Network slicing – the right way to deliver 5G

As telcos look for solutions to garner maximum return from their 5G network investments, here is a solution that makes it a win-win proposition.

By Hemant Kashyap

Network operators have transformed their networks from hardware-centric to software-centric. By being able to use each network function as an application, these developments have allowed network operators to create network slices that provide service assurance by creating virtual wireless networks as part of the overall wireless network, as also bringing in greater speeds, lower latency, greater capacity, ultra-reliability, and greater flexibility in the network operations and more.

According to GSMA, by 2025, operators can expect USD300-billion opportunity driven by network slicing that will enable them to separate the business traffic from general internet traffic, the bulk of which will come from manufacturing, logistics, and automotive sectors. However, for this to happen there is also a need to align network slicing and private networks. The technology panel discussion at the Voice&Data TLF 5G Conference discussed the trends in network slicing, and what it makes possible, along with challenges to overcome on the way to that. The session was moderated by Ibrahim Ahmad, Consulting Editor, CyberMedia.

“Slicing a network essentially means that a network operator logically separates different topologies based on the use case, and the priority.”

Saurabh Tewari, Director & CTO (Telecom), Dell Technologies

What makes slicing possible?

“I think 5G is the first generation for the enterprise. I think everything revolves around what we can do with enterprise,” said Pankaj Kitchlu, Systems Engineering Director (India-SAARC), Juniper Networks. Pointing to the changes, he added that the architectural shift happens more towards giving a deterministic, predictable, hands-free environment.

“I think 5G will co-operate and collaborate and bring everything together as a platform. We didn’t have platforms in any of the previous generations. So far, we’ve had upgrades; now we have a new network entirely,” Kitchlu said. Similar views were expressed by the other two panelists – Saurabh Tewari, Director and CTO (Telecom), Dell Technologies and Saurabh Mittal, Head-Solution and Integration Network R&D, -*-Bharti Airtel.

Talking about the actual changes that will happen with the new technology, Mittal highlighted that the changes will mostly come as network virtualization, cloudification, and microservice architecture. “5G-based networks have to be absolutely agile. The radio has to be agile and flexible for reconfiguring for 5G, and the transport has to be programmable to meet the required SLA, QoS, and Network Topology,” he added.

There has been a semi-regular trend when progressing through generations. “When you look at legacy networks – 2G focused on voice, 3G as well. Data was always an afterthought. On 4G, the voice became an afterthought, as the focus shifted to data. But when you move towards 5G NR, instead of the older concept of APNs, where you would give a small IP pool, on which we could isolate certain networks, one can have a logically separated network,” Tewari pointed out.

To enable slicing, networks must have automation, disaggregation, and shared architectures, Tewari explained. “One big advantage of disaggregation is that it allows telcos to use network components from multiple vendors. Because of this disaggregation, you are no longer bound by what one vendor is doing. You can share the same in the semiconductor industry and implement it very quickly,” he said.

Challenges to network slicing

There are several challenges to overcome before companies can implement sliced networks. Keeping services up while the transformation happens is the biggest challenge the telcos are facing. “Right now, we are changing the wheels while we are driving, which is the biggest challenge,” Kitchlu stated; and rightly so as telcos remain one of the few mission-critical services, and the networks just can’t go down.

“We didn’t have platforms in any of the previous generations. So far, we’ve had upgrades; now we have a new network entirely.”

Pankaj Kitchlu, Systems Engineering Director (India-SAARC),

Juniper Networks

To enable slicing, networks must have disaggregation. One big advantage of disaggregation is that it allows telcos to use network components from multiple vendors.

The challenges lie in Capex, operations, product life cycles, merging B2B and B2C traffic on one network, scalability, and regulatory challenges. Networks are established to enable the scalability of processes. With Industry 4.0 use cases there will be billions of connected devices over a network. The real challenge lies in how to manage the said scale according to the demand of the end-user.

Another issue that lies in delivering network slicing is to manage B2C and B2B traffic across the same network. “How do we manage the right level of segregation and still manage the expectations,” Mittal asked, pointing out that telcos are looking at network gear vendors to ensure they meet the requirements.

One of the most significant roadblocks here is the regulatory issues. The government has not allowed telcos to ever implement QoS over network delivery. Since the whole premise of network slicing is to establish the same differences, it raises a problem. The government’s decision on 5G-based slicing will decide whether or not it will become a possibility.

