Minimization of Drive Test (MDT) - An Innovative Methodology for Measuring Customer Performance on Mobile Network - ITU
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
Minimization of Drive Test (MDT)
An Innovative Methodology for Measuring
Customer Performance on Mobile Network
“The GeoSynthesis Project”
Andrea Scaloni
ITU Workshop on "Benchmarking of emerging technologies and applications. Internet related performance measurements"
Geneva, Switzerland, March 11th 2019
Agenda
Agenda
What is MDT and how does it work?
Key Performances Indicators available
Potentiality of MDT for Operators, TLC, Vendors
2
Confidential © Nokia 2016
Agenda
Agenda
What is MDT and how does it work?
Key Performances Indicators available
Potentiality of MDT for Operators, TLC, Vendors
3
Confidential © Nokia 2016
The Minimization of Drive Tests (MDT) concept
MDT is built on three main pillars: Main strengths:
• Accuracy: plain GPS data with high precision (< 10 m
1. Periodic reporting of GPS location of the in outdoor environment)
UE, if the GPS receiver is enabled and the • Simplicity: no terminal agent to be installed on
UE supports GPS reporting over Layer 3 friendly users’ terminals, nor probes tapping data from
(RRC Measurement Report) the network, no high-resolution maps
2. Periodic reporting of legacy/ordinary L3 • Convenience: effective methodology for drive test
and L2 measurements at UE and NB/eNB, minimization
already used for signaling and radio • Short lead time: data can be collected by centralized
resource management systems (Data Collector) and processed to be
3. MDT Data collector and Big Data platform available a short time after collection
for processing and analysis • Statistical relevance of georeferenced data
• Flexibility: off-the-shelf modules & bespoke reports
A NEW methodology was NECESSARY to thanks to low-level data made available to network
manage and process a big amount of data. optimization engineers for customized aggregation
A SMART and EFFICIENT process with and correlation.
different METHODOLOGIES to share data to • No Impact on User Plan data throughput or extra
different stakeholders billing for final user
4
Confidential © Nokia 2016
Positioning information source (3GPP TS 37.320)
GPS reporting capability of UE from real
UMTS networks:
• The feature RAN2496 (RU50) enables sending UMTS: 20 ÷ 25%
periodic GPS measurements locations of UE, LTE: 3 ÷ 5%
supporting UE-Based reporting during CS/PS
connection. Only UEs in Cell_DCH state
(Immediate MDT) will report measurements
• Periodicity from 2 to 32 s L3 Data L3 Data
• Measurements are contained in measurements RNC Collector Collector
report between UE and RNC and it possible to
correlate this information with other events
(RSCP, Ec/N0, etc.)
UMTS LTE
NodeB NodeB
LTE
• Immediate MDT: LTE1308 (LTE16) enables
GPS periodic position identification of UEs via
Cell trace interface eNB in connected mode.
• The information can be correlated to other
network events or UE using call trace LTE: UE in Connected and
UMTS : UE in Connected
• Reporting interval from 120 ms to 60 min Mode and GPS enabled
Idle Mode and GPS
• Logged MDT: LTE 1049 (LTE15A) enables GPS enabled
periodic position identification with radio
information of UEs in idle Mode.
