Performance tradeoff between mobility and voice quality among different VoIP deployment strategies

Voice over Internet Protocol (VoIP) is a new paradigm of telephony service. Many organizations nowadays are interested in adopting VoIP. Nevertheless, different deployment strategies exist. This study describes all current possible VoIP deployments (No Mobility, Limited Area Mobility and Full Mobility), their properties and characteristics. It attempts to systematically compare these possible deployments with respect to mobility level and end-to-end voice quality. This was done by means of the popular measures of voice quality, packet discard, packet loss and Mean Opinion Score (MOS). Performance tradeoffs between both aspects are also discussed. Results reveal that Quality of Service (QoS) is satisfactory in No Mobility and Limited Area Mobility deployments. However, this is not the case for Full Mobility deployment using UMTS. The study also pays particular attention on the utilization of the two popular CODEC, G.711 and G.729 among these deployments. Significant findings are discussed and directions for future works are also suggested.