LTE Optimization Guideline

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819 LTE Optimization

Engineering Guideline

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This manual should be read and used as a guideline for properly installing and operating the product. This manual should be read and used as a guideline for properly installing and operating the product. This manual may be changed for the system improvement, standardization and other technical reasons This manual may be changed for the system improvement, standardization and other technical reasons without prior notice.

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INTRODUCTION

Purpose

This manual describes LTE Optimization process flow, practices and call release cause.

Document Content and Organization

This manual contains the following:

CHAPTER 1. LTE Optimization Process Flow

This chapter describes the site,

This chapter describes the site, cluster and market level optimizations.

cluster and market level optimizations.

CHAPTER 2. LTE Optimization Practices

This chapter describes the

This chapter describes the coverage improvem

coverage improvement, interference control,

ent, interference control, LTE handover

LTE handover

optimization, EUTRAN/CDMA20

optimization, EUTRAN/CDMA2000

00 Handover, RAN parameters, eNodeB

Handover, RAN parameters, eNodeB control

control

paramete

parameters and param

rs and parameter referen

eter reference guide.

ce guide.

CHAPTER 3. Call Release Cause

This chapter describes the call

This chapter describes the call release cause.

release cause.

CHAPTER 4. References

This chapter includes

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819

819 LTE LTE Optimization Optimization Engineering Engineering GuidelineGuideline

Revision History

Version

Version DATE DATE OF OF ISSUE ISSUE REMARKSREMARKS AuthorAuthor 1.0

1.0 11. 11. 2012. 2012. First First Edition Edition Abhishek WarhadkarAbhishek Warhadkar 1.1

1.1 12.2012 12.2012 Added Added section section 2.8, 2.8, UpdatedUpdated Chapter 4 References Chapter 4 References

Abhishek Warh Abhishek Warhadkaradkar

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Figure 1: Site level t esting process flow ... ... 2-2 Figure 2: Cluster Drive testing scenario ... ... 2-3 Figure 3: LTE Cluster Optimization Process Flow ... ... 2-3 Figure 4: LTE Optimization Practices... 2-4 Figure 5: Indicators of DL Interference ... ... 2-5 Figure 6: Example of an overshooting sector ... ... 2-6 Figure 7: Improvement in SINR as a result of down-tilt ... ... 2-7 Figure 8: X2 based Active handover call flow ... 2-10 Figure 9: A3 Event description ... ... 2-11 Figure 10: Example of Handover optimization ... 2-15 Figure 11: Operational procedure for Neighbor Relation Optimization ... ... 2-15 Figure 12: Example of optimum PSS planning ... ... 2-21

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CHAPTER 1. LTE Optimization

Process Flow

LTE performance optimization activities can be divided into three different levels:

1. Site level

2. Cluster level

3. Market level

1.1 Site Level Optimization

Single sites are the basic building blocks of wireless networks. Contiguous sites form clusters and

clusters constitute markets. Therefore optimization of a network begins with individual sites. Site

level testing is a critical step in the process to ensure each site is meeting all t he key performance

indicator (KPI) targets. This type of testing can also be referred to as site level drive testing, site

level shakedown or site level acceptance testing. It can begin as soon as a site is on-air and

functional. Scope for site level testing can vary from basic to a detailed. Most operators and OEMs

perform the following basic tests as a part of site level testing:

A. Peak uplink and downlink throughput test

B. Intra-eNB handovers

C. Inter-eNB handover to immediate first tier neighbors

D. Radio latency test

E. Call success test

Additionally, sector level parameters and data fill are also verified during the course of this activity.

Examples are listed below:

1. Commissioning tests: These tests certify there are no discrepancies in configured

parameters such as Transmit power, Diversity paths etc.

2. Sweep tests: VSWR and uplink noise tests guarantee that sites do not have any anomalies

in coax, fiber and antenna installation. Uplink noise test also eliminate possibility of

external interference.

3. RF parameters: Site and sector level parameters such as PCID, RACH, sector orientation

or azimuth are also verified.

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4. Alarm testing

Figure 1: Site level testing process flow

1.2 Cluster Level Optimization+

Cluster level performance testing or optimization activity is the next key factor in network

optimization. A cluster is a group of several on-air contiguous sites. Contiguous coverage between

sites of a cluster is a critical factor in ensuring seamless mobility. Site level testing as described in

the previous section is usually considered a prerequisite for cluster level testing. Once a cluster is

formed, a baseline drive test is conducted to capture the pre-optimization performance of the cluster.

A cluster drive route must be carefully designed to cover each sector of all sites so that major roads,

thruways, points of interest and demographics important to operators are covered. The drive data is

then analyzed and studied for potential optimization changes to improve user experience.

Suggested changes are implemented and a re-drive is conducted to recapture the performance

improvement. All changes made during the optimization phase must be documented for future

reference. Cluster optimization becomes challenging when there are common elements such as a

shared antenna between two technologies. A balance or trade-off must be considered while

optimizing such networks as improving one network may negatively impact the other underlay or

overlay network.

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Iperf/ftp clients Test UEs eNB EPC Iperf/FTP servers eNBmonitoring tool Testequipment invehicle eNB Pre-determinedroute IntraeNB HOpoint ` ` IntraeNB HOpoint ` IntereNB HOpoint ` IntraeNB HOpoint

Figure 2: Cluster Drive testing scenario

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Examples of major KPIs included in cluster level optimization testing are as fol lows:

1. Connection/call success rate

2. Connection/call drop rate

3. Average uplink throughput

4. Average downlink throughput

5. Average Radio latency

6. Handover success rate and Handover latency

The objective of cluster level testing is to meet or exceed all KPI targets. In situations where one or

more KPIs are not met, possible recommendations should be evaluated: addition of new sites or

sector, antenna replacement, addition of capacity carriers etc. are put forth to achieve required

performance. Figure 1D explains basic LTE optimization practices.

Figure 4: LTE Optimization Practices

LTE standard has a large number of configurable parameters which can affect the performance

aspect of the network. To maintain consistency, several of these parameters must be set to a global

default value. Global default value also referred to as „Golden Parameters‟ must be discussed and

consulted between the OEM and Operator so that an optimized value can be determined based on

laboratory testing, simulating techniques and real world subscriber scenarios.

RF design simulations can also assist in finalizing the physical changes intended coverage

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changes which can be useful in evaluating the impact before implementation. Costly measures such

as physical changes, antenna azimuth or radiation center changes must be carefully assessed to

minimize customer impact and service degradation below set target. Overlapping coverage between

sites is crucial to accomplish optimal handover performance.

