CAC for VoIP Traffic over Wireless Systems with Voice Activity Detection and Background Noise Transmission

This paper presents a VoIP traffic model applicable to wireless access transmission media, which is usable for determination of admissible call number threshold value. The main observation is the influence of Voice Activity Detection function and Comfort Noise Generation in particular. The CAC threshold value determination is based on a fluid-flow approach to packet loss evaluation. The well known bufferless fluid-flow method is applied but a new simple exact formula for voice packets loss is developed. The suggested methods are illustrated with numerical examples, comparisons are made and some conclusions are drawn.