The document discusses drive test data analysis procedures. It begins with an overview of the common procedures for analyzing drive test data, which includes checking KPI requirements, coverage distributions, problematic points, and identifying and verifying solutions. It then covers specific issues that may be identified such as coverage holes, sudden signal drops, lack of a dominant server, overlapping coverage, and crossed feeders. Methods for detecting these issues through drive test data are provided. Potential causes of poor signal quality are also examined, along with solutions to improve quality issues.
Drive Tests and Propagation Prediction software are the two methods that are used to check the coverage area of a particular wireless system. Generally prediction software is used in conjunction with the radio signal measurements in order to determine an accurate picture of signal propagation. In some cases, field measurements may be needed to be taken in order to calibrate the prediction software.
Drive Tests and Propagation Prediction software are the two methods that are used to check the coverage area of a particular wireless system. Generally prediction software is used in conjunction with the radio signal measurements in order to determine an accurate picture of signal propagation. In some cases, field measurements may be needed to be taken in order to calibrate the prediction software.
NETWORK PROBLEM IDENTIFICATION
REQUIREMENT FOR DRIVE TESTING
DRIVE TEST PROCESS
DRIVE TEST OUTPUTS
MEASUREMENT METRICS
DRIVE TEST ANALYSIS
NEPTUNE AND PROBE
Drive Test
OMC Statistics
Customer feedback
On completion of the module one should be clear about the parameters required during drive test what does it mean and how much it is important.
Parameters regarding in windows like :
a) Current Channel
b) Radio parameters
c) Serving + Neighbors
Time: It is system time of computer.
Cell name: It displays the name of the sector which is serving according to the cellfile that is loaded in TEMS.
CGI : It stands for the Cell Global Identity which is unique for every sector of the site. It consists of MCC,MNC,LAC,CI.
Cell GPRS Support: Tells sector is having GPRS or not. Values are Yes or No .
Band : It tells in which Freq. Band mobile is operating e.g. GSM 900/ 1800.
BCCH ARFCN: It tells by which BCCH is the mobile station getting served.
TCH ARFCN: On which Traffic Freq. call is going on.
BSIC (Base Station Identity Code) : It is combination of Network Color Code (NCC) (0 – 7) & Base Station Color Code (BCC) (0 – 7). e.g. 62. It is decoded by mobile on every Sync. Channel Message.
Mode: It is shows in which state is mobile operating, Idle, Dedicated & Packet.
Time slot: On which time slot of current TCH call is going on. Viz. time slot no. of TRX.
NETWORK PROBLEM IDENTIFICATION
REQUIREMENT FOR DRIVE TESTING
DRIVE TEST PROCESS
DRIVE TEST OUTPUTS
MEASUREMENT METRICS
DRIVE TEST ANALYSIS
NEPTUNE AND PROBE
Drive Test
OMC Statistics
Customer feedback
On completion of the module one should be clear about the parameters required during drive test what does it mean and how much it is important.
Parameters regarding in windows like :
a) Current Channel
b) Radio parameters
c) Serving + Neighbors
Time: It is system time of computer.
Cell name: It displays the name of the sector which is serving according to the cellfile that is loaded in TEMS.
CGI : It stands for the Cell Global Identity which is unique for every sector of the site. It consists of MCC,MNC,LAC,CI.
Cell GPRS Support: Tells sector is having GPRS or not. Values are Yes or No .
Band : It tells in which Freq. Band mobile is operating e.g. GSM 900/ 1800.
BCCH ARFCN: It tells by which BCCH is the mobile station getting served.
TCH ARFCN: On which Traffic Freq. call is going on.
BSIC (Base Station Identity Code) : It is combination of Network Color Code (NCC) (0 – 7) & Base Station Color Code (BCC) (0 – 7). e.g. 62. It is decoded by mobile on every Sync. Channel Message.
Mode: It is shows in which state is mobile operating, Idle, Dedicated & Packet.
Time slot: On which time slot of current TCH call is going on. Viz. time slot no. of TRX.
Vous avez choisi d’assister à la conférence sur l’hypnose et la gestion du stress. Deux notions que la plupart d’entre nous n’a pas l’habitude de mettre ensemble. C’est pourquoi M. Rémi Côté, psychologue et conférencier, est ici pour nous parler d’un protocole d’autohypnose pour la gestion du stress ou de l’anxiété. Le Dr Rémi Côté Ph.D. est membre de l’Ordre des psychologues du Québec depuis 1990. En 1997, il termine sa thèse de doctorat portant sur l’analyse dynamique de l’influence des perceptions de contrôle et d’équité sur la satisfaction, l’estime de soi et la motivation. En 2002, il est formé à l’intégration de l’hypnose en psychothérapie. Depuis, il utilise cette technique dans le but d’augmenter l’efficacité de ses interventions en psychothérapie.
