Ever since the internet was introduced to the world, the demands placed on it by users have constantly evolved. It was once a blessing to simply be connected, but now that more than half the world relies on the internet for work, schooling, and day-to-day activities, the broadband industry must shift its focus to delivering a quality user experience.
For decades, speed has been used as the primary indicator of broadband performance. At the same time, networking experts have long realized that speed is just one dimension of broadband performance, and newer, increasingly interactive applications have made users aware that more than just speed is required to provide the best possible experience. As a result, the industry needs to look beyond conventional measurements of speed and even latency, to improve overall broadband experience and to facilitate the management of network performance against service and application requirements.
Making the network invisible to the customer
Because our ‘always on’, ultra-connected lifestyle now demands so much more from our networks, Quality of Experience can no longer be ignored. For example, the emergence of applications such as Virtual Reality, Augmented Reality, and other high bandwidth, latency-sensitive applications have the potential to place tremendous strain on broadband networks.
Notably, VR technology has become more accessible and widely used over the past few years and it only continues to grow in popularity, with an estimated base of more than 171 million users worldwide and applications in gaming, healthcare, education, architecture, and other markets.
As VR technology and applications evolve, they require much more responsiveness from the network, including stringent latency requirements that are critical to providing customers with a realistic and comfortable experience. In effect, a network providing VR must be invisible to the customer, delivering data packets so quickly and reliably that its presence between the user and the application is not detected.
Latency, or the amount of time it takes for a data packet to travel from one point to another, is one of the network performance metrics used to describe customer QoE and consumers have become increasingly aware of its importance. However, conventional latency measurements do not necessarily provide enough information to drive improvements to network performance, especially when supporting demanding applications and services.
The industry needs to be able to break latency into its components, each of which is affected by distinct factors within the network. By understanding the individual components that make up latency, network designers can focus on the most effective techniques to provide performance optimized for subscribers, services, and applications.
Treating the ‘network illness’ with the right cure
Broadband Forum’s Broadband Quality of Experience Delivered project, published as a series of specifications under the TR-452 umbrella, defines metrics that capture variability in network quality, relating directly to end-user QoE. The framework uses principles of Quality Attenuation (written ∆Q) to characterize the performance metrics, measurements, and analysis required by innovative broadband networks, tackling factors such as latency, consistency, predictability, and reliability.
Quality Attenuation measurements provide the capability for decomposing latency into distinct components, matching them to the sources of performance degradation. For example, packet delay is decomposed into a constant component (due to distance travelled and also bounded by the speed of light), a variable component (caused by queuing or buffering), and a serialization delay (tied to link speeds).
Quality Attenuation then builds a representative statistical distribution of these latency components as well as packet loss, based on the measured transit times of variable sized packets sent over a network segment over time. This makes Quality Attenuation a powerful tool for evaluating both the nature and the causes of network performance issues.
For example, Broadband Quality Attenuation can be used to identify quality degradation due to an inadequate scheduling operation when the network is under load. This in turn allows network operators to optimize broadband performance more cost-effectively via configuration changes, treating the root cause of the issue rather than just increasing link speeds, which could entail significant expenditure without solving the problem.
The time is right
In this new gigabit era – with the likes of DOCSIS 4, XGS-PON, 25G, 50G, 100G, coherent PON, and Wi-Fi 7 either available now or on the horizon – more speed has diminishing benefits as perceived by customers. Instead, a new generation of interactive apps and services requires a more responsive network. As this evolution continues, speed will no longer be the main differentiator, but rather just one factor in the quest for a more comprehensive understanding of network performance, based upon service and application QoE.
By focusing on QoE, service providers can achieve reduced churn, new Average Revenue Per User growth opportunities, service differentiation, and lower OPEX applied to customer support and network planning. Services differentiated for specific QoE can be offered initially to particular target groups and ultimately, to the wider broadband subscriber market. These offerings can be powered by Broadband QED, which provides the needed framework to specify, measure, and analyze, and ensure the quality required for these next-generation applications driving value-added services.
Gavin Young is responsible within Vodafone Group for the fixed broadband access technology strategy, architecture, vendor roadmaps and standards across the 17 countries where Vodafone currently has fixed access assets, including fiber, cable and DSL access technologies plus fixed-mobile access. Young was a founding director of the Broadband Forum, for which he served as technical chairman for 12 years, in addition to serving as co-chair of the UK21CN consultation’s broadband group and on other technical boards. He is chairman of the Ofcom Spectrum Advisory Board and is active in several CableLabs initiatives, and is a fellow of the IET. This piece is exclusive to Broadband Breakfast.
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