| 摘要 |
MOBILE HANDOVER BETWEEN A PRIVATE RADIO COMMUNICATIONS NETWORK (12, 12'', 12", 14) CONNECTED TO THE PUBLIC SWITCH TELEPHONE NETWORK AND A PUBLIC LAND MOBILE NETWORK (10) ALSO CONNECTED TO THE PUBLIC SWITCH TELEPHONE NETWORK ARE PROVIDED BY A RADIO COMMUNICATIONS MOBILE TERMINAL (30) SUPPORTING SIMULTANEOUS COMMUNICATION CONNECTIONS BETWEEN THE TWO UNCOORDINATED NETWORKS. THE MOBILE TERMINAL (30) MONITORS A BASE STATION (16) OF THE PUBLIC LAND MOBILE NETWORK (10) DURING IDLE FRAMES OF COMMUNICATION CONNECTIONS WITH THE PRIVATE RADIO COMMUNICATIONS NETWORK (12, 12'', 12", 14), THEREBY SYNCHRONIZING THE MOBILE TERMINAL (30) TO BOTH THE BASE OF THE PUBLIC LAND MOBILE NETWORK (10) AND THE PRIVATE RADIO COMMUNICATIONS NETWORK (12, 12'', 12", 14). CALL INTERRUPTION IS PREVENTED DURING HANDOVER BY MAINTAINING SIMULTANEOUS COMMUNICATIONS WITH THE PRIVATE RADIO COMMUNICATIONS NETWORK (12, 12'', 12", 14) AND THE PUBLIC LAND MOBILE (10) NETWORK THROUGH THE USE OF TWO HALF-RATE CHANNELS OR DUAL-SLOT COMMUNICATIONS WHERE BOTH THE PUBLIC LAND MOBILE NETWORK (10) AND PRIVATE RADIO COMMUNICATIONS NETWORK 912, 12'', 12", 14) OPERATE PURSUANT TO COMPATIBLE TDMA STANDARDS. HANDOVER IS INITIATED WHEN THE MOBILE TERMINAL (30) DETECTS A SIGNAL QUALITY WHICH VIOLATES A PREDETERMINED SWITCHING CRITERIA AND PASSES THE PSTN PHONE LINE NUMBER OF THE PRIVATE RADIO COMMUNICATIONS NETWORK (12, 12'', 12", 14)TO THE BASE STATION (16) OF THE PUBLIC LAND MOBILE NETWORK (10) WHICH IN TURN REQUESTS RE-ROUTING OF THE CALL FROM THE PSTN SWITCH (66). (FIG. 1)
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