Mobility Function Introduction 2013-12-13

8/10/2019 Mobility Function Introduction 2013-12-13

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Mobility Function Introduction

Alex.Lin


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UE status in LTE


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Mobility Function List

Handover(Intra&Inter-Frequency/Inter-RAT)

Redirection

Reselection

CSFB(Circuit Switched Fallback)


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Handover

Intra frequency HO

Inter frequency HO

Inter-RAT HO

Cell A

Freq 1

Cell B

Freq 1

Cell A

Freq 1

Cell B

Freq 2

LTE Cell A UMTS Cell B


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Redirection

When the UE capability or eNodeB does notsupport handover, redirection is one of methodsfor users to move from serving cell to neighboring

cell. When perform redirection, eNB would send RRC

CONNECTION RELEASE message includingRedirectedCarrierInfo IE to indicate UE to camp

on the specified frequency The time delay of redirection is larger than

handover


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Reselection

The cell reselection procedure allows the UE to

select a more suitable cell and camp on it.

When the UE is in either CampedNormally state

or Camped on Any Cellstate on a cell, the UE shall

attempt to detect, synchronise, and monitor

intra-frequency, inter-frequency and inter-RAT

cells indicated by the serving cell. UE measurement activity is also controlled by

measurement rules defined in TS36.304


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CSFB

The LTE network is an entire IP switched network.When the IMS network does not support VoIMSor UEs not support VoIP, CSFB provides amechanism to enable traditional CS services

fallback from E-UTRAN access to 2G/3G CSdomain access.

CSFB application can reuses the CS domaininfrastructure to protect the operators

investment in 2G/3G network, and the LTEnetwork can be used to provide the high speeddata services for customers


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Reselection

Handover (Data or Voice & CS-Fallback)

Redirection

LTE 1800

Mobility Function Map

LTE 2600

3G

F3

F2

F1

2G

LTE 1800

LTE

2600

3G

F3

F2

F1

2G

LTE 1800

LTE

2600

3G

F3

F2

F1

2G

INTRA SITE INTERSITE

Reselection mesh

Handover (Data & Voice & CS-Fallback) mesh

Redirection Mesh


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Function Chart

Mobility Function Chart

Source Target

4G 3G 2G

Function

Current

Version

Support

Status Function

Current

Version

Support

Status

Current

Version

Support

Statu

s

4G

1)Intra-Frequency

HO

2)Inter-Frequency

HO

1)YES

2)YES

1)ON

2)NO

HO(UE:Active) YES ON HO(UE:Active) YES OFF

Redirection(UE:Act

ive)YES ON

Redirection(UE:A

ctive)YES OFF

Reselection(UE:IDL

E)YES ON

Reselection(UE:ID

LE)YES OFF

CSFB(Voice Call) YES ON CSFB(Voice Call) YES OFF

3G

HO(UE:Active) YES OFF

1)Intra-Frequency

HO2)Inter-Frequency

HO

1)YES2)YES 1)ON2)ON

HO(UE:Active) YES ON

Redirection(UE:Act

ive)

YES,base

on load OFF

Redirection(UE:A

ctive)

YES,bas

e onload OFF

Reselection(UE:IDL

E)YES ON

Reselection(UE:ID

LE)YES ON

2G(BSC

Version:

6.20.713)

HO(UE:Active) NO OFF HO(UE:Active) NO OFF1)Intra-Frequency

HO

2)Inter-Frequency

HO

1)YES

2)YES

1)ON

2)ON

Redirection(UE:Act

ive)NO OFF

Redirection(UE:Act

ive)NO OFF

Reselection(UE:IDL

E)NO OFF

Reselection(UE:IDL

E)YES ON


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Measurement Event-A1

Event A1 Serving becomes better than

threshold)

Inequality A1-1 (Entering condition)

Inequality A1-2 (Leaving condition)

