Telecom industry looks at how to slice up 5G networks

By Joanne Taaffe

A self-driving car and a device that sends occasional updates on the humidity levels of a golfing green don't need the same levels of latency and performance from a network.

5G design will mean a network will no longer have to cater for both. Instead network slicing, which is a key feature of 5G, lets operators automatically create separate, virtual end-to-end networks over the same physical infrastructure.

This makes it easier and affordable for operators to quickly allocate the right network resources to very different applications. But that doesn’t mean operators will need or want to create as many network slices as there are possible applications. Instead the industry looks set to coalesce around creating a limited number of interoperable network slices dedicated to key applications and industries.

Slicing breadSpeaking at the 5G World 2018, GSMA Technical Director Michele Zarri advised operators to collaborate with each other on creating around a dozen generic slices. “Only a handful of slices, maybe 10 or 15, can serve the vast majority of the use cases,” said Zarri. “You can have a safety net of 10 slices that every operator creates as this makes it easier for manufacturers. It does not block innovation, it is complementary and allows for roaming.”

Erwin van Rijssen, head of 5G core strategy at Ericsson, also believes there will be a ceiling on how many network slices operators use. “We currently believe the number of slice types will be limited to a handful or two.”

Limiting the number of slices enables standardisation, which has fuelled the success of the mobile industry. Not only will standards enable services to roam across different operators’ network slices, they will also make it easier to use lower cost, standardised hardware.

Getting to grips with change

But network slicing represents a big shift in how operators manage their networks and collaborate with their wholesale and enterprise customers. And many of them are still feeling around for the best approach.

Up until now operators' customers and their services have had to work within the constraints of a hardware-defined network, originally designed simply to get information from A to B.

Network slices represent a shift to flexible, software-defined, virtual networks. They’ll allow operators to dynamically allocate network resources, giving wholesale and enterprise clients access to customisable network functions that cater for different services, data speeds, latency, reliability and levels of security.

5G networks slicesAs a result, 5G promises to be about much more than merely moving data around; operators and their customers are set to use smarter, more automated networks to analyse data and use the results to shape services.

An operator may decide, for example, to dedicate one network slice to mobile broadband services, another to the automotive industry, a third to smart city applications such as street lighting and a fourth to virtual reality applications.

In Germany Deutsche Telekom is trialling network slicing with the Port of Hamburg, which is both a tourist destination and a major industrial shipping zone. This means the mobile network has to cater for both essential industrial applications and tourists sending pictures and videos. Deutsche Telekom is using network slicing to create virtual networks, each dedicated to specific applications, including the management of traffic lights within the port area; the collection and processing of environment data in real-time; and virtual reality applications that monitor critical infrastructure such as water gates and construction areas.

China Mobile meanwhile has researched how network slicing can be used to enable future power grids.

But creating a relatively small number of generic network slices doesn’t translate to a cap on how many customers or applications can use each slice. Or limit the potential dynamism of the network.

Network instances

Operators will be able to automatically subdivide each single network slice into an isolated network instance. Unlike a network slice, a network instance does not need to be configured on the radio access network, making it much easier to switch on and off automatically – especially on a virtualised, software-based network.

And operators will be able to combine instances of network slices to support the very different network requirements of interconnected services.

When it comes to a self-driving car, passengers may want access to a high bandwidth, mobile broadband slice so they can watch films. At the same time the car's system navigation system will need to access to a network slice that provides a highly reliable, low latency service. A company offering a self-driving car service will be able run these different services by combining instances of each network slice.

DoCoMo, for example, has created a dedicated slice for Toyota, but will create instances of a slice to support discrete services, says van Rijssen.

“The number of slice instances can be unlimited,” says van Rijssen, adding: “It's still early days when it comes to network slicing. Network operators are still defining the best way to use it and building experience through early deployments.”

 

[Image licensed to Ingram Image]

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