for other cell phone users, too, since it means iPhones will be using a little less bandwidth on already strained networks.