Figure - available from: International Journal of Communication Systems
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(A) Representation of hyperbolas of horizontal line shaped network. (B) Analytical CCF of horizontal line shaped network
Source publication
This paper proposes a novel estimation technique for dimensionality of deployed underwater sensor network (UWSN). In order to obtain the dimension, probing requests are sent from two anchor nodes (i.e., receivers), which are placed inside the network through buoy, to sensor nodes. Then, the sensor nodes transmit Gaussian signal as feedback to the a...
Citations
... So far, three estimation schemes are investigated using CC. They are: two-sensor scheme [25]- [28], three sensor schemes with SL (sensors in line) approach [29] and TS (triangular sensors) approach [30]. System models of these estimation schemes are shown in Fig. 1, where N nodes are uniformly distributed across 3D spherical regions in underwater but sensor arrangements are different for each cases. ...
... To tackle the problem of protocol complexity in estimating underwater network size, Anower et al.[25]-[28] and Chowdhury et al.[29],[30] propose a new CC-based scheme utilizing two and three probing nodes (sensors), respectively. These schemes employ astraightforward probing protocol and are unaffected by the capture effect. ...
The limited bandwidth (BW) of undersea communication presents a significant challenge to the node counting technique based on cross-correlation (CC), which traditionally use Gaussian signals with infinite BW. To address this, a band-limited Gaussian signal is employed for counting nodes, impacting the cross-correlation function (CCF) and the derived estimation parameters. To correlate the estimation parameters for finite and infinite BW scenarios, a scaling factor (SF) is determined for a specific BW by averaging their ratios across different node counts. Efficient estimation in a band-limited condition is feasible if the SF for that BW is known. Previous investigations have been limited to 5 kHz and 10 kHz BW. Given the typical undersea BW range of 1–15 kHz, it is important to establish a relationship between the SF and BW. This relationship, derived and validated through simulation in this study, allows for determining the SF and achieving accurate node count under any band-limited condition within the 1–15 kHz range.
Underwater node coverage is the basis of various applications in underwater wireless sensor network (UWSN). It is easy to cause the coordinates of underwater nodes drift affected by water flow action. Some sparsely deployed underwater nodes may form coverage holes, which makes it impossible to locate underwater targets effectively. Combined the water flow situation, this paper proposes an improved brain storm optimization integrated with virtual force algorithm (IBSO-VFA) for improving UWSN coverage performance. After analyzing the water jet model integrated with the resultant force along Z axis, the velocity components of east, north and depth directions can be derived, which can reveal the coordinate evolution model of drifted underwater nodes under water flow action. Underwater nodes present non-uniform distribution of partly sparse and partly dense coverage, even with a lot of coverage holes. Inspired by the virtual force algorithm, the drifted underwater nodes are driven to their relative communicable positions. Meanwhile, the brain storm optimization has been improved and applied to avoid falling into local coverage optimum by pure VFA. Based on the node maximum coverage, the dual mapping of signal domain and localizability domain is established in consideration of ranging and coordinate errors. Finally, a comprehensive performance test is conducted to evaluate IBSO-VFA performance in terms of coverage rates, k-coverage and localizability area. The results indicate that the IBSO-VFA can maximize the UWSN coverage and localizability performance. The proposed IBSO-VFA can provide a close-to-practical coverage model for drifted underwater nodes, and can provide a theoretical basis for ocean information perception in UWSN.
