Improving TCP/IP Performance over Third-Generation Wireless Networks

摘要

As third generation (3G) wireless networks with high data rate get widely deployed, optimizing TCP performance over these networks would have a broad and significant impact on data application performance. One of the biggest challenges in optimizing TCP performance over the 3G wireless networks is adapting to the significant delay and rate variations over the wireless channel. In this paper, we make two main contributions. First, we present a Window Regulator algorithm that uses the receiver window field in the acknowledgment packets to convey the instantaneous wireless channel conditions to the TCP source and an ack buffer to absorb the channel variations, thereby maximizing long-lived TCP performance. It improves the performance of TCP Sack by up to 100% over a simple drop-tail policy with small buffer sizes at the congested router. Second, we present a wireless channel and TCP-aware scheduling and buffer sharing algorithm that reduces the latency of short TCP flows while still exploiting user diversity for a wide range of user channel conditions.