Professional VoLTE QoE Testing on Android. Real MOS. No MOS Box.
Objective VoLTE and VoNR call quality measurement on any rooted Qualcomm Android device. ViSQOL MOS scoring, RTP jitter, RTCP-XR delay, full IMS/SIP signaling capture, and call drop root cause analysis — correlated with chipset-level RF measurements in real time.
HiCellTek VoLTE QoE is a professional measurement module for Android that computes objective VoLTE and VoNR call quality scores using ViSQOL (Google Research, Apache 2.0), captures RTP jitter and packet loss (RFC 3550), RTCP-XR round-trip delay (RFC 3611), full IMS/SIP call flows (RFC 3261, 3GPP TS 24.229), and active codec type (AMR-WB TS 26.171, EVS TS 26.441). No reference audio signal or external MOS hardware is required. MOS scores are timestamped, GPS-tagged, and correlated with serving cell RF conditions.
What professional VoLTE QoE measurement requires
Consumer "VoLTE check" apps test whether VoLTE is enabled on the device. They do not measure call quality. Professional QoE measurement requires access to four distinct data sources simultaneously.
Audio signal (for MOS)
Objective MOS scoring requires analysis of the actual audio signal received during the call. Consumer apps report signal level (RSRP), not perceived audio quality. ViSQOL runs directly on the decoded audio stream.
RTP stream metrics
Jitter (inter-arrival time variation per RFC 3550), packet loss ratio, and RTCP-XR delay (RFC 3611) require access to the RTP/RTCP packets — not visible via standard Android telephony APIs.
IMS/SIP signaling
Call setup latency (INVITE to 200 OK), re-INVITE for codec renegotiation, BYE cause codes, and registration events require full IMS stack visibility per RFC 3261 and 3GPP TS 24.229.
RF radio conditions
To correlate MOS degradation with its radio cause (handover, RSRP drop, SINR collapse, PCI change), the RF KPI stream must be captured simultaneously at chipset level via Qualcomm DIAG.
ITU-T P.800 MOS Scale
The Mean Opinion Score (MOS) is a 1–5 scale standardised by ITU-T P.800 for voice quality assessment. A MOS of 4.0 or above is defined as Good quality and aligns with the HD Voice threshold (ITU-T P.10).
Source: ITU-T P.800 (Methods for subjective determination of transmission quality). HiCellTek displays real-time thresholds against these boundaries.
What HiCellTek measures
Every KPI is timestamped, GPS-tagged, and correlated with serving cell RF conditions.
ViSQOL MOS Score
Objective Mean Opinion Score computed by ViSQOL (Google Research, Apache 2.0). Produces a 1.0–5.0 score per ITU-T P.800 from the live audio signal — no reference audio, no lab equipment. Scored per call and per 3-second segment. Timestamped and GPS-tagged.
RTP Jitter and Packet Loss
Inter-arrival time variation (jitter) and packet loss ratio per RFC 3550. Captured from the RTP stream via Qualcomm DIAG — not estimated from Android audio APIs. Round-trip delay reported via RTCP Extended Reports (RFC 3611).
SIP Signaling Analysis
Full IMS/SIP call flow capture per RFC 3261 and 3GPP TS 24.229: INVITE, 183 Session Progress, 200 OK, BYE, re-INVITE. Call setup time (INVITE to 200 OK in ms), SIP response codes, and registration event tracking.
Codec Detection and Bitrate
Active codec identified in real time: AMR-WB (3GPP TS 26.171, 6.60–23.85 kbps), EVS (TS 26.441, up to 128 kbps fullband), AMR-NB (TS 26.071, 4.75–12.2 kbps). Mid-call codec switches and SDP renegotiation events captured.
Call Drop Cause Codes
Root cause analysis for VoLTE call drops: IMS release cause from SIP BYE (RFC 3326), EMM/ESM bearer loss cause from NAS (3GPP TS 24.301), handover failure during call from RRC Reconfiguration (TS 36.331). All correlated with RF conditions at drop time.
RF Correlation and GPS Tagging
Every MOS score, RTP metric, and SIP event is timestamped and GPS-tagged. Correlated with serving cell RSRP, RSRQ, SINR, PCI, EARFCN, and handover events for complete radio-to-QoE mapping.
VoLTE QoE testing scenarios
EU operators typically run quarterly VoLTE QoE audits across coverage areas. HiCellTek automates MOS collection along predefined routes — GPS-tagged per cell — and generates Excel reports with per-PCI MOS distribution and codec breakdown, ready for regulator submission.
A VoLTE call drops. Is it a SIP registration failure, an EMM bearer release, a handover failure, or a RTCP-XR congestion event? HiCellTek captures all four simultaneously and correlates them at the exact drop timestamp, enabling root cause identification in a single session.
