It's almost summertime, and a series of outdoor festivals and events are planned in town, for the next weeks/months. This is known to attract many people and tourists, using public/private transportation (bus, taxi) to travel from/to airport and move around the city, as well as attending various shows and events scheduled in different city parks, stadiums and other outdoor areas. 5G traffic demand will be very high and challenging. The city administration and few partner companies provide transportation services with various buses/taxis inside the city, as well as shuttles between the airport (located outside the city area) and hotels. In addition, one of the partner companies provides small vehicles/carts used to display marketing/advertisement messages/banners, that can be deployed to drive/transit inside parks, around stadiums or recreational/tourist areas. Those vehicles are (or can be) equipped with 5G mobile BS relays for inside/outside users and, upon request and/or specific commercial agreements, can be used and configurable by MNOs to interconnect and operate as part of their 5G RAN.

Operator A, with existing 5G macro coverage in/around the city, decides to acquire the service offered by the transport administration and use some of those vehicle relays, in particular:

• advertisement carts, to extend challenging macro 5G coverage and capacity for outdoor users in hot-spot locations where city's events or high-density gatherings are expected.
• buses and taxis, to provide a better 5G in-vehicle experience to its subscribers (or inbound roamers), as well as improving the overall RAN capacity in certain challenging macro areas, e.g. along the highway to the airport, and/or macro cells serving popular bus/taxi locations/routes in the city.

1. Operator A enables the vehicle relays to operate and interconnect with its 5G macro RAN and network.
2. Operator A configures initial relays operating parameters and conditions, e.g. in terms of radio spectrum, vehicles location/itinerary, time of the day, transit/stop in target areas, vehicle speed, etc.
3. On a certain day, prior to the events season, Operator A activates the relays.
4. 5G traffic starts flowing through all activated vehicle relays. Operator A can re-configure some of the relay operating parameters (e,g, spectrum, time/location of operation) based on observed 5G traffic and RAN performance.
5. Toward the end of the summer, based on lower 5G traffic demand, Operator A decides to deactivate relay operation (on its network) for the advertisement carts and few of the city taxis. Service on city buses and shuttles from/to airport is continued.

The operator A is very happy about the improved performance of its 5G network during the busy city summer, and the better service provided to its 5G customers.

Current stage-1 requirements (e.g. on wireless self-backhaul, in TS 22.261), as well as existing stage-2/3 functionalities and architecture options (e.g. IAB) do not assume or address full relay mobility (e.g. BS relays on board of moving vehicles), thus may not cover the identified new potential requirements, which are intended to be specific to mobile BS relays.

[PR 5.1-1] [PR 5.1-2]

• activation and/or deactivation of mobile relay operation;
• configuration of 5G spectrum (licensed or unlicensed) used by the mobile relay, over the radio links toward UE and RAN;
• configuration of relay operating conditions e.g. based on geographic areas or locations, specific time period(s), vehicle's speed, itinerary, etc.

In the urban environment, temporary needs are raised up for extra cellular coverage and connectivity during various social events (e.g., music festival, sport race, etc.) at a designated area, where pertinent QoS cannot be fulfilled for a large amount of users. In this case, vehicles installed with on board base stations may act as relay and help to offer convenient and efficient service to UEs. They can be situated in specific locations (e.g. outside stadiums), and provide 5G coverage to neighbouring UEs outside the vehicles.

To enable this use, following pre-conditions should be met:

• A car shall be equipped with on-board base station.
• The mobile base station relay is capable of providing 5G connectivity to UEs in the vicinity of the car.
• The mobile base station relay is able to connect the NG-RAN and 5G Core network.

1. When the car starts the engine, the mobile base station relay registers to the 5G network and obtains the necessary configuration information (e.g., operating frequency bands). After getting authorized, the mobile base station relay is able to provide 5G access.
2. The car drives into the permitted area, where the mobile base station relay is able to provide 5G access to neighbouring UEs in the vicinity of the cars.
3. UE A is connected to the mobile base station relay when it moves into the permitted area.
4. As the car moves out of the permitted area, the mobile base station relay cannot work anymore and UE A is disconnected.
5. When the car drives into another permitted area, the mobile base station relay works again and UE B is connected.
6. When the car reaches the destination, its engine is turned off and the mobile base station relay stops working automatically.

The authorized UEs in the vicinity of the car are provided with extended 5G connectivity by the mobile base station relay.