• Logging interval from 1.280 to 61.440 s
• Logginq duration from 10 to 120 min
5
Confidential © Nokia 2016
The GeoSynthesis Project MDT opens an innovative approach to Network Capacity and Performance Optimization with GPS georeferenced data correlated to radio events reported in the UMTS and LTE signaling messages. Network Capacity and Performance optimization is best supported by georeferenced information providing a clear view about network quality, radio signal coverage and traffic localization. Specific events or complete call traces can be located on map for hundreds of thousands of users. This is a brand new process and, in order to take the maximum value from this comprehensive source of information, the GeoSynthesis Project was built around this concept. 6 Confidential
MDT data processing : Nokia GeoSynthesis Ecosystem
Coverage maps
Analysis and correlation of • Radio Levels
• Radio Quality Interference maps
Radio Measurements • Radio Path Loss
Statistical Anonymous Data • Radio
Propagation
Processing • Distance UE-NB Traffic maps
L3 Data Collector L3 Data Collector • UE Profiling
LTE UMTS • Traffic Analysis
• Mobility Analysis
Event maps
LTE
NodeB UMTS End-User Analysis
RNC NodeB
UE Signalling UE Signalling
Average figures
UMTS LTE
Mid-sized city (100 nodes), per day
Distinct users ~ 2×104 ~ 5×104
Connections
7 ~ 2×105 ~ 8×105
GPS & measurement
Confidential © Nokia 2016 reports ~ 5×106 ~ 2×106
Agenda
What is MDT and how does it work?
Key Performances Indicators available
Potentiality of MDT for Operators, TLC, Vendors
8
Confidential © Nokia 2016
MDT measurements in detail (UMTS)
Connected Mode Idle Mode
• GPS location shape: latitude, longitude, altitude, uncertainty
semi-axes
• RSCP and Ec/N0 of up to 3 Active Set cells
• RSCP and Ec/N0 of up to 2 best monitored cells
• Ue Tx Power
Layer 3 • UeRxTxTimeDifference Type 1 for each of the Active Set cells
Estimated distance over the radio path
• Round Trip Time for each radio link in Active Set
• Transport Channel DL BLER for each radio link in Active Set
• SIR and SIR Error
Layer 2 Unlike LTE, UMTS has quite a few Layer 2 periodic reports: payload
and TTI assignment are not available. Payload can be retrieved with
other non-periodical internal RNC reports and pivoted on each GPS
coordinate. TTI assignment cannot be retrieved, thus preventing a
reliable throughput estimation.
9
Confidential © Nokia 2016
MDT measurements in detail (LTE)
Connected Mode Idle Mode
• GPS location shape: latitude, longitude, altitude, uncertainty semi- • GPS location shape: latitude, longitude, altitude, uncertainty semi-
axes axes
• RSRP and RSRQ of serving cell (primary cell in case of CA) • Acquisition timestamp
• RSRP and RSRQ of 1st to 8th monitored LTE intra-frequency • RSRP and RSRQ of serving cell
neighbour cells, identified with PCI • RSRP and RSRQ of 1st to 8th monitored LTE intra-frequency
neighbour cells, identified with eutraCelId
Layer 3 • RSRP and RSRQ of 1st to 8th monitored LTE inter-frequency
neighbour cells, identified with eutraCelId (**)
• RSCP and Ec/N0 of 1st to 8th monitored UMTS neighbour cells,
identified with PSC
• RxLev of 1st to 8th monitored GSM inter-RAT neighbour cells,
identified with BSIC
• PUCCH and PUSCH SINR
• Power Headroom
• Timing Advance (instantaneous or continual)
• Rank Indicator
MIMO
• Single/Dual code word Tx
Layer 2 • Single/Dual code word Tx failures
VoLTE MOS (*)
No MDT data
• Downlink/uplink delays
• Downlink/uplink PDCP data volumes
• Number if TTIs with buffered data L2 Throughput
• Wideband CQI
• Uplink Modulation and Coding Scheme
• PDSCH and PUSCH Physical Resource Blocks allocation
(*) Modified Wideband E-Model (ITU-T G.107.1) (**) Inter-frequency layering policies overridden: lower-priority
10 layers are measured by Idle UE even when the higher-priority
layer is beyond threshSrvLow
Confidential © Nokia 2016Agenda
What is MDT and how does it work?
