Designing and testing of Bluetooth Low Energy (BLE) system for small wooden boat identification and e-certification

This paper presented the implementation of Bluetooth low energy (BLE) devices implanted on 7 small wooden boats. The BLE implantation is aimed at boat identification and certification. We use four parameters to measure the performance of BLE signal strength, e.g., solar panel usage (with/without solar panel usage), weather effect (sunny/rain), sea wave form (shallow/tidal waters), and distance. The specification of BLE and boat identification system is also presented. From the experiment, we found that BLE signal strength performance is impacted by four parameters including its combined parameters: (a) the highest hour of the detected signal is generated when the boats are connected to the solar panel; (b) the boats transmitting the signal in sunny weather; (c) the boats are in shallow water sea wave; (d) the boats are in sunny weather and connected to solar panel will have a detectable distance for up to 30 m compared to without solar panel connection, it will only have a detectable distance for up to 15 m. It is suggested for future recommendations to expand this study with the newest BLE version and better solar panel equipment to get higher signal strength performance.


Introduction
Wooden small boat in Indonesia is known as people's shipping (Pelayaran-Kapal-Rakyat) that has been widely used by most of the people near coastline. Pelayaran-Rakyat or also known as Pelra uses sailing boats including Pinisi, motorized sailing boats, and/or simple motorboats with Indonesian flags of certain sizes. People's shipping contains national cultural values which are not only found in the way of managing the business and its management, for example, regarding the working relationship between ship owners and ship crews but also in the type and shape of ships used.
Most of the boat is being used as a fishing boat and few of them are used for public transportation as a traditional passenger boat. They have been used since the time before the formation of the Indonesian state and became the main mode of transportation connecting island to island in Indonesia. It is undeniable that the presence of these boats is very helpful to run economic activities in the area.
Management of supervision and regulation of boats with a size of less than GT.7 had been conducted by local governments through regional transportation agency before it was given to central government in 2014 [1]. Each local government transportation agency had conducted initial measurement and safety inspection before the boat was commenced for operation. The certification is carried out after conducting a physical examination related to seaworthiness of the boat and then provides a certificate, which is valid for one year from the inspection.
Physical inspection of the ship includes the condition of the ship, the strength of construction and safety equipment for the seafarers and fishermen who are operating the boat. This is done to make sure that the boat meets the minimum safety requirement as well as for the safety of the boat crew. After the completion of boat building, the boat will be inspected for the first time as it is called initial inspection [2]. The boat then is certified when it is fulfilling the requirement.
Manual physical is complicated and takes time, therefore, it needs to simplify the physical inspection using technology. A good database system is needed to simplify the boat identification using certain digital scanning to the boat. However, the application of digital technology on these traditional boats become challenges for boat researchers. Large number of small boats without any identification have made this issue an urgent problem to be resolved. Therefore, in order to overcome the difficulties to identify the wooden boat, a new concept of electronic tagging using Bluetooth low energy (BLE) identification is proposed to be used on board of low freeboard small wooden boat. The idea of proposing Bluetooth low energy system (BLE) is mimicking the handphone or laptop identification system by implanting small chip with low energy for keeping the digital identification. Thus, implementing BLE into small wooden boat has high potential to be developed. This BLE-based system is important to be studied and analyzed considering the conditions of the boat.
As far as the author knows, that till now, until this paper is made, there is no result supporting that BLE has ever been used for small wooden boat identification. Therefore, this paper will be focused on the study of the implementation of BLE into the boat identification system. To do so, the parameters are also observed and tested in relation to the signal strength performance of the BLE devices for small boat identification system and its potential as a tool to support electronic certification system.

