QualTest Sevana

Mobile-to-mobile test and monitoring

Would you like to setup mobile-to-mobile test call or monitor end-to-end call quality on a set of mobile phones?
Sevana QualTest is the solution that lets you establish this within one business day and receive full details on the quality score (MOS) and audio issues that have potentially degraded the call quality.
Analysis is performed directly on the phone, or one can have multiple phones connected to an USB port to make simultaneous tests.
All test results are aggregated directly at the backend of your choice.This can be Sevana QualTest backend or your existing monitoring solution.
Another option is to use one of easy integrations of QualTest, which our clients prefer most.

Contact us for more details.

QualTest Sevana

QualTest – Mobile Test Probe

Sevana QualTest mobile test probe is an application that checks current network conditions and estimates voice quality in mobile and VoIP networks. If your goal is to set up end-to-end or single-ended automated tests, receive test results at any backend of your choice, manage tests and watch test results and reporting at a friendly GUI, then QualTest is a good fit.

Keep an eye on call quality with sevana.biz

Sevana Software

Sevana Digital Signal Processing for Telecommunications

What is Sevana offering?

We offer knowledge and experience of our scientists and developers to solve complex software tasks in telecom, digital signal processing and other areas that require the unique skills we have.⠀

We are experts in:⠀
•⠀Audio processing and Digital Signal Processing⠀
• VoIP and SIP client and server systems development⠀
•⠀High performance network programming and real-time systems
•⠀System architecture design⠀
•⠀Complex algorithms design and development⠀

Working with us means:⠀
•⠀Access to experts with 20+ years of experience⠀
•⠀Access to Sevana knowledge base⠀
•⠀Access to Sevana base of libraries and algorithms⠀
•⠀Professional management⠀
•⠀Reliable SDLC⠀
Contact us for more details on Sevana Digital Signal Processing for Telecommunications

Sevana Software

sevana-is-sharing-source-code
C++ wrapper for libevent library

Sevana is sharing with open source community its tiny C++ wrapper for libevent library under MIT license. This helps us  to quickly build HTTP clients and servers reducing development costs due to API simplicity and integration. We actively use it in our products to provide high performance HTTP processing.

Visit repository

PVQA Sevana Test and Measurement

Call quality issues maintenance prior your cusotmers complain

Do you want to know about call quality issues prior your customers start complaining?

Sevana libraries collect all the QoS and QoE data of the calls in real-time, providing immediate alerting on changes that affect callers’ perception, and discover and store reasons for call audio degradation. Map audio impairments on network metrics and discover QoE and QoS patterns, specific to certain routes, destinations, originations, or parts of the traffic.

Every call, analyzed by the system, creates big data that one can study, using data analysis tools, to predict network behavior and call quality.

AQuA Test and Measurement

End-to-end audio quality testing: is there a simple but powerful tool for end-to-end audio quality testing and file comparison?

Meet Sevana AQuA – Audio Quality Analyzer 🔉
It is a simple but powerful tool to provide perceptual voice quality testing and audio file quality comparison.
The human ear is a non-linear system, which produces an effect named masking. Masking occurs on hearing a message against a noisy background or masking sounds.
AQuA perceptual model is based on research of four different scientists who discovered influence of different frequency bands (the so-called critical bands) to human perception.
The value of spectrum energy in frequency bands can be used for different purposes; one of which is the sound signal quality estimation.
However, using only critical bands discovered by one scientist does not allow getting an estimation objective enough, since they show only one of the aspects of perception or speech production.
AQuA can determine energy in various critical bands as well as in logarithmic and resonator bands, that allows taking into account more properties of hearing and speech processing.
We know three tools of this kind available on the market: POLQA, ViSQOL, AQuA. Please contact us if you know other tools or like to evaluate Sevana AQuA.

PVQA Server Sevana Test and Measurement

Real-time network statistics and KPIs one can benefit from using PVQA Server

Learn about network MOS and variety of waveform KPIs related to impairments that affect voice quality in real-time
📞 Agility
Add proactive maintenance layer based on PVQA call quality monitoring and let your support engineers be notified when call quality issues prevail in conversation
⠀📞 Quality issue root-cause discovery
Based on impairments analysis speed up problem root-cause identification, discover packet loss patterns inside the call audio
⠀📞 Flexible setup
Integrate PVQA library into existing system or create a new one suitable for any hardware and OS
Keep an eye on call quality with Sevana!

PVQA Sevana

How to find call issues that affect callers’ perception?

Sevana PVQA analysis detects and informs about such annoying problems inside the call audio as:

VAD clipping – this impairment detects incorrect work of Voice Activity Detector (VAD). Detector finds edges of active and inactive fragments of the signal considering VAD worked too late (in the beginning of the speech) or too early (in the end of the speech).

Clicking – is a single energy spike in the spectrum of the audio, which may happen for different reasons.
Audio gaps – is a zero-signal level inside speech, a gap in speech that may be caused by different reasons.
Dead air – is a constant signal level inside speech and may have positive and negative value.
Noise – this means that noise level present in the call affects human perception and disturbs the caller.

… and will also let you discover patterns of impairments specific to certain suppliers, partners, or other networks:

Click + DeadAir-01 – high probability that packet loss affected the call audio
Click + VAD clipping – possible packet loss

PVQA Sevana Test and Measurement

Caller quality of experience measurement. Do you know about issues bothering your callers that you might not know?

Sevana PVQA technology detects these impairments to predict caller’s quality of experience aside from network quality of service:

💡 Silent Call – one leg of the voice call has no speech (silentcall)

💡 Echo – this is typically due to a blockage or mismatch, which results in the signals bouncing back from where they came. Additionally, the presence of echo effect in packet switched networks can be traced back to the functionality of the line. Where standard lines function with a delay of 10 milliseconds, packet switched networks can have up to 400 milliseconds of delay. As a result, the echo effect is much more noticeable.

💡 Amplitude clipping – is typically a result of a misconfigured voice gateway on the voice path.

💡 Dynamic clipping – notifies about possible clipping happening in another network as the audio waveform corresponds amplitude clipping, however, it is not present at the moment.

These and other impairment detectors allow you an effective caller quality of experience measurement. Contact us to learn more.

Mobile QualTest Sevana Test and Measurement

How to make mobile test call from one mobile phone to another?
Using Sevana QualTest it is easy:

✅Measures quality of mobile calls with regular non-rooted Android phones and iPhones
✅Enables uploads and shares test results
✅Runs both active (with reference audio) and passive tests
✅May be integrated with QualTest Host and correspondent Backend to automate making and receiving mobile test calls
✅Measures quality of mobile calls in the field
Within QualTest one can easily setup these two test scenarios:
🔊 initiate test calls and measure MOS when installed as system application. It is available on rooted phones only. One can view / share / upload test results right from the phone.
🔊 initiate and accept calls without analysis on mobile phone. Rooted phone is NOT required. In this mode application notifies its desktop (Raspberry Pi) counterpart (Qualtest Host, further down QH) about progress of the call. QH handles audio streams via cable adapter and communicates with backend.