# Seamless 5G Multi-Hop Connectivity Architecture and Trials for Maritime Applications
## 4 Trials in the Baltic Sea Corridor (Tallinn-Helsinki)
### Description of 5G-ROUTES Use Cases  
The 5G-ROUTES project will trial four different maritime use cases, which will focus on the quality and coverage of connectivity services at the sea. The corridor between Finland and Estonia is used for piloting and serves as example for other maritime environments. It offers a fruitful piloting environment, since it has a lot of vessel traffic and it provides a cross-border transport corridor, which also belongs to the TEN-T core network [34]. Use cases #1 and #2 will focus on passenger services. Use case #1 will include a sophisticated mobile game, which is built on augmented reality. In the game, users will share a collaborative gaming experience via their mobile phones, i.e., the devices will be connected to a game server deployed on MEC hosts close to the 5G core. The devices will continuously share their locations, orientation and interactions with other players. At the same time, the server will process the players' data in real time and respond back to the devices with information to compose the game scene. Use case #2 will focus on a virtual reality application, where the users will use a VR headset and a laptop connected to the 5G network to participate in an immersive meeting session onboard a ferry. In a different location, the presenter will be captured in front of a green screen and embedded in a virtual environment, which will be streamed to a multicast streaming server deployed in the core/edge. On the ferry, the audience will see the VR stream (4K/8K video data) and will be allowed to interact with the details in the immersive scene. This node will distribute the VR stream to the audience on the ship. The viewers will be able to point out details of the immersive scene and send voice messages back to the presenter. Use case #3 will focus on freight transportation and the continuous tracking of cargo. The aim is to drive a test vehicle inside the ferry and attach the vehicle's OBU and IoTsensors to the 5G network. While the ferry is moving, the connection between the IoT sensors, the OBU and the backend systems will be analyzed. Real-time kinematic (RTK) location data sent from a server in the shore and temperature data will be used as sample data to demonstrate the data flow between the devices and the backend systems. Massive machine-type communication (mMTC) will be piloted and tested under this use case. For these tests, an Android application has been developed, which runs on several mobile phones (at the time of writing, almost no smartphone allows attaching to 5G SA private networks. Smartphone vendors use whitelisting, allowing phones to attach to certain networks, usually from main network operators. Thus, the Android application will most likely have to run inside Windows BlueStacks Android emulator.) at the same time. Each of these devices will open and maintain thousands of TCP data streams and send status messages from the devices over each stream every 1 to 60 s. With this mMTC pilot, the aim is to demonstrate the use case where various devices and units are simultaneously and continuously connected to the same 5G base station. This could, for example, happen in ports, when freight vessels carrying containers and trailers are approaching the dock and where other freight vessels are waiting for their transportation. Use case #4 will focus on smart ferry applications. The main goal of this use case is to utilize IoT connectivity and equip the vessel with several IoT sensors. These sensors will report continuously about the vessel's situational awareness information, such as temperature, air quality, humidity, etc. Such data can be used to obtain a general overview of the conditions of the ferry or to monitor safety- and security-related issues, which are more critical to vessel operators and staff. It is different than use case #3, as it will consider the ferry itself as opposed to the goods and vehicles the ferry transports.