Research problem
The number of boats has never been identified properly due to locally record of registration and without technology information involvement. The possibility that a boat was registered by a different local office after sometimes has also existed. It could make duplication of boat identification. Once the boat "Pas Kecil" certificate expired not in the original port where it was registered, the possibility that this boat is re-registered in nearby port is huge. Instead of the boat has to go back to the origin port just to renew its certificate, most of the boat would be better re-record as an initial record in nearby port. That will make the possibility that the same boat has been recorded for several times.
Pas Kecil is a nationality certificate given for boat less than GT.7. According to the Ministerial decree no. PM 39 Year 2017 related to the Ship's Registration [3], boat of less than GT.7 need not to be registered. However, they need to be inspected and measured before recorded in national database.
In recent years, the government is decided to focus on taking care of these vessels. To improve their safety and make sure that they are all are recorded. The database of wooden boats gross tonnage of less than GT.7 is required to be established. Good database of these boats can be achieved only if boat identification and certification digital system are established well. Therefore one of the important issues is regarding the identification system, which is suitable to be implemented on small wooden boat such as fishing boat and traditional boat. It is also the policy of the government to enhance the system of certification and to cut off several difficult parts of the process that were taking a very long time in the process with high technology that may be implemented for these types of boats. Unfortunately the boat it is being implemented with the high technology is the most traditional boat that made with wooden material in traditional manufacturing way and there is no any engine or motor generator that can supply the power that most of electronic equipment would have definitely require it.

Research goal
The purpose of this study is to find out what parameters can be used to certify small wooden boats that have installed BLE devices through boat identification system. Then, another purpose of this study is to determine the parameters that influence the strength of the BLE signal on small wooden boats. Thus, it can be determined which boats need to be re-certified in terms of BLE signal strength. This means that boats with the lowest BLE signal performance need re-certification.
The methodology and criteria for selection of the boats for this study is given in section two. The development of model is given in section three with modification of BLE available and combined with solar panel system as energy source. The BLE parameter testing is presented in the 3 Theoretical review

Power from solar panel
According to Rahmatmand et al. [4] solar panels will generate electric power at an angle between 30° and 45° where the least favorable months are December and the month's strongest daily radiation in June and July. Pratama et al. [5] calculating the tendency of the sun angle which we use as the localization/placement of the solar panel on the top of the boat as below: Then the illumination which needed by solar panel resulted from the sunlight in ocean surface is Where IR is the density of the resulting Bluetooth wave calculated based on broad unity; A is the area of the solar panel; λ is the wavelength; E is the dimension of the photopic luminosity function of the human eye centered about 555 nm to obtain illuminance.
(1) = 23.45sin ((2 ) 284 + n 365 Solar panels should be provided to supply adequate power to the BLE system. The panel produces energy per unit of second called power. This power is formed from the irradiation of the sun with the symbol Wrated. Power from Wsolar solar radiation is usually lower than Wrated and the power scale can be harvested from ideal calculations that are linear with solar irradiation. In addition, the harvested power limit is calculated as Psolar = min (Prated WWrated solar; PSolar max). Solar panels should be provided to supply adequate power to the system. Panels are advertised using their rated power, which we showed by Prated. This power is only achieved capable of certain rated solar irradiation, Wrated. Actual Wsolar solar radiation is usually lower than Wrated and the actual harvestable power scale is roughly linear with solar irradiation. Thus, the harvestable power can be calculated as:

Selection of boats for this study
From about 20 boat owners that were willing to participate in this research, only 7 boats were eligible for BLE implantation with solar panels to be installed. The criteria for selecting boats for this study are given in Table 1

Components of Bluetooth Low Energy (BLE) in the boat identification system
BLE which used in this study has components of Sensor data, control of devices and low-bandwidth applications. It also has low power and low duty data cycles. In addition, its advantages is the operation of over 40 RF Channels and RF band (MHz) 2400 with Bit rate (kbps) 24,000 (HS) and modulation of FHSS (2 MHz channel width). One of the major advantages of Bluetooth low energy (BLE) is the compatibility the device with numerous commercial mobile phones, tablets and laptop computers [6]. The possibility that BLE can be used to constitute a universal remote control. This advantage may increase the demand to choose BLE instead of other model of identification system. This advantage is going to be applied for small boat identification. Considering that small boats berth normally gathering boat to boat and in large number of boats [7]. The implementation of BLE is similar like when a remote control is used to open and lock a car in parking area. However, this system is planned to be used different numbers of target at the same time with a single reader or controller. Each of target position and the correct information that can be crosschecked with the actual condition.
It is almost the same as classic type of Bluetooth, the BLE protocol stack consist of two major components, namely BLE Controller and BLE Host. These two things (Controller and Host) either reside on the same physical device or might be used by different device. The different from ordinary system of car remote control is that a car remote control only can recognize single host attached to the car. He controller in this system required to identify several number of boat with different unique ID in the same display where can identify individual position of each boat ID.
It requires several steps to make this system works. It requires a web based application and monitoring system and mobile application that a Marine Inspector should carry in large number crowd of boats where he/she can find the intended boat by this mobile application. In addition it can be apply for stakeholder who wants to monitor boat individual position.
The selected boats will be installed with BLE sensors as beacons. Then a trial of the beacon will be carried out with an additional power supply from a solar panel. In the next stage of the test, it will be tested on two observed condition: (a) beacon with solar panel; (b) beacon without solar panel [8]. Both testing aimed to measure the signal strength of the BLE device. Furthermore, external factors, especially from environmental factors, are also important. Considering the ship which is less than GT.7 as the smallest ship in existence, the ship has a very low freeboard so that it is very easily exposed to sea water. External factors such as weather conditions are one of the challenges that must be taken into account. Ocean waves higher than 2 m can get on the boat and damage all electronic equipment. With the goal of providing adequate BLE signal, the ship/boat needs power supply to run its electronic devices. Therefore, parameters such as weather and sea wave will also be measured for their impact on BLE signal strength. These results will be given in the experimental results section.