Use for close inter-frequency measurement

and release the active measurement gaps

ThreshHysMs

ThreshHysMs


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Event A2 (Serving becomes worse than

threshold)



Use for open inter-frequency measurement and

setup measurement gaps

ThreshHysMs

ThreshHysMs


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Event A3 (Neighbour becomes offset better

than serving)



Use for intra/inter frequency handover base on

coverage

OffOcsOfsMsHysOcnOfnMn

OffOcsOfsMsHysOcnOfnMn


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Event A4 (Neighbour becomes better than

threshold)



Use for handover base on Load

ThreshHysOcnOfnMn

ThreshHysOcnOfnMn


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Event A5 (Serving becomes worse than threshold1 andneighbour becomes better than threshold2)

Inequality A5-1 (Entering condition 1)

Inequality A5-2 (Entering condition 2)

Inequality A5-3 (Leaving condition 1)

Inequality A5-4 (Leaving condition 2)

Use for intra/inter frequency handover base on coverage

1ThreshHysMs

2ThreshHysOcnOfnMn

1ThreshHysMs

2ThreshHysOcnOfnMn


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Measurement Event-B1

Event B1 (Inter RAT neighbour becomes

better than threshold)

Inequality B1-1 (Entering condition)

Inequality B1-2 (Leaving condition)

Use for inter-RAT handover base on coverage

ThreshHysOfnMn

ThreshHysOfnMn


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Measurement Event-B2

Event B2 (Serving becomes worse than threshold1 andinter RAT neighbour becomes better than threshold2)

Inequality B2-1 (Entering condition 1)

Inequality B2-2 (Entering condition 2)

Inequality B2-3 (Leaving condition 1)

Inequality B2-4 (Leaving condition 2)

Use for inter-RAT handover base on coverage

1ThreshHysMs

1ThreshHysMs

2ThreshHysOfnMn

2ThreshHysOfnMn


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Measurement rules for cell re-

selection

Start

Re-

selectio

n

Search

EUTRAN

Intra-

frequency

SServingCell>Sintrasearch

Do not perform measurements of E-UTRAN intra-frequencies

SServingCellSnonin

trasearch

Do not Perform measurements of

higher priority E-UTRAN inter-

frequency or inter-RAT frequencies

SServingCell


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Cell Selection - Criteria S

The cell selection criterion S is fulfilled when:

where:

Srxlev > 0

Srxlev = Qrxlevmeas

(Qrxlevmin+ Qrxlevminoffset) - Pcompensation

Srxlev Cell Selection RX level value (dB)

Qrxlevmeas Measured cell RX level value (RSRP).

QrxlevminMinimum required RX level in the cell (dBm)

Qrxlevminoffset Offset to the signalled Qrxlevmintaken into account in the Srxlev evaluation as

a result of a periodic search for a higher priority PLMN while campednormally in a VPLMN [5]

Pcompensation max(PEMAX_HPPowerClass, 0) (dB)

PEMAX_HMaximum TX power level an UE may use when transmitting on the uplink in

the cell (dBm) defined as PEMAX_H in [TS 36.101]

PPowerClassMaximum RF output power of the UE (dBm) according to the UE power

class as defined in [TS 36.101]


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Cell Reselection - Criteria Rs

Criteria Rs is for intra-frequency and equal

priority inter-frequency Cell Reselection

criteria

The cell-ranking criterion Rsfor serving cell

and Rnfor neighbouring cells is defined by:

where:

Rs = Qmeas,s + QHyst

Rn = Qmeas,n- Qoffset

QmeasRSRP measurement quantity used in cell reselections.

Qoffset For intra-frequency: Equals to Qoffsets,n, if Qoffsets,nis valid, otherwise thisequals to zero.

For inter-frequency: Equals to Qoffsets,nplus Qoffsetfrequency, if Qoffsets,nisvalid, otherwise this equals to Qoffsetfrequency.