Coverage verification
New site Performance Verification and Field optimization
Network Problem trouble shooting like Drop calls, Handover failure, Poor Coverage patches, Poor RX Quality patches, etc
Benchmarking Drive test to find out Coverage and Quality comparison against competitors networks
And first-class of all, a threat to hone your competencies. It’s adequate if you experience in over your head. We all did sooner or later, this subsequent step is about pushing thru that worry and on the point of address something as hard because the 200-301. In case you get caught, reach out. In case you see others caught, assist them.
How is this newsletter going to help you? Apart from providing you with a brief glimpse of the test’s topics and shape, we are able to additionally assist you discover efficient education substances. Cisco’s internet site is a extraordinary starting point, but you shouldn’t restriction your self to it. Despite the fact that you would possibly have by no means heard approximately them, you have to attempt exam dumps as they may grow to be your secret tool to get a passing rating in 2 hundred-301 assessment. But now, let’s start with the exam details.
Do not permit yourself face your ccna two hundred-301 exam without proper guidance to remorse later when you fail in cisco licensed community associate real exam because many people had been there. Let assist you to your cisco two hundred-301 ccna real examination preparation. To help you put together on your cisco certified network partner (ccna) 200-301 exam.
To meet customers' requirements for high-quality networks, LTE trial networks must be optimized during and after project implementation. Radio frequency (RF) optimization is necessary in the entire optimization process. This document provides guidelines on network optimization for network planning and optimization personnel.
This presentation will show you how to right size customer networks, take advantage of ARM, Band steering and Client Match. Check out the webinar recording where this presentation was used. https://attendee.gotowebinar.com/recording/4688596131469180162
Register for the upcoming webinars: https://community.arubanetworks.com/t5/Training-Certification-Career/EMEA-Airheads-Webinars-Jul-Dec-2017/td-p/271908
This presentation will show you how to optimize IAP’s traffic prioritization features for Voice and Video deployments and relative best practice solutions widely practiced across multiple verticals. Check out the webinar recording where this presentation was used. https://attendee.gotowebinar.com/recording/3338982991176626689
Register for the upcoming webinars: https://community.arubanetworks.com/t5/Training-Certification-Career/EMEA-Airheads-Webinars-Jul-Dec-2017/td-p/271908
Hello my friends
Unfortunately, if you want any of these files, please contact me by email and mention any reference you find, to give it to you.
My email: molham.shoriss@outlook.com
LTE
LTE Introduction
LTE Fundamental
LTE RNP Introduction
LTE Principles (Huawei eRAN 3.0)
LTE Access Fault Diagnosis
LTE Access Transport Network Dimensioning
LTE Air Interface ISSUE 1.05
LTE Cell Planning ISSUE1.10
LTE eRAN 3.0 Scheduling - Feature Parameter Description
LTE eRAN3.0 Idle Mode Behavior
LTE eRAN3.0 KPI Introduction
LTE eRAN3.0 - Mobility Management in Connected Mode - Feature Parameters Description
LTE Handover Fault Diagnosis
LTE Network Tuning ISSUE 1.00
LTE Protocols and Procedure
LTE Radio Network Capacity Dimensioning
LTE Radio Network Coverage Dimensioning
LTE Radio Resource Management Overview
LTE Scheduling
LTE (Eicsson)
01.LTE SAE System Overview
LTE 10A Air Interface
LTE L10A Access Transport Network
LTE L10A Radio Network Design
LTE L12 Initial Tuning
LTE L14 Radio Network Functionality LTE
LTE Protocols and Procedures
LTE System Techniques
LTE Throughput Troubleshooting Techniques
LTE Radio Access Radio Interface Dimensioning and Planning
MIMO in WCDMA and LTE
LTE L14 Radio Network Functionality LTE
LTE Huawei
LTE System Overview
LTE Air Interface
LTE Protocols and Signaling Procedures
LTE Network Performance Management (KPIs)
LTE Radio Network Coverage Dimensioning
LTE Cell Planning
LTE Access Fault Diagnosis
LTE Handover Fault Diagnosis
LTE Call Drop Diagnosis
LTE Traffic Fault Diagnosis
LTE Interference Troubleshooting Guide
LTE Optimization
LTE Troubleshooting Access Failures
Features 1. Idle Mode
Features 2. Intra Rat Handover
Features 3. Power Control
Features 4. Scheduling
Features 5. CS Fallback
Features 6. Physical Channel Resource Management
HedEx for LTE
eRAN_eRAN13.0_02_en_GEG09124
5G
5G System Design (Wiley)
HedEx for 5G
(For Engineer) 5G RAN2.0 Solution Technical Guideline
Hello my friends
Unfortunately, if you want any of these files, please contact me by email and mention any reference you find, to give it to you.