“All of these are going to be challenges, which we can address satisfactorily for the person that matters the most in the entire ecosystem – the customers,” Tewari concluded.

Security – an inherent part of network slicing

Slicing a network essentially means that a network operator logically separates different topologies based on the use case and the priority. “This allows for significant isolation between critical services, and consumer services,” Tewari said. Therefore, slicing will in fact generate far more secure networks.

Kitchlu, however, pointed that there were some aspects and operations that will fall under the untrusted zone – a network zone susceptible to attacks. “Since these operations are internet-driven and not telco-driven, this might force network providers to look to harden this untrusted zone.”

Furthermore, since network slicing allows telcos to separate one aspect of a network from the rest, a threat, when detected, can be quarantined in a specific slice. Since there are no physical network aspects the slices are logical and programmed into the network. Hence, the attackers can’t compromise anything more than the particular slice which they attacked.

However, the era of point security has ended with centralized networks. As networks decentralize and get closer to the edge, the security needs to be connected as well. “I think the real-time nature of the services needs real-time reinforcement. It isn’t easy. If there’s detection, there’s a compromise. There has to be some sort of connected policy,” Kitchlu said. What’s more, with 5G, or any new generation, in fact, higher bandwidths bring with them more threat surface area. “Now, physical securities can’t be guaranteed,” Mittal added.

For a while now, network security had been the last thing on the agenda. However, as the industry panel confirmed, the industry now looks to create networks with security as an intrinsic aspect. “So, security will be the least of our concerns. But too much security can be a bit of a concern,” Tewari stated.

Slicing – an exercise in cooperation

Since 5G will usher in the era of private networks, and user-specific use cases, cooperation will form the bedrock of optimum service delivery. Therefore, the customers, especially the enterprise, need to closely collaborate with network SPs to get the best out of networks. Slicing will make a lot possible, besides just differentiating QoS.

“Only time will tell how things will unfold. But I am sure that there is need for much more collaboration with the B2B customers.”

Saurabh Mittal, Head-Solution and Integration Network R&D, Bharti Airtel

Telcos understand that they have to interact with their enterprise customers; to sit and deliberate on the customers’ demand in order to create a network slice capable of meeting the said demands. “Only time will tell how things will unfold. But I am sure that there is a need for much more collaboration with the B2B customers,” Mittal said.

“If we have to get an industry-specific use case consumed, you have to have an expert from that industry. It is very important that collaboration in 5G happens in multiple spheres,” Kitchlu said. Of course, network operators don’t know anything about telemedicine, or disaster management. As such, there has to be a doctor and an NDRF person on board to assist telcos with delivering what is needed. That makes deploying the new network a much more exciting, and collaborative exercise.

On the same matter, telecom vendors and telcos are looking at the use cases they can develop with 5G. This will allow them to monetize more of their assets and get a decent return on their CAPEX. Added Tewari: “I’m sure that everyone involved in the telecom sector is working together in making that ecosystem more and more secure, scalable and very, very high performance. As each and every product is secured, you end up securing the entire ecosystem.”

“Rather than keeping the promise of continuity, this is the promise of disruption, of disaggregation, of change,” Kitchlu concluded.

Industry 4.0 will add billions of connected devices over a network. The real challenge will be to manage the said scale according to the demand of the end user.

Too much, too good thing

People within the telecom industry have repeatedly voiced an opinion that creating too many slices can lead to network underutilization. However, experts seem to think that is not the case. Unequivocally, the expert panel had said that the whole premise of network slicing is to increase network utilization.

Basically, a network slice creates a shared network for every single use case. This slice is logical; that means that network administrators can modify the algorithms and parameters of a slice as they wish. Therefore, this will lead to an improved overall network structure.

Right now, the network service providers are waiting for the 3GPP Release 17 for more standardization related to network slicing. Since the process still remains a work in progress, the industry believes that with Rel 17, they can implement slicing more efficiently.

“Slicing is endlessly customizable,” Tewari highlighted as he talked about the best practices for network slicing. “So, you need a very strong feedback mechanism, which the upper layers of the network can consume and take a decision from,” he added.

Essentially, creating slices will allow telcos to deliver capabilities. It can be a drone supply chain, or a person streaming 8k content. Everything will happen on the same network, albeit on different slices.

hemantka@cybermedia.co.in