  In this paper, we provide a comprehensive review and updated solutions
related to 5G network slicing using SDN and NFV. Firstly, we present 5G service
quality and business requirements followed by a description of 5G network
softwarization and slicing paradigms including essential concepts, history and
different use cases. Secondly, we provide a tutorial of 5G network slicing
technology enablers including SDN, NFV, MEC, cloud/Fog computing, network
hypervisors, virtual machines & containers. Thidly, we comprehensively survey
different industrial initiatives and projects that are pushing forward the
adoption of SDN and NFV in accelerating 5G network slicing. A comparison of
various 5G architectural approaches in terms of practical implementations,
technology adoptions and deployment strategies is presented. Moreover, we
provide a discussion on various open source orchestrators and proof of concepts
representing industrial contribution. The work also investigates the
standardization efforts in 5G networks regarding network slicing and
softwarization. Additionally, the article presents the management and
orchestration of network slices in a single domain followed by a comprehensive
survey of management and orchestration approaches in 5G network slicing across
multiple domains while supporting multiple tenants. Furthermore, we highlight
the future challenges and research directions regarding network softwarization
and slicing using SDN and NFV in 5G networks.
