An apparatus and a method for controlling a small base station using a macro base station may reduce interference between the small base station and the macro base station. It also relates to processes for the preparation of said compositions, multi-layered pharmaceutical compositions comprising at least one layer with this composition, as well as processes for the preparation of said multi-layered composition. As the encrypted configuration data is input, a determination is made as to whether or not the encrypted configuration data is authentic. The voice communication device associates the signaling key identifier and an encryption algorithm identifier with the subset voice stream during transmission of the subset voice stream to a receiving voice communication device.