129142407 LTE Radio Procedures

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HUAWEI TECHNOLOGIES CO., LTD.

LTE Radio Interface Procedures



HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 2

Contents

1- FAQs

2- Reselection3- SIBs

3- Registration

4-Paging

5-Handover

6-DL Power

Control

7-DL Scheduling8-ANR

9-ICIC

IDLE Mode

Connected Mode

Self Optimization Network

Frame Structure//Throughput Calculations e




FAQs




Frame Structure (FDD)

Related Concept

1- Radio Frame

2-Subframe

3-Slot

4- Subcarrier

5- Resource Block (Scheduling Minimum Unit)

6- Resource ElementChannel

BW (MHz) RB

Number Subcarrier

Number

1.4 6 72

3 15 180

5 25 300

10 50 600

15 75 900

20 100 1200




Number of Scheduled User in 1 TTI

Scheduling information is in PDCCH frame.

1- Total Number of RE for PDCCH=100(RB for 100Mhz)*12(SC)*3

2- Total Number of bits for PDCCH in 1 TTI=100*12*3*Modulation

2bits for QPSK4bits for 16QAM

6bits for 64QAM

Based on CQI

Take 6 as example:

Total Number of bits for PDCCH in 1 TTI=100*12*3*6=21600

Number of bits required by each user for scheduling= 17

Total User support for scheuding =21600/17=1270 Users

Note : Actually need to consider PCFICH+PHICH (from diagram)

i.e. (1270-PCFICH-PHICH)/17 ~~ 1000 users approx




Downlink CalculationDownlink maximum throughput = Number of RB× 12 (Number of Sub-carrier with

one RB)× 14 (Number of Symbols with a Sub-frame)× [ 1－ (RS overhead and PDCCH

overhead) ]× Modulation symbols efficiency× MIMO× 1000 (Number of Sub-frame

in one second)× Coding rate

Example:

Calculate the FDD LTE system 10M, 2 * 2 MIMO, 64QAM, the Coding rate is 1.

The single cell downlink physical layer theory rate = 50*12*14*(1-(2/21+1/21))*6*2*1000*1 =82.4Mb

50 50 RB

12 One RB includes 12 sub-carrier

14 A sub-frame 14 symbol

6 64QAM each symbol represents 6 bits

2 2*2 MIMO1000 1s=1000ms

2/21RS overhead (total symbol of one RB=12*14=168, RS symbol number=16, 16/168=2/21)

1/21PDCCH overhead (If downlink sub-frame PDCCH accounted for only a symbol, and the PDCCH s

symbol of the sub-frame, this is the minimal overhead in PDCCH, a downlink sub-frame occupies 8 sub

minimal PDCCH overhead is 8 symbols, 8 / (14 * 12) =8/168= 1/21.

82.4Mbps this is an ideal value, because the SCH, BCH also take up some of the resources, and consid

the actual Downlink peak rate around 70Mbps




Uplink Calculation

Uplink maximum throughput = Number of RB× 12 (Number of Sub-carrier with one RB)×

14 (Number of Symbols with a Sub-frame)× ( 1－ RS overhead )× Modulation symbols efficiency×

1000 (Number of Sub-frame in one second)× Coding rate

Example:

Calculate the FDD LTE system 10M, None MIMO, 16QAM, the Coding rate is 1.

The UE uplink physical layer theory rate = 46*12*14*(1-1/7)*4*1000*1=26.5Mbps

46 46 RB

12 One RB includes 12 sub-carrier

14 A sub-frame 14 symbol

4

16QAM each symbol represents 4 bits1 Coding rate

1/7Pilot overhead

1000 1s=1000ms

UE cat4 does not support 64QAM and MIMO in uplink, and consider the PUCCH occupied 4RB, the pilo

the uplink can reach the peak rate 25.6Mbps, in fact should also consider the impact of sounding and P

peak rate around 25Mpbs




E-UTRA

Operating

Band

Downlink

FDL_low [MHz] NOffs-DL Range of NDL FUL_lo

1 2110 0 0 – 599

2 1930 600 600 - 1199

3 1805 1200 1200 – 1949

4 2110 1950 1950 – 2399

5 869 2400 2400 – 2649

6 875 2650 2650 – 2749

7 2620 2750 2750 – 3449

8 925 3450 3450 – 3799

9 1844.9 3800 3800 – 4149

10 2110 4150 4150 – 4749

11 1475.9 4750 4750 – 4949

12 728 5000 5000 – 5179

13 746 5180 5180 – 5279

14 758 5280 5280 – 5379

…

17 734 5730 5730 – 5849

18 860 5850 5850 – 5999

19 875 6000 6000 – 6149

20 791 6150 6150 - 6449

21 1495.9 6450 6450 – 6599 …

33 1900 36000 36000 – 36199

34 2010 36200 36200 – 36349

35 1850 36350 36350 – 36949

36 1930 36950 36950 – 37549

37 1910 37550 37550 – 37749

38 2570 37750 37750 – 38249

39 1880 38250 38250 – 38649

40 2300 38650 38650 – 39649

NOTE: The channel numbers that designate carrier frequencies so close to th

extends beyond the operating band edge shall not be used. This implie

channel numbers at the lower operating band edge and the last 6, 14,

upper operating band edge shall not be used for channel bandwidths o

Channel raster

The channel raster is 100 kHz for all bands, whichmeans that the carrier centre frequency must be an

integer multiple of 100 kHz.

Carrier frequency and EARFCNThe carrier frequency in the uplink and downlink is

designated by the E-UTRA Absolute Radio Frequency

Channel Number (EARFCN) in the range 0 - 65535.

The relation between EARFCN and the carrier frequency

in MHz for the downlink is given by the following equation,

where FDL_low and NOffs-DL are given in table 5.7.3-1 and

NDL is the downlink EARFCN.

FDL = FDL_low + 0.1(NDL – NOffs-DL)

The relation between EARFCN and the carrier frequencyin MHz for the uplink is given by the following equation

where FUL_low and NOffs-UL are given in table 5.7.3-1 and

NUL is the uplink EARFCN.

