Retrieving Packets from Losing during Service Disruption Time, During Vertical Handover among UMTS and WLAN

----------------------------------------------------------------ABSTRACT-----------------------------------------------------------------In voice activity based communication Choi et al show that using of mutual silence period to do the vertical handover (VHO) is a perfect choice to minimize the packet loss. However according to their proposal, after starting the VHO and before completing it, if one party breaks the silence pushing VoIP packets in channel, those will be lost though those packets may contains significant even very worthy information. In this paper we have shown that by using a small buffer, monitoring the VoIP packets at service disruption time, managing those in the buffer and then sending packets from it after completing VHO until the buffer becomes empty. In our experiment it was found that the proposed method improves the Choi et al’s proposal and prevents the packet losses surprisingly.