Caching location data in mobile networking

Each Location Directory (LD) provides the information to locate the forwarding address of a Mobile Host (MH) in a mobile networking system. The LD should be updated when the MH moves from one access zone to another access zone. If an Internet Access Point (IAP) (or base station) could cache some useful LD information entries, then, after receiving a packet from an MH in its access zone, the IAP could check its cached LD and make an optimal routing decision. With the LD distributed over the Internet Access Points, the authors avoid Dogleg Routing because they no longer need to forward the packet to the Mobile Router (MR) where a master copy of the LD is located. The authors investigate how the LD data structure is used, updated, and distributed among Mobile Routers, Internet Access Points and Mobile Hosts. Furthermore, they present the LD design and implementation in the mobile IP network