Many mobile network nodes (MNNs) in public transport move together as a large-scale mobile network. Therefore, RFC 3963 proposes a network layer solution called network mobility (NEMO) as the basic support protocol for network mobility management. NEMO is designed so that network mobility is transparent to nodes in the mobile network, thereby reducing the signaling overhead. However, NEMO does not specify how authentication, authorization and accounting (AAA) should be handled, and it inherits the drawbacks of long handoff latency from Mobile IPv6 (MIPv6). In this paper, we develop a lightweight mutual authentication mechanism (LMAM) with low computational overhead and achieve local authentication based on NEMO and the AAA model over IEEE 802.16e networks. Moreover, LMAM can resist various attacks. In addition, we propose an enhanced hierarchical Mobile IPv6 (E-HMIPv6) scheme to reduce intra-domain handoff latency. We then integrate LMAM into E-HMIPv6 without increasing the signaling overhead. Our analysis results show that the integrated scheme, called LE-HMIPv6 outperforms existing schemes in terms of authentication and handoff latency.