FUL = FUL_low + 0.1(NUL – NOffs-UL)

Carrier Frequency EARFCN Calculation(3GPP : 36.104)

Table 5.7.3-1 E-UTRA channel number




Example

FDL (center Freq) = FDL_low + 0.1(NDL (EARFCN) – NOffs-DL)

Or

NDL (EARFCN)= 10*(FDL (center Freq) - FDL_low ) + NOffs-DL

Say FDL (center Freq) = 1815

NDL (EARFCN)=10*(1815-1805)+1200

NDL (EARFCN)=1300




IDLE Mode Behavior

Idle Mode OverviewPLMN Selection

Cell selection & cell reselection

System Information reception

Tracking area registration

Paging monitoring procedure




Idle Mode Overview

A UE that is powered on but does not have an RRC connection to the radio network

is defined as being in idle mode. In the case of idle mode management, the eNodeB

sends configurations by broadcasting system information, and accordingly, UEs selectsuitable cells to camp on. Idle mode management can increase the access success rate,

improve the quality of service, and ensure that UEs camp on cells with good signal

quality.

PLMN Selection




PLMN Selection

A PLMN identity consists of a Mobile Country Code (MCC) and

a Mobile Network Code (MNC).

When a UE is powered on or recovers from lack of coverage,

after the cell search, the UE first selects the last registered

PLMN and attempts to register on that PLMN. If the registration

on the PLMN is successful, the UE shows the selected PLMN on

the display, and now it can obtain service from an operator. If

the last registered PLMN is unavailable or the registration on

the PLMN fails, another PLMN can be automatically or

manually selected according to the priorities of PLMNs stored

in the USIM.




Cell Selection & Reselection

Cell search is a procedure in which a UE achieves time and frequency

synchronization with a cell, obtains the physical cell ID, and learns the

signal quality and other information about the cell based on the

physical cell ID. Before selecting or reselecting a cell, a UE performs

a cell search on all carrier frequencies.

In the Long Term Evolution (LTE) system, Synchronization Channels

(SCHs) are specially used for cell search. There are two types of

SCH: Primary Synchronization Channel (P-SCH) and

Secondary Synchronization Channel (S-SCH).

The cell search procedure on SCHs is as follows:

The UE monitors the P-SCH to achieve clock synchronization with a

maximum synchronization error of 5 ms. Physical cell IDs have

one-to-one mapping with primary synchronization signals. Therefore,

the UE acquires the physical cell ID by monitoring the P-SCH.

The UE monitors the S-SCH to achieve frame synchronization, that is, time synchronization with the cell.

Cell ID groups have a one-to-one relation with secondary synchronization signals. Therefore, the UE acquires the num

of the cell ID group to which the physical cell ID belongs by monitoring the S-SCH. The UE monitors the downlink refe

signal to acquire the signal quality in the cell. The UE monitors the Broadcast Channel (BCH) to acquire other informat

about the cell.




Cell Selection Criteria

During cell selection, a UE needs to check whether a cell fulfills the cell selection criteria. The cell selection is b

on the RSRP of the E-UTRAN cell. Before a UE can select a cell to camp on, the RSRP of the cell must be highe

the user-defined minimum receive (RX) level Qrxlevmin of the cell.

The formula for cell selection decision is as follows:

Srxlev > 0

where Srxlev = Qrxlevmeas - (Qrxlevmin + Qrxlevminoffset) - Pcompensation

Qrxlevmeas is the measured RX level in the cell (RSRP), expressed in decibels with reference to one milliwatt (

Qrxlevmin is the minimum required RX level (set in the eNodeB) in the cell, expressed in units of dBm.

Qrxlevminof fset is the offset to Qrxlevmin . This offset is taken into account when the UE attempts to camp on aa higher-priority PLMN. That is, when camped on a cell in a VPLMN, the UE considers this offset parameter, wh

was signaled from the associated cell in the higher-priority PLMN, in the Srxlev evaluation.

Pcompensat ion is generated according to the function max(PMax - UE Maximum Output Power, 0). The value is

expressed in decibels (dB).

PMax is the maximum allowed transmit power of the UE in the cell, expressed in units of dBm. It is used in upli

transmission.

http://d/Abid/Document/1/LTE/LTE_TRaining_XiaoPeng/03%20Feature---eRAN%202.1(English)/eNodeBParaHtml/lte/para/CellSel-QRxLevMin.html



http://d/Abid/Document/1/LTE/LTE_TRaining_XiaoPeng/03%20Feature---eRAN%202.1(English)/eNodeBParaHtml/lte/para/CellResel-PMax.html

http://d/Abid/Document/1/LTE/LTE_TRaining_XiaoPeng/03%20Feature---eRAN%202.1(English)/eNodeBParaHtml/lte/para/CellResel-PMax.html







Cell Reselection

The signal strength of both serving cell and neighboring cells varies with the

movement of UE and so the UE need to select the most suitable cell to camp o

This process is called cell reselection.

Cell reselection process:

Measurement Start criteria

Cell reselection criteria

Intr

Inte

Inte




Intra frequency Measurement

If the intra frequency measurement triggering threshold is not configured, the

performs intra frequency measurements always.

If the intra frequency measurement triggering threshold is configured:

Srxlev > SintraSearch,

the UE does not perform intra frequency measurement.

Srxlev <= SintraSearch,

the UE perform intra frequency measurement.




Inter Frequency // RAT Measurement

For the neighbor with higher priority

The UE always perform inter frequency / RAT measurement

For the neighbor with Low or equal priority If the threshold is not configured , the UE always perform inter frequency/RAT measurem

If threshold is configured:

When Srxlev > SNonIntraSearch, UE does not perform inter frequency / RAT

measurement

When Srxlev <=SNonIntraSeach, UE perform inter frequency / RAT measurement

From SIB, UE can get the serving cell & inter frequency / RAT neighbors’ priority

For the high priority cells, UE measure them always, for low priority cells, UE measure them incase of ser

Than threshold.

The intra frequency cells have the same frequency priority, frequencies of different RATs must have diffe

Intra Frequency//Same Priority Cell Reselection




Intra Frequency//Same Priority Cell ReselectionDecision A UE makes a cell reselection decision according to cell reselection criteria. When making a decision on reselection to an in tra-

frequency or equal-priority inter-frequency cell, the UE checks whether the signal quality of a neighboring cell is higher than that

serving cell. The UE evaluates the neighboring cell only after the cell meets the cell selection criteria.

