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Paging and time keeping system with transmission of time slot identification used for synchronization Patent #: 5168271
ApplicationNo. 990596 filed on 12/14/1992
US Classes:380/271, Having receiver selection (e.g., pager)340/7.21, Two-way paging340/7.55, Display380/270Wireless communication
ExaminersPrimary: Swann, Tod R.
Attorney, Agent or Firm
Foreign Patent References
International ClassH04K 001/02
AbstractA paging system which sends and receives encrypted messages. The message may be encrypted either by the sender of the message or by the paging system. Multiple keys may be used for encrypting and decrypting. Public key systems may also be used and integrated into this paging system. The paging system can send out time update messages containing the current time and date. The pagers use the time update messages to automatically update the time in an internal clock. Time stamps can be inserted into the encrypted messages to prevent unauthorized users from replaying old messages.