Proxy Mobile IPv6 has been proposed to overcome limitations of host-based mobility protocols in IPv6 networks. In Proxy Mobile IPv6, mobility entities such as Mobile Access Gateway and Local Mobility Anchor have been newly introduced. These entities eliminate the burden of requiring host-based mobility stack and the signaling cost concentrated to a mobile host. However, there has been no attempt to apply paging technologies, which can also reduce the signaling cost focusing to Local Mobility Anchor, into Proxy Mobile IPv6. In this paper, we propose a paging extension scheme for Proxy Mobile IPv6 to enable an efficient mobility management that reduces the location update signaling cost for the mobile host in the idle mode. Performance analysis results demonstrate that our paging extension scheme improves the scalability by supporting large numbers of mobile hosts with decreased signaling cost under various system parameters.