The cell-ranking criteria R_s for the serving cell and R_n for neighboring cells are defined as follows:

R_s = Qmeas,s + Qhyst

R_n = Qmeas,n - CellQoffset

where:

Qmeas,s is the measured RSRP of the serving cell, expressed in units of dBm.

Qhyst is the hysteresis for the serving cell used in the ranking criteria, expressed in units of dB. It is set in the eNodeB.

Qmeas,n is the measured RSRP of the neighboring cell, expressed in units of dBm.

CellQoffset is the offset for the neighboring cell used in the ranking criteria, expressed in units of dB. It is set in the eNodeB.

According to the cell reselection criteria, the UE should reselect the new cell only if both the following conditions are met:

The new cell is ranked higher than the serving cell during the cell reselection time.

More than one second has elapsed since the UE camped on the serving cell.

During cell reselection, the UE needs to check whether access to that cell is allowed according to the cel lAccessRelatedInfo Info

Element (IE) in the SIB1. If the cell is barred, it must be excluded from the candidate list, and the UE does not consider the cell as

candidate for cell reselection. If the cell is unsuitable because it is part of the list of forbidden TAs for roaming or it does not belo

the registered PLMN or an EPLMN, the UE does not consider this cell and other cells on the same frequency as candidates for

reselection for a maximum of 300 seconds.

Inter-RAT/Inter Frequency High Priority Cell

http://d/Abid/Document/1/LTE/LTE_TRaining_XiaoPeng/03%20Feature---eRAN%202.1(English)/eNodeBParaHtml/lte/para/CellResel-Qhyst.html

http://d/Abid/Document/1/LTE/LTE_TRaining_XiaoPeng/03%20Feature---eRAN%202.1(English)/eNodeBParaHtml/lte/para/EutranIntraFreqNCell-CellQoffset.html

http://d/Abid/Document/1/LTE/LTE_TRaining_XiaoPeng/03%20Feature---eRAN%202.1(English)/eNodeBParaHtml/lte/para/EutranIntraFreqNCell-CellQoffset.html

http://d/Abid/Document/1/LTE/LTE_TRaining_XiaoPeng/03%20Feature---eRAN%202.1(English)/eNodeBParaHtml/lte/para/CellResel-Qhyst.html




Inter-RAT/Inter Frequency High Priority CellReselection Decision

For the high priority cells, the UE perform cell reselection if following c

are met:

In “ reselection time”, “Sxlev” of a neighbor is higher than “ ThreshXHigh”


Note: If the highest cell is unsuitable because is part of list of forbidden Tac for roaming or it

not belong to registered PLMN or an EPLMN, the UE does not consider this cell as candidate

reselection for a maximum of 300 seconds.

Inter-RAT/Inter-Frequency low Priority Cell




Inter-RAT/Inter-Frequency low Priority CellReselection Decision

For low priority cells, the UE perform cell reselection if the following c

met:

No cell on a higher priority frequency meets the criteria

In “ reselection time”, “Srxlev” of the serving cell is lower than “ ThrshServLow”,

value of the evaluated neighbor cell is greater than “ ThreshXLow”


System Information Block Contents




SI Block Content

MIB Downlink bandwidth of a cell , Physical HARQ Indication Channel (PHICH) parameters, and System FrameNumber (SFN)

SIB1 Parameters related to cell access and cell selection and scheduling information of SI messages

SIB2 Common radio parameters used by all the UEs in a cell

SIB3 Common cell reselection parameters for all the cells and intra-frequency cell reselection parameters

SIB4 Intra-frequency neighboring cell list, reselection parameters of each neighboring cell used for cellreselection, and intra-frequency cell reselection blacklist

SIB5 Inter-frequency E-UTRA Absolute Radio Frequency Channel Number (EARFCN) list and reselectionparameters of each EARFCN used for cell reselection

Inter-frequency cell list and reselection parameters of each neighboring cell used for cell reselection

Inter-frequency cell reselection blacklist

SIB6 UMTS Terrestrial Radio Access (UTRA) Frequency Division Duplex (FDD) neighboring EARFCN list andreselection parameters of each EARFCN used for cell reselection

UTRA Time Division Duplex (TDD) neighboring EARFCN list and reselection parameters of each EARFCNused for cell reselection

SIB7 GERAN neighboring EARFCN list and reselection parameters of each EARFCN used for cell reselection

SIB8 CDMA2000 pre-registration information

CDMA2000 neighboring frequency band list and reselection parameters of each band used for cellreselection

CDMA2000 neighboring cell list of neighboring frequency band

SIB9 Name of the home eNodeB

SIB10 Earthquake and Tsunami Warning System (ETWS) primary notif ication

SIB11 ETWS secondary notification

System Information Block Contents




MIB

i) MIB is transmitted at a fixed cycles (every 4 frames starting from SFN 0)

S t I f ti T 1




System Information Type-1

1- MCC/MNC

2- Tracking area code: TAC

3- Cell identity

Scheduling information of other SIBs

SIB1 Parameters related to cell access and cell selection and scheduling information of SI messages

i) SIB1 is also transmitted at the fixed cycles (every 8 frames

starting from SFN 0).

System Information (Sib 3)




System Information (Sib-3)

SIB3 Common cell reselection parameters for all the cells and intra-frequency cell reselection pa




System Information(Sib-4//Sib-6)

SIB4 Intra-frequency neighboring cell list, reselection parameters ofeach neighboring cell used for cell reselection, and intra-

frequency cell reselection blacklist

SIB6 UMTS Terrestrial Radio Access (UTRAneighboring EARFCN list and resel

used for cel

UTRA Time Division Duplex (TDDreselection parameters of each E

Tracking Area Registration




Tracking Area Registration

TA in SIB1:

A UE informs the EPC of its Tracking area in 2 ways.

Attach/Detach

TA update (Periodic + Normal)

EPC send paging messages to all enodeB in the TA. A TA is identified by

Tracking area identifier (TAI), which consist of MCC+MNC+TAC

Attach//Detach




Attach//Detach

When a UE needs to obtain service from a network but is not registered to the

network, the UE perform an attach procedure for TA registration

When the UE fails to access the EPC or the EPC doesn’t allow the access of t

UE, a detach procedure is initiated. After the detach procedure, EPC no longe

pages the UE.

