According to tests done by Apple’s cohort in mobile domination, the recently released iOS 4.2 contains something called “Network Controlled Fast Dormancy”, which is a technology created by Nokia Siemens to improve network response and battery life.
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.
When your cellphones needs to connect to a network for any reason, it switches from a battery-saving idle state to a battery hogging active state. This toggling takes time, and can drain your battery rather quickly, depending on the interval between connections. NCFD causes the phone to operate in an intermediate state so it can reconnect much more quickly, and a positive side effect of this is a better battery life, since the phone doesn’t have to connect from scratch each time an application pesters it for data.
Tests done by Nokia claim that this technology can improve battery life by as much as 83%, and generates up to 50% less smartphone signaling (which eases the strain on networks). NCFD will likely be integrated into many more phones and network in the near future, and will benefit both the user and carrier.