Small boat design without long mast and tent cover
This section is focusing on the small boat design that can be implanted with BLE devices and solar panel. The specification of the boat is also presented here. It is important to know all the boats has same type and specification as shown in figure below (Figs. 1 and 2).

Location of BLE Transmitting Identification device in the boat without mast and tent cover
The BLE Transmitting Identification device can be placed inside the boat as to the safest place from the weather destruction or damage due to normal operation. The boat of less than GT.7 normally equipped with outboard engine or sail for its movement. They have mainframe that it is called as keel. It will depend on which model of BLE to be used. The small BLE transmitting system can be place embedded to the keel of the boat. This BLE device will be put in the safest place inside the boat that less exposed by water. If the boat does not have any mast to mount solar cell, then it has to be decided to choose the safest place and have to consider the maximum sunlight that can be received (Fig. 3).

Placement (location) of solar panel device in the boat with mast and tent cover
The location of solar panel connected to BLE is also become our consideration. For the boat with long mast, the solar panel will be mounted on the top of the mast while the BLE transmitting device will be placed under the deck below the mast. Other alternative of placing BLE identification system is that when the boat equipped with mast and sail. The BLE transmitter or host to be placed on the mast together with the solar panel. They are sealed to make sure that there is no water ingress into the device. The box should be tightly secured as not to allow it to be fall or damage due to sea waves or strong wind. The illustration is shown in Fig. 4

Specification of solar panel
Solar panel used for generating power of Bluetooth Low Energy is a Polycrystalline high sensitivity cell 12 V 1.5 W with small size of 15 cm square area to produce high wattage. This BLE identification tags use 13000 mAh 4.2 V battery that is connected with Diode Bridge SEP RJ KBK SO8. Polycrystalline high sensitivity than ordinary Polysilicon solar cell. The solar panel used 4.2 V as to make sure that the battery will be charged fast and full.     The rechargeable battery will be charged by the solar panel so there are enough energy power for Bluetooth low energy to operate at all times wiConclusionthout the necessary of changing the battery (Fig. 5).

Specification of BLE device
In this modified system, the present battery type applied is 3-volt rechargeable battery that attached with 22 mm x 37 mm high sensitivity mono-crystalline solar cell. The solar panel that can produce 1 W per hour will give enough source of energy to be store the received energy in the rechargeable battery and consume dby BLE identification transmitting system for the remaining years until one of the parts get damaged due to wear and tear [9]. However, if the system other than the solar panel is placed in a sealed container and secure from any water ingression or direct sun-light, it is possible that the system will last long for a lifetime.
The solar panel will be mounted to the highest and safest place. It will be sealed but should still be able to receive direct sunlight to generate into power source. However, the system will have to use positive and negative cable wiring from solar panel on the top-mounted place to rechargeable battery down in the secure and safest place. If then somehow the wire is broken [10]. So there is no power input to the battery. In this case, the battery will still support the BLE transmitting identification system and because the consumption of the power of this Bluetooth is very low, the BLE will still transmit information for a year at least. Those models will still work even during night time without power generator. Actually, one year of operation without power generator is enough time for marine inspector or the owner to discover during boat at least annual maintenance if there is something wrong with the system such as broken wire.
The reader detector will read the BLE transmitter's remaining power and approximate distances. However, BLE signal is not stable and easy to get lost. The distance given is also not giving continuous information as shown in Fig. 10. The other problem is that when several BLE transmitting signal at the same time. The data can be read, but the exact direction is unknown. This requires further research and innovation to get better result.
The method it is made is by modifying available BLE on the market to be used as an identification device. However, another challenge regarding power supply is solved by using solar panel generating device and the battery to keep the BLE identification system keep working even in the dark time.
6 Specification of boat identification system

