A method for handling Circuit Switched Fallback includes receiving an indication that Circuit Switched Fallback is supported and registering to a Circuit Switched domain by tunneling Circuit Switched Registration information to the Circuit Switched domain. The channel has confronting ribbed flanks. An adjustable counterweight may be attached to free end of the adapter arm to balance weight of the heavy adapters. The apparatus also includes a spatial-temporal integrator unit configured to receive a plurality of measurement bases.