One of the most main subjects for all-IP mobile networks is mobility management. A network-based mobility management protocol, which is called Proxy Mobile IPv6 (PMIPv6), was developed by IETF. In order to improve handover delay time, a fast handover is integrated into PMIPv6 to speed-up the handover process, which is called PFMIPv6. However, the PMIPv6-based schemes predominantly focus on one MN instead of multiple MNs. It is many possible scenarios that there are multiples MNs move from the same previous access network to the same next access network simultaneously. In the fast handover approach, these many MNs start the same handover preparation procedure individually and generate many replication signaling messages during handover. In this work, a Group-Based Fast Media Independent Handover Control Scheme for Proxy Mobile IPv6 (GB-FMIH-PMIPv6) is proposed to resolve the above issues. In the proposed scheme called as GB-FMIH-PMIPv6, n MNs, which intend to handover from the same original network to the same next network at the same time, is formed as one group, for which only 1 set of messages for handover processing is used instead of using n sets of messages for these n MNs. Therefore, when the number of MNs is increased, handover signaling cost is reduced significantly and the handover procedure can be simplified. As a result, the seamless handover service can be improved.