Waveform collection for use in wireless telephone identification

DETAILED DESCRIPTION The present invention is embodied in a system and method for collecting a reference waveform from an authorized wireless telephone in a wireless telephone network.
The collected reference waveforms are used by a fingerprint analyzer to distinguish telephone calls made by the authorized wireless telephone from telephone calls made by an unauthorized wireless telephone.
In one aspect, the system includes a processor that maintains a pool of unassigned telephone numbers and selects one telephone number from the pool at random.
The randomly selected telephone number is provided to a valid subscriber of an authorized wireless telephone.
The randomly selected telephone number is to be called by the valid subscriber using the authorized wireless telephone for the purpose of collecting reference waveforms.
A radio frequency (RF) receiver of the system monitors and receives call request transmission signals from a plurality of wireless telephones.
Each call request transmission signal contains a destination such as a telephone number and an identification of its wireless telephone such as MIN/ESN.
The processor looks for the call request transmission signal whose destination and the wireless telephone identification respectively correspond to the randomly selected telephone number and the identification of the authorized wireless telephone.
This insures that that particular call request transmission signal belongs to the authorized wireless telephone of the valid subscriber rather than an unauthorized wireless telephone belonging to a pirate since the pirate has no way of knowing the randomly selected telephone number provided to the valid subscriber.
The processor then extracts the reference waveform that represents a transmission characteristic of the authorized wireless telephone and stores the extracted reference waveform in memory for use by the fingerprint analyzer.
In another aspect of the invention, the system collects 10 to 40 reference waveforms to insure that there are sufficiently large number of samples from which to derive a fingerprint