Boat identification application design
The development of boat identification system has four steps, e.g., development of web based application, web monitoring development, mobile application for Marine Inspector, and the mobile monitoring application for stakeholder.
Web based application will be made once the BLE identification system is successfully made. That will include the web monitoring development. There shall be a system of boat detection that can be monitored by mobile application by the Marine Inspector, the office where the Marine Inspector is based and the stake holder (boat owner, skipper) itself. However, for the time being, for the purpose of research a different person testing, the available in the online store, the universal program can be used (Fig. 6).
The boat identification consisted of three parts, Boat detection, application display layout with Bluetooth identification, and the boat profile as output. The system is intended to be used to make the identification of boat become more accurate and easy for the Marine Inspector and Tonnage Surveyor to check and to confirm that the boat is the boat previously inspected with present data. The mobile application will be made with the custom requirement and will be able to be used only by dedicated a. The boat is berthing or stay in boat lines and the inspector will scan the boat signal coming from BLE devices using BLE reader. b. The android app, which is in the hand of Marine Inspector, will scan the BLE signal and collecting its BLE ID implanted in the boat. c. The Marine Inspector will check in the list of numbers of boats signal transmission. After the boat is founded, the inspector will inspect physically by boarding to the boat. d. The result of inspection will be input to the boat including its BLE ID. The system will send the information to the server and update the information. In the future, if the inspectors are different person, they could read the latest updated information from the server. The information could also become the proof for issuing Electronic Pas Kecil [11] certificate.

Role of actors/stakeholders in boat certification
Boat Owner, as the owner of the boat of less than GT.7, is the person who will apply for the inspection and measurement of the boat. The result of this initial inspection will be the process of recording and issuing electronic pass kecil and the boat will be attached with BLE identification system. The boat owner will have to submit the application and provide required documents such as boat builder certificate, owner identification and a proof letter showing that the boat is truly owned by her/him. The illustration is shown in Fig. 7. Admin is the system operator who is conducting inventorying of BLE data. The admin will have to collect any information prepared by the Marine Inspector and Tonnage Surveyor regarding the boat they are visiting. However, the decision to issue certificate of electronic pass kecil is not under his/her authority (Fig. 8).
Super Administrator is the person or unit in charge of overall performance system monitoring. He/she is the one holding the source code of the system. Any change in the system structure will have to get permission from Super Administration.
Marine Inspector or Pejabat Pemeriksa Keselamatan Kapal, (Ship Safety Inspector Official) is a government official who is a state civil apparatus within the Directorate General who has qualifications and expertise in the field of ship safety and is appointed by the Minister [12]. His/ her role is to input its inspection report record for each boat inspected.
Tonnage Surveyor or Ahli Ukur Kapal, is a government official who is a state civil apparatus within the Directorate General who has qualifications and expertise in the field of ship tonnage measurement and is appointed by the Minister. [6] His/her role is to input its measurement report record for each boat measured.   where all policy, instruction, procedures and guidance of issuing safety inspection data [14].
Director of Shipping and Marine Safety, Is the head of department and responsible for successful the implementation of shipping and marine safety policy [14]. The director must get adequate information from the system Operator since the system operator who administers the BLE identification system.
BLE identification system shall be the operator who uses the tools that can be easy, which is a Marine Inspector. The Marine Inspector is required to install a web application where he/she can read BLE information transmitted by the host. Marine Inspector does not need to search manually the intended boat among large numbers of wooden fishing boats or traditional boat. Marine Inspector could confirm the presence of the boat before he/she boarded the boat. They will know in an earlier time if the skipper had replaced the boat without informing the inspector.

