Keio University, Graduate School of Media and Governance
MAUI Project
Ph.D. Dissertation

[ English | Japanese ]
Back to Index Page

TITLE Floating Ground: An Architecture for Network Mobility and Ad Hoc Network Convergence

This dissertation proposes the Floating Ground Architecture (FGA) for future mobile ad hoc networks. In order to avoid wasting capability of distributed communication network, maximizing the availability of the IP connectivity under various situations including mobile environment is critical. To achieve this goal in challenging network environments such as disaster recovery operations, the network must provide 1) dynamic extension of the network and 2) fine-grained connectivity. Dynamic extension extends the network in an ad hoc fashion using wireless multi-hop communication, and fine-grained connectivity provides higher network coverage in dense networks. Dynamic extension must work over fine-grained wireless media such as Wi-Fi, however existing solutions are brittle, and do not adequately meet these two requirements because of the following three problems: P1) inadequate scalability of routing protocols, P2) redundant routing under nested router arrangement, and P3) difficulties of deployment.

To solve these problems, FGA introduces a new logical layer, called Floating Ground (FG), between the fixed network infrastructure and the mobile network, and aims to bridge these different types of network systems. Thanks to the effect of this buffer layer, the architecture achieves 1) spontaneous deployment and 2) optimized route in a deeply nested router arrangement. Furthermore, 3) scalable signaling of Floating Ground operation achieves the fine-grained connectivity. As an implementation of Floating Ground Architecture, we propose 1) Extended MANEMO Tree Discovery (EMTD) for scalable signaling among large numbers of Mobile Routers provides the Floating Ground, and 2) NAT-MANEMO builds on the Floating Ground to optimize the redundant route with regard to minimize the modification of the system.

Through the evaluation of our proposed architecture using actual software implementation, the scalability of EMTD is studied in various scenarios. NAT-MANEMO achieves better communication performance than existing protocols, and does not break the original handoff capability. Qualitative analysis of NAT-MANEMO shows that it minimizes modification of the network components and existing standardised protocols, and is therefore more suitable for spontaneous deployment than competitive approaches.

This architecture helps to maximize the achieved Internet connectivity under challenging network environments such as mobile ad hoc networks, and contributes making the Internet on which people depend more reliable.

Keywords: Mobile Ad hoc Network, MANET for NEMO (MANEMO), Floating Ground, Routing Scalability, Route Optimization, Spontaneous Deployment.

CONTACT To obtain the dissertation, please contact;
TAZAKI, Hajime ( tazaki at )

MAUI Proejct
Last update:

Back to Project Home Page