1. Introduction

1.1 Team background

Our team consists of 5 students stemming from a wide range of disciplines, backgrounds and cultures.We have a space lawyer from France and four aerospace engineers from Italy, Sri Lanka and India, and focused on different thematics, ranging from telecommunications to computer sciences, from propulsion to system engineering.

1.2 Why Internet on the ocean?

Based on our expertise, we scanned all the challenges and established our choice considering 5 different criteria:

• the relevance of the topic;
• the compliance with our knowledge;
• the diversity of the applications that our solution could propose;
• the impact on the future;
• the usage optimization of data and available resources.

"Internet on the ocean" is apt with all these criteria, and it paved the way to several ideas. As a matter of fact, this challenge tackles multiple unsolved issues, stimulating the team to undertake it.

2. The problems

2.1 Rescue area

Planes losing control usually crash in the ocean, giving the ground stations not enough information on the exact regions they are located. Search and rescue vessels are sent to speculate the area to look for the missing aircraft, but if they cannot be promptly located, it could result in the death of its passengers. More or less 3000 people lost their lives from the 19th century till nowadays.

2.2 Heavy weather

There have been multiple cases of fishermen/sailors who lost their lives because of heavy weather, storms, lightning, tsunami, waves etc....

3. The solution

3.1 Wireless mesh network

Our solution for these issues consists in a wireless network based on already existing data buoys spread throughout the ocean. The latter represent the nodes of a mesh that works with a technology known as internet ad hoc. The fishermen/sailors are able to connect their phones/laptops to the nearest buoy, which connects to another one, and so on up to an Internet Service Provider based on ground. The internet service allows the users to forecast the weather and prevent eventual upcoming threats.

Moreover, thanks to a software defined radio mounted on the data buoys, each node (of the nodes) can collect the Automatic Dependent Surveillance - Broadcast (ADSB) signal transmitted by planes in radio band frequency. The received signal communicates flight data, such as current position, destination and flight number. Ultimately, our service guarantees a real-time monitoring of planes with each of the data buoys, providing an accurate tracking path. As a consequence, in the occurrence of a plane crash, we are able to estimate a precise area for the rescue vessels/planes to speculate.

3.2 How?

In order to get our system to operate, we provide three different products, which will be implemented on each data buoys.

• A COTS router, working as the node of our mesh network and providing the connectivity. The frequency exploited will be 2.4 GHz for network and 1090MHz (RX only) for ADS-B data.
• Mesh network is demonstrated using Espressif Systems ESP32-WROOM-32 development kit and range up to 32 Km with preliminary link budget is assured with 2.4Hz 15dBi Outdoor Omni-directional Antenna.
• A software defined radio connected to each router. This component is capable of acquiring the ADSB signal sent from the aircraft, providing the router of the plane data aforementioned.
• Another type of node is used to acquire Automatic Dependent Surveillance Broadcast messages from Aircrafts. The RTL-SDR based software defined radio tuned on 1090MHz with homebrew dipole antenna equipped on Raspberry-Pi Single Board computer [Fig 3.1] serves as miniature radar. Prime function of this unit is to receive ADS-B messages and broadcast them on mesh network.
• An ESP32 used as bridge between mesh and router connected to ISP.
• An antenna, increasing the range reached by the signal to 32 km.
• All the prototype codes are maintained on https://github.com/wi-sea.

Fig.3.1: The router and the software defined radio

All these components are Off-The-Shelf, hence nothing will be made in-house.

Fig.3.2: Wireless mesh network

4. Market and future

4.1 Business plan

We are aiming to cover at first the areas where the major number of planes' disappearances occurred. Based on the cost of the products per data buoy, maintenance and legal affairs, we are assuming that an initial capex of more or less 150,000 USD will be necessary. Taken into account this value and the number of fishermen and sailors cruising the mentioned areas, we will charge our service at an initial value of 10 USD/month per phone/laptop connected. As such, we will be able to cover the first expenditure in about 1 year.