Effect of solar panel (sunlight power) on BLE signal strength
From Fig. 9, it can be seen that the highest hour of detected signal is generated when the boats are connected to the solar panel. Compared to without solar panels, it appears that the BLE signal strength decreased sharply by half so that boats without solar panels were only detected in a very short hour. For example, boat1 when connected to the solar panel will be detected for up to 30 h. Whereas, when the solar panel is removed, the boat was only detected for up to 15 h.

Effect of sunny/rain weather on BLE signal
There are two types of sea waves which must be considered by fishermen sailing with small boats, e.g., capillary wave and wind wave. Capillary waves located near the The effect of signal during sunny weather and signal during rainy weather is also revealed in this study, the results of which are shown in Fig. 10.
From the picture it can be seen that the highest hour of detected signal is generated when the boats are in sunny weather. Compared to sunny weather, when the boats are in rain weather, it appears that the BLE signal strength drops sharply to one-third. For example, for boat1 when the weather is sunny it will have a detectable signal for up to 28 h, while in rain weather it will only be detected for up to 7 h.

Effect of sea wave on BLE signal
The signal in the shallow waters area to the signal in the tidal waters area is also compared. The signal is stronger when the waves are smaller and on the other hand shallow water has calm wave characteristics so that it stabilizes BLE signal strength, while tidal waters cause boats to sway so that the signal transmitted is not optimal.
From Fig. 11, it can be seen that the highest hour of detected signal is generated when the boats are in shallow water sea wave. Compared to shallow water sea wave, when the boats are in tidal water sea wave, it appears that the BLE signal strength drops slightly. For example, boat1 in shallow water has a detectable signal for up to 25 h, while in tidal water it will only be detected for up to 20 h. This means that the seawaves only have a small impact on the reduction of BLE signal strength.

Effect of distance on BLE signal
Measuring the effect of distance on signal strength is also our concern. We want to test the impact of distance on the signal strength of the tested boats. To do so, we implemented two steps. Firstly, we tested the BLE connected to solar panels and BLE without solar panels. In this case, the solar panels have batteries that strengthen BLE. Without solar panels, BLE has very little power so the distance range is also small which impacts the hour of detected boats.
From Fig. 12, it can be seen that the highest hour of detected signal is generated when the boats are in sunny weather. Compared to sunny weather, when the boats are in rain weather, it appears that the BLE signal strength drops sharply to a half. For example, for boat1 when boat connected to solar panel, it will have a detectable distance for up to 30 m compared to without solar panel connection, it will only have a detectable distance for up to 15 m.

