Co-authored by : Brijesh Unnikrishnan

Network Slicing - The Concept and the need

The movie “Cars” by Pixar is reality in the making. Lightning McQueen, the protagonist, uses AI to win races and communicate with Mater and Sally Carrera.

We are at the onset of the technology era where cars have started driving and communicating with each other. Traditional 4G mobile network limited by typical fixed QoS range for network control and specialized hardware based infrastructure cannot simply accommodate this evolution.

Next generation 5G telecom network with single COTS based NFV infrastructure can be leveraged instead. It dynamically aligns itself with the needs of its own smartphone users, as well as the smartphone consumers of its MVNO (Mobile Virtual Network Operator) client. In fact, a dynamic request for another new public safety network can be met in no time.

Network slicing will enable operators to deploy multiple independent end-to-end mobile networks.

Each slice can be customized for different services and businesses bringing windfall revenue savings.

Vertical Network Slicing - Initial 4.5G and 5G evolution

The initial 5G evolution is expected to include vertical network slicing, wherein capacity scaling of a given service is performed with the same infrastructure.

A new business can be integrated over existing infrastructure, instead of adding a new network altogether.  For example, a smartphone slice can be utilized by an operator as well as the MVNO. If a new business of public safety or MVNO opens up, the same network can be utilized. Here one slice of MVNO is completely different from the other slice of public safety network in application, architecture, and signaling. Vertical slicing can be achieved by using COTS based infrastructure with NFV and SDN implementation.

Horizontal Network Slicing - Advanced 5G evolution

Advanced 5G evolution is expected to include horizontal slicing. Imagine a situation where a non-linear core network infrastructure capacity expansion by a scaling factor of 10 will bring an end device scaling factor of 10000. Horizontal slicing scales the capacity by communication, edge cloud computing, and computing offloading through the creation of a virtual cloud. Edge cloud computing is the usage of edges of network infrastructure like base stations to horizontally slice computing from end devices. Similarly, wearables with little computation power can horizontally slice computing to devices.

Both vertical and horizontal slices behave as independent slices. Typically, the traffic flow in vertical slices would be between the end device and the core network. However, the end-to-end traffic flow in a horizontal slicing would be between two end devices, e.g. between a wearable device and a portable device or an access point.

Benefits:

• Cost efficiency and resource optimization by scaling the same infrastructure vertically
• Non-linear capacity expansion of core network infrastructure through introduction of edge cloud computing and computing offloading with communication
• Dramatically transforming 3G/4G quality of service challenges of all slice against all devices to vertical slicing with specific slices to specific device categories
• Optimized and scalable networks by slicing every element from core network (CN) to radio access network and radio
• Enhanced user experience and quality of service through a combination of vertical and horizontal slicing
• Implementable across core network, radio access networks as well as radio

Software defined anything as enabler for Network Slicing

Software defined network and Network Function Virtualization along with network orchestration is key to implementing network slicing. An SDN controller shall allocate the network resources for a particular user or a service. Thus a network slice or an end-to-end virtual network is created for a user or service. Virtual Network Function applications, running on SDN devices via NFV, built on this slice will ensure end-to-end QoS. SDN enables designers and service providers to architect the exact needs for each slice ranging from front haul, network core, backhaul, cloud services, and data servers.

Shaping Network slicing standardization

Vertical slicing is the starting point of transformation in 5G network optimization.

Industry standardization bodies and forums like ETSI ISG, 3GPP, ITU-T, IETF/IRTF, NGMN, and WWRF have identified network slicing as a part of the 5G technology study. Amid RAN, CN and Radio, CN is likely to be transformed first by this concept. Needless to say, HCL is accelerating the in-house 5G capability and showcasing their expertise in Mobile World Congress 2017.

References

http://www.3gpp.org

https://www.ngmn.org/publications/technical.html