SA-mode VoNR (Voice over NR) behaves differently from VoLTE: IMS over 5G NR SA uses a 5QI 1 bearer (3GPP TS 23.501) with different jitter and delay budgets. HiCellTek validates NR voice quality during site walks before handover to production.
EVS (Enhanced Voice Services) delivers significantly higher MOS than AMR-WB, but its rollout depends on network-side IMS configuration and UE capability negotiation. HiCellTek captures codec negotiation (SDP in SIP INVITE) and active codec during calls — enabling evidence-based EVS rollout decisions.
Frequently Asked Questions
What is VoLTE QoE measurement and why does it matter for operators?
VoLTE (Voice over LTE) carries voice calls as IP packets over the LTE data bearer using the IMS (IP Multimedia Subsystem) architecture. Unlike circuit-switched voice, VoLTE quality depends on radio conditions, RTP packet delivery, codec performance, and IMS signaling latency. QoE (Quality of Experience) measurement quantifies subscriber-perceived call quality using objective scoring models — avoiding the cost and delay of human listener panels (per ITU-T P.800). For operators, sub-3.0 MOS scores in a coverage area correlate with increased churn and NPS deterioration.
How does ViSQOL measure MOS without a reference audio signal?
ViSQOL (Virtual Speech Quality Objective Listener, Google Research, Apache 2.0) is a perceptual model trained on a large corpus of speech quality assessments. It analyzes the spectro-temporal structure of the degraded audio signal and produces a MOS estimate correlated with ITU-T P.800 subjective scores. Unlike PESQ (ITU-T P.862) or POLQA (ITU-T P.863), which require a clean reference signal for comparison, ViSQOL works intrinsically — making it suitable for field measurement on live subscriber calls where no reference is available.
What VoLTE MOS threshold indicates acceptable call quality per ITU-T standards?
Per ITU-T P.800 and the G.107 E-Model, a MOS of 4.0 or above is considered Good quality and aligns with the ITU-T P.10 definition of HD Voice. A MOS of 3.5 represents the lower bound of acceptable quality. Scores below 3.0 are considered Poor, where audible degradation is noticeable and subscriber satisfaction drops significantly. HiCellTek displays MOS in real time against these thresholds with colour-coded alerts.
Does HiCellTek measure VoNR (Voice over NR, 5G) call quality?
Yes. The VoLTE QoE module applies to both VoLTE (IMS over 4G LTE, 5QI 1 bearer) and VoNR (IMS over 5G NR SA, per 3GPP TS 23.501 and ITU-T Q.3956). The same ViSQOL MOS engine, RTP/RTCP-XR metrics, and SIP signaling capture apply to NR voice bearers. NR-specific events (beam switches during call, SCG reconfiguration) are correlated with MOS degradation events.
What codecs does HiCellTek detect and how does codec choice affect MOS?
HiCellTek detects AMR-WB (Adaptive Multi-Rate Wideband, 3GPP TS 26.171, max MOS ~4.5), EVS (Enhanced Voice Services, TS 26.441, max MOS ~4.7 in fullband), and AMR-NB (Narrowband, TS 26.071, max MOS ~4.1). EVS fullband at 24.4 kbps provides the highest perceptual quality. Mid-call codec switches — for example due to poor radio conditions causing a fallback from EVS to AMR-NB — are captured and correlated with MOS degradation events.
Can HiCellTek identify the root cause of a VoLTE call drop?
Yes. HiCellTek correlates multiple layers for call drop root cause analysis: the SIP BYE cause code (RFC 3326), the EPS bearer release cause from NAS (3GPP TS 24.301 EMM/ESM), the RTP stream termination event, the RF conditions (RSRP, SINR) at the moment of drop, and any handover failure event from RRC (TS 36.331 RRCConnectionReestablishment). This multi-layer correlation is only possible via Qualcomm DIAG access — it is not available through standard Android telephony APIs.
How do I export VoLTE QoE measurement data for inclusion in a report?
HiCellTek exports VoLTE QoE data in Excel (per-call MOS summary + per-segment timeline), CSV (raw timestamped KPIs), and GeoJSON (GPS-mapped MOS and codec events). The HLOG v1 encrypted export preserves the full measurement session for audit purposes. The Desktop Companion provides post-campaign MOS trend charts, call drop maps, and codec distribution analysis.
Measure VoLTE MOS on your network today
14-day free trial with full VoLTE QoE module access. No credit card. Compatible with Samsung Galaxy S/A, OnePlus, Pixel (Qualcomm, rooted).
Pro EUR 249/month/device · Team EUR 399/month (3 devices min) · Enterprise on quote