PET: enhancing TCP performance over 3G & beyond networks

TCP flow control algorithms have been designed for reliable links where losses are primarily due to congestion. However, wireless networks suffer from significant packet losses due mainly to bit errors and handoffs. When wireless service is merged with wireline networks in 3G and beyond, TCP's performance will deteriorate further. To mitigate this problem, in this paper we propose a performance enhancing TCP (PET) that decouples loss recovery from congestion control using the enhanced active queue management (AQM) and explicit congestion notification (ECN). PET not only keeps the end-to-end semantics of TCP, but also is capable of performing well over both wireline and wireless links. PET works in two modes: distributed mode and integrated mode, depending on whether all routers in the path are ECN-Capable. We conduct extensive simulations to show that PET provides comparable performance as the standard TCP does over large bandwidth product networks and significantly improves the performance of 3G and beyond networks in the presence of burst errors.