## 1 Introduction  
Beginning in 2019, fifth-generation mobile communication systems (5G) have been commercialized worldwide [1, 2]. However, current leading services are primarily driven by 3G/4G-enabled smartphone platforms. The extraordinary features of 5G, such as ultra-high throughput, have not been fully leveraged [3]. No de facto service or scenario has been demonstrated in 5G mobile communications, including enhanced Mobile Broadband (cMBB), massive Machine Type Communications (mMTC), or Ultra-Reliable and Low Latency Communications (URLLC), as defined by International Telecommunication Union (ITU-R) M.2083 [4] in 2015. Therefore, mobile communication companies around the world are scrambling to ship 5G services in various areas and release more functions gradually. Meanwhile, the shift from Mobile Virtualized Network Operator (MVNO) to Mobile Network Operator (MNO) is progressing [5], and new operators [6, 7] are being established in markets dominated by the existing mobile network operators. In this trend, virtualization, which can support everything from Radio Access Networks (RAN) to applications, helps to quickly provide service at low cost. As a result, various operators [8] can more easily start and provide mobile services. Thanks to innovation in virtualization technologies, edge computing enables third-party applications to access network/computing/disk resources in resource pools without being aware of their physical locations. As its name implies, edge computing utilizes resources in proximity to users. The European Telecommunications Standards Institute (ETSI) has defined Multi-access Edge Computing (MEC) as able to support mobile networks as well as fixed/WiFi networks [9; 10; 11]. With the assistance of near-site computing resources, MEC can handle large amounts of mobile user data and alleviate traffic load on the backhaul [12; 13; 14], as shown in Figure 1. Beginning with the 4G era various consortia and organizations of interest have been devoting efforts to promote MEC, as seen in many demonstration experiments and press releases [15; 16; 17; 18; 19]. However, no practical service has been delivered yet. These discussions remain ongoing while 5G service has started. As stated in [20; 21; 22; 23], new infrastructure is required in order for MEC to take off the MEC, as current mobile networks are not very compatible with virtualization technology. In addition, key use cases are eagerly awaited, and management and operation strategies for MEC applications should be clarified. On the other hand, the 3 rd Generation Partnership Project (3 GPP) has involved MEC as local data networks in the architecture design from Release 15 [24]. It defined the N6 interface to associate MEC with the User Plane Function (UPF) of the 5G Core (5 GC) and designed a local breakout for data traffic routing. Moreover, in globally published white papers on Beyond 5G (B5G), MEC employing virtualization technology has been acknowledged as one key enabler and an essential architectural network component. In previous studies, we have focused on \"who will use MEC (whether and how)\". Specifically, we first proposed a new Private/Local Operator to deploy MEC and analyzed the number of MEC that could maximize revenue [25; 26]. In order to consider the impact of MEC on other operators, Private/Local Operator and Cloud Owner were discussed and analyzed using game theory [27; 28]. The above results allowed us to establish an MEC ecosystem. However, what remains is the uncertainty of MEC management, which will affect operators' operational decision-making about how to manage the life cycle of third-party applications in MEC. In this light, this paper builds on previous work [28], proposes a detailed MEC/Cloud Orchestrator to make it work, and provides a PoC implementation of the E2E system. Specifically, the contributions of this paper are unique and distinctive in two aspects. First, we clearly explain the definition of players related to MEC and each player's role therein.