- “Network slicing allows the operator to provide dedicated logical networks with customer specific functionality, without losing the economies of scale of a common infrastructure. It allows services to be abstracted from the network resources. As such, a variety of use cases with diverging requirements can be fulfilled… Typically a set of end-user services are provided by one network slice of a mobile network operator. Some UEs can access more than one network slice simultaneously for services of more diverse*
- A network slice is a separate logical mobile network which delivers a set of services with similar characteristics and is isolated from other network slices.
- Network slicing “requirements” :
- The infrastructure resources should be shared across many network slices
- Some functions may be common to more than one network slice: RAN, HSS, mobility management …
- Network slices isolation
- A network slice, namely “5G slice”, supports the communication service of a particular connection type with a specific way of handling the C- and U-plane for this service. To this end, a 5G slice is composed of a collection of 5G network functions and specific RAT settings that are combined together for the specific use case or business model … The intention of a 5G slice is to provide only the traffic treatment that is necessary for the use case, and avoid all other unnecessary functionality.
Standards and industry cooperation
- Network slicing requires collaboration between 3GPP standards and other networking organizations to work on common interfaces. This is fundamental to developing a system that is interoperable between providers, that can be built and operated using multi-vendor technology.
- Network slicing also needs industries collaboration outside the standards process. This is critical to ensuring standardized components work together in reality, as well as in theory.
- Operators need to develop industry ecosystems or partnerships with enterprises that not only share the risk, but enable the early co-design of dedicated network requirements that ultimately will help to guarantee success for all parties
Slicing progress in 3GPP
3GPP has recently completed the Rel15 normative specifications regarding service and operational requirements to support network slicing and work has started on both system architecture aspects and related management and orchestration capabilities
3GPP Rel15 defines basic slice architecture and features with focus on network slice creation at core side
It defines the enablers to support Network Slicing involving 5QI quality indicators, and L1 / L2 configurations, with possibility to prioritize some services or devices in lower layers (e.g. at MAC scheduler level).
- Main highlights of Rel16:
–Wireless and Wireline Convergence for 5G
–Service Based Architecture & Network Slicing Enhancements
–Support of Cellular IoT, V2X services, in 5G System
–Voice service continuity between legacy systems and 5G System
–5G New Radio – Unlicensed
–plus the usual enhancements to existing features without any focus on Network slicing in RAN groups at this stage
RAN features for slicing
- At this stage, 3GPP RAN2 has defined a set of features to differentiate eMBB and URLLC use cases
- Depending on suppliers’ implementation and network setup, a set of RAN features can be applied per network slice
|eMBB||uRLLC – Low Latency||uRLLC – ultra Reliability|
|Flexible Numerology (BWP)|
|QoS flows mapping|
|Downlink pre-emption||Multi-slot transmission (for grant based)|
|No fixed time relations for FDD and TDD||Low rate MCS – enhanced BLER target and CQI tables|
|UL channel access
-Grant based (short PUCCH)
-Grant free (contention based access)
|Long PUCCH (w/wo multi-slot transmission)|
3GPP SA1 TR 22.864
3GPP RAN3 TR 38.801