An Integrated Architecture for Seamless Soft Handoff in Mobile Ad Hoc Networks

We present an integrated architecture for seamless soft handoff in mobile ad hoc networks, where various managers residing on multiple layers are proposed to handle handoff issues in a cross-layer and cooperative manner. At the link adaptation layer, the virtual interface provides link transparency to the upper layers and session management is handled at the interface manager. The device and system monitor reports information about the wireless interfaces, and the policy manager incorporates various aspects of factors for comparing interfaces. The handoff is optimized to execute policy-based decisions to keep network traffic delay and traffic congestion to a minimum. At the network layer, essentially most IP-based ad hoc routing protocols can be accommodated, and the architecture can naturally host QoS protocols, like Differentiated Services with admission control. In particular, we present our hybrid Mobile Agent Routing (MAR) protocol that possesses such desirable behaviors and supports various traffic types. At the transport layer, the transport manager is instructed by the interface manager to adapt the transmission rate according to the new wireless link. Finally at the application layer, the security manager handles various aspects of security concerns, including defense against man-in-the-middle attacks.