Distributed Server Delivery of Immersive VoIP Service: Balancing Between Voice Latency and Access Upload Cost

As a future communication tool to the distributed virtual environment, the Immersive VoIP service delivers to each user a real-time mix of nearby user voices which are all rendered according to their respective virtual world positions. In this work, we conjecture that the voice latency constraints between Immersive VoIP users would vary according to their virtual world distance of separation. As verified in our subjective listening tests, this conjecture is more realistic than fixed latency constraint, in terms of user perceptual experience and network feasibility. Empowered by the Bandwidth Reduced server assignment algorithm, the proposed two-hop distributed server architecture achieves a better balance between access bandwidth cost and voice latency when compared against the central server and the peer-to-peer architectures. The two-hop architecture targets the challenging scenario where there lacks clear correlations between the virtual world and the underlying physical network. In addition, we have also investigated the necessary frequency to execute the server assignment solutions to mitigate sensitivity to virtual world mobility.