Low-energy-consumption high-throughput underwater sound break-tolerant and delay-tolerant communication network protocol stack

Abstract

An underwater acoustic communication network protocol stack is designed and realized according to characteristics of an underwater network environment, and a distributed multi-hop peer-to-peer topological structure is adopted as a deployment mode of underwater nodes for a set of communication rules among all devices in an underwater acoustic communication network; aiming at the problems of long delay and easy interruption of underwater acoustic communication, the invention provides an underwater acoustic communication network protocol stack with break-tolerant and delay-tolerant capabilities, so as to ensure as low energy consumption as possible and higher network throughput rate under network delay; the coverage layer adopts a storage-carrying-forwarding working mode, proposes a divergence waiting protocol CDK-SQ based on contact probability according to the difference of historical contact information of underwater nodes in allusion to the problem of unstable underwater end-to-end link data transmission, proposes a CDK-SQ-TG routing protocol in combination with an active feedback mode and a deletion strategy in allusion to the problem of CDK-SQ network congestion, and carries out routing on the underwater end-to-end link. The feasibility and the performance effect of the CDK-SQ-TG are verified from the three aspects of delivery rate, average delay and overhead rate, and the method has huge practical significance and wide application prospects.

Description

technical field [0001] The present application relates to an underwater acoustic tolerant, fault-tolerant and delay-tolerant communication network protocol stack, in particular to a low-energy-consumption and high-throughput underwater acoustic tolerant, fault-tolerant, and latency-tolerant communication network protocol stack, which belongs to the technical field of underwater underwater acoustic communication network protocol stacks. Background technique [0002] Effectively improving the ability of marine resource exploration, marine environment monitoring and protection, and marine disaster early warning is an inevitable requirement for the sustainable development of the marine economy in the future. The capability of marine environment observation directly affects the success or failure of marine resource utilization and marine environmental protection. [0003] There are two problems in the existing ocean profiler observation system: first, the working mode of the prof...

AI Technical Summary

Problems solved by technology

[0003] There are two problems in the existing ocean profiler observation system: one is that the working mode of the profiler adopts single-point observation, and the observation data is directly transmitted to the control center through cables or radios. Poor performance and expandability; Second, there is no information interaction between profilers, which makes it impossible to perform high-resolution, three-dimensional observations in a certain area of ​​the ocean

[0005] First, the delay is high and variable: the end-to-end delay is composed of a single-hop delay, and the single-hop delay is composed of propagation delay, transmission delay, processing delay and queuing delay. As a communication medium, sonar obviously brings additional propagation delay

[0006] Second, the uplink and downlink rates are asymmetric: the limited network environment cannot be predicted, the uplink and downlink rates are determined by the specific environment, and the propagation speed of sonar will be affected by the temperature and pressure of seawater

[0008] Fourth, low signal-to-noise ratio and high bit error rate: There are signal attenuation and noise interference phenomena in the restricted network, which makes the sink unable to correctly analyze the data, channel attenuation, multipath interference, Doppler effect and other phenomena in the underwater acoustic communication network Both cause problems of low signal-to-noise ratio and high bit error rate

[0009] Fifth, limited resources: resources mainly include memory, energy, and bandwidth. Due to process limitations, the memory space and energy of nodes are limited, and the available bandwidth of underwater acoustic waves is limited. There are only 5KHz in long-distance transmission systems exceeding ten kilometers. bandwidth

[0012] First, there are two main aspects in the construction of the underwater acoustic communication network on the seabed at this stage: one is that the observation node collects data independently and transmits it directly to the control center through cables or radios. The mobility of such working methods and poor scalability; second, there is no information interaction between the observation nodes, and they cannot work together. In view of the problems existing in the existing technology, there is a demand for real-time high-resolution continuous three-dimensional ocean observation technology, so there is an urgent need to use marine environment observation As a background, the network protocol part of the underwater acoustic communication network system in ocean observation technology is designed and implemented;

[0013] Second, the existing underwater acoustic communication network cannot meet the assumptions of the TCP / IP protocol family. First, the delay is high and variable. Compared with the radio on land as a communication medium, sonar as a communication medium obviously brings additional transmission. Time delay; the second is the asymmetry of uplink and downlink rates, and the propagation speed of sonar will be affected by the temperature and pressure of sea water; the third is intermittent connection, which is caused by factors such as node movement or node energy exhaustion, and underwater acoustics The communication network saves energy consumption through the way of node dormancy, which prolongs the life of the network; the fourth is the low signal-to-noise ratio and high bit error rate, channel attenuation, multipath interference, Doppler effect and other phenomena in the underwater acoustic communication network Both will cause problems of low signal-to-noise ratio and high bit error rate; fifth, resources are limited, limited by the process, the memory space and energy of the node are limited, and the available bandwidth of underwater acoustic waves is limited. In the long-distance transmission system exceeding ten kilometers There is only a bandwidth of 5KHz, which leads to the particularity of the underwater acoustic communication network protocol, and there is no corresponding solution in the existing technology;

[0014] Third, limited by the technology level, the energy of underwater nodes is limited. In addition, the underwater acoustic communication has a long delay and is easy to be interrupted. The existing technology underwater communication has weak tolerance to interruption and delay. The underwater acoustic communication network is a typical restricted network. Using a fault-tolerant and delay-tolerant network protocol system, in a traditional wireless sensor network, communication requires at least one stable connection between the source and the sink.

In the underwater environment, the network topology changes dynamically, the nodes are sparsely distributed, the transmission rate of the acoustic wave is limited, and it is impossible to build a stable end-to-end connection with each other, which brings great challenges to the design of underwater acoustic-capacity-delay-tolerant network routing protocols. great challenge;

[0015] Fourth, the nodes in the underwater acoustic-delay-tolerant network are sparsely distributed, and the link stability cannot be guaranteed. In order to improve the message delivery rate, a multi-copy routing mechanism is usually used. However, the energy of underwater nodes Compared with the relatively limited memory, the multi-copy routing mechanism will inevitably bring additional network overhead, thereby increasing memory usage and energy consumption

When the memory space is insufficient, the node will enter the congestion state, affecting the normal delivery of the message; it is relatively difficult to build an end-to-end continuous and stable link in the underwater acoustic fault tolerance network, the main reason is the high delay of the underwater acoustic link Moreover, the transmission rate is easily affected by the external environment. The underwater node cannot obtain the congestion status of its communication node in real time and perform corresponding actions. The congestion problem is relatively severe; the divergent waiting protocol based on the contact probability overcomes the blindness of the divergent waiting protocol. But at the same time, it also caused two problems. On the one hand, the node with a relatively high contact probability has a relatively heavy resource burden. It may receive a large number of copies in a short period of time and cause network congestion; on the other hand, it has been successfully delivered. The redundant copy of the message cannot be deleted in time, which leads to network congestion, and lacks a reasonable congestion control mechanism to ensure the performance of the CDK-SQ routing protocol;

Images