Vehicles with onboard base stations, so called vehicle-mounted relays (VMR), are expected to act as relay and help provide efficient data delivery. This use case addresses the needs of users who are not moving with the vehicle-mounted relay but that can benefit from its offered connectivity when users and vehicle-mounted relays are close.
In particular, this use case addresses the needs of those UEs that either have limited connectivity (e.g., when connected to a macro cell) or that have too demanding bandwidth needs.
Our first use case is about a user, Tom, an emergency physician who just arrived at a car accident. Tom is attending several injured persons. Tom is having a call with other clinicians at a close-by hospital discussing the health state of the patients and to which hospital the patients should be transferred. Tom would also like to retrieve the Electronic Health Record (EHR) of the patients to do a better assessment. However, the network connectivity at his current location - the accident area -- is insufficient, in particular, to download some bulky files in the EHR of the patients. In this situation, it is beneficial if the 5G system can schedule the transfer of the EHR content requested by Tom so that the EHR is transferred by means of a relay mounted on one of the ambulances approaching the accident area. This example is shown in Figure x-1 where the ambulance is denoted AMR, i.e., Ambulance-Mounted Relay. In Figure x-1 Tom's UE is denoted UE. At location L0 and time T0 the EHR data transfer is requested by the UE. The data is then transferred when the AMR is at location L2 since at this location the communication link between donor gNB and AMR and between AMR and UE offer the best end-to-end performance. The location is chosen by using, known or predicted, the AMR mobility pattern to optimize the network behaviour. In some cases, the AMR could receive the EHR data from the donor gNB at location L1 and time T1 and when the AMR is at location L3 at time T3, the AMR could rapidly deliver the requested EHR data to Tom's UE. In this alternative approach, the locations L1 and L3 are chosen to optimize the individual link performance between donor gNB and AMR and between AMR and UE. The choice of these locations is also based on the known or predicted AMR mobility pattern.
Other relevant and related use cases include:
IoT devices requiring the delivery of a software update. Some IoT devices might lack a good connection but be able to retrieve the software update from a vehicle-mounted relay, when it is close by.
Users requiring access to bulky resources, e.g., a movie, but with insufficient connectivity at their current location. Users might retrieve the files from an approaching vehicle-mounted relay selected based on the mobility pattern of the VMR.
From clause 6.2.2 of TS 22.261
: "The 5G network shall allow operators to optimize network behaviour (e.g. mobility management support) based on the mobility patterns (e.g. stationary, nomadic, spatially restricted mobility, full mobility) of a UE or group of UEs." However, this requirement is not based on mobility information of vehicle-mounted relays.
Clause 6.6 of TS 22.261
(Efficient content delivery) includes various requirements on efficient content delivery. However, these requirements are not based on mobility information of vehicle-mounted relays.
The 5G system shall be able to provide a means to optimize network behaviour to efficiently deliver data based on the mobility information (e.g., itinerary), known or predicted, of the vehicle-mounted relays.