Mobile network coverage audit: complete methodology and deliverable...

A mobile network coverage audit is a structured mission whose objective is to objectively evaluate the quality of radio service delivered to subscribers over a defined geographic area. Whether conducted for internal needs (optimization), regulatory compliance (national telecom regulators), or contractual purposes (operator/subcontractor SLA), it follows a rigorous methodology. This guide presents the end-to-end process.

Types of mobile network coverage audits

Regulatory compliance audit

National regulators impose on operators the obligation to demonstrate network coverage according to defined criteria:

Percentage of population covered (> -100 dBm 4G)
Coverage of main road axes
Indoor coverage in inhabited areas

Regulatory audits require standardized measurements, performed according to defined protocols, with calibrated equipment and reports in specific formats.

SLA performance audit

Between an operator and a subcontractor (integrator, equipment vendor), SLAs define performance commitments to validate during commissioning:

Minimum coverage over the contractual area
Median RSRP >= X dBm over Y% of the area
DL throughput >= X Mbps in Z% of measurements

SLA audits are triggered at site acceptance or after a major network update.

Optimization audit (internal)

Internal audits are conducted proactively by the network optimization team to:

Identify degradation zones before subscriber complaints
Validate the impact of maintenance or optimization interventions
Prepare arguments for vendor negotiations

Phase 1: Scope and objectives definition

Audit specification

Before starting, formally define:

Geographic area:

Precise delimitation (GeoJSON polygon, list of municipalities, area around a site)
Surface area in km2
Zone type: dense urban, suburban, rural, industrial, tourist

Technologies to measure:

LTE only (2G/3G included or not)
5G NR (NSA or SA)
Multi-operator (benchmarking)

Indicators to collect:

Radio coverage (RSRP, RSRQ, SINR)
Performance (DL/UL throughput, latency)
Voice quality of service (VoLTE MOS)
Accessibility (CSSR)
Signaling (L3 messages)

Expected deliverables:

Coverage map (heatmap per indicator)
Descriptive statistics (median, P10/P90 percentiles)
List of degraded zones with GPS location
Executive report (actionable recommendations)
Raw data (CSV, QMDL)

Measurement route planning

For a comprehensive coverage audit:

Road axes: all main roads (highways, national roads, expressways)
Residential areas: grid pattern routes in dense housing zones
Industrial/commercial zones: routes covering major business areas
Targeted indoor: walk test in buildings identified as critical (hospitals, train stations, shopping malls)

Density rule: in urban areas, target one measurement point every 50-100 m (approximately 100-400 measurements/km2).

Phase 2: Field data collection

Drive test protocol

Recommended duration: 1h-4h depending on surface area (approximately 15-25 km2 measurable per drive test day in urban areas)

Capture parameters:

Sampling rate: 1 Hz minimum
GPS: active throughout the session, accuracy < 5 m
Active test scenario: continuous iperf3 DL (or 30s DL / 10s pause cycle)
L3 capture: enabled permanently

Startup checklist:

Terminal attached to the correct PLMN (verify IMSI and selected PLMN)
5G NR active (verify serving technology at startup)
GPS accuracy < 5 m (wait for full GPS fix before starting)
Capture session started (verify recording in progress)
iperf3 scenario active (verify iperf3 server accessible)

Indoor walk test protocol (if applicable)

For buildings to measure:

Duration: 30-90 min depending on building size
Measurements per floor
Stationary points in critical zones (3 min minimum)

Field data management

Recommended file naming convention:

AUDIT_{OPERATOR}_{ZONE}_{DATE}_{SESSION}.hlog
AUDIT_{OPERATOR}_{ZONE}_{DATE}_{SESSION}.qmdl

Example: AUDIT_OrangeFR_Paris13_20260301_S01.hlog

Phase 3: Data processing

Import and quality verification

Verifications to perform:

Number of GPS positions (consistent with session duration?)
GPS gaps (location absences > 30 seconds — unlocated segments to exclude)
Technology distribution (% LTE, % 5G NR, % 3G/2G)
Number of RSRP measurements < -115 dBm (values probably out of coverage — exclude or process separately)
Duration of iperf3 tests (temporal coverage of throughput tests)

KPI statistics calculation

For each indicator, calculate:

Median (P50)
P10 percentile (worst 10% — represents degraded user experience)
P90 percentile (best 10% — represents network potential)
Minimum and maximum
Percentage of measurements below critical thresholds

Typical reference thresholds:

Indicator	Target (P50)	Degraded threshold (P10)
LTE RSRP (dBm)	> -90	> -105
5G NR RSRP (dBm)	> -85	> -100
SINR (dB)	> 12	> 3
LTE DL throughput (Mbps)	> 20	> 5
5G NR DL throughput (Mbps)	> 80	> 20
Latency (ms)	< 30	< 80
VoLTE voice MOS	> 4.0	> 3.5

Results mapping

RSRP map: interpolated heatmap (IDW or Kriging) over the audit zone. Overlay measurement points to show sampling density.

SINR map: particularly useful for locating interference zones (low SINR despite adequate RSRP).

Throughput map: identify bottleneck zones (low throughput despite good radio coverage — capacity problem).

Serving cell map: to identify ping-pong zones or aberrant coverage patterns.

Phase 4: Analysis and recommendations

Identification of problem areas

For each zone identified as degraded (RSRP < -100 dBm or SINR < 5 dB):

Precise location: polygon or list of GPS coordinates
Characterization: zone type (residential, commercial, industrial, road axes)
Subscriber impact: estimated number of subscribers in the zone (if demographic data available)
Root cause hypothesis: coverage (site distance), interference (low SINR despite adequate RSRP), handover (technology transition)
L3 verification: L3 messages captured in the zone (handover failures? NAS rejects?)

Action prioritization

Classify problem areas by priority:

Critical: severely degraded zones (RSRP < -110 dBm, or CDR > 2%) with high subscriber traffic
High: degraded zones (RSRP -100 to -110 dBm) with operational or regulatory impact
Normal: marginal zones, limited impact, actionable within the standard optimization plan

Deliverable report structure

Executive report (5-10 pages)

Section 1 — Summary: overall network status, zones of excellent coverage, identified problem areas

Section 2 — Methodology: equipment used, dates and scope, measurement protocols

Section 3 — Results by indicator: statistics tables + maps

Section 4 — Problem areas: prioritized list with GPS location

Section 5 — Recommendations: proposed actions, expected gain per action

Technical appendices

Raw CSV files (one per indicator)
QMDL files for the vendor
Metadata (session list, equipment, software versions)

Delivery format

PDF: executive report for management and client
Excel/CSV: KPI data for technical teams
QMDL: raw traces for vendor tickets
GeoJSON: geolocated problem areas (integration into planning tools)
KMZ/KML: for visualization in Google Earth / GIS

Conclusion: the coverage audit as a continuous management tool

A coverage audit is not a one-off exercise — it should be integrated into the continuous optimization cycle of the mobile network. Operators who measure regularly (monthly in critical zones, quarterly across the entire territory) have significantly better-performing networks than those who measure reactively (only after subscriber complaints).

The reduction in field measurement costs — enabled by professional Android tools — makes this continuous monitoring approach economically viable, even for teams with constrained budgets.

Mobile network coverage audit: complete methodology and deliverables