My email: molham.shoriss@outlook.com
PHP Frameworks: I want to break free (IPC Berlin 2024)Ralf Eggert
In this presentation, we examine the challenges and limitations of relying too heavily on PHP frameworks in web development. We discuss the history of PHP and its frameworks to understand how this dependence has evolved. The focus will be on providing concrete tips and strategies to reduce reliance on these frameworks, based on real-world examples and practical considerations. The goal is to equip developers with the skills and knowledge to create more flexible and future-proof web applications. We'll explore the importance of maintaining autonomy in a rapidly changing tech landscape and how to make informed decisions in PHP development.
This talk is aimed at encouraging a more independent approach to using PHP frameworks, moving towards a more flexible and future-proof approach to PHP development.
Connector Corner: Automate dynamic content and events by pushing a buttonDianaGray10
Here is something new! In our next Connector Corner webinar, we will demonstrate how you can use a single workflow to:
Create a campaign using Mailchimp with merge tags/fields
Send an interactive Slack channel message (using buttons)
Have the message received by managers and peers along with a test email for review
But there’s more:
In a second workflow supporting the same use case, you’ll see:
Your campaign sent to target colleagues for approval
If the “Approve” button is clicked, a Jira/Zendesk ticket is created for the marketing design team
But—if the “Reject” button is pushed, colleagues will be alerted via Slack message
Join us to learn more about this new, human-in-the-loop capability, brought to you by Integration Service connectors.
And...
Speakers:
Akshay Agnihotri, Product Manager
Charlie Greenberg, Host
UiPath Test Automation using UiPath Test Suite series, part 3DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 3. In this session, we will cover desktop automation along with UI automation.
Topics covered:
UI automation Introduction,
UI automation Sample
Desktop automation flow
Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
Kubernetes & AI - Beauty and the Beast !?! @KCD Istanbul 2024Tobias Schneck
As AI technology is pushing into IT I was wondering myself, as an “infrastructure container kubernetes guy”, how get this fancy AI technology get managed from an infrastructure operational view? Is it possible to apply our lovely cloud native principals as well? What benefit’s both technologies could bring to each other?
Let me take this questions and provide you a short journey through existing deployment models and use cases for AI software. On practical examples, we discuss what cloud/on-premise strategy we may need for applying it to our own infrastructure to get it to work from an enterprise perspective. I want to give an overview about infrastructure requirements and technologies, what could be beneficial or limiting your AI use cases in an enterprise environment. An interactive Demo will give you some insides, what approaches I got already working for real.
Accelerate your Kubernetes clusters with Varnish CachingThijs Feryn
A presentation about the usage and availability of Varnish on Kubernetes. This talk explores the capabilities of Varnish caching and shows how to use the Varnish Helm chart to deploy it to Kubernetes.
This presentation was delivered at K8SUG Singapore. See https://feryn.eu/presentations/accelerate-your-kubernetes-clusters-with-varnish-caching-k8sug-singapore-28-2024 for more details.
Transcript: Selling digital books in 2024: Insights from industry leaders - T...BookNet Canada
The publishing industry has been selling digital audiobooks and ebooks for over a decade and has found its groove. What’s changed? What has stayed the same? Where do we go from here? Join a group of leading sales peers from across the industry for a conversation about the lessons learned since the popularization of digital books, best practices, digital book supply chain management, and more.
Link to video recording: https://bnctechforum.ca/sessions/selling-digital-books-in-2024-insights-from-industry-leaders/
Presented by BookNet Canada on May 28, 2024, with support from the Department of Canadian Heritage.
Neuro-symbolic is not enough, we need neuro-*semantic*Frank van Harmelen
Neuro-symbolic (NeSy) AI is on the rise. However, simply machine learning on just any symbolic structure is not sufficient to really harvest the gains of NeSy. These will only be gained when the symbolic structures have an actual semantics. I give an operational definition of semantics as “predictable inference”.
All of this illustrated with link prediction over knowledge graphs, but the argument is general.
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
1. Internal
Drive Test Analysis
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved
www.huawei.com
Version1.0
2. Upon completion of this course, you will be
able to:
Understand the common procedure
Of drive test data analysis
Identify the basic problems and cause
of the problems
Propose the solutions to solve the
network problems
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3. Chapter 1 Common procedure of drive test data
analysis
Chapter 2 Case study for drive test analysis
Chapter 3 Practice on drive test analysis
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4. Common procedure of DT data analyze
1. Check if the Drive test KPIs meet the requirement. If not, identify the problematic log
files. Capture the figure and events (e.g. locations, time, identify problematic cells)
2. Check the RxLevel and RxQual distribution, check if they are related to the points
that miss the KPI requirement?
3. (If new site or cluster) Check the distribution of each BCCH (CGI), pay attention to
the crossed feeder.
