-7-trillion/#gs.vkg80p 13 5G Network Slicing for V2X Communications: Technologies and Enablers proximity to the end user devices (or vehicles) - intelligent transport system (ITS) applica- tions, such as the V2X AS in Figure 13.1. The MEC system facilitates IT cloud capability at the edge of the network, and its access-agnostic characteristics guarantee smoother deploy- ment independently of the underlying communication network. In a typical MEC-based deployment, cars communicate with RSUs and base stations (BSs), whereas MEC hosts are co-located with RAN elements to allow the consumption of ITS applications running on the MEC platform. The MEC-based system exposes a set of standardized interfaces to such applications, enabling developers and car OEM suppliers to implement ITS services in an interoperable manner across heterogeneous access networks, mobile operators, and vendors. The engagement of the ETSI MEC Industry Specification Group (ISG) with V2X network- ing involved two stages. The first stage entailed the collection of V2X use cases and the definition of challenging requirements for the MEC-based system. The results of such activ- ity are listed in the Group Report (GR) ETSI MEC ISG-MEC 022. Interestingly, it emerged that some of the collected requirements, commonly identified by automotive stakeholders, stem from the multi-MNO and multi-OEM scenarios. Specifically, an ITS operator might be interested in offering an ITS service to its own users across different communication net- works, thereby involving a set of vehicles from different manufacturers. The second stage is envisaged to include in the future new normative activities to close the gap identified by the study, e.g. by defining standardized interfaces to overcome potential interoperability issues in the multi-MNO multi-OEM scenario. 13.4.2 ETSI MEC-Based Programmable Interfaces The ETSI MEC ISG specified a list of programmable interfaces, available within published working documents. Such interfaces, dubbed as application programming interface