# Key Technologies in the Context of Future Networks: Operational and Management Requirements
## 4 Future Trends and Challenges  
The current necessities address the direction of the business and the requirements of Future Networks. It is expected that 5G networks will cover the increase of traffic volume by means of improving spectrum utilization, enhanced energy efficiency mechanisms, resource virtualization, resource sharing, self-management and self-organization capabilities [8]. The concept of Future Networks envisages a broad range of opportunities in different fields. In other words, it will cover not only the traditional network fields but also other domains, such as e-health, energy efficiency, emergency services, public safety, IoT, machine-to-machine (M2M) communication, Information Centric Networking (ICN), among others. The applicability of SDN, NFV, SON and cloud computing opens the door to facilitate the deployment and management of services in an open business environment. Indeed, if we take into account technologies and advances of different initiatives, a possible architecture for future networks is proposed (Figure 4). On one hand, it presents a layered structure: infrastructure, virtualization, control and application layers, similar to the SDN approach. On the other hand, VNFs and NFV M&O modules are incorporated in order to control the NFVI. For its part, cloud technologies are present on the cloud computing layer and SON capacities will aid in the decision process in the control layer. Figure 4: Future Network Architecture. Future Networks could incorporate all of these concepts or part of them. Despite of the advantages of this proposal, there are some challenges that need to be overcome in order to successfully combine these technologies. Firstly, the unified definition and standardization in the separation of the data plane and control plane and the provision of virtualized instances will enable the easy development and integration of the future network technologies. In addition, the complexity of the mobile network elements constitutes a big challenge by itself. At the same time, these kind of systems will require effective pricing schemes and business models with two objectives in mind: (i) Customers pay only for the provisioned service and (ii) stakeholders receive revenues according to their SLAs. Another important issue is how legacy networks will coexist with new systems, which is still a relatively unexplored field. In the management and orchestration field, significant changes are required not only to improve the processing of data information but also to optimize the deployment and allocation of network resources. A unified management framework could allow enhanced traffic monitoring, provide self-management capabilities and network customization. A virtualized environment faces some issues, such as finding the best place to allocate virtual functions (operator infrastructure or cloud), migration and scheduling process. Mechanisms are also needed to provide load balancing, energy efficiency algorithms, inter-domain capabilities, among others. In parallel, all of these characteristics should be provided in a secure and trusted environment with enhanced capacities to recovery from failures. Moreover, The SDN centralized control or the dynamism of cloud computing are challenges that need to be covered. Table 2 shows the challenges and future trends that must be covered in order to fulfill the user needs of 5G networks.