Neighbor list implementation ensures successful handover between contiguous sites and sectors.

An initial neighbor list plan can be generated using RF design tools or any other similar tool

capable of designing neighbor plans. Maintaining updated neighbor lists for every site is

recommended to facilitate successful handovers in an evolving network. Neighbor lists from

underlying technology, if available, can be useful first-hand information.

LTE parameters like Physical cell identity (PCI), Root sequence index, Traffic area codes, Traffic

area lists etc. must be planned prior to the commencement of optimization activity. These

parameters can be tweaked during the optimization phase.

The addition of new sites or sectors to the network is considered when existing sites cannot provide

sufficient coverage in terms of reliability and sustainability. Optimization engineers should propose

such ideas to the RF design group to consider during cell planning exercise and network expansion.

1.3 Market level Optimization

For an evolving network, optimization can be a routine activity. Deployment of new macro sites,

small cells, in-building solutions are always considered to meet the high demand of capacity and

bandwidth. Regular network tweaks and optimization efforts are always needed when new network

elements are integrated to serve increased demands and improvement of user experience.

Market level optimization can be considered a final step in accomplishing a high performing LTE

network. This activity is similar to cluster level activity where multiple optimized clusters are

evaluated and analyzed to ensure proper networking and mobility between them.

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CHAPTER 2. LTE Optimization

Practices

2.1 Coverage Improvement

Cell site planning is an important factor in network design process. Antenna selection, antenna

radiation center, antenna tilt (mechanical or electrical) and antenna azimuth governs the coverage

of any given cell site. Lack of coverage also referred to as lack of dominant server or coverage hole

happens when any given geographic region does not have enough RF coverage to serve both fixed

and mobile subscribers. Strength of Reference signal is used in determining the coverage holes.

In LTE terms (as defined in TS 36.214), Reference signal received power is defined as:

Reference signal received power (RSRP), is defined as the linear average over the power

contributions (in [W]) of the resource elements that carry cell-specific reference signals within the

considered measurement frequency bandwidth.

For RSRP determination the cell-specific reference signals R

0

according TS 36.211 [3] shall be

used. If the UE can reliably detect that R

1

is available it may use R

1

in addition to R

0

to determine

RSRP.

The reference point for the RSRP shall be the antenna connector of the UE.

If receiver diversity is in use by the UE, the reported value shall not be lower than the

corresponding RSRP of any of the individual diversity branches

2.1.1 Techniques to improve coverage

1. Antenna orientation and tilt – Pointing the antenna in direction of interest and adjusting the

tilt (mechanical or electrical) is the most common practice to control coverage. Availability

of the remote electrical tilt (RET) feature has made this task more convenient by not

requiring tower climb or visits to the cell site location. Electrical tilt change should also be

evaluated using proper design tools to estimate the effect before implementation. Minimum

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to no harm should be maintained while implementing change in tilt or azimuth. In other

words, while adjusting tilt and azimuth, one must make sure that the suggested change will

not adversely affect existing coverage and served subscribers.

2. Antenna diversity – Adding diversity in uplink is another practice to improve uplink cell

coverage. Uplink diversity improves the „receive sensitivity‟ of eNB resulting in better

uplink coverage.

3. Cell selection threshold QRxLevMin – This parameter specifies the minimum required Rx

level in the cell in dBm. Cell selection process and cell selection criteria as per 3GPP

standard 36.304 are:

Cell Selection process

Description

The UE shall use one of the following two cell selection procedures:

a) Initial Cell Selection

This procedure requires no prior knowledge of which RF channels are E-UTRA carriers. The UE

shall scan all RF channels in the E-UTRA bands according to its capabilities to find a suitable cell.

On each carrier frequency, the UE need only search for the strongest cell. Once a suitable cell is

found this cell shall be selected.

b) Stored Information Cell Selection

This procedure requires stored information of carrier frequencies and optionally also information

on cell parameters, from previously received measurement control information elements or from

previously detected cells. Once the UE has found a suitable cell the UE shall select it. If no suitable

cell is found the Initial Cell Selection procedure shall be started.

NOTE: Priorities between different RAT or frequencies provided to the UE by system information

or dedicated signaling are not used in the cell selection process.

Cell Selection Criteria

The cell selection criterion S is fulfilled when:

Srxlev > 0

Where:

Srxlev = Qrxlevmeas – (Qrxlevmin – Qrxlevminoffset) - Pcompensation

Where:

The signaled value QrxlevminOffset is only applied when a cell is evaluated for cell selection as a

result of a periodic search for a higher priority PLMN while camped normally in a VPLMN [5].

During this periodic search for higher priority PLMN the UE may check the S criteria of a cell

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using parameter values stored from a different cell of this higher priority PLMN.

Srxlev Cell Selection RX level value (dB)

Qrxlevmeas Measured cell RX level value (RSRP).

Qrxlevmin Minimum required RX level in the cell (dBm)

Qrxlevminoffset Offset to the signalled Qrxlevmin taken into account in the Srxlev

evaluation as a result of a periodic search for a higher priority PLMN

while camped normally in a VPLMN [5]

Pcompensation [FFS]

Cell reselection parameters in system information broadcasts

Cell reselection parameters are broadcast in system information and are read from the serving cell

as follows:

Qoffsets,n

This specifies the offset between the two cells.

Qoffsetfrequency

Frequency specific offset for equal priority E-UTRAN frequencies.

Qhyst

This specifies the hysteresis value for ranking criteria.

Qrxlevmin

This specifies the minimum required Rx level in the cell in dBm.

TreselectionRAT

This specifies the cell reselection timer value. For each target RAT a

specific value for the cell reselection timer isdefined, which is

applicable when evaluating reselection within E-UTRAN or towards

other RAT (i.e. TreselectionRATfor E-UTRAN is

TreselectionEUTRAN, for UTRAN TreselectionUTRAN for GERAN

TreselectionGERAN, forTreselectionCDMA_HRPD, and for

TreselectionCDMA_1xRTT).Note: TreselectionRAT is not sent on

system information, but used in reselection rules by the UE for each

RAT.

TreselectionEUTRAN

This specifies the cell reselection timer value TreselectionRAT for

E-UTRAN

TreselectionUTRAN

This specifies the cell reselection timer value TreselectionRAT for

UTRAN

TreselectionGERAN

This specifies the cell reselection timer value TreselectionRAT for

GERAN

TreselectionCDMA_HRPD This specifies the cell reselection timer value TreselectionRAT for

CDMA HRPD

TreselectionCDMA_1xRTT This specifies the cell reselection timer value TreselectionRAT for

CDMA 1xRTT

Threshx, high

This specifies the threshold used by the UE when reselecting towards

the higher priority frequency X than currentlyserving frequency. Each

frequency of E-UTRAN and UTRAN, each band of GERAN, each

band class of CDMA2000HRPD and CDMA2000 1xRTT will have a

specific threshold.