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4G->3G Handover Parameter

Open RAT Measurement, A2 Event

Handover Execute Measurement, B2 Event

Parameter Explanation(Unit) DiGi Value

RSRP Absolute Threshold of Event Decision(dBm) -100

Decision Hysteresis Range(dBm) 0

Time to Trigger 320ms[8]


Absolute Decision Threshold of E-UTRAN Serving

Cell for RSRP Measurement(dBm) -110

Absolute Decision Threshold of UTRAN System forRSCP Measurement(dBm) -100

Time Difference Between Event Occurrence and

Reporting 256ms[7]

Decision Hysteresis Range 0

UTRAN Neighbor Cell Supported PS HO Yes[1]

UTRAN FDD Frequency Number 1

Downlink center Frequency 10812


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3G->4G Handover Parameter

Parameter Explanation(Unit)

DiGi

Value Remark

RNC Switch for PS Handover with LTE 0

Choice Strategy in Multi-RAT Handover 0

0: GSM/GERAN prefer

1: EUTRAN prefer


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4G->3G Redirection Parameter


Redirection algorithm for Coverage Open

RSRP Absolute Threshold of Event Decision(dBm) -113

Decision Hysteresis Range 0

Time to Trigger 320ms[8]

UTRAN Frequency(ARFCN) 10812

Measurement Configuration FunctionRedirect

Measure[3]

Utran Frequency Redirection Priority 100

A2 Event


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3G->4G Redirection Parameter

Parameter Explanation(Unit) DiGi Value Remark

Switch of RRC Redirection

Triggered by Radio Resource

Congestion 0

Prior Redirect RAT Indicator 2

0: Off1: Prior to Inter-Frequency, secondly to

Inter-RAT (prior to GSM Cell)

2: Prior to Inter-Frequency, secondly to

Inter-RAT (PS prior to E-UTRA, CS prior

to GSM)

3: Prior to Inter-RAT (prior to GSM),

secondly to Inter-Frequency

4: Prior to Inter-RAT (PS prior to E-

UTRA, CS prior to GSM), secondly to

Inter-Frequency


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4G->3G Reselection Parameter

Parameter Explanation(Unit) DiGi ValueUTRAN FDD Frequency Number 1


The Timer for Cell Reselection in UTRAN

FDD(S) 2

Maximum Allowed Tx Power(dBm) 24

Minimum Required UTRAN FDD Cell Rx Level

when Cell Selection(Units:dBm) -115

Threshold for Reselecting to Low Priority

UTRAN FDD Cell(dB) 10

Utran FDD Cell Reselection Priority 6

Decision Threshold of Same/Lower PriorityRSRP Measurement 10

Lower Threshold of Serving Carrier 4

Minimum Recived RSRP Level During Cell

Selection(Units:dBm) -116

Minimum Recived RSRP Level Offset During

Selection(Units:dB) 2

Live network setting

Start measure Utran

network when:

LTE RSRP -105dbm


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3G->4G Reselection Parameter

Parameter Explanation(Unit) Default value

Number of EUTRAN Centre Frequencies 1

Reselection Threshold for Inter-RAT Layers of High Priority in

EUTRAN(dB) [20]

Qrxlevmin of EUTRAN for Cell Reselection(dBm) [-128]

Absolute Priority of Inter-RAT Layers in EUTRAN [7]

EUTRAN Allowed Measurement Bandwidth [3]

Absolute Priority of Serving Cell for Cell Reselection 6

Downlink EUTRAN Absolute Radio Frequency Channel Number [3400]

Absolute Priority Reselection Criteria Switch 1


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CSFB Parameter


Swith for CSFB base on Measurement YES

Redirection algorithm for Coverage Open

UTRAN-FDD RAT Priority 100


Utran Frequency CSFB Priority 100

UTRAN-FDD Target System of Idle Ue for CS Fallback 100

UTRAN-FDD Target System of connected Ue for CS Fallback 100


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Mobility Function Introduction 2013-12-13

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