Patent ID: 8355695

Claim:
A method for providing a security service to data traffic in a communications system, the system comprising a home operator network, a roaming operator network, and an interconnecting operator network, the method comprising establishing at least one operator-specific security association for securing data traffic in the system, wherein the method comprises establishing a first security association between an anchor node located in the home operator network and a concentrator node located in the interconnecting operator network; establishing a second security association between an access node located in the roaming operator network and the concentrator node located in the interconnecting operator network; and transmitting data traffic between the anchor node located in the home operator network and one or more user terminals roaming in the roaming operator network such that the data traffic transmitted between the anchor node and the concentrator node is secured by using the first security association and the data traffic transmitted between the access node and the concentrator node is secured by using the respective second security association, wherein the home operator network is the home network of said one or more user terminals.