Method for generating a broadcast challenge value
AssigneeQUALCOMM Incorporated
InventorRoy F. Quick, Jr.
Life of this patent
Estimating the term…
Abstract
A method for generating a broadcast challenge value includes the steps of applying a first updating algorithm to the most significant bits of the broadcast challenge value, and applying a second, distinct updating algorithm to the least significant bits of the broadcast challenge value. The updating algorithms can be maximal-length shift registers or other forms of pseudorandom noise generator. The sequence of successive unrepeated values can be extended for either one or both sets of bits by inserting an all-zeroes value once during the period of time before which an update value recurs. System-wide synchronization can be achieved via a global time reference.
Claims58
A method of updating a broadcast challenge value transmitted by a cellular base station on a control channel, comprising the steps of:
- applying a first updating algorithm to a plurality of most significant bits of the broadcast challenge value;
- and
- operating on a plurality of least significant bits of the broadcast challenge value with a second updating algorithm to generate an updated broadcast challenge value.
In a cellular system, a method of synchronously updating binary numbers used by a plurality of base stations to authenticate a plurality of mobile subscriber units, the method comprising the steps of:
- applying a first updating algorithm to a plurality of most significant bits of the binary number for each of the plurality of base stations;
- operating on a plurality of least significant bits of the binary number for each of the plurality of base stations with a second updating algorithm;
- and
- synchronizing across the plurality of base stations update values of the binary numbers that result from the applying and operating steps.
A cellular base station, comprising:
- an integrated circuit capable of running software;
- and
- a set of software instructions executed by the integrated circuit for applying a first updating algorithm to a plurality of most significant bits of a binary number and for applying a second updating algorithm to a plurality of least significant bits of the binary number to generate an updated binary number.
A cellular system, comprising:
- a system-wide time reference signal;
- a plurality of mobile subscriber units;
- and
- a plurality of base stations configured for wireless communication with the plurality of mobile subscriber units, each of the plurality of base stations comprising:
- an integrated circuit capable of running software;
- and
- a set of software instructions executed by the integrated circuit for applying a first updating algorithm to a plurality of most significant bits of a binary number and for applying a second updating algorithm to a plurality of least significant bits of the binary number, the binary number serving to authenticate any mobile subscriber unit requesting communication with a base station, and for synchronizing successive update values of the binary numbers with the system-wide time reference signal across the plurality of base stations.
A base station, comprising:
- first means for updating a plurality of most significant bits of a broadcast challenge value;
- and
- second means for updating a plurality of least significant bits of the broadcast challenge value to generate an updated binary number.
A cellular system, comprising:
- means for establishing system-wide time synchronization;
- a plurality of mobile subscriber units;
- and
- a plurality of base stations configured for wireless communication with the plurality of mobile subscriber units, each of the plurality of base stations comprising:
- first means for updating a plurality of most significant bits of a binary number, the binary number serving to authenticate any mobile subscriber unit requesting communication with a base station;
- second means for updating a plurality of least significant bits of the binary number;
- and
- means for synchronizing successive update values of the binary numbers across the plurality of base stations with the means for establishing system-wide time synchronization.
Dependencies are inferred from the claim text.