Key Performances Indicators available
Potentiality of MDT for Operators, TLC, Vendors
11
Confidential © Nokia 2016MDT potential for Operators, TLC, Vendors • Replacement of drive tests for site certification and quality assessment • Coverage analysis • End-user experience • Hot spot detection and network capacity upgrades • Detection of system/coverage anomalies: sector inversion/rotation • Tracking of single users/connections • Radio channel characterization 12 Confidential © Nokia 2016
Replacement of drive tests for site certification and quality
•assessment
Real network performance straight from the user in real traffic conditions
• Area of analysis wider and far more significant than in a classical drive test, which is limited only to few roads in a
short time frame
• 1 MDT campaign: >20000 Km2/day (1 Italian region)
• 1 Drive Test campaign:Coverage analysis
Localization of LOW
coverage/HIGH
interference areas RSRP coverage map
Best Server map
Best server maps from
real measurements and
not simulated by planning
tools
E-RAB drop events
Localization of main radio
events with GPS precision
(OSS KPIs offer cell-level
detail at most)
Network
Optimization
& Targeted OPEX Reduction
Capacity Upgrade &
Efficiency
14 Increase
Confidential © Nokia 2016End-user experience
L2 downlink data
L2 downlink throughput
volumes
Wideband CQI MIMO usage
15
Confidential © Nokia 2016Hot spot detection and network capacity upgrades
identification
• Detection of local peaks of traffic (density of Local peak of
MDT measurement reports) in space and traffic
time over a given search area
• Differentiation of traffic type (indoor, outdoor,
mobility)
• Analysis of network performances during
peak hours: serving cells, KPIs within the
hotspot
Drill-down of
Accurate small cells deployment plan traffic amount on
(best candidates’ list to ensure high pixel basis
Localization of (10x10 m)
ROI) traffic peak
Identification of high traffic areas that
requires capacity upgrade
16
Confidential © Nokia 2016Detection of system/coverage anomalies: sector
inversion/rotation
• Sector inversion/rotation is
evaluated by comparing the
barycentre of the space
distribution of measurement
samples with the nominal
azimuth of the sector related to
those samples
• If the barycentre of two
distributions reciprocally fit
(within a margin of 45°) different WR13L1
azimuths, then a sector
inversion is detected WR13L2
• If the barycentre of one
distribution doesn’t fit its nominal
azimuth but there is no other
reciprocal fitting with any other
azimuth, then a sector rotation
is detected
17
Confidential © Nokia 2016Radio channel characterization
• Innovative approach to cellular
radio propagation analysis, by
exploiting MDT features. UEs are
allowed to report their radio
measurements (e.g. RSRP,
RSRQ) and GPS coordinates
when available. The observation
of local variations of RSRP and
TA, together with GPS position,
opens to new fields of
investigation in the mobile radio
channel, unreachable with drive
tests, e.g.:
• Multi-path fading and level
notches
• Coherence bandwidth
• Doppler shift
• Paper published on IEEE Access
(Jan. 2019)
https://ieeexplore.ieee.org/d
18
ocument/8620498/
Confidential © Nokia 2016Tracking of single users/connections
• The geo-location of every measurement report within a single call allows a complete knowledge of the
connection history in time and space
• It is possible to know the experienced radio conditions before any event traced from L3 signaling
Mobility connection Outdoor/indoor connection
Connection starts Connection starts
Report iniziale
Connection drops
Connection drops
19
Confidential © Nokia 2016Detection of Mobility Flow form Smart City Concept
Venice February 26 2017 – Trial Trace with GeoSynthesis during Venice Carnival
A City Day Life during Carnival
User density distribution during a single day from 00:00 to 23:59 with a sampling period of 5 minutes in area of 10x10 m
20
Confidential © Nokia 2016What could be next?
• GPS reporting penetration (currently: 3÷5% in LTE) can be increased: some
UE manufacturers do not implement all MDT features for commercial reasons
• End-user measurements can be improved: throughput estimation, layer-2
resource (TTI) scheduling
• Reporting with MDT of additional measuraments already available from UE
internal sensors for innovative uses cases like :
• temperature
• humidity
• barometric pressure
• magnetic field
• thermal noise
• MDT extension to 5G
21
Confidential © Nokia 2016You can also read