4. Analyze the points that miss the KPIs point by . point. (
To make the analysis more
comprehensive , get more information from engineering parameters, BSC data
configuration, traffic statistic and BTS alarms)
5. Identify the possible causes of each problem points ,discuss with customers
4. Propose solutions and get approval from customers before execute the change
request
4. Re- Drive Test to verify the problem after implemented the solutions
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5. Chapter 1 Common procedure of drive test data
analysis
Chapter 2 Case study for drive test analysis
Chapter 3 Practice on drive test analysis
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6. Coverage
• Downlink RxLevel
• Coverage of single cell
• Coverage of whole network
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7. Coverage
EIRP(dBm)
L(dB)
Network Coverage is evaluated by:
RxLev = EIRP(dBm) – L(dB)
Where:
EIRP = Effective Isotropic Radiated Power
L = Propagation Losses
RxLev(dBm)
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Unexpected coverage
Good coverage (overshooting)
In urban area, Lower Antenna Height (=25m), Greater downtilt (=6 degree),
and Lower EIRP (=41 dBm) are used to control overshooting interference.
8. Coverage(one cell)
The following example shows the
downlink RxLevel(Dedicated Mode)
decreases when MS is driving away
from BTS.
The RxLevel decrease faster when
Antenna Downtilt increase.
Downtilt: 0 drgree
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Downtilt: 8 drgree
Variation
due to
shadowing
Global
means
RxLevel
Variation
s due to
Rayleigh
fading
9. Coverage(Network)
The picture shows the coverage of a city, which contains good and bad
coverage areas.
The distribution of downlink RxLev concentrates from -80 to -95 dBm.
Good Coverage
Bad Coverage
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10. Coverage Issues
• Coverage hole
• Sudden Decrease on Signal Level
• Line of Sight Lost
• Lack of Dominant Server
• Coverage Overlapping
• Overshooting
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11. Coverage Hole
Legend
RxLevel
RxQuality
Poor Coverage
Areas
Bad
RxQuality
Call
Drop
RxLevel(Serving Cell) is about (or less than) -95 dBm
RxLevel(Neighbours) are about (or less than) -95 dBm
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12. Sudden Decrease on Signal Level
RxLev(Serving Cell and
Neighbors) decrease in a
short time.
Check if there is big change
of testing environment, e.g.
check if the test was
performed on a highway
and that particular area was
a tunnel or not.
Signal level on the chart will
make a curve rather than
unstable changes.
This usually cause Ping
Pong Handovers
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Page 12
13. Line of Sight Lost
Signal Strength of Serving cell make fast up and down due
to far away server being blocked by obstacles from the
terrain. The other way, signal from the server lose line of
sight(LOS) to the mobile because of a hill of something.
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RxQuality goes
worse when the
level drops down
fast
14. Lack of Dominant Server
Signal Level of more
than one cell (Serving
Cell and Neighbors) are
not high enough.
This might happen
because the MS is
located on the cell
borders and there is no
any best server to keep
the call.
Lack of Dominant Server
Causes too many
handovers
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15. Coverage Overlapping
Signal Level of 3–4
cells are too closed to
each other.
This might point
overlapping cells.
This will cause quality
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problems because of
frequency reuse and
frequent HO
Immediate action to
optimize cell coverage
should be taken by
power reductions,
downtilt or other
configuration changes.
Page 15
16. Overshooting
Serving
BTS
cell
Other cell B
BSIC 1
Freq. A
MS is covered by the
serving cell, but is
outside the cell
BSC thinks that it is
neighbor cell A and
makes a handover to
cell A
The MS is not near cell
A so the assigned TCH
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Coverage spot
(island effect)
Neighbour cell A
BSIC 1
Freq. A
for the handover is not
used
Cell A will have unused
TCH (handover)
The call might be
dropped because it
cannot make the
handover or bad quality
17. Propose solutions for Coverage Issue
Solution of low coverage
Solution of no dominant cell ,overshooting and overlapping
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18. Solutions of Low Coverage
Possible solution can be listed as below:
New Site Proposal
Sector Addition
Site Configuration Change (Antenna Type, height, azimuth, tilt changes)
Loss or Attenuation Check ( Feeders, Connectors, Jumpers, etc..)
Proposal Remark How to do
New Site Proposal
Most effective solution,
but the cost is highest
Using prediction tool(U-net) to identify the best
locations to put new sites
Sector Addition
Effective solution
but only for Omni-Site
Using prediction tool(U-net) to identify the
recommended azimuth of new sectors
Antenna
Height Difficult, high cost
Using prediction tool(U-net) to identify the
recommended height, type, azimuth or down tilt of
sector.
