In a transmission output stage for a multifrequency mobile telephone, the transmit signal of operation at the low frequency is generated by a push-pull output stage which is operated in single-ended mode for generating the transmit signal at the higher frequency. The service switch point is coupled to a communications network. Prior to sending a response to the request to access the protected resource, information in the third user account is modified to indicate that the service provider relies upon the second identity provider to authenticate the user on behalf of the service provider rather than the first identity provider. Moreover, the femto access point can be employed by the multiple UEs as a network hub and can be employed by the UEs to perform authentication to connect to a core network.