What is the typical event sequence of IRAT Handover from 3G to 2G

Simple IRAT Handover Flow

Event 2d –entering into compressed mode –measurement of 2G candidates – Event 3a –Verification of 2G resources

Handover from UTRAN Command from 3G RNC to UE

Download Complete UMTS CS Call Flow

What are the typical KPIs you use to measure a network and what criteria?

• Access failure rate (≤ 2%).
• Call setup time (CS: over 95% of the time < 6-second for mobile-to
• PSTN, 9-second for mobile-mobile.  PS: over 95% of the time < 5 second).
• Dropped call rate (≤ 2%).
• BLER: over 95% of the blocks ≤ 2%.
• Average DL/UL throughput for PSD: 210kbps for loaded, 240kbps for unloaded.

Find the complete UMTS KPI from Here

Information on UMTS KPI BenchMark

CPICH Optimization

Good Document on CPICH Optimization from Maxis

CPICH Optimization

You can view Document Here

Content

• Objective
• Technical Background
• Deployment Area
• Performance Results
• Traffic Results
• Capacity Results
• Summary

Download Full Document in PDF from Here

Deployment of CPICH optimization is driven by:
–Improving current 3G coverage and increase 3G traffic
–Improve in-building penetration for 3G
–Reduce IRAT HO to 2G
–Offload traffic from 2G layer

How Can We Avoide IRAT Handover?
Traffic Shift Strategy for 3G to 2G

20 years of GSM from NSN

A very good PPT on 20 years evolution of GSM.
Good infographics presentation.

Find the whole Presentation Click Here

Find the whole Presentation Click Here

Key Highlights 

• The World’s First commercial GSM network –July 1st 1991
• Key steps to World’s First commercial GSM network
• VintageGSM mobile phones
• GSM Evolution -gradual improvements since 1990
• GSM dominates the world today…
• GSM umbrella coverage with Single RAN Advanced
• Advancingbusiness opportunitiesin GSM
• Liquid RadioOne Simplified Network
• Nokia Siemens Networks leadership in GSM family of technologies

What are the conditions you typically set to trigger IRAT handover?

RSCP and Ec/Io are used to trigger IRAT handover:

1.       RSCP ≤ -100dBm.

2.       Ec/Io ≤ -16dBm.

Find more document on IRAT
WCDMA IRAT Handover
Details on IRAT Parameter Optimization Document

How many channelization codes are available?

The number of channelization codes available is dependent on the length of code.  In the uplink the length is defined as between 4 and 256.  In the downlink the length is defined as between 4 and 512.

Know more about Scrambling Code

UMTS Scrambling Code Planning Guide

What is channelization code?

Channelization codes are orthogonal codes used to spread the signal and hence provides channel separation, that is, channelization codes are used to separate channels from a cell.

To Know more on WCDMA

100 WCDMA Documents

LTE Presetations 

Consider downlink only, what are the major components in calculating maximum path loss, starting from NodeB?

·         NodeB CPICH transmit power.

·         Jumper and feeder connector loss.

·         Antenna gain.

·         Over-the-air loss.

·         Building / vehicle penetration loss.

·         Body loss.

Parameter Dictionary from well known Vendor
Google Mapinfo Tool

How much is your HSDPA (max) link power?

HSDPA link power is typically 4 to 5dB below the maximum NodeB maximum output power.  For example, for 43dBm maximum NodeB power the HSDPA link power is 39dBm.

HSDPA Network Planning Guide

What is Difference between ARQ and HARQ?

HSDPA Measurement Events

What is a typical CPICH power?

CPICH power typically takes about 10% of the total NodeB power.  For a 20W (43dBm) NodeB, CPICH is around 2W (33dBm).

In urban areas where in-building coverage is taken care of by in-building installations, the CPICH may sometimes go as low as 5% because:

• The coverage area is small since users are close to the site, and
• More power can be allocated to traffic channels.

Find UMTS Questions and Answers

Nemo Outdoor and Analyzer Training Slides

How much power usually a NodeB is allocated to control channels?

The power allocated to control channels may depend on equipment vendor recommendation.  Typically no more than 20% of the total NodeB power is allocated to control channels, including CPICH.  However, if HSDPA is deployed on the same carrier then the total power allocated to control channel may go up to 25 to 30% because of the additional HSDPA control channels required.

What is Power Congestion in UMTS?

How We can tune 3G Network?

What is a typical EiRP?

