A cross-layer approach for TCP optimization over wireless and mobile networks

We propose a path recovery notification (TCP–PRN) mechanism to prevent performance degradation during a handoff. Even though Freeze-TCP achieves a performance increase during handoff, detecting accurate handoff time and the vulnerability of high variation in the round trip time (RTT) become obstacles for deploying Freeze-TCP in a real environment. The proposed protocol, TCP–PRN, quickly recovers lost packets by restoring the congestion window, preventing the congestion window to decrease, or immediately initiating the slow start algorithm. The simulation results of our study show better performance in a more realistic environment where the handoff prediction is difficult and the variation of RTT is higher.