Effective Voice Frame Pruning Method to Increase VoIP Call Capacity

Abstract

Voice over Internet Protocol (VoIP) is gradually dominating the telecommunication sector because it is free or inexpensive. However, one of the key problems of VoIP growth is inefficient bandwidth utilization. Several methods have been proposed to improve the VoIP bandwidth utilization, and they include VoIP packet aggregation and header compression. In this study, we investigate a new dimension to improve VoIP bandwidth utilization, that is, VoIP packet payload compression. The main idea of the proposed method, which is called the voice frame pruning (VFP) method, is to prune the leading/trailing zeros/ones of the VoIP packet payload on the basis of a certain mechanism. The VoIP packet payload is pruned at the sender side’s wide area network (WAN) gateway and restored to its original form at the receiver side’s WAN gateway. The implementation results of the proposed VFP method indicate good bandwidth savings based on the VoIP codec used. For example, the bandwidth savings of the LPC, G.723.1, and G.729 improved by up to approximately 5%, 8%, and 3.5%, respectively, thereby improving the VoIP bandwidth utilization and the capacity of VoIP calls.