The EiRP depends NodeB transmit power, cable and connector loss and antenna gain.  With a sample system of 43dBm transmit power, a 3dB cable and connector loss and a 17dBi antenna gain, the EiRP = 43 – 3 + 17 = 57dBm.

Download Excel sheet of UMTS Link Budget

What is a typical soft handover gain in your link budget?

•          CS-12.2k:      3dB (UL), 2dB (DL)
•          PS-64k:         1dB (UL), 0dB (DL)
•          PS-128k:       1dB (UL), 0dB (DL)
•          PS-384k:       1dB (UL), 0dB (DL)

Know more about 

How does Soft Handover Work?

WCDMA Soft Handover Procedure

What are fast fading and slow fading?

Fast fading is also called multi-path fading, as a result of multi-path propagation.  When multi-path signals arriving at a UE, the constructive and destructive phases create a variation in signal strength.

Slow fading is also called shadowing.  When a UE moves away from a cell the signal strength drops down slowly.

Download More

Detail Doc on Layer 3 Messages

Call Flow with Layer 3 Messages on Ericsson System

Cell Azimuth-Mapinfo Tool

If you want to create a azimuth than its a very good tool for that.

You can try it.

Download From here

Plan Checker A Mapinfo Frequency Planning Tool

Very Good Tool Developed by Nokia for Frequency Planning.
Plan_Checker7v3 By DayantiPratiwi

Plan Checker

Features:

• Verify Frequency Planning
• Useful for New Frequency Planning
• Verify Neighbor Data or Neighbor Relation
• And lots more on Drive Test Analysis

Click Here to Download.

Distance Calculator Tool for RF Engineers

Distance Calculator Tool for RF Engineers

Very Good tool You can Download.

Distance Calculator.

Its calculate distance between two latitude and longitude.

Download Link

Brief describe the advantages and disadvantages of soft handover?

Advantages:

·         Overcome fading through macro diversity.

·         Reduced Node B power which in turn decreases interference and increases capacity.

·         Reduced UE power (up 4dB), decreasing interference and increasing battery life.

Disadvantages:

·         UE using several radio links requires more channelization codes, and more resources on the Iub and Iur interfaces.

More Dowload For You:

Actix Tutorial

Why is there soft handover gain?

Soft handover gain comes from the following:

• Macro diversity gain over slow fading.
• Micro diversity gain over fast fading.
• Downlink load sharing over multiple RF links.  By maintaining multiple links each link could transmit at a lower power, resulting in lower interference therefore a gain.

Just for you:

Download WCDMA IRAT Handover Document.

Download Documnet on GSM to WCDMA Handover

Sometimes we say Ec/Io and sometimes we say Ec/No, are they different?

Io = own cell interference + surrounding cell interference + noise density

No = surrounding cell interference + noise density

That is, Io is the total received power density including CPICH of its own cell, No is the total received power density excluding CPICH of its own cell.  Technically Ec/Io should be the correct measurement but, due to equipment capability, Ec/No is actually measured.  In UMTS, Ec/No and Ec/Io are often used interchangeably.

Explore more:

KPI Monitoring and Improving Guide

What is Ec/Io?

Ec/Io is the ratio of the energy per chip in CPICH to the total received power density (including CPICH itself).

Explore More

Downlaod Complete Document on UMTS Call Flow

Why is Eb/No requirement lower for PS than for CS?

PS has a better error correction capability and can utilize retransmission, therefore it can afford to a lower Eb/No.  CS is real-time and cannot tolerate delay so it needs a higher Eb/No to maintain a stronger RF link.

Explore More:

E Book on WCDMA for UMTS Networks
Download WCDMA IRAT Handover Document.
Good Discussion Topic on Congestion Control

What are the Eb/No targets in your design?

The Eb/No targets are dependent on the service:

• On the uplink, typically CS is 5 to 6dB and PS is 3 to 4dB – PS is about 2dB lower.
• On the downlink, typically CS has 6 to 7dB and PS is 5 to 6dB – PS is about 1dB lower.

Explore More

• Information On All WCDMA Events From Here
• WCDMA Handover andCall Drop Analysis
• WCDMA Link Budget

What is Eb/No?

By definition Eb/No is energy bit over noise density, i.e. is the ratio of the energy per information bit to the power spectral density (of interference and noise) after dispreading.

Eb/No = Processing Gain + SIR

For example, if Eb/No is 5dB and processing gain is 25dB then the SIR should be -20dB or better.

Do You want to Know

What is difference between RSCP,RSSI,EcIo?

How to calculate maximum number of users on a cell?