TA Update (Periodic + Normal)




TA Update (Periodic + Normal)

TA update are performed in the following situations:

The UE detects a new TA

The periodic TA update timer expires(T3412)

The UE perform reselection to an E-UTRAN cell from another RAT

The RRC connection is released because of load balancing

The information on UE capabilities stored in the ECP changes

The DRX parameter changes

Paging Monitoring Procedure




Paging Monitoring Procedure

Key Concept

1- DefaultPagingCycle (T), DRX Cycle Coefficient.2- Paging Frame (PF)

3- Paging Occasion (PO)Function of IMSI

SFN for PF

SFN mod T = (T div N) x (UE_ID mod N)

For Subframe POThe subframe number i_s of a PO is derived from the following formula:

i_s =Floor (UE_ID/N) mod Ns

Paging Parameters in SIB2

BCCH-DL-SCH-Message ::= SEQUENCE

+-message ::= CHOICE [c1]

+-c1 ::= CHOICE [systemInformation]

+-systemInformation ::= SEQUENCE+-criticalExtensions ::= CHOICE [sys

+-systemInformation-r8 ::= SEQU

+-sib-TypeAndInfo ::= SEQUENCE

| +- ::= CHOICE [sib2]

| +-sib2 ::= SEQUENCE [00]

......

| | +-pcch-Config ::= SEQUENC

| | | +-defaultPagingCycle ::=

| | | +-nB ::= ENUMERATED [o

*Occasion (PO) is a subframe where there may be P-RNTI transmitted on PDCCH addressing the

paging message.

* Paging Frame (PF) is one Radio Frame, which may contain one or multiple Paging Occasion(s).

Meaning of ParametersSFN for PFSFN mod T = (T div N) x (UE_ID mod




Meaning of ParametersFor Subframe PO

The subframe number i_s of a PO i


T=DRX Cycle

N=N is min(T,NB). The NB parameter specifies the number of PO subframes in a DRX cycle. Based on

configuration on the eNodeB, NB can be set to 4T, 2T, T, T/2, T/4, T/8, T/16, or T/32.

Ns =max(1,NB/T).

UE_ID is IMSI mod 1024.

SIB-2

Understanding of NB




Understanding of NB

ExampleSFN for PFSFN mod T = (T div N) x (UE_ID mod N)




Example

IMSI: IMSI(448835805669362)

N=N is min(T,NB) N=min(T,T) T=128

Ns =max(1,NB/T) Ns=max(1,NB/T)Ns=max(1,T/T) 1

UE_ID is IMSI mod 1024 (448835805669362) mod 1024=1010

For Subframe PO

The subframe number i_s of a PO is deriv


SFN mod T=(128 div 128) x (1010 mod 128)= 114

i_s=Floor(UE_ID/N) mod Ns= Floor(1010/128) mod 1= Floor(7.890625) mod 1=7 mod 1= 0

0 1 2 3 4 5 6 7 8 9 10 11 12 13 … …. …. 114 … … 123 124 125 126 127

PF PF PF PF PF PF PF PF PF PF PF PF PF PF PF PF PF PF PF PF PF PF PF PF PF

0 1 2 3 4 5 6 7 8 9

PO




Connected Mode

Handover

Power Control (DL)

Scheduling (DL)

Handover Procedure




Handover Procedure

Mobility Management Overview

Intra Frequency handoverInter Frequency handover

Inter RAT handover

Mobility Management Overview




Handover Procedures Entities




a do e ocedu es t t es

Measurement Triggering




gg g

Only voice

Handover Events




Key Concept




y pStep Direction Message

1 UE <---> SS < Power On and Registration >

2 UE <---> SS < Now UE is in IDLE mode >

3 UE <--- SS Paging

4 UE ---> SS RRC Connection Request

5 UE <--- SS RRC Connection Setup

6 UE ---> SS RRC Connection Setup Complete

7 UE <--- SS Security Mode Command

8 UE ---> SS Security Mode Complete

9 UE <--- SS RRC Connection Reconfiguration

10 UE ---> SS RRCConnectionReconfigurationCompl



13 UE ---> SS Measurement Report


15 UE ---> SS PRACH

16 UE <--- SS RACH Response


18 UE <--- SS ueCapabilityEnquiry

19 UE ---> SS ueCapabilityInformation

20 UE ---> SS ulInformationTransfer + Detach Reque

21 UE <--- SS RRC Connection Release

RRC Connection Reconfiguration is use to

Modify/establish/release RB/to perform

Handover, to setup/modify/release measurement

Main IE:

Measurementconfiguration

Mobilitycontrolinformation

Nas-DedicatedInformation

RadioResourceConfiguration

SecurityconfigurationUe-RelatedInformation

Gap Mode



HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission.Page 40

p

A measurement gap is a time period during which the UE

performs measurements on a neighboring frequency of the

serving frequency. Measurement gaps are applicable to inter-

frequency and inter-RAT measurements. The UE performsinter-frequency or inter-RAT measurements only within the

measurement gaps. One UE normally has only one receiver,

and consequently one UE can receive the signals on only one

frequency at a time.

When inter-frequency or inter-RAT measurements are

triggered, the eNodeB delivers the measurement gap

configuration, and then the UE starts gap-assisted

measurements accordingly. As shown above, Tperiod denotesthe repetition period of measurement gaps, and TGAP denotes

the gap width, within which the UE performs measurements

Intra-Frequency handover




Event A3 will be trigger for Intra-frequency handover.

Handover Procedure




RRC Connection Reconfiguration == Measurement Control

Measurement Report == Measurement Report

RRC Connection Reconfiguration == Physical Channel

Reconfiguration or ActiveSetUpdate

RRC Connection Reconfiguration Complete == Physical

Channel Reconfiguration Complete or

ActiveSetUpdateComplete

LTE Vs WCDMA Jargon



HUAWEI TECHNOLOGIES CO., LTD.Huawei proprietary. No spread without permission. Page 43







The data forwarding process is as follows: Afte

eNodeB sends a handover command to the UE

detaches the connection from the source eNoeNodeB then forwards the uplink (UL) data tha

of order and the DL data to be transmitted, to

eNodeB.

Data forwarding prevents a decrease in the d

and an increase in the data transfer delay that

user data loss during the handover.

Intra-eNodeB handovers do not require data

the case of inter-eNodeB handover, the source

a data forwarding path by using the X2/S1 ada

mechanism.




