System and method for detecting three-way call circumvention attempts
Disclosed is a three-way call detection system and method for use with a telephone management system. Specifically, a three-way call detection system and method for detecting continuous noise indicative of an attempt to mask a three-way call attempt. The continuous noise detection system and method may be stand alone or used in conjunction with any existing three-way call detection system and method.
1. A method for detecting an attempt to mask a three-way call, said method comprising the steps of:
monitoring an audio stream;
detecting when a power level of said audio stream exceeds a pre-determined threshold;
calculating an elapsed time when said power level of said audio stream exceeds said pre-determined threshold; and
determining whether said elapsed time exceeds a maximum allowable period of time,
wherein the above steps are performed by a processor.
2. The method of claim 1 , wherein said power level is the signal power of said audio stream.
3. The method of claim 2 , further comprising the step of determining whether said signal power is evenly distributed across said elapsed time.
4. The method of claim 1 , wherein said pre-determined threshold is at least approximately −20 decibels (dBm).
5. The method of claim 1 , wherein said elapsed time is at least approximately 1500 milliseconds (ms).
6. An apparatus for detecting an attempt to mask a three-way call, said apparatus comprising:
an interface for receiving audio streams from a telephone line;
a microprocessor coupled to said interface for detecting when a power level of said audio stream exceeds a pre-determined threshold;
wherein said microprocessor monitors said audio stream for a pre-determined time; and
wherein said microprocessor determines whether said power level of said audio stream exceeded said pre-determined threshold for the duration of said predetermined time.
7. The apparatus of claim 6 , wherein power level is the signal power of said audio stream.
8. The apparatus of claim 6 , wherein said microprocessor includes a continuous noise detection algorithm for detecting a false three-way call.
9. The apparatus of claim 8 , wherein said continuous noise detection algorithm includes a power distribution filter algorithm and a zero crossing filter algorithm.
10. The apparatus of claim 9 , wherein said power distribution filter algorithm detects when said signal power is not evenly distributed across said pre-determined time.
11. The apparatus of claim 9 , wherein said zero crossing filter algorithm calculates whether the zero-crossing rate of said signal power is below a pre-determined threshold of human speech.