 To calculate the maximum number of users (M) on a cell, we need to know:

W: chip rate (for UMTS 3,840,000 chips per second)

EbNo: Eb/No requirement (assuming 3dB for CS-12.2k)

i: other-cell to in-cell interference ratio (assuming 60%)

R: user data rate (assuming 12,200 kbps for CS-12.2k)

η: loading factor (assuming 50%)

Take 12.2kbps as example:

M = W / (EnNo * (1 + i) * R) * η = 3,840,000 (3 * (1 + 0.6) * 12,200) * 0.5 = 32.8

The number of users could also be hard-limited by OVSF code space.  Take CS12.2k for example:

·         A CS-12.2k bearer needs 1 SF128 code.

·         Total available codes for CS-12.2k = 128 – 2 (1 SF64) – 2 (4 SF256) = 124.

·         Consider soft-handover factor of 1.8 and loading factor of 50%: 124 / 1.8 *.05 = 34 uers/cell.

More For You

Training On EDGE and GPRS

Document on BSS Parameter

GSM Call Flow      

What are the processing gains for CS and PS services?

CS12.2:      25dB

PS-64:        18dB

PS-128:      15dB

PS-384:      10dB

      HSDPA:       2dB

Click Here to Get
WCDMA Link Budget
GSM Link Budget

Why TMA are installed at the top near the antenna and not the bottom near the NodeB?

Based on Friis Equation, having a TMA near the BTS will have the top jumper and main feeder losses (noise figures) cascaded in and a TMA will not be able to help suppress the losses.

Download Useful Tools:

Lat Long Converter

Katharine Calculator

What is typical TMA gain?

TMA typically has a 12 dB gain; however, the effective gain comes from noise figure reduction and the gain is close or equivalent to the feeder loss.

Download Planning Tools:

WCDMA Planning Tool-MapInfo

What are the pros and cons (advantages and disadvantages) of TMA?

On the upside, a TMA reduces system noise, improves uplink sensitivity and leads to longer UE battery life.  On the downside, TMA imposes an additional insertion loss (typically 0.5dB) on the downlink and increases site installation and maintenance complexity.

Download Good Documents:

Training On EDGE and GPRS

Document on BSS Parameter

GSM Call Flow

How does TMA work?

A TMA reduces system noise, improves uplink sensitivity and leads to longer UE battery life.

Sensitivity is the minimum input power needed to get a suitable signal-to-noise ratio (SNR) at the output of the receiver.  It is determined by receiver noise figure, thermo noise power and required SNR.  Thermo noise power is determined by bandwidth and temperature, SNR is determined by modulation technique, therefore the only variable is noise figure.

The cascading noise figure can be calculated by Friis equation (Herald Friis):

NF_t = NF₁ + (NF₂-1)/G₁ + (NF₃-1)/(G₁*G₂) + ... + (NF_i-1)/(G₁*G₂*...*G_i)

As the equation shows, the first block imposes the minimum and the most prominent noise figure on the system, and the following blocks imposes less and less impact to the system provided the gains are positive.  Linear passive devices have noise figure equal to their loss.  A TMA typically has a gain of 12dB.

There are typically top jumper, main feeder and a bottom jumper between antenna and BTS.  A TMA placed near antenna with a short jumper from antenna provides the best noise figure improvement – the noise figure will be restricted to the top jumper loss (NF₁) and TMA ((NF₂-1)/G₁), and the remaining blocks (main feeder and bottom jumper) have little effect.

To summarize, a TMA has a gain that’s close to feeder loss.

More For You Only...

• What is the processing gain for 384 Kb/s service?
• What is Significance of Eb_No?
• What effect is there on signal by spreading and dispreading?
• What is the family of codes used for Chanelization in WCDMA?
• Define Active Set? Pros and Cons of having a small or longer Active Set

What is the difference between dB and dBm?

dBm is a unit of power level, measured in milli-watts in logarithm scale, that is,

dBm = 10 * log(W*1000)  where W is the power in Watts

dB is not a unit, it is the difference in dBm

Download Document on WCDMA Capacity Planning
Download WCDMA Radio Network Capacity Planning  
Download Document on RRC KPIs 

What is difference between dBi and dBd?

dBi is the gain in dB from isotropic source; dBd is the gain from a dipole source.

dBd + 2.15 = dBi.

Good Document for Telecom Engineers

Document on GSM to WCDMA Handover Fundamentals

Information On All WCDMA Events From Here

Documnet on GSM to WCDMA Handover  

Difference between Handover Failure and Reversion