When a handover fails, the UE performs a cell selection

procedure and then initiates a procedure of RRC connection re-

establishment towards the selected cell. The eNodeB makes a

decision based on whether the context of the UE is present or

not. If the eNodeB accepts the re-establishment request, the

UE accesses the selected cell, thus avoiding drop of the call

caused by the handover failure.

Inter-Frequency Measurement




Event A2 Triggering Algorithm




In a coverage-based inter-frequency handover, event A2 triggers

inter-frequency measurements. The triggering of this event

indicates that the signal quality in the serving cell is lower

than a specified threshold.

Ms: The measurement result of the serving cell

Hys: The hysteresis for event A2

Thresh: The threshold for event A2, it can be

defined separately with RSRP or RSRQ

Event A1 Stop Algorithm




Ms: The measurement result of the serving cell


Event A4 Handover Execution




Mn: The measurement result of the neighboring cell.

Ofn: The frequency-specific offset for the frequency of the

neighboring cell.Ocn: The cell-specific offset for the neighboring cell.


Thresh: The threshold for event A4

Inter-RAT Measurement




Measurement Trigger

Measurement Object




Measurement Object

Handover Trigger B1 Event




Handover Trigger B1 Event

Mn: The measurement result of the neighboring cell

Ofn: The frequency-specific offset for the frequency of the

neighboring cellHys: The hysteresis for event B1. The hysteresis values for

inter-RAT handovers to UTRAN,

LTE UMTS PS Handover Flow




LTE UMTS PS Handover Flow

Power Control




Classification of Power Control




Downlink Power Control Classification




The configured power must meet the requirements for the

downlink coverage of the cell

Fixed power assignment

Fixed power assignment is applicable to the cell-specificreference signal, synchronization signal, PBCH, PCFICH, and

the PDCCH and PDSCH that carry common information of the

cell. Users configure fixed power based on channel quality.

The configured power must meet the requirements for the

downlink coverage of the cell.

Dynamic power controlDynamic power control is applicable to the PHICH and the

PDCCH and PDSCH that carry dedicated information sent to

UEs. Dynamic power control lowers interference, expands cell

capacity, and increases coverage while meeting users'

QoS requirements. However, these channels can also support

fix power assignment, and in fact, this is our recommendation because the AMC function can also meet the requirem

Cell Specific RS Power Setting




The cell-specific reference signal is transmitted in all downlink

subframes. The signal serves as a basis for downlink channel

estimation, which is used for data demodulation.

The power for the cell-specific reference signal is set through

the ReferenceSignalPwr parameter, which indicates the Energy

Per Resource Element (EPRE) of the cell-specific reference

signal.

Synchronization Signal Power Setting




The synchronization signal is used for cell search and system

synchronization. There are two types of synchronization signals,

the Primary Synchronization Channel (P-SCH) and the

Secondary Synchronization Channel (S-SCH).

The offset of the power for the P-SCH and S-SCH against the

power for the cell-specific reference signal is set through the

SchPwr parameter.

PBCH/PCFICH Power Setting




On the PBCH, broadcast messages are sent in each frame. The

messages carry the basic system information of the cell, such as

the cell bandwidth, antenna configuration, and frame number.

The offset of the power for the PBCH against the power for thecell-specific reference signal is set through the PbchPwr

parameter.

The PCFICH carries the number of OFDM symbols used for

PDCCH transmission in a subframe. The PCFICH is always

mapped to the first OFDM symbol of each subframe.

The power for the PCFICH is set through the PcfichPwr

parameter, which indicates an offset of the power for the

PCFICH against the power for the cell-specific reference signal.

PDCCH/PDSCH Power Setting




Dynamic Power Control - PHICH




Dynamic Power Control - PDCCH




When PDCCH carry the following dedicate info,

power control should be performed to ensure the receive

reliability

Uplink scheduling information (DCI format 0)

Downlink scheduling information

(DCI format 1/1A/1B/2/2A)

PUSCH/PUCCH TPC commands

(DCI format 3/3A)

PDSCH Power Presentation




Regarding power control for the PDSCH, the

OFDM symbols on one slot can be classified

into two types. Above table shows the

OFDM symbol indexes within a slot wherethe ratio of the EPRE to the EPRE of RS is

denoted by ρA or ρB.

Automatic Neighbor Relation




ANR is a self-optimization function. It automatically maintains the integrity and effectiveness of neighb

increase handover success rates and improve network performance. In addition, ANR does not require

which reduces the costs of network planning and optimization.

Neighbor relations are classified into normal and abnormal neighbor relations. Abnormal neighbor recases of missing neighboring cells, unstable neighbor relations, PCI collisions, and abnormal neighbor

coverage. ANR automatically detects missing neighboring cells, PCI collisions, and abnormal neighbor

and maintains neighbor relations.

ANR classifications

Concepts Related to ANR-NCL




-NRT

-TempNRT

-BlackList

-HO Black List

-X2 Black List

-WhiteList

-HO White List

-X2 White List

-PCI Collision

-Abnormal Neighbor Cell

coverage

NCL




An NCL of a cell contains the information about the neighboring cells of a cell. Unle

otherwise stated, neighboring cells mentioned in this document exclude intra-eNode

neighboring cells. NCLs are classified into intra-RAT NCLs and inter-RAT NCLs. Ea

cell has one intra-RAT NCL and multiple inter-RAT NCLs.

An NCL includes the ECGIs (for E-UTRAN cells) or CGIs (for inter-RAT cells), PCIs

EARFCNs of the neighboring cells.

The eNodeB adds newly detected neighboring cells to the NCL. The NCL is used a

basis for creating neighbor relations. Neighboring cells in the NCL can be automatic

managed (for example, added, deleted, or modified) by ANR. They can also be

managed manually.

