ion-centric. Use of low-cost OpenSource databases for real-time services is another area of research. Use of these databases will enable virtualized services to be much more scalable and reliable. It will enable data (e.g., call state) to be available at multiple georedundant sites, increasing the reliability of a service. This will also be an enabler for a lower-cost mobile core going forward for IoT services that will require massive scale. Another area of research is the efficiency of control loops and dynamic Service Platforms instantiation. Currently, virtualized services that require high availability of five 9's are deploying highly redundant configurations. A highly efficient ecosystem for fault detection and rapid dynamic instantiation of VNFs could enable minimal redundant configurations in the future, thus further lowering the overall cost of virtualized services using NFV and SDN. Lastly, comprehensive API exposure of network functions across all service domains to enable third parties to build services using VNFs deployed in the cloud, will be an enabler of supporting additional business models to provide the network service. REFERENCES 1. 3GPP TS 23.228: IP Multimedia Subsystem (IMS). 2. 3GPP TS 23.402: 3GPP System Architecture Evolution. 3. IETF RFC 3261: SIP: Session Initiation Protocol. 4. IETF RFC 6733: Diameter Base Protocol. 5. 3GPP TS 23.060 V13.4.0 (2015-09): General Packet Radio Service (GPRS). 6. 4G Americas' Recommendations 5G Requirements and Solutions, October 2015. 7. NGMN White Paper, 2-17-2015. 8. 3GPP TS 23.002: Network Architecture. Taylor & Francis Taylor & Francis Group http://taylorandfrancis.com Network Operations Irene Shannon and Jennifer Yates CONTENTS 15.1 Introduction 15.1.1 Operations and Engineering Teams 15.2 Impact of NFV and SDN on Network Operations 15.2.1 NFV and Its Impact on Operations 15.2.2 NFV-Related Challenges 15.2.3 Role of ONAP in Network Operations 15.2.3.1 Deploying and Deleting VNFs 15.2.3.2 Network and Service Monitoring 15.2.3.3 Control Loops: Repairin