Selective Dynamic Coded Cooperative Communications for Multi-Hop Underwater Acoustic Sensor Networks

Abstract

Due to the limitation of acoustic velocity in underwater environments, propagation delay is a horrible problem in multi-hop underwater acoustic sensor networks (UW-ASNs). In this paper, we proposed an improved scheme of dynamic coded cooperation called selective dynamic coded cooperation (S-DCC) for the multi-hop UW-ASNs, aiming at reducing the end-to-end delay and improving the transmission efficiency. In S-DCC scheme, the cooperative node actively transmits blocks with limited redundancy; yet the receiver only selectively receives those cooperative blocks depending on its own decoding conditions. The S-DCC scheme can utilize the retransmission mechanism adequately to eliminate the waiting time and drastically shorten the overall transmission time, the gain of which increases linearly with the number of hops. Concerning the transmission delay and energy consumption, we evaluated the performances with the different maximum number of retransmissions and different data burst sizes for the proposed S-DCC scheme and other compared schemes. The simulation results showed that the proposed S-DCC scheme could achieve decent outage performance and reduce the end-to-end delay effectively without extra energy consumption compared with other existing schemes, especially for the cases with low transmission signal to noise ratio. Sea test data were also adopted to further verify the conclusions. INDEX TERMS Energy consumption, multi-hop networks, end-to-end delay, underwater acoustic communications.

ACOA-AFSA Fusion Dynamic Coded Cooperation Routing for Different Scale Multi-Hop Underwater Acoustic Sensor Networks

“…Especially, for the cooperative strategy, we adopt DCC scheme, where there is no extra transmission time scheduled for the cooperative node, making it bandwidth efficient compared to conventional DF /AF cooperation scheme or conventional coded cooperation scheme [29]. The DCC scheme can significantly reduce the transmission delay in the multi-hop UWA-SN due to the cumulative effect of the saved time for the relay in each hop, as indicated in our previous work [30].…”

“…The narrow transmission bandwidth and high propagation delay in UWA-SN require that the protocol should be able to improve channel utilization, and the drifting of underwater nodes with ocean currents requires that the complexity of the routing protocol should be low. Dynamic coded cooperation (DCC) technology can improve the bandwidth utilization [20,30], and the routing protocol based on AI algorithm could be fast and robust. Motivated by [11], to simultaneously reduce energy consumption and effectively improve network robustness, we propose ACOA-AFSA fusion cooperative routing algorithm for multi-hop UWA-SN in this paper, which combines the ACOA-AFSA with cooperative strategy and considers the feasibility in different scale underwater acoustic networks.…”

PB-ACR: Node Payload Balanced Ant Colony Optimal Cooperative Routing for Multi-Hop Underwater Acoustic Sensor Networks

“…However, the underwater acoustic channel is one of the most complicated wireless communication channels. The inherent time-space-frequency variation, narrow bandwidth, high noise, multi-path, and long propagation delay make the performance of underwater acoustic communications difficult to satisfy the requirements of practical applications [4]. Adopting the dynamic coded cooperation (DCC) technique, the cooperative routing in multi-hop UASNs has been studied in [4] to achieve decent outage performance and reduce the end-to-end delay effectively without extra energy consumption.…”

“…The inherent time-space-frequency variation, narrow bandwidth, high noise, multi-path, and long propagation delay make the performance of underwater acoustic communications difficult to satisfy the requirements of practical applications [4]. Adopting the dynamic coded cooperation (DCC) technique, the cooperative routing in multi-hop UASNs has been studied in [4] to achieve decent outage performance and reduce the end-to-end delay effectively without extra energy consumption. Especially, the transmission and reception conflicts can be reduced with the DCC scheme, and the data transmission efficiency is also improved due to full utilization of idle time for the relay nodes.…”

“…The main contributions are as follows: 1) In the proposed PB-ACR protocol, the ant colony algorithm is combined with the DCC technique to solve the complex routing problem of multi-hop UASNs with both relay and cooperative nodes. This is a solution due to the scarcity of underwater frequency resources and the complexity of underwater acoustic channels in UASNs: on the one hand, due to high attenuation, multi-hop can significantly improve the frequency utilization; on the other hand, for the multipath fading (frequency selective fading) of underwater acoustic channels, the use of DCC technique (especially in combination with OFDM) can improve robustness [4,33]. The proposed protocol helps to give full play to the advantages of intelligent algorithms in solving such a complex routing optimization, and the advantages of DCC technique in improving robustness and frequency utilization of underwater acoustic channels for UASNs.…”