NRT




SN LCI Local CellPLMN

TCI No Remove No HO

1 LCI#1 46001 TCI#1 TRUE TRUE

2 LCI#1 46001 TCI#2 FALSE FALSE

3 LCI#1 46001 TCI#3 TRUE TRUE

An NRT of a cell contains the information about the neighbor relations between a cell a

NRTs are classified into intra-RAT NRTs and inter-RAT NRTs. Each cell has one intra-R

one intra-RAT inter-frequency NRT, and multiple inter-RAT NRTs. The intra-RAT intra-fr

intra-frequency NRT are referred to as the intra-RAT NRT in this document.

shows an example of the NRT. The information in this table is for reference only.Table 3-1 An example of the NRT

TempNRT




A TempNRT is a temporary NRT. It has the same data structure as the NRT. Each cell has an intra-RAT intr

TempNRT and an intra-RAT inter-frequency TempNRT but does not have an inter-RAT TempNRT. The Intra

frequency TempNRT and intra-RAT intra-frequency TempNRT are referred to as the intra-RAT TempNRT in

After detecting a new intra-RAT neighbor relation, the eNodeB adds it to the intra-RAT TempNRT. Then, tregularly maintains the neighbor relation in the TempNRT. If the new neighbor relation is normal, the eN

intra-RAT NRT.

Blacklist

HO Blacklist




HO Blacklist

An HO blacklist contains the information about neighbor relations that cannot be used for a handover or

from the NRT by ANR. The neighbor relations in the HO blacklist must meet the following conditions:

NO Remove = TRUE

NO HO = TRUE

A neighbor relation can be added to the HO blacklist manually.

X2 Blacklist

An X2 blacklist contains the information about an eNodeB and its neighboring eNodeBs. X2 interfaces ca

automatically between the eNodeB and the neighboring eNodeBs. If an X2 interface has been set up, it w

automatically.

Whitelist

HO Whitelist




HO Whitelist

An HO whitelist [1] contains the information about neighbor relations that can be used for a handover b

automatically from the NRT by ANR. The neighbor relations in the HO whitelist must meet the following

NO Remove = TRUE

NO HO = FALSE

A neighbor relation can be added to the HO whitelist manually.

X2 Whitelist

An X2 whitelist contains the information about an eNodeB and its neighboring eNodeBs. The X2 interfac

the eNodeB and the neighboring eNodeBs cannot be removed automatically

PCIA PCI is the identifier of a physical cell. A maximum of 504 PCIs are supported, according to reference do

collisions occur inevitably. PCI collisions negatively affect handover performance and the handover succe

PCI collision handling

http://localhost:7890/pages/GEA0714M/02/GEA0714M/02/resources/Description/ANR%20Management.htm?ft=0&fe=10&hib=3.6.1&id=GEA0714M_02_10045

http://localhost:7890/pages/GEA0714M/02/GEA0714M/02/resources/Description/ANR%20Management.htm?ft=0&fe=10&hib=3.6.1&id=GEA0714M_02_10045




PCI collision handling,

The PCI of an E-UTRAN cell corresponds to:

The primary scrambling code (PSC) of a UTRAN FDD cell

The cell ID of a UTRAN TDD cell

The base transceiver station identity code (BSIC) of a GSM/EDGE radio access network (GERAN) cell

The pseudo number (PN) offset of a CDMA cell

Abnormal Neighboring Cell Coverage




Abnormal neighboring cell coverage (also called cross-cell coverage) refers to the coverage of a cell that is

of the serving cell but can be detected by a UE in the serving cell. The eNodeB regards this cell as a neighserving cell and therefore attempts to add the neighbor relation to the NRT,. The signals of an abnormal n

generally unstable and therefore the success rate of handovers to this cell is low. The coverage of neighb

abnormal in any of the following scenarios:

l The antenna tilt or orientation changes because of improper installation or a natural phenomenon such

l In mountains, the signals of the umbrella cell cover lower cells.

Classification of ANR




Intra-RAT ANR

Intra-RAT Fast ANR

Inter-RAT ANR

Inter-RAT Fast ANR

Intra-RAT ANR

1. The source eNodeB delivers the inter-frequency measurement




Source

configuration to the UE and requests the UE to measure inter-frequency

neighboring cells that meet the measurement configuration.

2. The UE detects that the PCI of cell B meets the measurement configuration and

reports it to the source eNodeB. Then, the source eNodeB checks whether the intra-

RAT NCL of cell A includes the PCI of cell B. If yes, the procedure ends. If no, the

following steps continue.

3. The source eNodeB instructs the UE, using the newly discovered PCI as a

parameter, to read the ECGI, Tracking Area Code (TAC), and PLMN ID list of cell B.

4. The source eNodeB schedules appropriate idle periods to allow the UE to read

the ECGI, TAC, and PLMN ID list of cell B over the broadcast channel (BCH).

5. The UE reports the detected ECGI, TAC, and PLMN ID list of cell B to the source

eNodeB.

The source eNodeB adds the newly detected neighboring cell of cell B to the intra-RAT NCL of

cell A and adds the neighbor relation to the intra-RAT TempNRT

Intra-RAT Fast ANR

Before a UE performs handovers, the eNodeB can obtain the information about all neighboring cells with




reaching or exceeding certain RSRP (it is specified by the FastAnrRsrpThd parameter) based on the repo

measurements. This reduces the impact of event-triggered UE measurements on handover performance

performs handovers.

Inter-RAT ANR

1. The source eNodeB delivers the inter-RAT measurement configuration

http://localhost:7890/pages/GEA0714M/02/GEA0714M/02/resources/lte/para/ANR-FastAnrRsrpThd.html

http://localhost:7890/pages/GEA0714M/02/GEA0714M/02/resources/lte/para/ANR-FastAnrRsrpThd.html




(including target RATs and EARFCNs) to the UE, activates the measurement

gap mode, and instructs the UE to measure the neighboring cells that meet

the measurement configuration.

2. The UE detects that the PCI of cell B meets the measurementconfiguration and reports it to cell A. If the source eNodeB detects that its

NCL does not include the PCI of cell B, it proceeds to the following step.

3. The source eNodeB instructs the UE, using the newly discovered PCI as a

parameter, to read other parameters of cell B, such as CGI.

4. The source eNodeB schedules appropriate measurement gaps to allow the UE to

read the CGI and other parameters of cell B over the BCH.

5. The UE reports the source eNodeB the CGI and other parameters of cell B.

The source eNodeB adds the newly detected neighboring cell to its inter-RAT NCL and

adds the neighbor relation to the inter-RAT NRT.

Inter-RAT Fast ANR




After inter-RAT fast ANR is activated, the eNodeB delivers the inter-RAT measurement configuration to th

UE to detect neighboring GERAN, UTRAN, and CDMA cells by using periodic measurements.

