Hop-by-hop reliable transmission control method for underwater wireless sensor network

Abstract

The invention discloses a hop-by-hop reliable transmission control method for an underwater wireless sensor network. Based on a digital fountain code technology irrelevant to a code rate, optimized degree distribution and recursive coding ideas are adopted, and an RLT (recursive LT) coding scheme is designed, so that rapid and efficient coding and decoding are realized; packet collision and end-to-end delay are reduced; and the network throughput is increased. Through collection of feedback information of a receiving node, the packet corruption probability of an underwater acoustic channel is accurately estimated, and the coding packet quantity of next transmission is further computed, so that the transmission overhead of extra packets is reduced. The fourth-layer reliable transmission mechanism and the second-layer medium access control mechanism of a conventional TCP / IP (Transmission Control Protocol / Internet Protocol) protocol stack are organically fused, so that block-by-block and hop-by-hop reliable transmission of the underwater wireless sensor network is realized on the basis of RLT coding, and transmission-reception conflicts, multi-transmission-single-reception conflicts and data-ACK conflicts caused by simplex communication of an underwater Modem are reduced. As an effective and practicable technical scheme, the method has a good application prospect.

Description

technical field [0001] The present invention generally relates to the technical field of network communication, and more specifically relates to a reliable transmission mechanism of an underwater sensor network. Background technique [0002] UWSN Underwater Wireless Sensor Networks (UWSN Underwater Wireless Sensor Networks) has broad application prospects in environmental monitoring, resource exploration, disaster prevention, etc., and has gradually become the focus and research focus of governments, national defense, industry and academia around the world. UWSN uses acoustic wave communication, and the bit error rate of the underwater acoustic channel is high, usually at 10 -3 -10 -7 Between ranges; underwater acoustic communication has a long propagation delay, and its delay is close to the second level; the bandwidth is narrow, usually on the order of tens of kbps; compared with traditional Modem, acoustic Modem consumes more energy, and underwater nodes usually With ba...

AI Technical Summary

Problems solved by technology

[0003] 1) The high bit error rate of the underwater acoustic channel leads to a large packet error rate during hop-by-hop transmission, making the probability of successful end-to-end packet transmission close to zero

Therefore, the traditional, end-to-end reliable transmission mechanism will lead to too many retransmissions in the UWSN network, which will bring too much energy consumption, aggravate the low-bandwidth underwater acoustic network load and packet conflicts, and reduce channel utilization.

[0004] 2) The low propagation speed of the underwater acoustic signal leads to a large end-to-end delay, which brings a big problem to the real-time control of the traditional end-to-end reliable transmission mechanism

[0005] 3) The long delay and low bit rate of the underwater sensor network lead to the extremely low channel utilization of the traditional simple stop and wait ARQ mechanism in UWSN; the underwater acoustic Modem uses half-duplex communication, which limits the use of efficient traditional pipelined ARQ protocols

However, LT codes are designed for block-by-block transmission with a large number of data packets, and are not suitable for underwater sensor networks where the transmission time between nodes is very limited due to node movement, and there are many large degree nodes, which increases the encoding and decoding overhead and communication overhead

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