# A Modular Experimentation Methodology for 5G Deployments: The 5 GENESIS Approach
## 2 Background and Related Work
### Standardization on 5G KPI Testing and Validation  
Playing a key role in the standardization of mobile communications, the 3 rd Generation Partnership Project (3 GPP) also defines the corresponding tests aiming at verifying that mobile technologies conform to standards. Over the years, 3 GPP has defined the testing procedures for Universal Mobile Telecommunications System (UMTS, i.e., 3G), Long Term Evolution (LTE, i.e., 4G) and more recently 5G New Radio (NR). Focusing on the user-end device, i.e., User Equipment (UE), 3 GPP TS 38.521-\(X\) series details how a 5G NR UE must be verified at radio level, characterizing both transmit and receive parameters in terms of maximum transmit power, receiver sensitivity, and spurious emissions, among others. Conformance to Non-Standalone (NSA) scenarios, which combine NR and LTE cells for the Radio Access Network (RAN), is covered in [9], while NR-only Standalone (SA) is analyzed in [10; 11], which address sub-6 GHz and mmWave frequency bands, respectively. Performance aspects that are related to demodulation under different propagation and Signal-to-Noise Ratio (SNR) conditions are defined in [12]. Additional specifications cover the testing of several 5G NR signaling protocols [13; 14; 15], while [16] focuses on Radio Resource Management (RRM) testing, including the reporting of power and quality measurements, handover latency, timing accuracy, and other functional metrics. Another relevant aspect at the UE side is the battery consumption, for which the Global Certification Forum (GCF) and CTIA-The Wireless Association have proposed a testing methodology in [17], among others. Moving at the network side, 3 GPP TS 28.552 [18] provides specifications for performance measurements of Next-Generation Radio Access Network (NG-RAN), 5G Core (5 GC), and network slicing. Moreover, Radio Resource Control (RRC)-related KPIs are measured according to [19; 20], while using the measurement template given in [21]. As regards NFV, the European Telecommunication Standard Institute (ETSI) Group Specification (GS) NFV-TST [22] covers the testing of functional blocks of the architecture. The above activities and documents focus on testing of 5G components separately, and they do not address a fully E2E KPI validation. As analyzed later, our proposed testing methodology allows for both per-component testing and E2E KPIs validation. On this latter aspect, an initial recommendation is given in 3 GPP TR 37.901 [23], which addresses the testing of LTE UE at the application layer. In particular, it specifies the procedure to run throughput tests in a wide set of network scenarios and conditions. When also considering the need for running similar tests for 5G, 3 GPP has recently initiated a study on 5G NR UE throughput performance at the application layer, which is progressing as TR 37.901-5 [24], as an evolution of TR 37.901. Our work in 5 GENESIS aims at generalizing these recommendations, in order to cover not only throughput, but also other E2E KPIs from specific verticals, e.g., the Mission Critical Push to Talk (MCPTT) access time, for which a test case has been already defined and used [25]. Following the E2E approach, 3 GPP TS 28.554 [26] uses a network slicing perspective and currently covers KPIs related to accessibility, integrity, utilization, retainability, mobility, and energy efficiency. These KPIs are based on internal counters of the network, which are only accessible to the network operators; in our methodology, in order to provide direct information on the achievable performance under different 5G use cases, the definitions of KPI privilege instead the end-user perspective, in terms of Quality of Service (QoS) and Quality of Experience (QoE). TS 28.554 also specifies a template that allows for the categorization of KPIs along with methods, tools, and calculation steps needed for measuring and validating them. However, it lacks specifications for the test sequence and the definition of E2E scenarios.