Not all bandwidth is created equal: What is QoE and why does it matter?

Not all bandwidth is created equal: What is QoE and why does it matter?

By Craig Thomas, VP Marketing & Business Development at Broadband Forum

The more users access their broadband networks – and over the last couple of years, that increase has been unprecedented and rapid – the more acutely aware they become of the network experience they’re receiving.

For service providers, this offers both challenges and opportunity. It’s important that they are as accurate as possible measuring the experience that their customers are receiving. That means that increasingly outdated measurements of service quality – like speed or bandwidth alone – must be replaced by parameters that better gauge the actual experience of their subscribers.

Key to understanding this is defining the difference between Quality of Service (QoS) and Quality of Experience (QoE), and how the applicability and relevancy of these measurements have changed as the broadband market has evolved.

New meets old

The standard, and traditional, way to measure network performance is QoS. It focuses on objective network characteristics like latency, jitter, and packet loss. These components are still relevant, but today, service providers – as they offer new services and products – must deal with the added complexity that next-generation services create. This means that standard QoS is facing a redundancy of usefulness as a standalone litmus test for quality, as it cannot accurately detect the nuances that can greatly affect network performance.

In other words, the QoS’s limitation is that it cannot consider the relationship between the end-user and the technology. It may be able to measure technical performance but cannot give the full picture of a network’s performance. For example, whilst a service provider may hit Service Level Agreements (SLAs), which are the minimum thresholds for service performance, it doesn’t factor end-user satisfaction and this will not correlate 100% with QoS metrics.

That’s why, in recent years, we’ve seen the rise of QoE, or ‘Quality of Experience’ as a measurement of the network service delivery as experienced by the customer. QoE aims to show how the service quality is experienced from a subjective, user point of view. It does this through a combination of active and passive network traffic monitoring mixed with automation and real-time analysis – examining the information within the data sent over the network, not just the efficiency of data transport across the network itself.

By combining these QoE estimates with objective, technical QoS measures, a better picture can be drawn of how network performance translates into customer satisfaction. However, the task doesn’t stop there.

Not all bandwidth is created equal

We’re living in the age of gigabit broadband. In the past, bandwidth quantity and speed has been used a measure of how good a broadband network is. Functionality – such as looking at what can be done with the broadband connection, like synchronization support for small cell/mobile backhaul – was another way to determine quality.

Bandwidth, however, is an increasingly weak proxy to measure the application outcomes that customers value.

• The same bandwidth on two different networks can deliver different user experiences.
• Likewise, the same bandwidth and average latency can deliver different user experiences.
• The same bandwidth, average latency and the same jitter can deliver different experiences.
• The same bandwidth, average latency, the same jitter and the same packet loss can deliver different user experiences.

It’s clear that our metrics need to go further.

Previously there was a link between increased bandwidth and how well the application’s (e.g. a web page) load time was. In the gigabit era, this coupling is less clear. And network quality metric inadequacies make it impossible to know if a service provider is improving user experience, especially when looking at a network of multiple gigabits.

Broadband Forum’s QED framework is looking holistically at this challenge. Specifically, the network attenuation technique, that looks at performance and the linkage to application outcomes.

The framework uses Quality Attenuation (written ∆Q) to address the need for improved performance measurements and analysis required by cutting-edge broadband networks, tackling factors such as latency, consistency, predictability and reliability. Broadband QED provides a framework for decomposing a trip time into distinct components, matching them to the performance degradation sources, for example, packet loss/delay, and relating them to geographical network topology, network features, and network load/scheduling.

As new applications place increasing demand on networks, it’s important for service providers to look beyond factors such as data rate and ping time to move from a fast network to a quality network where everything just works.

Register now for the ‘Latency – Challenges & Opportunities for the Communication Industry vBASe  Webinar’ at 10am ET/4pm CEST on May 31, 2022 to hear from a host of panelists from Cartesian, Domos, Friendly, Meta, Omdia and Vodafone. You can also catch up on the ‘Connected User – Advanced in Service Management’ vBASe Webinar, to hear from speakers from Axiros, F-Secure, Incognito and KAON Broadband.

What else is Broadband Forum doing for QoE? 

The Open Broadband – WWC Reference Implementation for 5G-RG (OB-5WWC) is designed to help vendors and operators bring products to market more quickly, with reduced development times and cycles. The project will bring the benefits of the 5G ecosystem to fixed-line services and offer a full end-to-end solution to operators.

OB-5WWC aims to create a reference implementation of the Broadband Forum specified Wireless Wireline Convergence solution for 5G capable residential gateways (5G-RGs) and builds on the Broadband Forum and 3GPP specifications already available.

The Access and Transport Architecture (ATA) Work Area (WA) defines and specifies the architecture and requirements for access, routing and transport network infrastructure. ATA produces industry-agreed specifications for applications such as mobile transport infrastructure (fronthaul and backhaul), data center interconnect, residential broadband Internet access, etc. as well as specifications for testing these networks and their application. (E.g., Performance monitoring and testing, Application Level Testing and testing quality of experience.). This work is typically in the form of architecture, equipment requirements, test guidance, implementation guidance, and education materials.

A critical element of the work is the long-term support of existing network elements alongside virtualized software-based network functions, resulting in a stable network that may be evolved over time. This enables seamless migration of new networking technologies based on their market acceptance, at the same time protecting existing infrastructure investment, and deployment into new territories.

Broadband Forum’s Broadband User Services Work Area develops specifications and publications to create a new kind of broadband experience for the end-user and provides new means for service providers and application developers to monetize the broadband user’s connection. This ranges from managed Wi-Fi, IoT or smart home services, broadband and in-home performance management, and more – all of which open up large markets and profitable business models.

Broadband Forum has also offered a view of what the networks of the future might look like, demonstrating a technology called dynamic session steering which uses software-defined networking (SDN) to reconfigure a user’s connection on the fly based on the application they’re using.

The exhibition was the latest breakthrough in Broadband Forum’s work on its Cloud Central Office (CloudCO) project. Launched in 2016, CloudCO reimagines traditional central office hosting infrastructure by shifting to an SDN-based model which incorporates cloud capabilities and virtualization to make network functions more agile. By standardizing the interfaces between different elements, CloudCO also aims to enable interoperable multi-vendor deployments.

The demonstration highlighted how an operator might change the user plane location of an existing subscriber session in order to meet the SLA requirements of different applications.