Threshx, low

This specifies the threshold used in reselection towards frequency X

priority from a higher priority frequency. Eachfrequency of E-UTRAN

and UTRAN, each band of GERAN, each band class of CDMA2000

HRPD and CDMA20001xRTT will have a specific threshold.

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Threshserving, low

This specifies the threshold for serving frequency used in reselection

evaluation towards lower priority E-UTRANfrequency or RAT.

Sintrasearch

This specifies the threshold (in dB) for intra frequency measurements.

Snonintrasearch

This specifies the threshold (in dB) for EUTRAN inter-frequency and

inter-RAT measurements.

TCRmax

This specifies the duration for evaluating allowed amount of cell

reselection(s).

NCR_M

This specifies the maximum number of cell reselections to enter

medium mobility state.

NCR_H

This specifies the maximum number of cell reselections to enter high

mobility state.

TCRmaxHyst

This specifies the additional time period before the UE can enter

normal-mobility.

4. Cell selection threshold Qqualmin - Minimum required quality level in the cell (dB). This

is applicable only for FDD cells.

5. Uplink Power control – Uplink power control determines the average power over a

SC-FDMA symbol in which the physical channel is transmitted. PUCCH supports transmission

of ACK/NACK, CQI report and scheduling requests. Coverage can be controlled by UEs

Physical Uplink Control Channel (PUCCH) and Physical Uplink Shared Channel (PUSCH).

Parameters p0_nominal_pusch and p0_nominal_pucch are t wo critical parameters which

define PUSCH and PUCCH transmit power.

2.2 Interference Control

Downlink (DL) inter cell interference which reduces the signal quality is a major factor

contributing to degraded service. It usually impacts cell-edge users which lack good quality RF

signal due to the presence of multiple serving sectors of similar signal strength. DL inter-cell

interference scenario can also be observed in dense urban areas where multipath factor can results

in strong signals from various sectors in one geographic region. DL interference if not corrected

can lead to poor throughput performance on both downlink and uplink. Therefore an improved DL

coverage in terms of both signal strength and quality provides better user experience.

Indicators such as low Signal to noise ratio (SINR), low scale Channel quality indicator (CQI),

Transmission mode (transmit diversity), low Reference Signal Received Quality (RSRQ) and hi gh

Block error rate (BLER) are common indicators of DL interference. Low SINR and low CQI

reports result in lower and more robust modulation scheme for data transmission. The first step in

optimization efforts is to improve the coverage and quality of existing serving cells resulting in

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good quality of service (QoS).

RSRQ is defined in TS 36.214 as:

Reference Signal Received Quality (RSRQ) is defined as the ratio N×RSRP/(E-UTRA carrier

RSSI), where N is the number of RB’s of the E -UTRA carrier RSSI measurement bandwidth. The

measurements in the numerator and denominator shall be made over the same set of resource

blocks.

E-UTRA Carrier Received Signal Strength Indicator (RSSI), comprises the linear average of the

total received power (in [W]) observed only in OFDM symbols containing reference symbols for

antenna port 0, in the measurement bandwidth, over N number of resource blocks by the UE from

all sources, including co-channel serving and non-serving cells, adjacent channel interference,

thermal noise etc.

The reference point for the RSRQ shall be the antenna connector of the UE.

If receiver diversity is in use by the UE, the reported value shall not be lower than the

corresponding RSRQ of any of the individual diversity branches.

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DL interference is usually controlled by maintaining equal power boundaries for cells within a

contiguous cluster. Containing the coverage of a cell only to its intended service region ensures that

the cell is not overshooting and adding to DL interference elsewhere. For boomer sites, use of

mechanical tilt is common practice to contain the coverage and direct the energy in intended

service areas. In reference to mechanical tilt, the gain reduction occurs in the direction or azimuth

of antenna whereas with electrical tilt, there is identical gain reduction in all directions. Antenna

selection during design process is also crucial in planning a good quality network. Knowledge of

antenna characteristics such as horizontal and vertical beam width and side lobes should be utilized

in selecting optimized tilts and azimuth. Transmit attenuation can be used to control excessive DL

interference.

A proper drive test must be conducted to identify the root cause of DL interference. The use of

scanners is recommended; scanner log analysis is useful in pin-pointing overshooting sectors.

Introduction of a new channel or carrier is another approach to tackle interference. However, many

operators do not have this option due to limited licensed spectrum. The idea of new macro or small

cell additions and capacity carriers are considered in cases where DL interference cannot be

controlled due to several network constraints.

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Figure 7: Improvement in SINR as a result of down-tilt

Other than general optimization practices to control interference, LTE also offers features such as

„Inter cell Interference Coordination (ICIC)‟ technique which dynamically controls interference

based on UE‟s CQI reports.

Downlink ICIC (DL-ICIC) enhances cell-edge UE performance by adjusting the power for UE

based on reported channel condition. Cell center users get different power allocation based on UE‟s

feedback.

Average CQI Threshold metric is used to differentiate cell edge and cell center users. DL power

control mechanism uses the channel estimation to adjust the Pa parameter which leads to:



If the user is estimated to be in cell center condition, UE specific DL power related

parameter Pa is lowered, which results in power reduction of data subcarriers for that UE

and further decreases interference to neighboring cells



If UE is estimated to be in cell center condition, Pa is increased and hence data subcarriers

power is increased to maintain edge UE‟s quality

The ratio of PDSCH EPRE to cell-specific RS EPRE among PDSCH REs (not applicable to

PDSCH REs with zero EPRE) for each OFDM symbol is denoted by either

 _A

or

 _B

according

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Uplink ICIC (UL-ICIC) feature is used to control uplink interference. Below flow explains how

uplink power control is implemented using indicators such as Interference over thermal (IOT),

Interference overload indicator (IOI).



eNBs exchange IOI over X2 Interface

o

IOI Information is set as (High/Medium/Low) on per PRB basis



eNB estimates the IOT (Interference Over Thermal) on per PRB basis



IOT is an estimation of interference from neighboring cells



IOT is estimated as:

o

RSSI - Serving_signal_power - Thermal Noise

o

Serving Signal Power = Based on UE Channel Estimation (using SRS/DMRS)

o

Thermal Noise = Based on minimum RSSI over a collection period



Following parameters are then used to determine the IOI indication based on IOT

Parameter

Range

Default

Description

UL TARGET IOT

1 to 128

(step size :

0.25dB)

32 (8dB)

The desired IOT (interference over thermal) from neighboring

cells used for the ICIC Procedure as explained below

UL IOI

THRESHOLD

STEP

1 to 128

(step size:

0.25dB)

2 (0.5dB)

Interference overload indicator(IOI) is a signaling to the

neighboring cells to indicate the interference status

(high/medium/low) for ICIC operation

IOI is set as:

If current IOT < (ulTargetIot – ulIoiThresholdStep ), IOI =

low status

If current IOT > (ulTargetIot + ulIoiThresholdStep ), IOI =

high status

Else, IOI = medium status.

eNB calculates ICIC metric of each UE at every ICIC period

ICIC metric= (IOI_factor) + (delta_interference) + (Fairness Factor)

o

IOI_factor is cell-specific



Reflects the estimated neighboring eNBs‟ interference level experienced.



