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An Automated Assurance & Operations deep-dive into mobile voice

Renata Da Silva
May. 11 2023

Mobile voice may not be the most innovative service for telcos, but it is one of the most profitable and mission-critical. In a previous blog we looked at fixed voice, and it’s certainly true there is lots of commonality between them – they both remain commercially lucrative and the customer experience is extremely sensitive to the performance and reliability of the underlying network. But when it comes to mobile voice specifically, according to GlobalData these services’ share of total mobile revenues, while trending down, remains sticky when contrasted with a steeper down-trend in monthly MOU, suggesting a lower cost-to-serve and greater profitability going forwards.

Why is mobile voice business-critical?

But why is mobile voice, in particular, a business-critical service for telcos? For two reasons: first, quality of service is one of the most important factors impacting the customer’s decision to choose, or to leave, a particular operator. A highly performance-sensitive service like voice, for which network performance issues have a uniquely direct impact on the customer (think dropped calls, silent calls, poor voice quality, call setup delays) is therefore on the frontline of customer decision-making.

The second reason is the rise of higher quality, more feature-rich mobile voice technologies, VoLTE and VoNR. It has two effects: it puts further downward pressure on cost-to-serve by eliminating the need for circuit-switch and associated spectrum costs, and it creates more opportunities to differentiate on service quality with better voice quality, lower setup time and greater call stability.

In a sentence, new mobile voice technologies are creating greater opportunities for operators to differentiate on service quality, attract and retain customers, and reduce cost-to-serve. Like seatbelts in a car: not the first thing you’ll see in the advertisement, but fundamental to the buying process and just expected by the buyer.

What challenges are involved in deploying mobile voice technologies?

But it is not simply a case of deploying VoLTE and VoNR  and then waiting to reap the benefits. As the experience of the initial rollouts of VoLTE indicates, deploying a completely new technology for voice service delivery brings a completely new set of challenges in assuring the service itself.

For example, where packet loss does occur in a VoLTE session, the impact on customer experience is immediate and significant. This wouldn’t be the case with a traditional circuit-switch session over 2G or 3G.

Roaming is also a particularly stubborn problem for VoLTE, since the technology itself wasn’t initially enabled for calls across multiple operators, and falling back to circuit-switch mid-session when the device is out of LTE range causes short, but very much perceptible, periods of disconnection. The device itself (the UE) can also be the root cause of VoLTE issues, with one-way audio issues, long delays and call failures commonly reported even now.

How to overcome these challenges

To summarize the problem and the solution; migrating from circuit-switch to packet-switch networks means that mobile voice is now exposed to the same potential problems as mobile data, and these can arise from the device, backhaul, transport or core network domains so the troubleshooting process is significantly more complex than in the circuit-switch voice.

But, in contrast with most mobile data use cases, when faults do arise in the underlying network, the impact on the end-user experience is immediate and significant.

The solution to ensure VoLTE and VoNR quality must encompass end-to-end cross-domain visibility from the user and service dimensions to the RAN, transport, and core network domain resources, so that perceived customer experience can be monitored and the root-causes for mobile voice can be quickly identified and resolved.

How can Infovista Automated Assurance and Operations help?

This is where Automated Assurance & Operations comes in.

  • It brings together customer experience, application and service, and network intelligence into a single platform to accelerate and automate cross-domain correlation and root-cause analysis
  • It provides visibility into perceived customer experience – per-subscriber – rather than inferring it from the conditions of the underlying network and being blind to problems arising from the device and air interface    
  • It introduces a broad set of automation so that detection, analysis, resolution, and validation can be streamlined to deliver a more reliable, differentiated customer experience

A remit as broad as this means that the potential applications, users, and stakeholders are extensive, so we took the concept of Automated Assurance & Operations and built use case-based solutions to support specific processes within network and service operations, creating value quickly for specific users.

Use case example: VoLTE and VoNR monitoring and assurance

One of these is our solution package for VoLTE and VoNR 360º assurance, powered by Infovista Ativa™.

Designed to support the end-to-end service assurance process for mobile voice, the solution specifically solves the problems I mentioned above, that CSPs face in the adoption not just of VoLTE but also VoNR in the context of 5G networks. Unlike the legacy service assurance systems that it replaces, the solution combines data about customer experience (by looking at the traffic packets themselves that run across the network) with data about the core network (by looking at the networks functions and applications that manage the traffic), and the radio access network (using call-trace and performance management information). Some of the specific features that allow the solution to turn this combination of data into actionable intelligence are below:

  • Horizontal (device, RAN, transport and core network) correlation: The solution incorporates call-trace data from the RAN domain with core protocol data and E2E resource performance data across radio core and transport, so the user can quickly detect the root-cause of a degradation in QoE, or customers impacted by a service outage region
  • Geospatial heatmaps and visualization: The solution presents correlated data about QoE and RAN performance in a geospatial heatmap view. Single subscribers’ mobility can also be visualized to support, for example, detailed troubleshooting of problems impacting a specific customer
  • Per-subscriber experience monitoring: The solution can provide per-subscriber and per-segment insights into actual QoE, supporting the identification of cells or clusters that are the root-cause of perceived QoE degradations
  • Automated root-cause analysis: The solution includes workflow automation of previously manual troubleshooting tasks and can integrate with the CSP’s troubleshooting and trouble-ticketing systems. Pre-configured automated workflows include tilt and swapped feeder identification, recommendations for problematic RF areas, and on-the-spot visualization and validation of touchdown main beam point, inter-cell distance and traffic hotspots
  • End-to-end QoS observability with correlated RAN & core call tracing: The solution supports QoS assurance, subscriber QoE analysis and troubleshooting based on correlated RAN and core domain call traces. It supports drill down from multi-domain KPIs or PDU/L3 detailed troubleshooting for selected subscribers or network elements from the same user interface

These features are not a statement of our vision but rather features of our Automated Assurance & Operations solution for VoLTE and VoNR monitoring, available now and powered by Infovista Ativa™.

You can find out more about Ativa by visiting our website or request a demo from our experts to explore exactly how it works and find out how quickly it can deliver mission-critical customer experience differentiation in your business. 

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