5G Network Slicing and Convergence Maria Cuevas, Head of core network and services research BT plc
Contents 1 2 5G drivers Network slicing a b c d e Key drivers Key requirements / technical challenges Target architecture Slice selection Operator challenges 3 Convergence a b c Customer benefits Operator benefits Use Cases
5G Drivers The next generation of telecoms networks is NOT just about faster broadband Industry background Growing demand for Mobile Broadband Traditional services declining High expectations for the evolution of connected devices Digital transformation across all industries Source: ITU-R Recommendation M.2083-0 (2015) Key drivers New business opportunities Technology enablers Network slicing Improved customer experience Convergence 3 Operational excellence Network slicing / Convergence
Network Slicing - drivers Multiple logical networks dedicated to different services/service types KEY DRIVERS Rapid deployment of new services Need to deploy new services with no disruption to existing ones Agility is required to compete and meet market demand NFV and SDN enable orchestration across slices End goal is fully automated deployment of new network slices Support for different operational models Different SLAs (e.g. security, reliability etc.) may require isolation between different slices Slicing can be done on a per service-type or even for individual customers Conflicting functional requirements Source: NGMN 5G white paper Some functional requirements may be mutually exclusive, e.g. high data throughput versus low latency or highly-mobile versus fixed access. Optimisation of each slice for the specific functionality required (e.g. non-mobile slice) There may be alternative approaches to meet this particular goal (e.g. flexible anchor points, early detection of mobile devices etc.) 4 New Business Opportunities + Operational Excellence
Network Slicing requirements/technical challenges Multiple logical networks dedicated to different services/service types 5 Key requirements End to end or partial Common s across slices Isolation, security, service assurance Shared infrastructure Elasticity Roaming Simultaneous access to multiple slices Multi-access slices 3 rd party integration and exposure Slice Selection Technical Challenges Mobility Management Authorisation RAN slicing Subscriber Identity Integration to 3 rd party systems Exposure to 3 rd party management Dynamic and automated management and orchestration Multi-access network support / convergence
Network Slicing key architectural principles Multiple logical networks dedicated to different services/service types Access Network slices network slices Data Network and Service Slices Customer domains Flexible Mobile Service Steering Slice Selection / Binding X Common X X X Y Y Y Common Y Service #1 Service #2 SF #3 Service #1 Service #1 Service #2 Service #2 Service #3 Service #3 CD#1 CD#2 CD#3 CD#4 CD#5 X Y Service #1 Service #2 SF #3 Multi-access slices Simultaneous access to multiple slices Partial or end to end slices slice selection / binding Common s Flexible deployment of core functions Slice-specific or shared service functions Flexible Mobile Service Steering within slices Integration with Customer Domain 6
Network Slicing slice selection Multiple logical networks dedicated to different services/service types Session Management (SM) Mobility Management (MM) Authentication (AU) Slice Selection (SSF) Subscriber Repository Common Slice Selection NG2+ NAS sig. Common NG2+NAS signalling handler/front End CP NFs for Slice A RAN Common CP NFs U P NFs for Slice A UE provided info Network Slice CP NFs for Slice B Subscription info CP NFs for Slice C U P NFs for Slice C U P NFs for Slice B Network Slice A Network Slice B Network Slice C AU, MM, SM distribution User Plane (NG3, NG-Gi) Slice Network function 1... Slice Network function n Proxy versus redirect Granularity RAN slice binding NextGen NextGen UE NGNAS NGuu NextGen Access NGc NGu Access Control Agent (ACA) Hx Ax HSS NextGen Control Plane NextGen User Plane Network Slice Instance Control Plane CUx Network Slice Instance User Plane NextGen Network Slice Instance 7 NOTE-1: A network slice may contain only the control plane without the user plane NOTE-2: HSS is also accessible by the network function(s) within the Network Slice, e.g. PCRF
Network Slicing operator challenges Multiple logical networks dedicated to different services/service types When is it best to slice? Disparate functional requirements may be met via alternative approaches e.g.: optimal anchor point (re)selection flexible mobile service steering (re)selection of efficient user plane paths Multiple customers SLAs may be supported via flexible capacity management through SDN and NFV and differential QoS Will operational complexity outweigh the benefits? Decoupling hardware resources from network functions brings accountability challenges. If operational requirements are significantly different, underlying resources and associated management may not be common. Exposure of network management to 3 rd parties implies significant security challenges. 8
Customers want seamless connectivity Convergence requires an end-to-end approach to building and managing networks Converged User Experience Internet Operator Single set of identities and credentials Converged Consistent set of policies (e.g. traffic management policies). Mobile Backhaul (e.g. Ethernet, fixed BB, wireless) Exchange PCP FTTC Consistent set of services (e.g. parental controls, access to content) Automatic network selection onto best available network for bandwidth and latency (including simultaneous access to multiple networks) Mobile access (4G, 5G, macro, small cell) Fixed access: Broadband, superfast, ultrafast Seamless mobility between access networks (e.g. video/voice call continuity) 9
Operators want to optimise their networks Convergence requires an end-to-end approach to building and managing networks Optimized Converged Network Internet Operator Flexible traffic routing to make best use of available networks Converged Improved reliability Mobile Backhaul (e.g. Ethernet, fixed BB, wireless) Exchange FTTC Reuse of backhaul transport as well as core network assets Single set of service platforms and value added services PCP Simplified charging and billing Fixed access: Broadband, superfast, ultrafast Best customer experience (converged user experience) Mobile access (4G, 5G, macro, small cell) New service opportunities 10
Converged use cases fixed hybrid access Convergence requires an end-to-end approach to building and managing networks Operator Public UE PC Home Devices Mobile Network Backhaul Converged Transport Internet IOT Gaming Router Hub Fixed Network Backhaul Simultaneous use multiple access networks Private Bandwidth boost Failover Fast provisioning 11 Symmetric Bandwidth
Converged use cases mobile hybrid access Convergence requires an end-to-end approach to building and managing networks Operator Public Mobile Network Backhaul Converged Transport Internet Router Hub Fixed Network Backhaul Private Simultaneous use multiple access networks Bandwidth boost Failover Symmetric Bandwidth 12
Converged use cases femtocell access Convergence requires an end-to-end approach to building and managing networks Femtocell Operator Public Converged Local resources Router Hub Fixed Network Backhaul Transport Internet Corporate Unified set of identities Consistent set of policies Same set of services Access to Local Area Network 13 Seamless mobility best available network
Summary and Conclusions Key drivers for 5G are new business opportunities, improved customer experience and operational excellence Network slicing and Convergence are key technology enablers to achieve the above There are lots of technical challenges with network slicing that need to be addressed Keeping the right balance between flexibility and operational complexity is going to be key A fully converged architecture is required to deliver a truly seamless customer experience Operators need to make best use of their fixed and mobile assets Convergence should be one of the pillars of 5G rather than an afterthought 14