Buffering requirements for lossless vertical handoffs in wireless overlay networks

The evolution of mobile multimedia services outlines a-trend towards the coexistence of heterogeneous wireless overlay networks. These networks extend traditional wired and internetworked processing "islands" to hosts on the move over coverage areas ranging from in-room, in-building, campus, metropolitan, and wide-areas. For these networks to work as a seamless internetwork, optimal mobility management has to be implemented. One main task in this aspect is handling the problem of handoffs smoothly. Beside the traditional horizontal handoffs between cells of the same network, vertical handoffs between different networks have more impact on system performances. In this paper, we determined the required buffer sizes to achieve lossless upward vertical handoffs for such networks under different circumstances. In addition, our simulation results show that the average packet. delays are within the acceptable QoS limits for most multimedia-traffic types.