IOI_factor is calculated from IOI information from all neighboring eNBs

by averaging the IOI information of all PRBs and all eNBs.

o

Delta_interference is UE-specific



Contributed IOT – Target IOT

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

Contributed IOT is estimated interference to neighboring eNBs created by

UE



Amount of contributed IOT can be determined by path loss between UE

and neighboring eNBs and by using the UE Transmit Power information

from PHR (Power Headroom Report)



Path loss can be obtained using the measurement report from UE

or



Estimation based on UE‟s channel condition (CQI, RSRP etc.)

o

Fairness Factor is UE-specific



Results in fairness among UEs, without which, cell center UEs could have

very low ICIC metric causing them to use high power



Power control

o

For UEs with high ICIC metric, TPC (Transmit Power Command) of -1dB is used.

o

For UEs with low ICIC metric, TPC of +1dB is used.

2.3 LTE Handover Optimization

Handover success rate is another important KPI focused on in optimization process. Having a good

success rate indicates that sites in network connect to each and user can enjoy uninterrupted access

to network in mobility scenarios. The impact of LTE handover performance depends on what a

type of applications users are running at their end. For example, poor handover performance or

high handover latency have low impact on applications such as file transfer where a small

interruption can be tolerable whereas bad handover performance may have severe impact on VOIP

applications where a handover drop results in voice call drop.

2.3.1 Active mode handover

Active mode handover can be of three different types:

1. Intra/Inter Frequency – Handover between cells using sane or different center frequencies

2. Intra/Inter eNB – Handover between cells of the same or different site

3. S1/X2 based – Handover involving MME interaction or directly between two eNBs using

X2 links

UE can be configured in connected state to report several different types of measurements based on

event types as explained below.

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o

Event A1



Serving becomes better than a threshold



Used to deactivate Gap Measurements

o

Event A2



Serving becomes worse than a threshold



Used to activate Gap Measurements

o

Event A3



Neighbor becomes offset better than the Serving



Used to trigger Intra-FA Handoff

o

Event A4



Neighbor becomes better than a threshold



Used for ANR

Figure 8: X2 based Active handover call flow

Next section discusses the configuration related to Event A3 which is used to facilitate Intra-FA

LTE handover.

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Figure 9: A3 Event description

• In active mode measurements are performed only when Serving Cell RSRP falls below a

configurable threshold (Smeasure)

• The A3 event parameters for Active mode measurement are transmitted via RRC

Connection Reconfiguration Message

• The parameter a3offset defines the (neighbor + offset > serving) criteria.

• Additionally, there is a cell individual offset that can be configured per neighbor

( Ind_offset ).

• This criterion must be satisfied over a configurable period of time for the measurement

report to be done (TimeToTrigger ).

• The measurement criteria can be based on RSRP or RSRQ and is configurable

(TriggerQuantity).

• The measurement report can be configured to report RSRP/RSRQ or both

( ReportQuantity).

• Periodic reports can be generated after the Event criteria are met based on a configurable

parameter (reportInterval ).

• Number of reports generated based on the event is controlled using a configurable

parameter (reportAmount )

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LSM Command

LSM Parameter

Unit

Range

Default

RTRV-EUTRA-A3-CNF

A3_Offset

0.5db -30db to +30db

4 Time_To_Trigger ms

0,40,64,80,100,128,

160,256,320,480,512,640,1024,1280,2560

,5120

480ms

Trigger_Quantity

RSRP or RSRQ

RSRQ

Report_Quantity

Same as Trigger Quantity

Or

Both

Both (RSRQ &

RSRP)

Report_Interval

ms

120ms, 240ms, 480ms, 640ms, 1024ms,

2048ms, 5120ms, 10240ms, 1min,

6min, 12min, 30min, 60min

240ms

Report_Amount

1,2,4,8,16,32,64, infinity

8 CHG-MEAS-FUNC

S_Measure

*RSRP

Range

0 ~ 97

60

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LSM

Command

LSM Parameter

Range/Size

Default

Details

CHG-QUANT-EUTRA

Rsrp_Filter_Coefficient

fc0, fc1, fc2, fc3,

fc4, fc5,

fc6, fc7, fc8, fc9,

fc11, fc13,

fc15, fc17, fc19

4 The RSRP measurement is

filtered by the UE before

sending the measurement report

using the following formula. M

is the latest measured result, F

is the filtered result and the

factor “a” is based on the filter

coefficient. More the

co-efficient the new filtered result

is influenced more by the

previous filtered value than the

current measured value.

a = 1/2(k/4)

rsrqFilterCoefficient

fc0, fc1, fc2, fc3,

fc4, fc5,

fc6, fc7, fc8, fc9,

fc11, fc13,

fc15, fc17, fc19

4 The RSRQ measurement is

filtered by the UE before

sending the measurement report

using the following formula. M

is the latest measured result, F

is the filtered result and a is

based on the filter coefficient.

More the co-efficient the new

filtered result is influenced

more by the previous filtered

value than the current measured

value.

A3 offset and Smeasure are two critical parameters which can be tweaked to improve handover

performance.

Additionally, „cell individual offset‟ and „Hysteresis‟ parameters can be applied to

improve handover performance.

A3 event description as per 3GPP TS 36.331:

The UE shall:

1> consider the entering condition for this event t o be satisfied when condition A3-1, as

specified below, is fulfilled;

1> consider the leaving condition for this event to be satisfied when condition A3-2, as specified

below, is fulfilled;

Inequality A3-1 (Entering condition)

Off Ocs Ofs Ms Hys Ocn Ofn Mn      

Inequality A3-2 (Leaving condition)

Off Ocs Ofs Ms Hys Ocn Ofn Mn      

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The variables in the formula are defined as follows:

Mn is the measurement result of the neighbouring cell, not taking into account any offsets.

