TCP performance evaluation during handover among Bluetooth network access points

TCP is a reliable transport protocol that performs well in fixed networks where congestion is the primary cause of packet loss. However, TCP´s packet recovery schemes lead to non-optimized data flow resuming after handover procedures in wireless LAN environments. The Bluetooth system is a low cost, short range wireless technology that can be used to provide network access; the handover procedure among Bluetooth access points is relatively slow compared to other standards because Bluetooth was born as a cable replacement with no mobility support. In this document TCP performance over the Bluetooth system is analyzed with particular attention to its behavior during the handover procedure that has been developed in our laboratories. TCP measurements, collected on a real-time prototype, show that packet losses during Bluetooth handovers result in TCP stream interruption that can last for more than two seconds even though layer two handover time is about 350 ms.