GAIA 5G serves as a demonstrator testbed for automotive scenarios within the 5GASP European project. This initiative stems from a collaborative effort between the University of Murcia and Odin Solutions. In this ecosystem, GAIA 5G seamlessly integrates and equips developers with essential tools for testing their 5G network applications within an authentic 5G network environment. Also, thanks to this framework, the showcased use case involved deploying the vOBU 5G network application and validating it by mirroring a real OBU within a vehicle, seamlessly transitioning between two distinct MEC domains.
Figure below illustrates the architecture of the vOBU 5G network application, comprising four key components: (i) the OBU, a physical device installed within the vehicle and directly linked to the sensors; (ii) the vOBU situated in the MEC, functioning as a digital counterpart of the physical OBU; (iii) the vOBU manager, situated in the cloud, responsible for the control and orchestration of vOBUs; and (iv) the aggregator, acting as the primary database of the system and serving as a single point of entry for services.
When an external client seeks access to vehicle data, their query is routed through the aggregator, which strives to maintain an updated copy of information from the vehicle sensors. If the requested data is not available, the query is redirected to the vOBU, which retains the latest copy of the desired information and can fulfill the request. In the eventuality that the queried data is unavailable in both the aggregator and the vOBU, it must be retrieved directly from the vehicle.
Moreover, the vOBU 5G network application continuously monitors the vehicle’s location and the status of the 5G network, identifying the serving cell. Upon the vehicle’s relocation to a different area, triggering a connection to another cell associated with a separate virtualization domain, a migration process is initiated. During this process, a duplicate of the vOBU currently serving the vehicle is instantiated in the new MEC domain. Once operational, the new vOBU assumes responsibility for servicing the vehicle, while the previous vOBU is terminated.
To integrate a network application into the 5G infrastructure, it must engage with the 5G network in some capacity. This necessity led to the selection of the vOBU solution within the 5GASP project as a means to advance towards a 5G network application. Initially, the solution relied on interacting with the SDN controller of each architectural segment, which tightly coupled it with the underlying infrastructure and demanded in-depth knowledge of the network. However, during the development of the 5GASP project, a novel approach was conceived and implemented. The 5G core specification incorporates the Network Exposure Function (NEF), defined as the interaction point of the 5G core where applications can request monitoring and performance data regarding network operations. Among the myriad of network information available, the NEF specifically provides access to the serving cell of the client at any given moment, thus this data becomes instrumental in initiating the migrations suggested by the vOBU solution.
Due to the absence of implementations of the NEF in both open-source 5G core solutions and commercial deployments, alternative measures needed to be devised. This is where the tools provided by the 5GASP project come into play, aiding developers in validating their 5G network applications in testbeds with characteristics akin to real-world scenarios.
Recognizing the challenges posed by the unavailability of the NEF, the 5GASP project consortium took proactive steps. They prepared and deployed an instance of the NEF Emulator, originally developed in the European project EVOLVED-5G. This emulator facilitates the interaction of 5G network applications with an emulated NEF, mimicking the behavior of a genuine NEF integrated into the 5G core infrastructure. Consequently, developers can continue their development efforts seamlessly, treating the emulator as if it were a real NEF.
As a result, the vOBU 5G network application underwent enhancements to enable interaction with the NEF Emulator. Within the emulator environment, a 5G network configuration similar to that of GAIA 5G was established. This setup included defining a client’s trajectory between two distinct cells, thereby enabling emulation of cell handovers. Through this interaction, the functionality of the vOBU 5G network application could be validated within a genuine 5G infrastructure, replicating the same interactions that would occur with a real NEF in place.
In addition to the development and validation framework provided by the 5GASP project, the GAIA 5G testbed boasts supplementary capabilities, including 5G network monitoring facilitated by dedicated software. These software tools expose crucial 5G network metrics, allowing applications within the infrastructure to retrieve information regarding the cell to which each OBU is connected.
Consequently, the vOBU 5G network application, with no need for further modifications, can function in the same manner as it does with the NEF emulator within the controlled 5GASP environment. This underscores the efficacy of the 5GASP framework. A 5G solution developed and validated in the 5GASP testbed can seamlessly transition to deployment in a real 5G network, operating safely and effectively.
