Abstract: A system for providing voice communications between an end terminal in a packet data network and a wireless communication device includes a packet communication supporting subsystem, a base station subsystem, and a Voice-over-Internet-Protocol Mobile Switching Center (“VMSC”). The packet communication supporting subsystem communicates with the packet data network and also operates to locate the wireless communication device. The base station subsystem communicates with the wireless communication device, and also communicates the packet data network through the packet communication supporting subsystem in the form of data packets. The VMSC communicates with the packet communication supporting subsystem through a packet-switched network and communicating with the base station subsystem through a circuit-switched network.

Abstract: A magneto optical recording medium capable of stable recording and readout using a DWDD system is provided. The magneto optical recording medium of the present invention comprises an optical disk substrate and a multilayer recording film comprising essentially a readout layer, an intermediate layer, and a recording layer successively formed on top of the substrate. The readout layer has a smaller magnetic domain wall coercivity than the recording layer. The intermediate layer comprises a magnetic layer whose Curie temperature is lower than the readout layer and the recording layer. A recorded/readout magnetic domain corresponding to recorded/readout information is formed only in a groove area of the optical disk substrate. The thickness of the recording film at the boundary between mutually adjacent recording track areas is smaller than the thickness of the recording film in the center portions of the recording track areas.