| 摘要 |
AN ACCESS PROCESS IN A TIME-SHARED MOBILE RADIO SYSTEM FOR A CONSIDERED MOBILE STATION OF A PLURALITY OF ACCESS-SEEKING MOBILE STATIONS. THE MOBILE STATIONS LISTEN (41) ON A DOWNLINK OF A CONTROL CHANNEL TO A BASE STATION AND CAN RING-UP. SUBSEQUENT TO DIALLING A NUMBER, THE MOBILES RECEIVE (42) FROM THE BASE STATION INFORMATION CONCERNING AN IDLE TIME SLOT ON A CONTROL-CHANNEL UPLINK. WHEN A TIME SLOT (I) IS IDLE, THE MOBILES SEND (43) A FIRST ACCESS MESSAGE-PART. THE BASE STATION REGISTERS THE STRONGEST ACCESS MESSAGE AND CALCULATES A UNIQUE CYCLIC REDUNDANCY CHECK SUM. THIS CHECK SUM IS SENT WITH A CHECK MESSAGE ON THE DOWNLINK AND INFORMS (44) THE MOBILES THAT THE ACCESS-PART WAS CORRECTLY RECEIVED (R) BY THE BASE STATION. THE MOBILES CHECK (45) THAT THE CHECK SUM COINCIDES WITH THEIR OWN RESPECTIVE ACCESS MESSAGE-PARTS. THIS IS THE CASE (YES) OF THE CONSIDERED MOBILE, WHICH IS ASSIGNED THE CONNECTION TO THE BASE STATION AND TRANSMITS (46, YES, 47) ITS NEXT ACCESS MESSAGE-PART ON THE UPLINK. THE CONSIDERED MOBILE RECEIVES (48) FROM THE BASE STATION A NEW CHECK MESSAGE WHICH LACKS THE UNIQUE CYCLIC REDUNDANCY CHECK SUM. FURTHER ACCESS MESSAGE-PARTS ARE TRANSMITTED (46, YES,47) UNTIL THE ACCESS PROCESS IS TERMINATED (46, NO) AND RECEIVED (48) CHECK MESSAGES LACK THE CHECK SUM. BY EXCLUDING THE CHECK SUM AFTER THE FIRST ACCESS MESSAGE-PART, THERE IS OBTAINED AN ACCESS METHOD WHICH IS LESS SENSITIVE TO DISTURBANCES.(FIG. 4)
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