4.2 Competitors

There are already available options to get internet on the ocean. But they are not easily accessible and reliable due to their higher costs and complexity. For instance, the cheapest internet service which is currently provided, costs 100 USD/month, much more than what we are offering.

4.2 Power

The data buoys are equipped with a solar panel providing more energy than required (we evaluated at least 3 W per data buoy).

4.3 Future plans

By the time our service achieve enough customers we intend to:

• Employ the Disruption Tolerant Network (DTN) introduced by NASA to enable a secure and guaranteed exchange of data with lower latency than conventional network.

• Augment the number of data buoys to increase the covered area of our network.

5. Challenges faced

Establishing a solution for the challenge Internet on the ocean means to tackle several issues that stimulated our interest but that proved the complexity of the matter. We decided to cope with this quest taking into account that a simple app that is the normal product of this competition would have not been sufficient. This challenge required plenty of brainstorming and endeavour to be solved.

From the engineering point of view, oceans are not smooth elements to deal with. The large distances and the disturbances generated by water resulted in a critical analysis of the link budget, and an accurate selection of the frequencies.

Furthermore, considered the low-cost requirement and the market competition already existing, this quest demanded an economic study, in order to provide a high quality service with the least expenditure.

6. Conclusion

6.1 Call-to-action

We are WiSea, an international team coming from different background who is aiming to enable a low-cost internet service by exploiting existing technologies and applying them to different scopes. As such, we guarantee a network that would allow predictions of weather threats and increase the accuracy in the location of rescue areas in case of plane crash.

6.2 Resources

2.4Hz 15dBi Outdoor Omni-directional Antenna, MODEL: TL-ANT2415D at: <https://static.tp-link.com/2018/201804/20180417/TL-ANT2415D(UN)2.0Datasheet.pdf>

Cardenas, Angelica & Pinto, Miguel & Pietrosemoli, Ermanno & Zennaro, Marco & Rainone, Marco & Manzoni, Pietro. (2019). A Low-Cost and Low-Power Messaging System Based on the LoRa Wireless Technology. Mobile Networks and Applications. 10.1007/s11036-019-01235-5.

J. E. Luzuriaga, M. Zennaro, J. C. Cano, C. Calafate and P. Manzoni, "A disruption tolerant architecture based on MQTT for IoT applications," 2017 14th IEEE Annual Consumer Communications & Networking Conference (CCNC), Las Vegas, NV, 2017, pp. 71-76.

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NASA, 2018. Disruption Tolerant Networking to Demonstrate Internet in Space [online] Available at:<https://www.nasa.gov/feature/goddard/2018/disruption-tolerant-networking-to-demonstrate-internet-in-space>[Accessed 18 Oct. 2019].

NASA, 2018. Disruption Tolerant Networking [online] Available at:<https://www.nasa.gov/content/dtn>[Accessed 20 Oct. 2019].

NOAA, 2019. National Data Buoy Center. [online] Available at:<https://www.ndbc.noaa.gov/> [Accessed 20 Oct. 2019].

R. Calvo-Palomino, F. Ricciato, B. Repas, D. Giustiniano and V. Lenders, "Nanosecond-Precision Time-of-Arrival Estimation for Aircraft Signals with Low-Cost SDR Receivers," 2018 17th ACM/IEEE International Conference on Information Processing in Sensor Networks (IPSN), Porto, 2018, pp. 272-277.

Shammas, J., 2015. Incredible images show underwater graveyard of World War Two planes at the bottom of Pacific Ocean - World News - Mirror Online. [online] Available at:<https://www.mirror.co.uk/news/world-news/incredibl...> [Accessed 19 Oct. 2019].

theOceans, 2019. Dangers. [online] Available at:<https://www.theoceans.net/expguide/dangers.shtml> [Accessed 20 Oct. 2019].

WiSea, When Water supports Air