1. A method of controlling asynchronous installation of a software update on a terminal device of a wireless network, the method comprising steps of: receiving an update notification message in respect of the software update, the update notification message comprising: a software identifier uniquely identifying an application affected by the update; a version number associated with the software update; and an address of an update script on a data network accessible by the terminal device, the update script being adapted to install the software update on the terminal device; logging the update notification message in an updates registry; and forwarding a notification message to the terminal device, the notification message including the software identifier, the version number and the address of the update script.