- Ultra-low cost for very low average revenue per user (ARPU) areas and/or MTC services - Flexible and fast introduction of new services and technologies - Ease of deployment. Plug and play, self-configuration/heal, etc. - Flexibility and scalability. Openness and multivendor capability at all levels, mod- ular provisioning, functional split of core/RAN Network domains/elements, decou- pling hardware and software - Fixed-mobile convergence, for seamless user experience and unified subscriber management 2.3.3 NGMN 5G Architecture Design Principles The 5G use cases demand very diverse and sometimes extreme requirements, with each use case requiring its own specific set of performance, scalability, and availability. NGMN anticipated that the relatively monolithic architecture of previous generation networks cannot efficiently address the necessary flexibility and scalability, in support- ing a considerably wider range of business needs. To accommodate more agile and efficient provisioning of new services, the 5G architecture should include modular network functions that could be deployed and scaled on demand. To enable concurrent active services sharing the same operator network, NGMN envisions an architecture that splits the overall system into three distinctive layers, namely, the business appli- cation layer, the business enablement layer, and the infrastructure resources layer, building on network function virtualization and software-defined networks as shown 2.3 NGMN Business application layer Use cases, business models, value proposition Operator OTT & Enterprise Vertical services 3rd party 5G system Business enabler APIs Business enablement layer Library of modular network functions & value-enabling capabilities State E2E management functions functions config & orchestration Common information repository Virtualization Infrastructure resources layer External public & private IP networks 5G devices 5G RAT family Access node Cloud node(edge & central) Networking node Figure 2.1 NGMN 5G architecture. in Figure 2