Type Difficult, high cost
Azimuth Easy to operate
Downtilt Easy to operate
Hardware
Feeders Only for troubleshooting
Referring to hardware checking guide
Connectors Only for troubleshooting
Jumpers Only for troubleshooting
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19. Solutions of overshooting or overlapping
Possible solution can be listed as below:
Site Configuration Change (Antenna Type, height, azimuth, tilt changes)
Cell Configuration Change (Carrier Power Type, Static TRX Power Class, Fine Tuning
of Static TRX Power…)
Proposal Remark How to do
Antenna
Height Difficult, high cost
Using prediction tool(U-net) to identify the
recommmended height, type, azimuth or
Type Difficult, high cost
Azimuth Easy to operate
downtilt of sector.
Downtilt Easy to operate
Parameter Output Power related
Easy to operate, but with
risk of coverage reduction
Referring to Data Configuration Reference
Help
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20. Cross Feeder
What is crossed feeder issue (1)
The term crossed feeder is used to describe the problem that
arises when the feeders for two or more sectors in a site are
inadvertently connected incorrectly. For Example, consider a new
cell site that has three sectors, A, B, and C:
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21. What is crossed feeder issue (2)
The crossed feeder problem would arise
if the feeder for sector A is connected to
sector C and vice versa. When this
happens, the sectors typically continue
to provide good coverage. However, the
network parameters for the two sectors
are also reversed. For example, the
parameters storing the sectors' BCCH
and lists of adjacent sectors would be
swapped.
For example, suppose we run a drive test
through the area served by the cell
whose feeders are crossed display the
ServBCCH attribute on the Map while
the cell sectors are colored by BCCH.
This is what we might see:
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22. What is crossed feeder issue (3)
There are 3 types of crossed feeder:
Crossed transmit feeders
Crossed receive feeders
Crossed transmit and receive feeders
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23. The problems raised by crossed feeder
issue
Crossed Normal Situation Feeder Situation
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24. The problems raised by crossed feeder issue
Crossed feeder will raise many problems, such as:
A greater degree of interference
A poor uplink signal strength
A poor performance of handover
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25. How to detect crossed feeder issue by DT
Crossed transmit feeders
Crossed transmit feeders will result in the swap of 2 or more sectors
BCCH frequency and TCH’s. As the sectors are pointing in the
incorrect direction, performance will suffer as the frequency plan has
been changed and a greater degree of interference will be present.
In DT, we will find that the handset receives the signal which shouldn't
have been received in the current cell.
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26. How to detect crossed feeder issue by DT
Crossed transmit feeders
In the example shown above, point A is in the area of coverage of Cell
D3, but the handset at point A receives the stronger signal of Cell D2. It
indicates that TX feeders were crossed between Cell D3 and Cell D2.
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27. How to detect crossed feeder issue by DT
Crossed receive feeders
It is not easy to detect this fault by DT, because the BCCH frequencies will
appear exactly as they were designed. However, the statistics for the cell
would help us to detect the fault:
Uplink signal strength would be very poor
Link balance would be larger than expected
Handover success rate would be very low
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28. How to detect crossed feeder issue by DT
Crossed receive feeders
The MR measurement is very useful in detecting this type of feeder
cross.
Uplink-and-Downlink Balance Measurement per TRX and TCH
Receive Level Measurement per TRX are the most useful statistics .
For example, if the uplink-and-downlink balance is always in level 10
or level 11, we can consider that there is something wrong in the
receive path of the site, crossed receive feeder is a possible problem.
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29. How to detect crossed feeder issue by DT
Crossed transmit and receive feeder
The symptom is similar with the fault “crossed transmit feeder”, and we can
detect the fault by DT easily .
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30. Poor Quality Issue
Downlink RxQual Issue
What is RxQual Issue
The problems raised by RxQual issue
How to detect quality issue by DT
Bad Quality due to Signal Strength – FER is Bad
Bad Quality due to Signal Strength – FER is OK
Bad Quality due to C/A Interference
Bad Quality due to Time Dispersion
The solution to RxQual issue
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31. What is RxQuality Issue
Bad RxQual is one of the biggest problems in a Network. The RxQual
that a network operator can offer to customers mostly depends on the
RxLevel and the interference of the network.
There are two types of RxQual problems, uplink RxQual and downlink
RxQuality. We can only detect downlink RxQual problem by DT,
however, if the downlink RxQual is bad in one cell, there is a risk that
there would be problems on the uplink as well.
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32. What is RxQual Issue
Bad
RxQua
lity
Good
RxQua
lity
RxQual is divided into eight levels which are from 0 to 7, the level 0 is the
best and the level 7 is the worst.
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33. The problems raised by RxQual Issue
Bad RxQual may raise many problems, such as:
Difficulty in accessing the network
Dropped calls due to bad quality
Poor handover success rate
Low MOS value (poor speech quality)
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34. Bad Quality due to Signal Strength – FER is Bad
As the signal strength drops
down, the quality of the call
becomes worse being effected
by interference and/ or fading.
