Abstract: A method of determining noise in an audio stream, the method comprising: acquiring a plurality of consecutive time frames of the audio stream each comprising samples of the audio stream; generating a discrete frequency spectrum for each frame responsive to the frame samples; partitioning the frequency spectrum of each frame into a plurality of same frequency bands; determining an audio energy for each frequency band in each frame; and determining an estimate of noise energy for each frequency band in a temporally last time frame responsive to a relatively small number of smallest values for the audio energy in the frequency band of the plurality of time frames.

Abstract: The invention provides a method of processing a registration message according to initial filter criteria in IMS network. The method is as follows: after a registration for a user is successful, the Serving Call Session Control Function (S-CSCF) downloads corresponding subscription data from a Home Subscriber Server (HSS), and an implicit registration set corresponding to the user is contained in the subscription data. The S-CSCF traverses all the Service Profiles in the implicit registration set and matches the registration message with the initial filter criteria in the Service Profiles. When the matching is successful, the S-CSCF sends a request message to corresponding application servers (AS) to perform a third party registration.