Why an end-to-end monitoring solution is essential for the success of LTE Voice


LTE Voice (VoLTE) represents the next generation user experience – with LTE Voice, operators can make use of enhanced capabilities to deliver and ensure high-quality, high-capacity, innovative communication services. This will allow them to differentiate from the crowd, with the potential to increase their market share.

However, managing voice over IP in a cellular communication system brings a lot of new challenges:


  • Subscribers expect the same quality of service they know from circuit switched voice services.
  • LTE voice support requires complex mechanisms and architecture in radio and core networks.
  • Subscriber mobility (handover) between LTE and legacy networks (e.g. GSM, UMTS) requires comprehensive management.


In order to overcome these challenges, CSP’s need to have a complete, end-to-end view of the service, allowing them to mitigate risk, increase both performance and efficiency, and deliver a seamless experience to the customer.


1. An end-to-end solution for correlating fault and performance data

For CSP’s it is essential to have a centralized view of the network, to identify what elements are underperforming, where an error has occurred and its impact on traffic flows, dropped connections and inevitably, the customer experience. This is especially so for LTE Voice since it has a much more complex call flow, utilizing both LTE and legacy networks. An end-to-end system will allow operators to link customer complaints through to network performance and network faults, allowing them to prioritise activity based on customer impact.

On the application side, voice delivery requires a certain quality of service (low latency and jitter), thus service prioritization is needed, in which voice traffic packets get higher priority. Being able to see all data through one user interface will support such activities, ensuring LTE Voice delivers on expectations.


2. An end-to-end solution for monitoring complex LTE Voice KPI’s

The use of a growing heterogeneous network creates new challenges in gaining end-to-end visibility of performance and availability for LTE and IMS networks and services. Because LTE Voice is relatively new, many of the metrics for measuring performance require further development. The KPI’s that should be monitored need to occur across all of the components in the data path including; eNodeB, PGW, SGW, MME, PCRF, CSCF, HSS, and IMS. All the multiple vendor technology not only has to be interoperable, but operators also need effective dashboards through which to monitor system-wide performance. An end-to-end solution will facilitate this by bringing multiple data sources into one centralised solution, allowing operators to easily create and customize multi-data source reports.


3. An end-to-end solution for root cause analysis

The end-to-end call experience using LTE Voice depends on so many factors and so many different equipment types, that determining what impacts each KPI is difficult. In addition to collecting a vast amount of data in order to optimize both the consumer experience and operational efficiency, there is a requirement to investigate the root cause of arising faults. An intelligent end-to-end solution can integrate root cause analysis functionality, highlighting what part of the Voice over LTE call flow is causing the problem, leading to a faster resolution.

Voice over LTE implementation is already on an accelerated path, and deployments are likely to rise as operators begin to understand its value, and handset manufacturers introduce new VoLTE-enabled mobile devices. Therefore, a suitable strategy for end-to-end monitoring will play a critical role in its commercial success.


Zen unified service assurance software collects and analyses vast amounts of network data, providing CSP’s with a real-time, end to end view of the network. Zen is unique in that it brings together fault management, performance management and customer experience management into one single platform. This functionality makes Zen an ideal choice to support a successful VoLTE implementation. Get in touch today to see how Zen can support your VoLTE roll-out, or see some real VoLTE dashboards in out VoLTE Management Use Case.