Consequently the system
becomes weaker to handle the
interference.
Drop calls and ping pong
handovers usually happen in
such environments.
RxLev (Serving Cell and
Neighbors) is not high enough
(about less than -95dbm).
Maybe there are
interferences in this region for
bad FER.
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Bad RxLev
Bad RxQual
Bad FER
35. Bad Quality due to Signal Strength – FER is OK
This case is similar with
the previous except for
FER. Signal strength is
also bad in this, but FER is
still fine.
FER is ok, it means that
there is no obvious
interference in the area.
The coverage is usually
the problem in this
situation.
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Bad RxLev
Bad RxQual
Fine FER
36. Bad Quality due to C/A Interference
There is adjacent channel
interference in this case and
the RxQual is not good.
Bad Quality due to Adjacent
Interference.
Adjacent BCCH between
best server and best neighbor.
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37. Bad Quality due to Time Dispersion
Site
MS
Time dispersion is caused by the reflections. The MS uses all or most of the
received power, instead of only the direct signal, there is a larger probability to
decode the information. So the RxQual will be very bad perhaps.
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Reflecting object
38. Bad Quality due to Time Dispersion
The MS is near the
cell, it is less than 1
mile far away.
The RxQual is very
bad for the bad C/R,
in which, R stands for
reflected signal and C
stands for original
signal.
The TA is too high.
It is because that TA
stands for the
reflected signal but
the original signal.
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39. The solution to RxQual issue (1)
RxQual Issue Solution
Bad Quality due to Signal Strength – FER is
Bad
Find out the interference source
(e.g. frequency planning) or /and
adjust the azimuth or down tilt of
the antenna or /and adjust the
power of the transmitter(s) to
improve coverage
Bad Quality due to Signal Strength – FER is
OK
There is no obvious interference in
this situation. Adjust the azimuth or
down tilt of the antenna or /and
adjust the power of the
transmitter(s) to improve coverage
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40. The solution to RxQual issue (2)
RxQual Issue Solution
Bad Quality due to C/A
Interference
Avoided adjacent frequencies in the same cell
and preferably in neighboring cells as well.
Bad Quality due to Time
Dispersion
Move the site to be placed near the reflecting
object to prevent time dispersion. Another
efficient solution is to modify the antenna
arrangement, either in azimuth (horizontally) or
by tilt (vertically).
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41. Interference Issue
Hardware Problem
TRX Problem
Feeder Arrester Problem
Intra-Interference
Adjacent channel Co-channel
Inter-modulation Interference
Inter-Interference
Other Equipment
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42. Co-Channel Adjacent Channel Interference
As beside Figure show Station A~D,
Supposing the frequency N have
already allocated to cell A-3.so
frequency N can not be allocate to
A1、A2、B1、B2、B3、C1、C2、
C3、D1、D2、D3; and frequency
N±1 can not be allocated to cell A1、
A2、A3、B1、C2、D1、D2
(No ,hoping)
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43. Co-Channel Adjacent Channel Interference
As below, From the neighbor
list ,BCCH 73 interfered
BCCH 72,it is adjacent
interference. When the co
channel or adjacent channel
happen
It will bring the strong
interference. The typical
phenomena:
High Rxlev
Worst Rxqual
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44. C/I Problem
C/I Definition
C/I: Carrier signal /Interference signal
Optimize C/I method
Improve Coverage
Decrease Interference
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45. C/I Problem due to poor coverage
RxLevel(Serving Cell) is about (or less than) -95 dBm;
RxLevel(Neighbours Cell) is about (or less than) -95 dBm;
Result: Worst C/I due to poor coverage.
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46. C/I Problem due to Interference (frequency)
RxLevel (Serving Cell) is about -70dBm; (strong)
RxLevel (Neighbors Cell) is about -65 to -80 dBm
Result: Worst C/I due to interference ( no dominant cell)
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47. The solution to Interference, C/I,BER issue (1)
Interference Issue Solution
Serious interference due to Co-channel or
Adjacent channel
Adjust cell frequency or adjust
coverage
Serious interference due to feeder or Arrester
Problem
Check whether the Feeder and
antenna tightening, or direct
replacement its.
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48. The solution to Interference,C/I,BER issue (1)
C/I Issue Solution
Worst C/I due to poor coverage
Improve coverage by adjusting
antenna azimuth and downtilt or
add new sites
Worst C/I to interference Ensure the interference source
and solution as interference
solution.
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49. The solution to Interference,C/I,BER issue (1)
BER Issue Solution
Worst BER due to poor coverage
Improve coverage by adjusting
antenna azimuth and downtilt or
add new sites
Worst BER due to interference Ensure the interference source
and solution as interference
solution.
