Zong-Hua Liu

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The IETF NEtwork MObility (NEMO) working group has considered how to enable an entire network to move from one location to another. Mobile Virtual Private Network (VPN) has been developed to secure mobile user's communication between untrusted external networks and the protected private internal network. However, the IETF's mobile VPN does not address how(More)
WiMAX forum is developing and standardizing the end-to-end network architecture. The access service network (ASN) gateway (GW) plays a critical role in the system. How to reduce the load in the ASN GW has become an important issue. However, the standards only define the ASN GW relocation procedure without specifying when the relocation should be performed.(More)
Mobile virtual private network (MVPN) has been developed to secure mobile user's communication between untrusted external networks and protected private internal network. The IETF's solution, however, leads to some problems: where should we put the external home agent (HA), how could we trust the external HA, and overhead of three tunnels. In this paper, we(More)
A mobile virtual private network (VPN) has been developed to secure a mobile user's communication between entrusted external networks and the protected private internal network. IETF's solution, however, leads to some problems: where the external HA (home agent) should be put; how to trust the external HA; the overhead of three tunnels. We propose an(More)
This paper describes the design principles and implementation of Dynamic Service Negotiation Protocol (DSNP). DSNP is a protocol to negotiate the Service Level Specification (SLS) at the IP layer. It can be used for service negotiation from host to network, network to host, and network to network. Dynamic negotiation not only provides flexibility to the(More)
The standards bodies have defined the interworking architecture between 3GPP LTE/SAE and 3GPP2 EV-DO. For inter-system handoff, pre-registration and pre-authentication are performed to establish the required resources before the actual handoff. However, the standards only define the handoff procedures without specifying when to reserve or release the(More)
The WiMAX Forum has defined a two-tiered mobility management to minimize handover delay and packet loss. However, it leads to another problem: When to perform ASN GW relocation? The standards only define the ASN GW relocation procedures without specifying when the ASN GW relocation should be performed. It is left for vendors and operators to develop their(More)
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