The principles of inter-RAT fast ANR are the same as those of intra-RAT fast ANR

PCI Collision HandlingA PCI collision occurs if two cells in an NCL have the same PCI but different ECGIs. PCI collisions may be c

network planning or abnormal neighboring cell coverage (also known as cross-cell coverage). If two intra




cells have the same PCI, interference will be caused.

When a PCI collision occurs, the eNodeB cannot determine the target cell for a handover. This deteriorat

performance and reduces the handover success rate. Therefore, eliminating PCI collisions is an importan

optimization.

After a PCI collision is eliminated, the PCI is unique in the coverage area of the cell and unique in the neicell.

PCI collision detections are triggered after intra-RAT ANR updates neighboring cells. PCI collision handlin

detecting PCI collisions and reallocating PCIs.

PCI reallocation is a process of allocating a new PCI to a cell whose PCI collides with the PCI of another c

eliminate PCI collisions.

If Optimization Analysis Mode is set to Immediate or Scheduled, the M2000 triggers PCI reallocation in by the value of Optimization Analysis Mode. The M2000 also provides suggestions on PCI reallocation u

collision alarm.

Overview ICICAll physical resource blocks (PRBs) occupied by user equipment (UEs) in

a cell are mutually orthogonal in the frequency domain; therefore,




intra-cell interference is very low. However, inter-cell interference is

relatively high because the frequency reuse factor is 1, in which case

every cell can provide services over the entire system band. For cell

edge users (CEUs), the impact of the inter-cell interference is especially

severe. Therefore, to increase the cell capacity and CEU throughput,inter-cell interference must be mitigated.

ICIC is a technology that collaborates with power control and media access control (MAC) schedulin

mitigate inter-cell interference. ICIC divides the entire system band into three frequency bands and

frequency bands at the edge of neighboring cells. CEUs, which cause high interference or may be se

interference, are preferentially scheduled in the cell edge bands to mitigate inter-cell interference. Tmitigation enhances the network coverage and improves the CEU throughput

DL

Static Dynam

Technical Principles of ICICKey Concept:

A3 Event for ICIC




CEU/CCU

Power Control

MAC Scheduling

The relationships between the key techniques are described

as follows:

i) CEU/CCU identification is a technique of identifying the UE

type (CEU or CCU) based on event A3.

ii) Edge band mode assignment is a technique of allocating

different edge bands to neighboring cells. Edge band

adjustment is a technique of expanding or shrinking the edge

band of a cell based on inter-cell interference and the cell

load. Edge band mode assignment and edge band adjustmentcollaborate to determine the edge band of each cell.

iii) Power control and MAC scheduling collaborate to allocate

PRBs to UEs based on cell edge bands and UE types. PRBs in

edge bands are mainly allocated to CEUs, and those in center

bands are mainly allocated to CCUs.

CEU/CCU IdentificationPrinciplesWhen initially accessing a network, a UE is recognized as a CCU by the serving cell; after a handover, the

CEU b th t t ll Aft h t i d f ll i th i iti l h d th N d B t t t




eNodeBs identify CEUs and CCUs based on ICIC event A3 as follows:

i) If an ICIC event A3 report contains the measurement result only about the

serving cell of a UE, the eNodeB treats the UE as a CCU. An example of this is

when the UE moves from the cell edge to the cell center.

ii) If an ICIC event A3 report contains the measurement result about at least one

neighboring cell, the eNodeB treats the UE as a CEU.

CEU by the target cell. After a short period following the initial access or handover, the eNodeB starts to

(referred to as ICIC event A3 in this document) to determine whether the UEs are CEUs or CCUs.

ICIC Event A3 Based on RSRP Measurement




Entering Condition for ICIC Event A3




Leaving Condition for ICIC Event A3




More Parameter of ICIC Event A3




Edge Band Mode Assignment

Edge band mode assignment is a technique of allocating

different edge bands to neighboring cells. There are three edge

band modes: MODE1 MODE2 and MODE3 whichrepresent




band modes: MODE1, MODE2, and MODE3, whichrepresent

low-, medium-, and high-frequency bands, respectively. The

bandwidth of each band is about 1/3 of the physical downlink

shared channel (PDSCH) or physical uplink shared channel

(PUSCH) bandwidth. The PRBs available to CEUs in a cell using aspecific edge band mode correlate with the ICIC policy and

system bandwidth. The policy can be either dynamic ICIC or

static ICIC.

If there are three cells per eNodeB, as shown in Figure 3-2,

neighboring cells use different edge band modes so that CEUs

in the cells are served by different frequency bands in the

system band. Theoretically, the use of three edge band modes

can eliminate inter-cell interference in the frequency domain.

Edge Band Adjustment (Only in Dynamic ICIC)There are two ICIC policies: static ICIC and dynamic ICIC. The difference between them is that only dynam

bands.

i) Edge band expansion condition

http://localhost:7890/pages/GEA0714M/02/GEA0714M/02/resources/Description/ICIC.htm?ft=0&fe=10&hib=3.2.7&id=GEA0714M_02_10021







i) Edge band expansion condition

The current cell expands its edge band if its edge band is heavily loaded while the edge bands in its neig

loaded. Figure is used as an example to describe edge load evaluation: Yellow grids for the current cell re

defined in static ICIC, and green grids with Y denote the PRBs that CEUs in the current cell actually use be

defined in static ICIC. In this situation, the current cell determines that the number of PRBs required by Cnumber of cell edge PRBs defined in static ICIC. The edge load of the current cell is high while the edge lo

cell is low.

ii) Edge band shrinking condition

− Active shrinking: The current cell actively shrinks its edge

band if its edge load is relatively low.

− Passive shrinking: When the neighboring cell expands itsactual edge band within the edge band defined in static ICIC,

the current cell shrinks its edge band if the PRBs used by the

current and neighboring cells collide. Figure shows an example

of passive shrinking.

SchedulingThe eNodeB implements scheduling at the media access control (MAC) layer and provides time-frequen

and downlink through scheduling. On the premise of guaranteed quality of service (QoS), scheduling aim

the channel with better quality and maximize system throughput by using different channel qualities am






the channel with better quality and maximize system throughput by using different channel qualities am

Scheduling Policies

Max C/I

l Round robin (RR)




l Round robin (RR)

l Proportional fair (PF)

l Enhanced proportional fair (EPF)

Scheduling Policy Effect Factor Scheduling Priority Usage

Max C/I Channel quality The UE with better channel quality has a higher priority inscheduling.

