The fire in station use case is to describe an emergency situation and managing the situation in context of railway smart station. Through this use case work, technical keywords are deduced and numbers of potential requirements are come from the keywords.

Fire detectors are 3GPP UEs. The passengers have their own 3GPP UEs as their smart phone. There is a fire situation in somewhere of a railway smart station. A fire detector senses the situation and report to railway smart station system via 3GPP network. Some passengers also recognize and register the situation to the station system via railway smart station app in their 3GPP UEs and some of them notify it to the fire fighting force and/or police.

1. The Railway Smart Station System indicates the fire situation from the fire detector. While the fire is getting bigger and bigger, the number of fire detectors providing sensing information is also increasing. The system indicates the location and directions of the fire spreading by analysing the information from the detectors.
2. The Railway Smart Station System starts a fire emergency protocol. It declares the situation to the near firehouses and police stations, and provides the station information via a specific interface that is not in scope of 3GPP, e.g. the station map. It finds available devices in the station and controls the devices to handle the situation. For example, the system controls fire sprinklers to start supress the fire efficiently. An evacuation warning and emergency exit information are announced to people in the station via the audio broadcasting devices. Emergency messages are sent to the people as well. The system controls emergency lamps and direction lights to give guidance information for evacuating the people.
3. The system notices the situation to the neighbour stations and the incoming trains. The trains make emergency stop at a safe place and evacuate their passengers. The system sends emergency protocol information to the railway workers in the station depends on their group roles in the protocol.
4. The system video-streams the fire site using a camera near the fire place. The people in the station could watch the streaming and get the information of the fire site, e.g. location and range of the site.
5. The system gets UEs information and sets up roles to UEs of the workers, firefighters and police officers, and downloads information on the UEs to support the role via interfacing the systems of the fire department and the police. The role is changed dynamically depends on the status of duty of the workers, firefighters and officers.
6. The system and the UEs of the people get cooperation to count the number of people in the station. The people is included in the rescue group autonomously.

The devices in the station are monitored and controlled by the Railway Smart Station System. The railway workers, firefighters, police officers are on their duty using their UEs. The people in the station and the incoming train, escape the station and move to the safe place by using their UEs which are interfaced by the system.

The role and group management are fully covered by 3GPP system and MCX framework.

[PR-5.1.6-1] [PR-5.1.6-2] [PR-5.1.6-3] [PR-5.1.6-4]

It is needed to reduce train intervals to increase the track capacity. If the train intervals are less than some threshold, multiple trains should stop at the same platform. This is because we can reduce the interval between trains, but for safety reasons, reducing the time for passengers to get on and off and increasing the speed of trains entering the station is limited. In general, it takes more than 1 minute for the train to enter and exit the platform, including the time for passengers to get on and off, so if the train interval becomes shorter than 1 minute, there could be two trains on the platform. The scenario when two trains stop at the same platform is as follows:

• The passenger information system (PIS) of a smart station displays that Train 1 will stop in front of the platform, and Train 2 will stop at the back of the platform. Train 1 & 2 may have different routes.
• Step 1: A previous train is departing the platform, and Train 1 enters the platform while a part of the previous train is still at the platform. According to the previous train's location, Train 1 slows down its speed and goes in front of the platform.
• Step 2: After the previous train left the platform, Train 1 stops in front of the platform.
• Step 3: While Train 1 is stopping for passengers to get on and off, Train 2 enters the platform
• Step 4: Train 2 stops behind Train 1 and opens its doors. While the passengers of Train 2 are getting on and off, Train 1 start to depart the platform.

• Each train has at least one onboard UE (i.e., FRMCS UE), supporting both on-network and off-network communications.
• There is an edge server per station and the edge server can determine which platform trains stop and transmit/receive data to onboard UEs of Trains 1&2 through the 3GPP network.
• Each edge server can transmit/receive information to the PIS.
• Onboard UEs know the identities of the edge server on the train route.

1. Train 1 is stopping at Platform A of the smart station, and Train 2 is approaching. Trains 1 & 2 are connected and authorized to transmit/receive information to the server at the smart station.
2. The server determines that Train 2 stops at Platform A. The server informs Train 2 of the platform where Train 2 will stop, the stop location within the platform, and the existence of Train 1 at the platform. Also, the server informs Train 1 that Train 2 will stop behind Train 1.
3. Train 2 establishes a connection with Train 1 through on-network and then notifies the server of the connection establishment with Train 1. Trains 1&2 can share information such as acceleration/deceleration, braking, location, etc., through the connection to stop at the same platform.
4. The server allows Train 2 to enter the platform.
5. For redundancy, Train 2 can add a connection with Train 1 through off-network before entering the platform.
6. Train 2 stops behind Train 1 at Platform A and opens its doors for passengers to get on and off. Train 1 starts to depart.

• Train 1 establishes a connection with the server at the next station while Train 1 has a connection with the server at the current station.
• When the distance between Trains 1 and 2 becomes longer, Trains 1 and 2 stop sharing the information and disconnect from each other.

TR 22.990 covers utilizing off-network and on-network communications at the same time and the traffic characteristic of off-network communications.