Dr. Hugh Melvin

Voice over IP (VoIP) has become a mainstream technology in recent years, and will continue to evolve as core networks migrate to IP Cbased Next Generation Networks (NGN). One of the many advantages of this move to IP is that traditional narrowband codecs can be replaced by wideband and superwideband codecs, offering much better voice quality. On the other hand, delivering voice over unmanaged best-effort IP networks raises many challenges relating to latency, jitter, and packet loss. Various strategies have been developed to minimise the impact on quality of such network characteristics. These included, packet scaling or timewarping, adaptive jitter buffer management, and Packet Loss Concealment (PLC ). Such strategies have been shown to work well in a narrowband environment. This project will investigate the impact of such techniques on wideband and superwideband voice where the default quality and thus user expectations are higher.