Worst BER due to Transmission Checking transmission alarm in
M2000
Worst BER to TRX At first check equipment alarm in
M2000,ensure which TRX is
problem
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50. Handover Issues
What is…
Handover procedure in network?
Handover Um signaling flow?
Purpose of Handover Analysis in DT?
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51. Handover Procedure
Neighbor Cell_1
Serving Cell
Uplink MR (Measured by BTS)
•RXLEV Uplink
•RXQUAL Uplink
•TA
•Current BTS TX power
MS in dedicated mode
will continuously perform
Neighbor Cell2
Neighbor Cell2
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Page 51
Downlink MR (Measured by MS)
•Downlink RXLEV(Sever)
•Downlink RXQUAL(Sever)
•RXLEV_NCELL(n) on the 6 best
neighboring cells (+BSIC)
BSC
measurements on serving
and neighbor cells.
Measurement Reports
are sent to BSC and used
in the handover algorithm.
Serving BSC decides
whether a handover is
necessary and send HO
command
Serving Cell
52. Handover signaling on Um(TEMS Message)
Tell MS how to access to
Target TCH Channel
Target cell Description
Target channel Description
Channel Type, Timeslot
TSC
RF hopping
MAIO, HSN
BCCH of Neighbors
to beS merevainsugr Cedell:
DL DTX is ON
RxLev(sub) is -109+ 62 =--49dBm
RxQual (sub) is 0
Handover Complete Handover Success!!!
The RxLev of
Neighbors
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Inter cell Synchronous
Handover
Speech version: EFR
Only after SABM UA
in Layer2 Message,
handover success!
53. The purpose of Handover Analysis
The purpose of handover analysis in DT is
understand the wireless handover performance of network.
find out whether the handovers are healthy in this network.
what is typical handover failure in this network.
find out whether neighbor audit work is needed in this network.
To make optimization of HSR, the most effective way is based on traffic
analysis, combining DT events, neighbor audit, and data configuration
audit together.
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54. Handover Types
Different handover types by network topology
Different handover types by algorithm
PBGT handover
Quality handover
Edge Handover
Intracell Handover
Other types of handover
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55. Handover Types(Network Topology)
Operator
MSC MSC
BSC BSC BSC BSC
BTS BTS BTS BTS BTS BTS
CELL CELL CELL CELL
Synchronous
Case 2
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Case1 Intra cell HO
Case2 Synchronous Inter cell HO
Case3 Asynchronous Inter cell HO
Case4 Inter BSC HO
Case5 Inter MSC HO
Page 55
CELL CELL CELL CELL
Case 1
Asynchronous
Case 3
Case 4 Case 5
56. Handover Types(Algorithm)
In DT, the most common handover
types happens in following order of
priority
TA
RxQuality
OM Forced HO
Directed Retry
TA Emergency HO
Bad Quality HO
Edge HO
Layer HO
RxLevel
PBGT
OLUL
Interference HO
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HO
Rapid Level Drop HO
Load HO
PBGT HO
Fast Moving MS HO
Overlay/Underly HO
57. PBGT Handover
PBGT HO Exp:
When:
RXLEV_NCELL(n) – (RXLEVEL+
PWR_DIFF) HO_MARGIN
MS is handed over to the
neighboring cell .
HO_MARGIN is usually set to 3 to
6 dB.
Serving
Cell
Target
Cell
HO_MARGIN 0
RXLEV_NCELL(n)
RX LEVEL + PWR_DIFF
PBGT HO Power-budget
HO_MARGIN could be increased
to reduce number of handovers.
HO_MARGIN should be
decreased if faster handover
decision is wanted.
PBGT Handover is considered as
most healthy handover in a
network.
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Distance
A typical PBGT HO
58. Quality Handover
Quality Handover Exp:
When:
DL RxQuality = DL Quality HO
Threshold
handover caused by DL
RxQuality takes place.
When:
UL RxQuality = UL Quality HO
Threshold
handover caused by UL
RxQuality takes place.
DLUL Quality HO
Thresholds are generally
set to 6.
UL Quality HO can’t be
monitored in DT.
Handover was performed to a better quality
cell just after experiencing quality problems.
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59. EDGE Handover
Edge Handover Exp:
When:
DL RxLevel Edge HO DL
RX_LEV Threshold
handover caused by DL
RxLevel takes place.
When:
UL RxLevel Edge HO UL
RX_LEV Threshold
handover caused by UL
RxQuality takes place.
UL EDGE handover can’t be
monitored in DT.
Handover was performed to the cell with
higher downlink Rxlev.
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60. Intracell Handover Based on Interference
The Intra–cell Handover
feature aims to maintain
good quality by performing
a handover to a new
channel within the same
cell when uplink or
downlink interference is
detected.
Interference is defined by
bad RxQual and high
enough RxLEV.
