Improving TCP throughput for multi-hop wireless networks using multiple antennas
M. Park, Scott Nettles · 2006
We address the problems of TCP over multi-hop networks by designing a MAC protocol jointly with multiple antennas in the physical layer to mitigate fading and interference from neighboring nodes. We propose a protocol, TCP enhanced MIMA/AS-MAC (Mitigating Interference using Multiple Antennas with Antenna Selection diversity MAC), which improves the efficiency of small packet transmission of our previous design, MIMA/AS-MAC, by concatenating a small packet with a large packet. We evaluate the performance of the proposed system by measuring TCP throughput. The proposed system outperforms the MIMA/AS-MAC system by compactly packing small and large packets into a fixed-size MAC frame and also outperforms the 802.11 system with Alamouti encoding by mitigating interference from neighboring nodes. I. INTRODUCTION Although TCP is extremely successful in wired networks, it suffers from significant performance degradation in wireless networks. The reason is that key assumptions made by TCP no longer hold for networks because links are unreliable and thus packets are dropped not only due to congestion but also due to fading and interference during transmission. Although a number of solutions have been proposed to address the problem of TCP over (1), (2), these approaches do not eliminate the sources of the problem: fading and interference.