Cross-Layer Vertical Handoff for TCP Performance Enhancement in a Multi-Tier Tactical Network

Compared to a civilian network, tactical network for the future battlefield has to be essentially multi-tier overlay architecture for survivability and reliability. Vertical Handoff for that architecture could be a challenge because of drastic changes among overlaid networks. In the paper, design considerations and vertical handoff schemes are suggested: network-node assisted vertical handoff and neighbor-node assisted vertical handoff. By adopting cross-layer approach and rate-controlled link features such as AMC, it is possible to prepare an optimal TCP context proactively before moving, which facilitates immediate switching after a vertical handoff. In addition, direct mode operation capability of a future soldier terminal can be utilized in the neighbor-node assisted mode when a network-node is cut off temporarily due to action on a dynamic battlefield.