Intracell HO also can be
triggered by:
• Rate change between Full rate
and Half rate
• Handover between overlaid and
underlaid subcell. An example of intracell handover after
experiencing quality problems.
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61. Other types of handover
Other types of handover are not easy to judge or not easy to encounter
in DT test, for example :
TA handover
Directed Retry
Load handover
Rapid Level Drop HO
Fast Moving MS HO
For analysis of different types of handover or handover caused by
uplink, it is recommended by traffic analysis or single-user signaling
tracing.
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62. Handover Issues
What is …
Dragged Handover
Power Control Effect
Ping–Pong Handover
Missing Neighbor Relation
Fake Neighbor
Handover Failure
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63. Dragged Handover
There will be such cases that you will notice handover process taking
place a little late, which is called dragged handover.
First thing to check will be handover
margins between the neighbors. If
margins for level, quality or power
budget handovers are not set
correctly, If margins are too much,
handover will happen late, vice
A Quality handover
versa. should happen earlier
Dragged handover events often
occur after a GSM serving cell loses
dominance for a significant time
period.
Dragged Handover often cause Call
Drop or Handover Failure.
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64. Power Control Effect
Power Control Effect sometimes
may mislead us, you might think
that handover is happening too
late between two neighbors.
When the call is continuing on a
timeslot that belongs to
TCHTRX, power control feature
will try to reduce output power
as much as possible until a
Power control
quality problem occurs. That’s
why you will see serving cell
signal level is less than
neighbor’s level. It looks less
but in reality, the signal level on
BCCH TRX is still higher than
neighbors broadcasting level.
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65. Ping-pong Handover
Ping-pong handovers occur when the MS is handed over from one cell to
another but is quickly handed back to the original cell.
The shot shows two ping-pong
handovers displayed on
the map along with the
Servering CI attribute. The
first ping-pong handover is
from cell 12424 to cell 12368
and back and the second is
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Ping-pong HO
from cell 12424 to cell 12366
and back. Changes in the
value of the CI is shown below
the route. It can be clearly
visualized by lines to cells
display.
For most cases, Ping-pong Handover is caused by no dominant cell. There was
a handover back to cell 12366 after the second ping-pong handover, but this was
outside of the defined window. The change in dominance after the handover was
9dB, which represents a much healthier handover.
66. Missing Neighbor Relation
If a handoff is not performed to a neighbor cell that seems to be best
server, there is a possibility of a missing neighbor relation. This will
happen with sudden appearance of strong cell in the neighbor list
just after a handover.
The shot shows after
second handover in
the red box, a much
stronger Serving Cell
appears. ( suspect
there might be missing
neighbor in the 1st HO
attempt)
At this time Neighbor
audit should be
performed.
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67. Fake Neighbor Relation
Sometimes you will see a good
handover candidate in the
neighbor list but handover will
not take place and call will drop.
Although that overshooting cell
with a very good signal level
appears in neighbor list, in reality
it is not. Just because the
serving cell has another
neighbor cell use same with the
same BCCHBSIC ,so the
measurement of the
overshooting cell appears in the
list.
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68. Handover Failure
Handover Failure: Handover attempt was failed and the call returned back to its
all channel.
Target Cell is
BCCH is 13
BSIC is 65
Target channel is
Handover Failure
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900M RF hopping Channel.
Half Rate
MA list is 1, 17, 18, 19, 20, 21, 22, 23, 24
MAIO is 4, HSN is 31,
TSC is The 5.
handover has not
Channel mode is successfully AMR(SV3)
completed yet!
Handover Failure is
caused Another example: Excessive Nu bmy bTe20r 0o Ef xHpairneddover
Failure due to Hardware Problem
69. Proposal of Handover Issue
Dragged Handover
Ping–Pong Handover
Missing Neighbor Relation
Handover Failure
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70. Solutions of Handover Issues
Issue Proposal
Dragged Handover
Check if the parameter of handover, such as: PBGT, Quality, Interference, Edge
handover threshold, and P/N Value is set too high.
Check if there is no dominant coverage. Referring to the solution of Low Coverage.
Check if the traffic volume of target cell is high or has congestion at measuring time.
Ping-pong Handover
Check if there is hardware problem. Referring to hardware checking guide
Check if there is no dominant coverage. Referring to the solution of Low Coverage.
Check if the parameter of handover, such as: PBGT, Quality, Interference, Edge
handover threshold, and P/N Value is set too low .
Check if there is overlapping coverage area, which may also cause ping-pong
handover.
Missing Neighbor
Neighbor Audit. Check if there is neighbor missing according to data configuration in
OMC.
Handover Failure
Find out the cause of Handover failure form Um signaling flow from Layer2 and
Layer3 Message.
Check if the HSR between source and target cell is low. If it is, find the root cause of
handover failure reasons by traffic statistic analysis.
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