Ofn is the frequency specific offset of the frequency of the neighbour cell (i.e. offsetFreq as

defined within measObjectEUTRA corresponding to the frequency of the neighbour cell).

Ocn is the cell specific offset of the neighbour cell (i.e. cellIndividualOffset as defined within

measObjectEUTRA corresponding to the frequency of the neighbour cell), and set to zero if

not configured for the neighbour cell.

Ms is the measurement result of the serving cell, not taking into account any offsets.

Ofs is the frequency specific offset of the serving frequency (i.e. offsetFreq as defined within

measObjectEUTRA corresponding to the serving frequency).

Ocs is the cell specific offset of the serving cell (i.e. cellIndividualOffset as defined within

measObjectEUTRA corresponding to the serving frequency), and is set to zero if not

configured for the serving cell.

Hys is the hysteresis parameter for this event (i.e. hysteresis as defined within

reportConfigEUTRA for this event).

Off is the offset parameter for this event (i.e. a3-Offset as defined within reportConfigEUTRA

for this event).

Mn, Ms are expressed in dBm in case of RSRP, or in dB in case of RSRQ.

Ofn, Ocn, Ofs, Ocs, Hys, Off are expressed in dB.

2.3.2 Idle Mode Handover

Idle mode handover or cell reselection is the process used by UE and network to monitor UE‟s

location without it requiring radio resources. In Idle mode, UE remains attached at MME level but

remains RRC idle unless it requires RRC resources (for eg. To perform TAU or Paging procedures)

Maintaining most current and updated neighbor list on t he eNBs is critical to facilitate successful

handover. Neighbor list must be updated frequently to accommodate addition of new sites and

sectors in the network.

Condition where multiple handovers are recorded within a very short period between same two

cells in stationary or mobile scenario is known as Ping-Pong. Ping-Pong condition affects the end

user as more processing time results in poor user experience. This situation arises when both source

and target sectors meet the handover thresholds and are equivalent in signal strength. Ping-Pong

can occur in both strong and weak conditions. A3 offset, S-measure, Hysteresis and Cell individual

offset are some parameters which can be tweaked to reduce Ping-Pong rate. Fig 1I shows an

(28)

Figure 10: Example of Handover optimization

Samsung eNB's neighbor optimization function calculates the neighbor priority and optimally

manages the neighbor information based on calculated priority. In addition, it prevents handover

execution for a specific cell using handover blacklist feature. The priority i s calculated using

handover statistics. It maintains the optimum and most current neighbor information by

periodically calculating the priorities.

LSM Serving Cell UE (1) HO Statistics Measurement Report Target Cell HO preparation HO Command HO execution

(2) Ranking Calculation Period

 Change from NRT to

HO Black List

 Restore from HO Black

List to NRT (3) CLI command (NO HO = ON or OFF)  NR Ranking Calculation  Lower HO Quality Calculation  HO-to-Black-Cell Ratio Calculation

(29)

The automatic neighbor relation function through UE measurement is used for adding

neighbors via the LSM or the UE measurement in the following cases:



During UE handover



When source cell lacks the target cell neighbor information

This function can be turned on/off using the CHG-SONFN-CELL command.

The CHG-SONFN-CELL command has the following ANR_ENABLE field parameter values:



sonFuncOff: The ANR function is not performed.



sonManualApply: NR deletion (X2 based), handover blacklist addition according to

NR priority level and NRT recovery are performed automatically. Note that NR

deletion or blacklist addition requires user confirmation.



sonAutoApply: NR deletion (X2 based), handover blacklist addition according to NR

priority level and NRT recovery are performed automatically.

2.4 EUTRAN and CDMA2000 Handover

EUTRAN and CDMA2000 handover can be useful when both networks are overlaid on same

geographical region. A user traveling out of LTE coverage area can hand down to HRPD while

maintaining the same data session and uninterrupted data transfer. This feature is helpful in cases

where a new LTE network is deployed on a matured CDMA2000 network and UE can rely on

underlying network whenever it goes out of coverage on LTE

Implementation of Neighbor list for underlying CDMA network is needed to facilitate EUTRAN to

CDMA2000 handover. On LTE side, appropriate neighboring sectors with PN and channel

information are populated. Right HRPD neighbors can be selected based statistics such as

Handover matrix (HOM) data of CDMA network. Optimization drive test can also give useful

information in defining missing or appropriate neighbors for EUTRAN to CDMA2000

interworking.

Below table explains Parameters and Events used on EUTRAN to CDMA2000 interworking:

Message

IE

Parameter

Description

RRC

Connection

Reconfiguration

B2 Event

b2Threshold1Rsrp

RSRP threshold1 used for

triggering the EUTRA

measurement report for

(30)

b2Threshold1Rsrq

RSRQ threshold1 used for

triggering the EUTRA

measurement report for

CDMA2000 HRPD Event

B2.

b2Threshold2Cdma2000

CDMA2000 threshold 2 used

for triggering the inter-RAT

CDMA2000 measurement

report for CDMA2000

HRPD Event B2.

qOffsetFreq

hysteresisB2

Hysteresis applied to entry

and leave condition of

CDMA2000 HRPD Event B2.

timeToTriggerB2

timeToTrigger value for

CDMA2000 HRPD Event

B2. The timeToTrigger value

is the period of time that must

be met for the UE to trigger a

measurement report.

reportIntervalB2

The reporting interval of a

measurement report for

CDMA2000 HRPD Event

B2.

reportAmountB2

The number of measurement

reports for CDMA2000

HRPD Event B2.

maxReportCellsB2

The maximum number of

cells included in a

measurement report for

CDMA2000 HRPD Event B2.

triggerQuantityB2

Quantity that triggers the

Event B2 measurement The

trigger can be set for either

RSRP or RSRQ and is only

applicable on threshold 1.

RRC

Connection

Reconfiguration

A2 Event

a2ThresholdRsrp

A2 event is triggered when

source becomes worse than

the configured RSRP

threshold (Refer to standard

36.133 for RSRP Report

mapping)

a2ThresholdRsrq

Primary RSRQ threshold

value for eventA2. Used only

when triggerQuantityA2Prim

is set to RSRQ.

reportIntervalA2

Determines the reporting

interval of a measurement

report for Event A2

triggerQuantityA2

A1 event is triggered when

source becomes worse than

the configured RSRQ

threshold ((Refer to

(31)

standard 36.133 for RSRQ

Report mapping)

hysteresisA2

Hysteresis applied to entry

and leave conditions of Event

A2

timeToTriggerA2

The timeToTrigger value is

the period of time that must

be met for the UE to trigger a

measurement report for Event

A2

reportAmountA2

The number of reports for

periodical reporting for the

primary eventA2

measurement .

