Rescue of passengers on ships is an urgent and at the same time complex problem. Finding people in an enclosed space with complex infrastructure takes a lot of effort. The solution to this problem is the creation of an on-board navigation system based on Bluetooth technology, as reference stations of which it is proposed to use the signal of Bluetooth beacons with the emission of a signal at a frequency of 2.4 GHz of vertical polarization. This article is devoted to the construction of a methodology for assessing the attenuation of a Bluetooth radio signal through ship's bulkheads. Existing techniques for assessing signal attenuation when passing through obstacles of various thicknesses and structures are considered. The distance between the transmitter and receiver of the signal and the angles of their relative position relative to the obstacle were taken into account. The paper analyzes the applicability and accuracy of various techniques, as well as compares the calculated results with practical measurements on board. The experiment showed the attenuation level of the signal from the Bluetooth beacons to the receiver. An analysis was made of the coincidence of the attenuation level of the experimental signal in comparison with that calculated by the method proposed in the article. In addition, it was shown that it is possible, using theoretical calculations, to estimate the expected level of signal attenuation depending on the properties and parameters of ship bulkheads, as well as to predict the location of the network of Bluetooth signal receivers on the ship and resolve the issue of the need to install additional Bluetooth beacons or its absence for stable operation of the on-board positioning system.
Passenger transport, evacuation, victim rescue, indoor navigation, Bluetooth, radio beacon, obstacles, radio transmission, signal propagation, radio signal attenuation
1. Kamenev M.S. Prakticheskiy eksperiment po ot rabotke snyatiya pervichnyh dannyh dlya sostavleniya radiokarty pomescheniya // Morskie issledovaniya na Dal'nem Vostoke: sbornik dokl. Vseros. konf. (Vladivostok, 14-15marta2019 g.). - Vladivostok, 2019.
2. Gavrilenko V. G., Yashnov V. A. Peredacha infor macii po besprovodnym setyam v usloviyah peresechennoy mestnosti,- N. Novgorod, 2007,-S. 112.
3. Rappaport T. S. Wireless Communications: Princi ples and Practice. IEEE press. 2001.
4. Rodd S. F., Math M.M. // J. of Computer Applica tions. 2009. Vol. 2. № 2. April - June. P. 24.
5. Bluetooth technology. URL: https://www.blue-tooth.com/(dataobrascheniya 11.08.2021)
6. Wang, Y.; Yang, X.; Zhao, Y.; Liu, Y.; Cuthbert, L. Bluetooth positioning using RSSI and triangulation methods. In Proceedings of the 2013 IEEE 10th Consumer Communications and Networking Conference (CCNC), Las Vegas, NV, USA, 11-14 January 2013; pp. 837-842.
7. Danis, F.S.; Cemgil, A.T. Model-based localization and tracking using bluetooth low-energy beacons. Sensors (Switzerland) 2017,17, 2484.
8. Roshan P., Lieri D. Osnovy postroeniya bespro vodnyh lokal'nyh setey standarta 802.11.- M., 2004,- S. 304.
9. Wu, T.; Xia,H.; Liu, S.; Qiao, Y. Probability-based indoor positioning algorithm usingbeaconssensors (Switzerland)2019, 19, 5226.
10. Canton Patema, V.; Calveras Auge, A.; Paradell-sAspas, J.; Perez Bullones, M.A.A Bluetooth Low-Energy Indoor Positioning System with Channel Diversity, Weighted Trilateration and KalmanFil-tering.Sensors (Basel) 2017,17, 2927.
11. Sivuhin D.V. Obschiy kurs fiziki: v 5 t. T. 4. Optika - M., 1980 - S. 418.
12. Rozum, S.; Sebesta, J. SIMO RSS measurement in Bluetooth low power indoor positioning system.In Proceedings of the 2018 28th International Conference Radio elektronika (RADIOEL- EKTRONIKA),Prague, Czech Republic, 19-20 April 2018; Volume 1401, pp. 1-5.
13. Berning P.H. // Fizika tonkih plenok: v 2 t. / podred. G. Hassa. -M., 1967. T. 1.-S. 91.
14. Bluetooth SIG, I.Mesh Networking Specifications. URL: https://www.bluetooth.com/specifications/mesh-specifications/(data obrascheniya 13.08.2021)
15. Zhuang, Y.; Yang, J.; Li, Y.; Qi, L.; El-Sheimy, N. Smartphone-based indoor localization with blue-toothlowenergy beacons. Sensors (Switzerland) 2016, 16, 596.
