Reliable ELN to enhance throughput of TCP over wireless links via TCP header checksum

In wireless mobile networks, loss of packets is mostly because of corruption of data on the wireless link. TCP responds to these losses as if they are due to congestion, and this results in poor throughput. We suggest enhancements to TCP that, if implemented, will help the receiver in separately identifying corruption losses and congestion losses. Based on this information, the receiver will generate Explicit Loss Notification (ELN) for the sender. We derive an expression for the probability of a receiver generating successful ELN, assuming a generic link layer protocol that is used for data transfer over wireless links. We also suggest modifications to the sender behavior on receiving successful ELN from the receiver. We compare the proposed scheme (called "NewRenoEln") and the standard "NewReno" TCP via simulation, and find considerable improvement in data throughput over wireless links.