Supporting interworking and/or mobility between different wireless communication systems

Abstract

There is provided a method performed by a network unit, and a corresponding network unit as well as a corresponding wireless communication device, for supporting interworking and/or idle mode mobility between different wireless communication systems, including a higher generation wireless system and a lower generation wireless system, to enable secure communication with the wireless communication device. The method comprises selecting, in connection with a registration procedure and/or a security context activation procedure of the wireless communication device with the higher generation wireless system, at least one security algorithm of the lower generation wireless system, also referred to as lower generation security algorithm(s). The method also comprises sending a control message including information on the selected lower generation security algorithm(s) to the wireless communication device. The method further comprises storing information on the selected lower generation security algorithm(s) in the network unit.

Dependencies are inferred from the claim text.