Insights Blog

How Does Your International Voice Quality Measure Up to Consumer Expectations?

Posted by Martin Jansson on May 5, 2017 Topics: Mobile Operators, quality testing

Connected_people_sized.jpgMobile networks cover over 55% of the global population, on track to reach over 73% by 2020. But for increasingly mobile consumers, it’s not enough to just have a mobile connection. The connection has to be clear, and it has to work around the world.

Mobile operators have heard the consumer demand and are moving to an infrastructure better suited to boosting and maintaining international voice call quality. While over 150 operators offer High Definition (HD) voice, they still need to be able to support standard definition calls and older network infrastructures.

An IP Multimedia Subsystem (IMS) framework supports HD and LTE calls, but what about calls that leave the IMS framework and hit any one of the myriad networks that still run on circuit switch technologies? Because IMS uses packet switched networks and the two technologies don’t always communicate well, the risk of quality problems and bad service increases.

That’s why quality testing is needed more than ever. But how quality is defined can be a challenge for most operators.

Operators and carriers measure quality of service (QoS) in various ways: via transport parameters (round-trip delay, packet loss, jitter) or via service parameters (voice quality, ALOC, and ASR, among others). While each measure has its own merits, voice quality testing, measured by mean opinion score (MOS), is one of the most important.

It’s also one of the most difficult to measure. MOS is subjective, and as such, it’s difficult to confirm the actual quality. MOS was originally ranked by trained experts on a 1-5 scale, with 1 being the best quality. Today, it’s determined by analytics and algorithms. But to make international voice testing more complicated, there are several standards used within an MOS framework to assess quality (PESQ/POLQA, P.563, E-Model, and P.564).

While each method has its own strengths and weaknesses, PESQ/POLQA provide the most accurate testing result. (Note: Whatever method you end up using, be sure to stay consistent). First, PESQ/POLQA provides end-to-end testing, fully representing the user experience. Carriers and operators have full control of the testing scope and can reproduce results, leading to the most accurate and consistent MOS scores. And, during the transition to an all-IP environment with mixed circuit switched and packet switched technologies, active testing with test probes makes the call transparent to the transport network.

Being able to confirm quality is especially important in the transition to IP networks that support international voice. Existing and emerging international voice services like international VoLTE and HD voice require a strong quality testing foundation based on MOS. They also require a strong IPX network to facilitate a seamless global platform for SD and HD voice. HD voice introduces additional routing complexity, and there’s a need for increased awareness and transparency surrounding quality.

The world is more connected than ever, but quality connections can’t be made without strong quality testing. The transition to an all-IP environment introduces technical challenges and securing the quality in this environment is central. Having the right solutions in place assures quality, wherever your customers may roam.

To learn more about CSG’s approach to quality testing, CLI verification, FAS detection and testing services for SMS and roaming, please visit http://info.csgi.com/assure

Martin Jansson

Martin is a Director of Product Management at CSG International.