Current stage-1 requirements (e.g. on wireless self-backhaul, in TS 22.261), as well as existing stage-2/3 functionalities and architecture options (e.g. IAB) do not assume or address full relay mobility (e.g. BS relays on board of moving vehicles), thus may not cover the identified new potential requirements, which are intended to be specific to mobile BS relays.

[PR 5.2-1] [PR 5.2-2] [PR 5.2-3]

In order to fulfil the high demand of extra cellular coverage and capacity in large cities with a dense population, either buses or cars with on board base stations, are expected to act as relay and help provide convenient and efficient data delivery service to the city residents. Generally speaking, car is privately owned and the base station mounted on it usually supports a private working mode, i.e., it only allows individual access to the car owner's UEs, e.g., his/her family members, friends, etc. On the contrary, base station mounted on a bus usually works in a public manner. All the passengers in the bus or in the vicinity can access to the base station on the bus along its predictable itinerary regarding their extra 5G cellular access requirements.

To enable this use, following pre-conditions should be met:

• Alice wants to join a music festival and share the live show to her friend Bob.
• Alice's car is installed with an on-board base station.
• The bus that Bob takes is also equipped with on board base station along its itinerary.
• In the area around the spot of the music festival, the base station mounted on the vehicle is allowed to provide 5G coverage to neighbouring UEs outside the vehicles.
• Either the base station on a car or bus is able to connect the NG-RAN and 5G Core network.

1. Alice drives by her own car to the spot of the music festival with her family. Alice as well as her family's UEs is connected to the base station on her car, which has been set to provide private access only. Alice pickup her friend Mary at Mary's home when she drives her car to the fesitval, and Mary's UE is connected to the base station on Alice's car since Alice grant Mary to access, e.g. by giving Mary an Token. Mary uses her UE and the Token to access the Internet via the base station on the car during Alice drives.
2. Alice parks her car in a parking lot near the spot of the music festival. John is a stranger in the nearby. His UE tries to connect to the base station on Alice's car, but it fails without be granted authentication from Alice.
3. At the same time, Bob takes a bus back home, with a base station mounted on it. Bob's UE is connected to the base station on the bus, which provides public access to all the passengers on the bus.
4. Alice starts sharing video with Bob the live video during the concert festival.
5. At the festival, Alice meets three of her friends. Since long time no see, they decide to go back to Alice' home for further drinks and chatting. Then Alice set the base station on her car to provide open access. With this setting, all friends on the car can access the Internet via the base station on the car.
6. When Alice arrived at home, she parked her car and turn off the base station on the car. All her friends and Alice then not able to access the base stations on the car.

Alice shares the live video of the music festival to Bob via 5G access from the base station on her car. Bob is happy to watch a live show via 5G access from the base station on bus. Mary is happy to access the Internet via the base station on the Alice car during Alice drives. All friends of Alice are happy to access the Internet via the base station on the Alice car.

The mobility management of the vehicle mounted base station shall be taken into account. Multi-network connectivity and service delivery across operators will be used to assist this use case. The 5G system shall be able to maintain service continuity with minimum service interruption when the serving network is changed to a different serving network operated by a different operator.

[PR 5.3-1] [PR 5.3-2]

As part of a nationwide campaign to stimulate and increase use of public transportation, a mobile operator ("Green") and cities administrations launch a "premium 5G connection" service to be offered to Green subscribers, and tourists from partner roamers, when travelling on public buses, trams, trains and underground in the main cities of the country. The improved 5G connectivity would be provided by using 5G mobile base station relays installed on board of public transport vehicles, which inter-connect (wirelessly) to the 5G macro network as part of Green 5G network. Green decides to offer free and prioritized access to in-vehicle 5G relays to some of their executive customers, while for other Green subscribers (and roamers), access via relays would require and depend on a per-user permission, associated to a certain public transport ticket or membership. The user permission to access the relays may be specific per transport vehicles, and per geographic location/area. In addition, Green can configure other policies and parameters, as part of the RAN and/or relay settings, which may also depend on some macro RAN or other network constraints and conditions, for example it may limit/prioritize access to mobile relays based on time of the day, relay load, speed etc..

In the service flow below, as an example, the following public transport "city pass" options are assumed to be available, and corresponding relay access permission policies to be set and provisioned by Green:

• 1-month city pass: Access to mobile relays on all buses, city centre area only, during non-peak hours
• 6-month city pass: Access to mobile relays on all buses and trams, inside & outside city centre, non-peak hours
• 1-year city pass: Access to mobile relays on all public vehicles (including metro & trains), all city, any time
• "Executive" pass (for Green executives only): Full/unrestricted permission to access mobile 5G relays, nationwide

For executive users, further higher priority access could be configured in case of specific relay or RAN operating/capability conditions, e.g. related to relay load or mobility factors. As example, normal priority UEs may connect via relays on buses only if less than 5 users are active (via the relay) and/or at bus speed is in a certain range, while executive UEs would have unrestricted access/connection in the same conditions.

