A Transport Protocol to Exploit Multipath Diversity in Wireless Networks
A Transport Protocol to Exploit Multipath Diversity in Wireless Networks
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DOI：
10.1109/tnet.2011.2181979
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发表时间：
2012-08
期刊：
影响因子：
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通讯作者：
V. Sharma;K. Kar;K. K. Ramakrishnan-K.;S. Kalyanaraman
中科院分区：
文献类型：
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作者：
V. Sharma;K. Kar;K. K. Ramakrishnan-K.;S. Kalyanaraman
无线网络（包括无线网状网络）提供了使用多个路径的机会。主机的多宿主（可能使用不同的技术和提供商）也使端到端传输连接利用多条路径变得很有吸引力。在本文中，我们提出了一个多路径传输协议，基于精心制作的一套增强TCP，有效地利用异构，有损无线路径提供的可用带宽和多样性。我们的多路径LOSS-Tolerant（MPLOT）传输协议可用于在无线网络中获得显着的吞吐量增益，受到突发性，相关的损失，平均损失率高达50%。MPLOT是围绕端到端传输协议中的可靠性和拥塞控制功能的可分离性原则构建的。拥塞控制在各个路径上单独执行，并且可靠性机制在可用于端到端会话的路径的集合上工作。MPLOT通过显式拥塞通知（ECN）区分拥塞和链路丢失，并使用前向纠错（FEC）编码从数据丢失中恢复。MPLOT使用基于当前路径特征的动态数据包映射来为数据包选择路径。擦除码和块级恢复的使用确保了在MPLOT中，只要接收到块中必要数量的分组，接收传输实体就可以恢复所有数据，而不管丢失了哪些分组。我们提出了一个不同的设计选择的MPLOT的理论分析，并表明，MPLOT选择其政策和参数，使一个理想的权衡之间的吞吐量与数据恢复延迟。我们评估MPLOT，通过模拟，在各种测试场景下，并证明它有效地利用路径多样性，除了有效地聚合路径带宽，同时保持公平的传统TCP流在每条路径上。
Wireless networks (including wireless mesh networks) provide opportunities for using multiple paths. Multihoming of hosts, possibly using different technologies and providers, also makes it attractive for end-to-end transport connections to exploit multiple paths. In this paper, we propose a multipath transport protocol, based on a carefully crafted set of enhancements to TCP, that effectively utilizes the available bandwidth and diversity provided by heterogeneous, lossy wireless paths. Our Multi-Path LOss-Tolerant (MPLOT) transport protocol can be used to obtain significant goodput gains in wireless networks, subject to bursty, correlated losses with average loss rates as high as 50%. MPLOT is built around the principle of separability of reliability and congestion control functions in an end-to-end transport protocol. Congestion control is performed separately on individual paths, and the reliability mechanism works over the aggregate set of paths available for an end-to-end session. MPLOT distinguishes between congestion and link losses through Explicit Congestion Notification (ECN), and uses Forward Error Correction (FEC) coding to recover from data losses. MPLOT uses a dynamic packet mapping based on the current path characteristics to choose a path for a packet. Use of erasure codes and block-level recovery ensures that in MPLOT the receiving transport entity can recover all data as long as a necessary number of packets in the block are received, irrespective of which packets are lost. We present a theoretical analysis of the different design choices of MPLOT and show that MPLOT chooses its policies and parameters such that a desirable tradeoff between goodput with data recovery delay is attained. We evaluate MPLOT, through simulations, under a variety of test scenarios and demonstrate that it effectively exploits path diversity in addition to efficiently aggregating path bandwidths while remaining fair to a conventional TCP flow on each path.