Adaptive Batch Coding: A Balanced Congestion Control Strategy for Multi-Beam Antenna Networks

Abstract

Multi-Beam Smart Antennas (MBSAs) achieve concurrent communications in multiple beams, thereby providing higher throughput compared to regular directional antennas. Most of the transport control schemes used today are based on TCP, which is too conservative since it indiscriminately reduces the window size upon any packet loss. The other extremity is the de-congestion control strategy, which abandons both window size control and retransmission, aggressively saturates the network, and compensates packet loss via network coding. To adapt to the features of the MBSA-based networks, this paper proposes a balanced transport control strategy between the above two categories, which is based on the idea of Adaptive Batch Coding (ABC) . The proposed ABC scheme resists random loss through redundant coding and copes with congestion via window shrink and retransmission. Using a cross-layer design (between transport and routing layer), both the coding scheme and the traffic allocation are adaptively adjusted according to network conditions. A customized simulation system has been developed to comprehensively evaluate the performance of the proposed ABC protocol. Experimental results show that the proposed scheme overcomes the drawbacks of those two extremities. It achieves both high throughput and high throughput (under packet loss) in MBSA-based networks.