Insight into user Quality of Experience (QoE) has been a ‘holy grail’ for operators since the dawn of mobile networks. However, the emergence of 5G, and the new use cases, services, and customer QoE expectations it brings, requires a rethink of how QoE is measured and assured in the 5G era. How can operators monitor and assure 5G QoE?

The cloud-native, distributed, dynamically orchestrated 5G core network brings a plethora of new services, uses cases, and – in the case of 5G-StandAlone (5G SA) – network slicing. As well as offering operators significant new revenue streams and opportunities, it also brings new expectations – in terms of Quality of Service (QoS) and Quality of Experience (QoE) – from end users, whether consumers or enterprises.

This will require significant changes in the way 5G SA QoE and QoS is quantified, compared to 4G LTE and 5G-Non-Standalone (5G NSA) networks. At the same time, new use cases require completely new methodologies for measuring QoE. Think 4K video, AR/VR, real-time gaming, and so on.

5G SA requires a new QoE paradigm

As outlined in the previous blog (see ‘Measuring 4G LTE QoE with Emblasoft Evolver'), QoS refers to network performance, such as throughput, latency, packet loss, jitter, and so on, whereas QoE refers to customer satisfaction, experience, and the perceived integrity of the service. Of course, QoS can be mapped to QoE, but QoE also has non-technical aspects.

5G NSA is similar to 4G LTE in terms of measuring QoE – only the radio component in in 5G NSA is carried over 5G, the core network remains 4G. While there are some aspects of QoE that need to be measured over the 5G radio component, there is not too much difference in terms of network performance parameters, as the core is 4G. However, 5G SA brings a completely new cloud-native core architecture – which requires different ways of measuring QoS in terms of network performance (and, in turn, QoE).

But perhaps most importantly, by enabling network slicing, 5G SA QoE monitoring and assurance brings a whole new level of complexity when it comes to assuring QoS and QoE. Many applications and services may be running in dedicated network slices with each requiring a unique set of QoS and QoE parameters. It means that service providers must monitor and assure multiple, simultaneous services, each with their own KPIs and SLAs.

The core concepts of 5G SA QoE remain the same: Is the service available? Is the service maintained? How fast is the response time? What is the quality of service in use? However, new 5G use cases and innovative new services will bring higher, or even completely different, user expectations of QoE.

On top of all that, 5G SA enables not just eMBB (high-speed, high-quality consumer mobility), it also offers IoT/massive Machine-Type Communications (mMTC) applications, as well as mission-critical Ultra-Reliable Low Latency Communications (URLLC) communications for use cases such as remote surgery, factory automation, and autonomous driving.

QoS comes first

It makes measuring QoE in a 5G SA environment, not only extremely challenging for MNOs and service providers, but in many cases providers and UE are both breaking new ground in terms QoE expectations. 5G also brings faster throughput, greater complexity, higher data volumes, and much larger scalability. The addition of mission-critical applications, as well as machine-related UE SLA requirements, requires a new QoE paradigm.

Where 4G uses the EPS Bearer for QoS control, 5G uses something known as QoS Flow Identifier (QFI) as the mechanism for determining and standardising QoS in the network. 5G flows are mapped in the Access Network to Data Radio Bearers (DRBs), unlike 4G where the mapping is one-to-one between EPC and radio bearers. 5G QFI classifies all packets in the network into different QoS classes, with each class assigned its own QoS characteristics (such as packet delay and loss). In this way, different packets – for example, in different network slices – can be tailored to meet the specific requirements of that service, or slice.

QoE standards and frameworks for monitoring and assuring 5G SA services and slices are being introduced, developed, and optimised as new services and use cases come into being. However, like 4G, there are some QoS parameters that can be mapped directly to QoE.

Emblasoft Evolver: Assuring QoE in 5G SA networks and slices

Emblasoft Evolver, incorporating active monitoring, is a comprehensive test and assurance platform that enables operators to meet their KPIs and SLAs (both from a QoS and a QoE perspective) in both 4G and 5G networks.

In the case of 5G, Evolver enables the following QoS measurements to be captured, which can then be mapped to QoE requirements:

• Registration & PDU Setup Time
• QFI Validation
  • Latency (RTT)
  • Throughput
• Packet Loss
• Time to First Byte
• TCP and UDP based traffic
• Streaming media verification
• Slice Verification

As well as embracing DevOps – incorporating continuous integration (CI), continuous development (CD), and continuous testing (CT) – which is essential for maintaining service innovation and differentiation in the 5G era, our active agents or probes in the network can simulate any UE scenario allowing service providers to not only test new services and slices pre-launch, but also on a continuous basis.

Evolver with active monitoring enables a preventative approach post-launch throughout the lifecycle of a service or slice. It can continuously simulate realistic traffic through the core network enabling real-time detection of faults with real-time alarms, allowing service providers to rectify any issues before they impact the customer. It can do this for simultaneous services and slices in a highly scalable manner.

Active monitoring of QoE in 5G networks

Active probes within the network simulate and measure QoS and QoE from the perspective of the UE (human or machine) for individual services, such as video streaming, VoIP, and mission-critical 5G SA-based services and network slices. Any number of scenarios can be simulated, including changes of channels during a session, different numbers and types of users, or changes in requirements for each service or slice – all on-the-fly. It can do this simultaneously in the same cell or slice, or in different cells or slices.

It provides instant insight, and real-time fault alarms, into service or slice QoE under any imaginable scenario – all of which can be automated. Evolver can also emulate individual nodes in the network, so that isolated testing can be applied to any point in the network.

Results can be displayed in Evolver or exported via Prometheus to a tool such as Grafana. Test can also be set to be triggered by other events, or as scheduled or batch tests – making it ideal for dynamic eMBB purposes as well as, for example, regularly testing large estates of IoT devices. It can also be set so that specific triggers lead to an API event, which in turn triggers a corresponding action in the OSS or at a network node.

In short, Evolver with active monitoring is ideal for assuring 5G SA services and slices, enabling MNOs and service providers to meet their SLAs. To find out more about how Emblasoft can help, or to request a demo, get in touch today.