Value 0 means that reports are

sent as long as the event is

fulfilled.

Primary and secondary

measurement parameters refer

to the option to use different

settings for two simultaneous

measurements for eventA2.

maxReportCellsA2

The maximum number of

cells included in a

measurement report for Event

A2.

reportQuantityA2

Determines whether the

Measurement report for A2

event includes both RSRP and

RSRQ information or the only

RSRP or RSRQ as configured

by the Trigger event above.

filterCoefficientEUtraRsrp

Filtering coefficient used by

the UE to filter RSRP

measurements before event

evaluation The measurement

filter averages a number of

measurement report values to

filter out the impact of large

scale fast fading.

filterCoefficientEUtraRsrq

Filtering coefficient used by

the UE to filter RSRQ

measurements before event

evaluation The measurement

filter averages a number of

measurement report values to

filter out the impact of large

scale fast fading.

RRC

Connection

Reconfiguration

A1 Event

a1ThresholdRsrp

A1 event is triggered when

source becomes better than

the configured RSRP

(32)

threshold ( Actual Threshold

= Parameter - 140, 36.133

standards) dbm

a1ThresholdRsrq

A1 event is triggered when

source becomes better than

the configured RSRQ

threshold (Refer to 36.133

standard for RSRP Report

mapping)

triggerQuantityA1

Determines whether Event A1

is triggered based on RSRP or

RSRQ criteria.

reportQuantityA1

Determines whether the

Measurement report for A1

event includes both RSRP and

RSRQ information or the only

RSRP or RSRQ as configured

by the Trigger event above.

maxReportCellsA1

The maximum number of

cells included in a

measurement report for Event

A1.

hysteresisA1

Hysteresis applied to entry

and leave conditions of Event

A1.

timeToTriggerA1

The timeToTrigger value is

the period of time that must

be met for the UE to trigger a

measurement report for Event

A1

reportIntervalA1

Determines the reporting

interval of a measurement

report for Event A1

reportAmountA1

Determines the number of

measurement reports UE

needs to send when Event A1

criteria is met

SIB8

systemTimeInfo timeAndPhaseSynchCritical

CellReselection

Parameters

CDMA 2000

bandClass

Identifies the CDMA-eHRPD

frequency band class in which

the carrier frequency can be

found

cellReselectionPriority

Reselection priority of the cell

in the eNB. The range is 0-7,

where 0 indicates low, and 7

high in priority.

threshXHigh

ThreshXHigh of CDMA2000

HRPD band class DB.

threshXLow

ThreshXLow of CDMA2000

HRPD band class DB.

(33)

tReselectionSfUsageHRPD

Whether to use

tReselectionSfUsageHRPD of

HRPD reselection information

that is sent down to SIB8.

tReselectionSfUsageHRPD

determines whether to apply a

scaling factor for HRPD cell

reselection.

tReselectionHRPD

TReselctionHRPD included in

the HRPD Reselection

information sent to SIB8. The

default is 0, and can be

changed by the operator.

tReselectionSfHighHRPD

Value by which parameter

tReselectionCdmaHrpd is

multiplied if the UE is in a

high mobility state as defined

in 3GPP TS 36.304

tReselectionSfMediumHRPD

TReselectionSfMediumHRPD

included in the HRPD

Reselection information sent

to SIB8.

searchWindowSize

The size of the search window

in the eNB.

(34)

2.5 RAN Parameters

This section talks about two eNB sector level parameters called, Physical Cell Identity (PCI) and

Root Sequence Index (RSI).

2.5.1 Physical Cell Identity

PCI is derived from two physical layer signals – Primary Synchronization Signal (PSS) and

Secondary synchronization signal (SSS). There are 504 unique PCIs. The physical-layer cell

identities are grouped into 168 unique physical-layer cell-identity groups, each group containing

three unique identities. The grouping is such that each physical-layer cell identity is part of one and

only one physical-layer cell-identity group. A physical-layer cell identity

N _IDcell 3 N _ID(1)N _ID(2)

is thus

uniquely defined by a number

N _ID(1)

_{in the range of 0 to 167, representing the physical-layer}

cell-identity group, and a number

N _ID(2)

_{in the range of 0 to 2, representing the physical-layer identity}

within the physical-layer cell-identity group.

Each cells Reference signal transmits a pseudo random sequence corresponding to assigned PCI.

And channel quality measurements are also made on reference signals. Thus, an optimized

allocation of PCIs is needed to avoid problems in cell recognition or cell search. During PCI

planning, one needs to avoid same PCI and PSS on neighboring cell. This eliminates confusion in

cell search and also reduces interference which can occur due to PSS or reference signal collision.

(35)

2.5.2 Root Sequence Index (RSI)

The Preambles used in RACH procedure are derived from Root Sequence. Preambles are obtained

by cyclic shifts of root sequence which are based on Zadoff-Chu sequence. There are 838 Root

Sequences available. There are 64 preambles available per cell and UE randomly selects one

preamble to perform random access procedure. If number of preambles per root sequence is less

than 64 Preambles, continue deriving Preambles with next Root Sequence unit 64 preambles are

obtained.

Thus, unique assignment of Root sequence is recommended between neighboring cells. Below two

tables describes Ncs to Zero Correlation zone config mapping and LSM parameter for configuring

RSI and Zero correlation zone config parameter.

CS

N configuration N CS value

Unrestricted set Restricted set

0 0 15 1 13 18 2 15 22 3 18 26 4 22 32 5 26 38 6 32 46 7 38 55 8 46 68 9 59 82 10 76 100 11 93 128 12 119 158 13 167 202 14 279 237 15 419

-LSM Parameter

type

Parameter

Range

Default

CHG-PRACH-CONF

Root_sequence_Index

0 ~ 837 Planned

Zero_correl_zone_config 0 ~ 15

12 Prach_Config_Index

0 ~ 63

3 (Alpha)

4 (Beta)

5 (Gamma)

(36)

2.6 e-NodeB - Control Parameters

This section describes some parameters which can help improve call sustainability and reliability

resulting in better network performance.