1. Three users, Alice, Bob and Charlie (Green customers) have the following city pass/status
   • Alice: Executive;
   • Bob: 1-month pass;
   • Charlie: 6-months pass
   They work for the same company (Green) and same office building, located outside the main city area, and live in the same city centre neighbourhood.
2. Every day they share same itinerary and public transport vehicles to commute between home to work, i.e.
   1. Around 6am (non-peak hour), one bus from home to the tram station (city centre area), then a tram to the office (from inside to outside city centre).
   2. Around 6pm (peak hour), opposite itinerary to return home
3. During their commuting, they typically use their smartphone almost all the time (active 5G connection), to browse internet and/or various social media communication. Based on their city pass/membership and other policies assumed above, they will experience the following 5G access/connectivity situations:
   1. Alice:
      1. Home to office: connected via relay on the bus and the tram
      2. Office to home: same as above, high priority access
   2. Bob:
      1. Home to office: connected via relay on the bus
      2. Office to home: no access via relay
   3. Charlie:
      1. Home to office: connected via relay on the bus and part of the tram itinerary (till city centre limit)
      2. Office to home: partially connected via relay on the bus and the tram (inside city centre);
   • During peak hour, given normal priority rights, sometimes connection via relay on the bus is not possible, e.g. if/when other 5 Green passengers are on the bus and already actively connected via the relay.

All three users enjoy the premium 5G service from Green during their daily commuting to/from office, and are happy about their membership to the 5G-friendly public transport system!

Current stage-1 requirements (e.g. on wireless self-backhaul, in TS 22.261), as well as existing stage-2/3 functionalities and architecture options (e.g. IAB) do not assume or address full relay mobility (e.g. BS relays on board of moving vehicles), thus may not cover the identified new potential requirements, which are intended to be specific to mobile BS relays.

[PR 5.4-1]

• User/UE subscription and/or permission (can be specific to each preferred relay);
• User/UE or relay geographical location, time of the day, load, speed.

A mobile operator ("Blue") partners with the public transit organization of ConnectedTown to offer 5G connectivity to passengers of public city buses and trams. The 5G connectivity will be provided using 5G base station relays installed on board of those vehicles, connected to the Blue 5G RAN network.

Blue decides to give its own subscribers free access to 5G connectivity in city buses and trams, and to offer subcribers of other operators the possibility to subscribe to the service for a fee, with the following tariff plans available:

• 20 min access in any bus or tram;
• one day access in any bus or tram;
• one month access in any bus or tram.

4. Three users, Jack, Jill and Francois are about to enter a bus equipped with a Blue 5G on board relay
   • Jack is a Blue subscriber
   • Jill is a Purple subscriber
   • Francois is from France and visiting ConnectedTown during his vacation. He is a Rouge (French operator) subscriber
5. When on the bus
   1. Jack's UE automatically connects to the vehicle relay
   2. Jill and Francois get a notification on the UI of their UE informing them about the availability of in-bus 5G service and listing the corresponding app available for download.
6. Jill, who is commuting to work, recalls that Purple's coverage on the bus route is usually spotty. Since she rides the bus every weekday to go to work, she downloads the app and decides to sign up for the one month plan. Francois also downloads the app. He is only in town for a day and from the information provided by the app, he determines that the rate offered by Blue is cheaper than what he gets from the preferred VPLMN with which Rouge has a roaming agreement in ConnectedTown, so he signs up for the one day plan. Jill and Francois' UEs connect to the vehicle relay.

All three users enjoy the 5G connectivity from Blue, and - when leaving the bus - give positive feedback to the driver about the efficient and high-tech public buses.

Current stage-1 requirements (e.g. on wireless self-backhaul, in TS 22.261), as well as existing stage-2/3 functionalities and architecture options (e.g. IAB) do not assume or address full relay mobility (e.g. BS relays on board of moving vehicles), thus may not cover the identified new potential requirements, which are intended to be specific to mobile BS relays.

[PR 5.5-1]

• user/UE subscription and/or permission (can be specific to each preferred relay);
• user preference, for manual selection of a specific relay.