What is Network Slicing?

Wondering about network slicing? We discuss it and how it can help your overall network performance.

What is network slicing?

Network slicing is a technique that creates multiple virtual networks on top of a shared physical network to provide greater flexibility in the use and allocation of network resources. It is used most often in the discussion of 5G networks, in part because the 5G specification calls for network slicing as a fundamental capability, whereas 4G and earlier generations of cellular data services did not and could not support network slicing.

Each slice of a network can have its own logical topology, security rules, and performance characteristics — within the limits imposed by the underlying physical networks. Different slices can be dedicated to different purposes, such as ensuring a specific application or service gets priority access to capacity and delivery or isolating traffic for specific users or device classes.

Why Network Slicing Matters

In the cellular world, it allows businesses to control traffic resources on a more granular level. Each slice of traffic can have its own resource requirements, Quality of Service (QoS), security configurations, and latency requirements. For example, the characteristics of a network slice supporting high-definition streaming video would be different from the slice used to monitor an Internet of Things (IoT) lighting system.

In non-sliced networks, devices have access to more resources than they actually need. For instance, an employee’s cell phone wouldn’t need 100 Mbps to send a simple message over an app. Network slicing preserves resources by understanding the context and use case for each application and appropriately assigning the correct amount of resources.

Thanks to new core network technology like Network Function Virtualization (NFV), networking slicing is easier to accomplish over 5G networks. Enterprises, mobile network operators, and managed service providers all stand to benefit through the use of network slicing.

How does it work?

Network slicing is as old as virtual local area networks (VLANs) – virtual LANs connecting together devices that share one physical LAN. It has become more popular with the rise of networking that uses software controllers to communicate with hardware and direct traffic, also known as software-defined networking (SDN). SDN separates a network’s control plane, which controls how the data is forwarded, from the data plane, which actually forwards the data.

The control plane can define virtual networks by defining the rules for handling data packets and pushing those rules out to the data plane to be executed. Data plane control applies to both physical and virtual network devices managed under an SDN controller, a physical switch in a rack, or a virtual switch on a virtual machine.

After the network slices are created, each one is optimized to provide the resources and network topology for the specific service and traffic that will be using the slice. Additionally, each network is completely isolated so that no slice can interfere with traffic in another slice.

How does it fit within 5G technology?

Network slicing is critical to 5G because earlier generations such as 4G did not support it.  The primary role of it within 5G technology is to partition and virtualize the core network. Network slicing applies the same virtualization principles across the entire provider network architecture to deliver meaningful results like minimal throughput or priority delivery of data packets from specific types of devices or applications.

A 5G network operator can physically segregate traffic on different radio networks, slice a single network, or combine multiple networks and slice the pooled resources.  These capabilities allow network operators to support their target levels of spectrum efficiency, traffic capacity, and connection density – how many devices can connect from a given space.

Three main types of 5G services use network slicing: Enhanced Mobile Broadband (eMBB), Massive Machine-Type Communications (mMTC), and Ultra-Reliable Low-Latency Communications (URLLC).

What are the benefits of network slicing?

At a high level, network slicing maximizes the flexibility of 5G networks, optimizing the utilization of the infrastructure and allocation of resources.

Let’s take a look at some more benefits in detail:

• Increased scalability, flexibility, and cost savings by enabling more services to be offered at the same time with as few or as many resources needed, as virtualization eliminates dedicated and specialized hardware
• Increased demand for products and services that can be brought to market quickly and be easily adopted as workloads change and evolve, which, in turn, leads to more revenue for operators
• Peak performance and maximum return on investment, as the most complex requirements can be met within a short time with full use of all available resources

Network slicing use cases

It supports use cases that focus on performance, capacity, and security. Many use cases involve emerging IoT business models.

• Real-time performance. A company depending on a 5G network for autonomous vehicle management might contract for a mobile network slice with latencies under 5 ms and stringent guarantees of packet delivery on the minimum throughput required to ensure responsive control. The provider uses URLLC functionality to guarantee the slice on the lowest-latency equipment and paths between vehicles and cloud or edge resources and reserve enough capacity to meet the throughput target.
• Capacity. For a security monitoring system in a large auditorium, latency may not matter. However, the security company may want to buy guaranteed delivery of the camera data. In other words, the company wants its traffic to get 1.5 megabits per second of throughput per camera with no packets dropped ever. The provider might aggregate multiple connectivity and processing device options to meet the needs of this slice.
• Security. For a human health monitoring system in a metropolitan area, a hospital might want to isolate all traffic to and from pacemakers. This minimizes the risk of a leak of customer data and the threat of compromise of the control channel, so it requires a slice with single-user virtual resources.
• Media and entertainment. By offering specific slices for high-quality video streaming, virtual reality, and augmented reality applications, network slicing can improve the delivery of media and entertainment services. This guarantees a reliable and captivating user experience.

Conclusion

Network slicing is a vital component of enabling rapid, flexible, and cost-effective 5G connectivity at the strategic, tactical, and operational levels. Extensive virtualization and individualized resource allocation help optimize performance in real-time, greatly increase throughout, and enhance security at the edge.