HARQ Control

CQI Control

AMC Control

2.7 Parameter Reference Guide

Following mapping table provides a quick reference guide for optimization and troubleshooting

each of the LTE KPIs:

KPI

Parameters/Drive test log analyses

Soft Parameters eNB/LSMR

Connection

success rate

RSRP, SINR

QRxlevMin, QqualMin, Backoff

Parameter, MSG4HARQ, eHRPD

redirection parmeters

Connection

drop rate

RSRP, SINR, UL BLER, DL BLER

Check call release cause

Handover

Success Rate

RSRP, SINR

X2 link status, Neighbor list, A3 offset,

Smeasure, Cell Individual offset, ANR,

PCI collision

Handover

Latency

HO Interruption time

Backhaul delay, X2 interface

DL Throughput

RSRP, SINR, DL MCS, DL RB,

PDSCH TP, RI, CQI, DL BLER

_{DL ICIC}

UL Throughput

RSRP, SINR, UL MCS, UL RB,

PUSCH TP, CQI, UL BLER, PDCCH

BLER

UL ICIC

2.8 Relevant Documents and Processes

Please contact Sprint or STA National RF team for latest releases of following documents:

1. Site Modification Process Flow

2. Golden Parameters for LTE and eHRPD

3. Released feature request documentation (FRD)

4. 510 LTE eNB Maintenance Manual

(37)

CHAPTER 3. Call Release Cause

The Call Release Cause is explained below:

Value _{Call Release}

Cause Description Collection Time DEC HEX

256 0X0100

S1AP_CauseRadio Network_

unspecified

A failure occurs in GW during the handover, or the handover preparation fails if the MME cannot process the handover.

When the target eNB receives the Handover Cancel message from the source eNB.

283 0x011B S1AP_invalid_qos_ combination

The action fails due to invalid QoS combination.

- When gbrType of QCI received within

E_RABLevelQoSParameters IE of the Initial Context Setup Request message is GBR but

gbrQosInformation received is not present.

E_RABLevelQoSParameters IE of the E_RAB Setup Request

message is GBR but

E_RABLevelQoSParameters IE of the E_RAB Modify Request

message is GBR but

307 0x0133 S1AP_authenticatio n_failure

The action occurs due to the authentication failure.

Used in the UE context release when the call fails due to the authentication failure.

566 0X0236 X2AP_CauseMisc_ unspecified

Default X2 cause in the eNB.

When the target eNB receives the Handover Cancel message from the source eNB.

768 0X0300 RRC_TMOUT_ rrcConnectionSetu p The RRC Connection Setup Complete

message is not received after the RRC

Connection Setup message is sent to the UE.

When timRrcConnectionSetup message is received because the timer is ended that waits until the RRC Connection Setup Complete message is received after sending the RRC Connection Setup

(38)

Cause Description Collection Time DEC HEX 769 0X0301 RRC_TMOUT_ rrcConnectionReco nfig The RRC Connection Reconfiguration

Complete message is not received after the RRC Connection

Reconfiguration message is sent to the UE.

When timRrcConnectionReconfig message is received due to the timer termination while waiting to receive the RRC Connection Reconfiguration Complete message after the RRC Connection Reconfiguration message is sent to the UE - SB2DB State: sending

Initial Context Setup Failure

- SB2DB state: Initial Context Setup Failure

- Other State: sending UE Context Release Request

- INCELLue state: UE Context Release Request

- REESTue2 state: UE Context Release Request

- GAPprepare state: UE Context Release Request

- ANRprepare state: UE Context Release Request 770 0X0302 RRC_TMOUT_ rrcConnectionReEs tablish The RRC Connection Reestablishment

Reestablishment message is sent to the UE.

When

timRrcConnectionReEstablish message is received due to the timer termination while waiting to receive the RRC Connection Reestablishment Complete message after the RRC Connection Reestablishment message is sent to the UE

771 0X0303

RRC_TMOUT_ rrcSecurityModeCo mmand

The Security Mode Complete message is not received after the

Security Mode Command message is sent to the UE.

When the

timRrcSecurityModeCommand message is received due to the timer termination while waiting to receive Security Mode Complete message after the Security Mode Command message is sent to the UE 772 0X0304 RRC_TMOUT_ rrcUeCapabilityEnq uiry The UE Capability Information message is not received after the UE Capability Enquiry

message is sent to the UE.

When the

timRrcUeCapabilityEnquiry message is received due to the timer termination while waiting to receive the UE Capability

Information message after the UE Capability Enquiry message is sent to the UE 775 0X0307 RRC_TMOUT_intra _ HandoverCmdCom plete The RRC Connection Reconfiguration

Reconfiguration message is sent to the UE during the Intra handover.

When the timer ends while waiting to receive the RRC Connection Reconfiguration Complete message after the RRC Connection Reconfiguration message is sent to the UE during the intra eNB handover

(39)

Cause Description Collection Time DEC HEX 776 0X0308 RRC_TMOUT_inter _ X2HandoverCmdC omplete The RRC Connection Reconfiguration

Reconfiguration message is sent to the UE during the X2 handover.

When the timer ends while waiting to receive the RRC Connection Reconfiguration Complete message after the RRC Connection Reconfiguration message is sent to the UE during the intra X2 handover

777 0X0309 RRC_TMOUT_inter _ S1HandoverCmdC omplete The RRC Connection Reconfiguration

Reconfiguration message is sent to the UE during the S1 handover.

When the timer ends while waiting to receive the RRC Connection Reconfiguration Complete message after the RRC Connection Reconfiguration message is sent to the UE during the intra S1 handover

787 0X0313

S1AP_TMOUT_ s1InitialContextSet up

The Initial Context Setup Request message is not received after the Initial UE message is sent to the MME.

When the

timS1InitialContextSetup message is received due to the timer

termination while waiting to receive the Initial Context Setup Request message after the Initial UE message is sent to the MME

790 0X0316

S1AP_TMOUT_ _{The Path Switch Request} Acknowledge message is

not received after the Path Switch Request message is sent to the MME.

When the timS1PathSwitch message is received due to the timer termination while waiting to receive the Path Switch Request Acknowledge message after the

Path Switch Request message is sent to the MME

s1PathSwitch

792 0X0318

S1AP_TMOUT_ The UE Context Release Command message from the MME is not received because the handover is complete after the Handover Command message is received from the MME.

When the timS1RelocOverall message is received due to the timer termination while waiting to receive the UE Context Release Command message from the MME after the Handover

Command message is received from the MME

s1RelocOverall

794 0x031A

S1AP_TMOUT_ s1MMEStatusTrans fer

The MME Status

Transfer message is not received after the eNB Status Transfer message is sent to the MME.

When the timer ends while waiting for the MME Status Transfer message after the eNB Status Transfer message is sent to the MME

804 0x0324

X2AP_TMOUT_ The UE Context Release message is not received from the Target eNB because the handover is complete after the Handover Acknowledge message is received from the Target eNB.

