Apple yesterday released the fourth beta of iOS 5 for registered developers and for the first time has enabled over-the-air (OTA) updates. The update which can be delivered via a cellular or WiFi network is also a delta update, weighing in at 133MB for a GSM iPhone 4.
Whilst developers can continue to download full-size images from the iOS developer site, the enabling of OTA updates represents Apple's first foray into delta updates. A number of reports suggest that the delta update whilst tiny compared to full updates requires just under 900MB of free space to unpack and install and iPhones require a power source or over 50% battery life.
Features of the fourth beta of iOS 5 appear slim as Apple begins to shape and refine the mobile OS update expected to be released in mid-September.
It's all Tech has a run down of some of the changes that have popped up in the fourth beta of iOS 5.
The release of iOS 5b4 was accompanied by a release of Xcode 4.2 and the fourth beta of iTunes 10.5.