Analysis of Voice over Ip during Vertical Handovers in Heterogeneous Wireless and Mobile Networks

Roaming across different heterogeneous technologies such as 802.11, WiMAX and UMTS will become a requirement of future networking devices, especially for Voice over IP traffic, which nowadays is one of the most important services regarding the performance evaluation of wireline and wireless networks. In this paper we perform a study on the performance of voice packet transmissions during vertical handovers between 3GHSPA, WiMAX (IEEE 802.16) and WLAN (IEEE 802.11) wireless networks. In particular, we analyze the performance metrics, such as handover latency and packet loss, for obtaining the effects of vertical handover on the mobile node performance, by using the recommended parameter values for link triggers and router configuration in IEEE 802.21 standard. Results show that the handover latency is severely impacted by the choice of the time interval parameters on the link layer, especially in the case of UMTS to WiMAX vertical handover. Packet loss is also analyzed in order to have the best optimization in vertical handovers between UMTS, WiMAX and WLAN, for Voice over IP traffic.