When the timX2RelocOverall message is received due to the timer termination while waiting to receive the UE Context Release message after the Handover Acknowledge message is

received from the target eNB x2RelocOverall

805 0x0325

X2AP_TMOUT_ x2SNStatusTransfe r

The MME Status

Transfer message is not received after the eNB Status Transfer message is sent to the MME.

When the timer ends while waiting for the MME Status Transfer message after the eNB Status Transfer message is sent to the MME

(40)

Cause Description Collection Time DEC HEX

816 0X0330

RRC_TMOUT_ internalResourceSe tup

The response message is not received after the SetupReqe message is sent for setting the resource for the internal protocol blocks of the eNB.

When the

timInternalResourceSetup message is received due to the timer termination while waiting to receive the response after the SetupReq message is sent to assign resources to the protocol blocks within the eNB

- SB2DB state: Initial Context Setup Failure

- DB2DBScomplete state: UE Context Release Request, E_RAB Setup Response

- DB2DBMcomplete state: UE Context Release Request, E_RAB Modify Response

- DB2DBRfail state: E_RAB Release Response

- PHYREcomplete state: UE Context Release Request - INTERprepare_T state: Handover Failure 818 0X0332 RRC_TMOUT_ internalSecurityCon trol

After sending the

msgCpdcpSecurityContr ol message to the PDCB, cannot receive the

msgCpdcpSecurityContr olSuccess message

When receiving the

timInternalSecurityControl message because the timer is ended that waits until the

msgCpdcpSecurityControlSucces s message is received after sending the

msgCpdcpSecurityControl message to the PDCB

- SB2DBint state-SB2DBciph state

820 0X0334

RRC_TMOUT_ internalForwarding PathSetup

During Handover, after sending the

msgCgtpSetupReq message to the GTPB for setting uplink and

downlink path, cannot receive the

msgCgtpSetupCnf message

During Handover, when the timInternalForwardingPathSetup message is received because the timer is ended that waits until the msgCgtpSetupCnf message is received after sending the msgCgtpSetupReq message to GTPB for setting the uplink, downlink path 821 0X0335 RRC_TMOUT_ internalReestablish Control The msgCrlcControlSuccess or msgCpdcpControlSucces s is not received after the msgCrlcControl,

msgCpdcpControl

message is sent for RLC, PDCP reestablishment during inter eNB HO.

When the

timInternalReestablishControl message is received due to the timer termination while waiting to receive the

msgCrlcControlSuccess or msgCpdcpControlSuccess

message after the msgCrlcControl or msgCpdcpControl message is sent for RLC, PDCP

reestablishment during inter eNB HO

(41)

Cause Description Collection Time DEC HEX 822 0X0336 RRC_TMOUT_ internalBufferFlush The msgCpdcpBufferFlushCn f message is not

received after the msgCpdcpBufferFlush message is sent to the PDCB during handover.

When the timInternalBufferFlush message is received due to the timer termination while waiting to receive the

msgCpdcpBufferFlushCnf message after the

msgCpdcpBufferFlush message is sent to the PDCB during handover

823 0X0337 RRC_TMOUT_ internalDataTransfe rStart The msgCpdcpControlSucces s message is not

received after the msgCpdcpControl message is sent.

When the

timInternalDataTransferStart message is received due to the timer termination while waiting to receive the

msgCpdcpControlSuccess message after the

msgCpdcpControl message is sent

- INCELLresume state: key refreshing

- INTRAresume state: Intra Cell handover

- INTERstart_T state: Inter e NB handover

- REESTresume1 state: Reestablish

833 0X0341 RRC_USER_INAC_TIVITY UE is in inactive status.

When the

msgCmacPhyUserInactivityInd message is received from the MACB.

834 0X0342

RRC_ARQ_MAX_ RE_

TRANSMISSION

After sending only as much as the RLC Max retransmission count, the UE status does not become active for a certain period of time.

When the timer ends while running the

timInternaReestablshTimeToWait timer after the

msgCrlcMaxRetransInd message is received from the RLCB

835 0X0343 RRC_RADIO_LINK _ FAILURE

The radio link with the UE failed.

The MAC notifies the ECCB of the possible release of the uplink

LTE Optimization Guideline

819 LTE Optimization

819 LTE Optimization

Engineering Guideline

Engineering Guideline

COPYRIGHT

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This manual is proprietary to SAMSUNG Electronics Co., Ltd. and is

This manual is proprietary to SAMSUNG Electronics Co., Ltd. and is protected by

protected by

copyright.

copyright.

No information c

No information contained here

ontained herein may be

in may be copied, translate

copied, translated, transcribed o

d, transcribed or duplicated fo

r duplicated forr

any commerc

any commercial purposes or disclosed to

ial purposes or disclosed to the third party in

the third party in any form without the prior

any form without the prior

written consent of

written consent of SAMSUN

SAMSUNG Electronics Co., Ltd.

G Electronics Co., Ltd.

TRADEMARKS

TRADEMARKS

Product names mentioned i this manual may be trademarks and/or registered trademarks of

Product names mentioned i this manual may be trademarks and/or registered trademarks of

their respective companies.

their respective companies.

INTRODUCTION

INTRODUCTION

Purpose

Purpose

This manual describes LTE Optimization process flow, practices and call release cause.

This manual describes LTE Optimization process flow, practices and call release cause.

Document Content and Organization

Document Content and Organization

This manual contains the following:

This manual contains the following:

CHAPTER 1. LTE Optimization Process Flow

CHAPTER 1. LTE Optimization Process Flow

This chapter describes the site,

This chapter describes the site, cluster and market level optimizations.

cluster and market level optimizations.

CHAPTER 2. LTE Optimization Practices

CHAPTER 2. LTE Optimization Practices

This chapter describes the

This chapter describes the coverage improvem

coverage improvement, interference control,

ent, interference control, LTE handover

LTE handover

optimization, EUTRAN/CDMA20

optimization, EUTRAN/CDMA2000

00 Handover, RAN parameters, eNodeB

Handover, RAN parameters, eNodeB control

control

paramete

parameters and param

rs and parameter referen

eter reference guide.

ce guide.

CHAPTER 3. Call Release Cause

CHAPTER 3. Call Release Cause

This chapter describes the call

This chapter describes the call release cause.

release cause.

CHAPTER 4. References

CHAPTER 4. References

This chapter includes

Revision History

Revision History

TABLE OF CONTENTS

TABLE OF CONTENTS

CHAPTER 1.

CHAPTER 1. LTE