We present a new method to improve the bandwidth of HMIPv6 networks called HMIPv6-BI. This approach proposes a modification to the Hierarchical Mobile IPv6 protocol. The goal of HMIPv6-BI is to minimize the Bandwidth usage of the Radio Link between the Access Router (AR) and the Mobile Node (MN). Currently, in HMIPv6 a tunnel is established between the Mobility Anchor Point (MAP) and the MN. By contrast, the principle used by HMIPv6-BI is to move the Tunnel End Point until the AR. In consequence, this method decreases the number of bytes traveling over the wireless interface due to the absence of the tunnel headers required in the original approach. Furthermore, HMIPv6-BI allows the usage of Multicast Tunnel (this approach is named TMCast+HMIPv6-BI) in order to reduce the Handover Latency. Finally, modeling and simulation results indicate that HMIPv6-BI provides better performance as compared to the standard approach.