To verthroug

RR None Each UE has equal opportunity to be scheduled. To versched

PF Service rate and channel quality The UE with a small ratio between the service rate and channelquality has a higher priority in scheduling.

To verand fa

EPF Service rate, channel quality, and QoSrequirement

In ope

Scheduling Scheme




Semi Persistent

Dynamic

Semi-Persistent Scheduling

Semi-persistent scheduling is introduced to reduce the overhead of control signaling. Semi-persistent

process where one user uses the same time-and-frequency resources in a specified semi-persistent s

ms in Huawei eNodeB) until they are released. Semi-persistent scheduling is mainly used for processi

constant rate, regular packet arrival, and low delay requirements, such as the Voice over IP (VoIP). By

persistent scheduling, VoIP services can save the overhead of control signaling and increase the VoIP

Dynamic Scheduling

In dynamic scheduling, scheduling is performed every Transmission Time Interval (TTI) of 1 ms and al

scheduled are notified with the scheduling information through control signaling within this TTI. Dyn

no requirements on the size and arrival time of data packets. Therefore, dynamic scheduling is applic

DL SchedulerDownlink scheduling allocates time-and-frequency resources at

the Physical Downlink Shared Channel (PDSCH) for transmission




of system messages and downlink data. Downlink scheduling

described in this chapter is based on the EPF scheduling

strategy.

Downlink scheduling calculates available scheduling resources

based on the current remaining power. In addition, the

scheduling priority and Modulation and Coding Scheme (MCS)

are determined based on the amount of data at the Radio Link

Control (RLC) layer, QoS requirements of bearers, and UE

channel quality. In downlink scheduling, the UE channel quality

information is obtained through the CQIs reported by the UE.

The prioritization and MCS selection of scheduling depend onthe CQI information. Therefore, if reported CQIs cannot

properly reflect the actual channel conditions, the downlink

resource efficiency is low.

DL Scheduling

VoIP service

Th V IP i i i i i h d li h h hi h




The VoIP service experiencing semi-persistent scheduling has the highest

priority. Semi-persistent scheduling is used in the talk spurts of the VoIP

services.

Control-plane data and IMS signaling

Control-plane data consists of common control messages and UE-level control

messages. Common control messages consist of broadcast messages, paging

messages, and random access response messages. UE-level control messages

consist of Signaling Radio Bearer 0 (SRB0), SRB1, and SRB2.

The scheduling of IMS signaling is the same as that of UE-level control

messages.

HARQ retransmission data

Other initial transmission services

Other initial transmission services refer to the initial transmission services of

other QCIs excluding VoIP services and IMS signaling.

VOIP




Control-Plane Data and IMS Signaling




The scheduling priority of control-plane data is only lower than that of VoIP services. Control-plane

dynamic scheduling. Control-plane data consists of common control messages and UE-level control

scheduling of IMS signaling is the same as that of UE-level control messages. Handover and Power

Level Control messages.

HAQR Retransmission Data




Total Process of Other Services Prioritization

*UEs that experience semi-persistent scheduling

*UEs that experience HARQ retransmission sched




*UEs that run out of HARQ process numbers

*UEs that enter the measurement gap

*UEs that enter the DRX dormant period

*UEs that stay out of synchronization and have fa

Rate of non-GBR service > Min_GBR (DLMINGBR

Within Time T:

Rate of GBR service > T*{Maximum number of D

transport block bits received within a TTI}

Prioritization of Remaining ServicesPrioritization of Non-GBR Service

CQI




The service with higher spectral efficiency of the corresponding wideband CQI has a

higher priority.

Average rate of non-GBR servicesThe non-GBR service with a larger average rate has a lower priority.

UE differentiation factor

The UE differentiation factor reflects the priority of UEs of different levels. The UE with

a higher level set by operators has a higher priority in scheduling.

Weight factor {Bit Torrent Vs Non-Bit Torrent And/Or QCI}

Weight factors in downlink scheduling are classified into QCI class weight factors andservice type-based weight factors. Huawei eNodeB can distinguish between Bit Torrent

(BT) and non-BT services using a switch under the DlSchSwitch parameter.

Larger weight factor leads to higher priority of scheduling

Alloc

Serv

Max

Prioritization of GBR

Channel quality

The instantaneous channel quality of the UE is taken into account The UE with

Prioritization of GBR Service




The instantaneous channel quality of the UE is taken into account. The UE with

better instantaneous channel quality has a higher priority. In the case of the same

channel quality, the GBR service with QCI of 1 has a higher priority than other GBR

services.

Delay

The closer the waiting time of the first packet in the buffer is to the Packet Delay

Budget (PDB), the higher the priority is. The PDB value depends on the QCI.

Relative priority

The prioritization of GBR services is different from that of non-GBR services. This

factor is added to compare the priority of GBR services with that of non-GBRservices. Serv

MCS Selection & Resource Allocation




Calculation of Throughput based on MCS If you know the MCS index, you can calculate the throughput for that specific MCS index as

Calculation Procedure for downlink(PDSCH) is as follows :




i) refer to TS36.213 Table 7.1.7.1-1

ii) get I_TBS for using MCS value (ex, I_TBS is 21 if MCS is 23)

iii) refer to TS36.213 Table7.1.7.2.1

iv) go to column header indicating the number of RB

v) go to row header ‘21’ which is I_TBS

vi) you would get 51024 (if the number of RB is 100 and I_TBS is 21)

vii) (This is Transfer Block Size per 1 ms for one Antenna)

If we use 2 antenna, it is 51024 bits * 2 Antenna * 1000 ms = about 100 Mbps

Calculation Procedure for uplink(PUSCH) is as follows :

Same as the downlink as above except that you have to refer to 36.213 Table 8.6.1-1 at step

Uplink Analysis Parameter Calculation






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Copyright©2011 Huawei Technologies Co., Ltd. All Rights Reserved.

The information in this document may contain predictive statements including, without limitation, statements refinancial and operating results, future product portfolio, new technology, etc. There are a number of factors that

results and developments to differ materially from those expressed or implied in the predictive statements. Therefo

is provided for reference purpose only and constitutes neither an offer nor an acceptance. Huawei may change the

time without notice.

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