Discussion
BLE-based boat identification system can be effectively used for ship identification and ship certification. Here, to explore the mechanisms that lead to the identification of ships, especially ships with increasingly weak BLE signals, and thus for small vessel systems, we conducted checks on BLE signals generated by seven boats and assessed the  In addition, the signal strength status on each ship tends to be irregular into various sizes and subtype parameters. This prompted this research to emerge. In recent years, the merging of computer technology and BLE with Bluetooth signal monitoring techniques has advanced our knowledge of signal performance manipulation. By observing parameters such as the highest hour of the detected signal, transmitting the signal in sunny weather, shallow water sea wave condition, and sunny weather condition in combination with solar panel, all have proven that BLE can be used for the identification of small ships and our methods can be judged to have been successful in responding to the need for the application of BLE for identification of small vessels. Solar panel analysis used for generating power of Bluetooth Low Energy is done under different parameters. With the development of finite element techniques, BLE identification studies on various environmental circumstances have been conducted.
Other researchers Park et al. [15] It established a limited boat identification development model for ships to analyze ship movements, signal changes and solar panel impacts under complex conditions. The results showed that solar panel is placed in sealed container and secure from any water ingression or direct sun-light, it is possible that the system will last long for a lifetime.
The solar panel is able to receive direct sunlight can generate optimal power source which can be increased by increasing solar panel capacity. BLE signal strength can increase by adding solar panels that are concentrated on the rear side, and increase according to the distance traveled by ship.
Another researcher Lee et al. [16] find that the specification of boat identification system is determined by identification application design. This is because the system of boat detection must be monitored by the Marine Inspector and the office where the Marine Inspector must notify the boat owner and skipper. Lee et al. [16] established a boat identification application design model. The results showed that the system could be used to make the identification of boats become more accurate and easy for the Marine Inspector and Tonnage Surveyor. They can check and confirm that the boat is the boat previously inspected with present data. The mobile application was useful since the system can simplify three tasks, e.g., boat detection, application display layout with Bluetooth identification, and the boat profile as output.
Eich et al. [17] established from the role model of actors/ stakeholders in boat certification. The boat owner will have to submit the application and provide required documents such as boat builder certificate, owner identification and a proof letter showing that the only boat owner can use the ships. Such BLE identification system helps the Marine Inspector to use web application and can read BLE information transmitted by the boats.
Other researchers built boat identification models with different parameters according to field conditions. The results showed that parameter testing results improved with the increase in solar panel power, and that the increase in signal performance was more pronounced when the ship was connected to the solar panel.
In recent years, with the wide application of ship identification techniques, there have been efforts to use solar panel parameters combined with sunny/rain weather on BLE signals. There have been limited efforts to build models to study environmental effects on the strength of BLE signals. It has revealed the punctuality and power of signal manipulation.
To provide a theoretical and experimental basis for BLE signal optimization, other researchers Themeßl et al. [18] analyzing the effect of signal during sunny weather and signal during rainy weather. The results showed that signal during rainy weather requires wave displacement on the detectable side of the signal that can last up to 28 h, while in rainy weather it will only be detected for up to 7 h.
The greatest strength of the effect of sea wave on BLE signal is mainly concentrated in the signal in the shallow waters area. Signal distribution is focused on the shallow water sea wave side. The results reveal signal strength performance and the highest hour of detected signal is generated when the boats are in shallow water sea wave. This BLE model shows that signal strength is associated Fig. 12 Experimental result of BLE signal strength with distance parameter a red line indicated BLE signal strength will be higher if the boat is equipped with solar panel to achieve more far distance; b brown line indicated BLE signal strength without any solar panel resulting short distance hours of detection with changes in environmental structure such as weather from the corresponding area of experimental result of BLE signal strength with sea wave parameters.
Tregoning et al. [19] measuring the effect of distance on signal strength. The impact of distance on the signal strength is also tested. The BLE connected to solar panels and BLE without solar panels are used to analyze the effect of parameters on ship signals in different positions. Moving ships tend to have lower signals than ships anchored on the coast. The environmental effects and weather and sea wave pressures are also controlled because it is more effective at detecting ship signals. Experimental result of BLE signal strength with distance parameters requires further study to determine the optimal position of the ship.

Conclusions
From Figs. 6, 7 and 8 it can be seen that the boats that have the lowest BLE signal are boats 5 and 7, so it is necessary to check the signal strength of the two boats. Especially in terms of installing BLE devices and solar instrument panels.
The use of electronic devices on board of small wooden traditional boat is a successful designed and implemented in this study. BLE devices has been implanted into boat identification system. However, tools of identification proposed here is an electronic device that requires modification of the application.
The use of Bluetooth Low Energy will be the way in which to identify the boat can be achieved more accurately. The accuracy of boat identification will give benefited during issuing electronic certificates. International Maritime Organization under FAL.5/Circ.39/Rev.2, 2016, IMO Guidelines For The Use of Electronic Certificates has made several requirements for issuing electronic certificates.
Four parameters have been identified on measuring the BLE signal strength, e.g., why the boats are connected to the solar panel, the boats transmitting the signal in sunny weather, the boats are in shallow water sea wave, and the boats are in sunny weather and connected to a solar panel.
The distance of transmitting data from BLE and the size of the BLE, which is not small, enough to embed it into the main frame of the boat is another challenge to be studied further. The lack of good resources including blogs, tutorials, and up-to-date books that help a beginner to learn BLE makes the task even more difficult. However, the possibility for wooden traditional boat that in fact is the most traditional ship to have an advanced technology applied is one of a good progress. The BLE identification system will not be only benefited for identification that assists Marine Inspector and Tonnage Surveyor to identify the boat prior to inspection but further can be used for safety navigation once the distance of transmitting can be made to a longer distance. However, further research and innovation are required to get better result of BLE signal strength performance.
Funding The authors have not disclosed any funding.

Conflict of interest
The authors have not disclosed any competing interests.
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