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Enhanced MOS in VoIP over priority erasure channels based on optimal packet classification

Neves, F.N. ; Soares, S.S. ; Assunção, P.A.

Enhanced MOS in VoIP over priority erasure channels based on optimal packet classification, Proc Conf. on Telecommunications - ConfTele, Castelo Branco, Portugal, Vol. 1, pp. 341 - 344, May, 2013.

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Abstract
This paper proposes an optimal packet classification algorithm to improve VoIP communications intelligibility over erasure channels, based on the evidence that not all voice packets equally contribute to the overall quality. The variable relevance of different voice packets is taken into account in order to selectively discard the less important ones when packet erasure events occur, e.g., congestion or fading. The proposed algorithm optimally classifies each voice packet as either high or low priority according to its relevance for the overall quality of a predefined voice segment. The results show that when this optimal algorithm is used in priority enabled erasure channels, the quality of the received voice, i.e., both Root Mean Squared Error (RMSE) and Mean Opinion Score (MOS), is significantly better than in the case of random erasures over non-prioritised voice. Comparative results show that the RMSE decreases about seven times and MOS increases from “Poor” to “Fair” when the proposed algorithm is used under stringent loss conditions.