07 intra frequency handover

RAN Feature Description Table of Contents

Table of Contents

Chapter 7 Intra-Frequency Handover........................................................................................7-1

7.1 Introduction to Handover..................................................................................................7-1

7.1.1 Overview...............................................................................................................7-1

7.1.2 Intra-Frequency Handover.....................................................................................7-1

7.1.3 Inter-Frequency Handover.....................................................................................7-2

7.1.4 Inter-System Handover..........................................................................................7-2

7.1.5 Parameter Setting Modes......................................................................................7-3

7.1.6 Terms and abbreviations.......................................................................................7-4

7.2 Availability........................................................................................................................ 7-5

7.2.1 Network Elements Required..................................................................................7-5

7.2.2 Software Releases................................................................................................7-5

7.3 Impact.............................................................................................................................. 7-6

7.3.1 On System Performance.......................................................................................7-6

7.3.2 On Other Features.................................................................................................7-7

7.4 Technical Description.......................................................................................................7-7

7.4.1 Intra-frequency Handover Configuration Model.....................................................7-7

7.4.2 Overview of Intra-Frequency Handover.................................................................7-7

7.4.3 Handover Procedure...........................................................................................7-10

7.4.4 Measurement Phase...........................................................................................7-10

7.4.5 Decision Phase and Execution Phase.................................................................7-30

7.4.6 Signaling Procedure for Intra-Frequency Soft Handover intra-NodeB.................7-32

7.4.7 Signaling Procedure for Intra-Frequency Soft Handover Inter- NodeB................7-35

7.4.8 Inter-RNC Soft Handover....................................................................................7-37

7.4.9 Signaling Procedure for Intra-Frequency Hard Handover....................................7-39

7.4.10 Signaling Procedure for Intra-Frequency Hard Handover Between RNCs........7-41

7.5 Capabilities....................................................................................................................7-43

7.6 Implementation..............................................................................................................7-43

7.6.1 Enabling Intra-Frequency Handover....................................................................7-43

7.6.2 Reconfiguring Intra-Frequency Handover Parameters........................................7-46

7.6.3 Disabling Intra-Frequency Handover...................................................................7-49

7.7 Maintenance Information................................................................................................7-50

7.7.1 MML Commands.................................................................................................7-50

7.7.2 Alarms.................................................................................................................7-51

7.7.3 Counters..............................................................................................................7-51

7.8 References..................................................................................................................... 7-52

Huawei Technologies Proprietary

i

RAN Feature Description List of Figures

List of Figures

Figure 7-1 Handover types supported by UMTS...................................................................7-1

Figure 7-2 Difference between intra-frequency soft and hard handovers..............................7-2

Figure 7-3 Extra resources required in intra-frequency soft handover (with two channels)...7-6

Figure 7-4 Intra-frequency Handover configuration model....................................................7-7

Figure 7-5 Handover procedure..........................................................................................7-10

Figure 7-6 Measurement model in the WCDMA system......................................................7-11

Figure 7-7 Triggering of event 1A........................................................................................7-16

Figure 7-8 Triggering of event 1B........................................................................................7-20

Figure 7-9 Triggering of event 1C.......................................................................................7-22

Figure 7-10 Triggering of event 1D.....................................................................................7-25

Figure 7-11 Procedure for softer handover.........................................................................7-33

Figure 7-12 Signaling procedure for softer handover..........................................................7-34

Figure 7-13 Procedure for inter-NodeB soft handover within an RNC................................7-35

Figure 7-14 Signaling procedure for inter-NodeB soft handover within an RNC.................7-36

Figure 7-15 Procedure for inter-RNC soft handover...........................................................7-37

Figure 7-16 Signaling procedure for inter-RNC soft handover............................................7-38

Figure 7-17 Intra-frequency hard handover (intra-RNC, inter-NodeB)................................7-39

Figure 7-18 Signaling procedure for intra-frequency hard handover (intra-RNC, inter-NodeB)

..................................................................................................................................... 7-40

Figure 7-19 Intra-frequency hard handover between RNCs................................................7-41

Figure 7-20 Procedure for intra-frequency hard handover between RNCs.........................7-42


ii

RAN Feature Description List of Tables

List of Tables

Table 7-1 RNC-oriented parameters and cell-oriented parameters.......................................7-3

Table 7-2 NEs required for intra-frequency handover............................................................7-5

Table 7-3 RAN products and related versions.......................................................................7-6

Table 7-4 Differences between soft handover and softer handover.......................................7-8

Table 7-5 Measurement events of intra-frequency handover..............................................7-13

Table 7-6 Functions of events in intra-frequency handover.................................................7-31

Table 7-7 Commands for reconfiguring RNC oriented intra-frequency handover algorithm

parameters...................................................................................................................7-46

Table 7-8 Commands for reconfiguring cell oriented intra-frequency handover algorithm

parameters...................................................................................................................7-47

Table 7-9 MML commands related to intra-frequency handover..........................................7-50

Table 7-10 Counters of soft handover.................................................................................7-51


iii

RAN Feature Description Chapter 7 Intra-Frequency Handover

Chapter 7 Intra-Frequency Handover

7.1 Introduction to Handover

7.1.1 Overview

Handover is a basic function of a cellular mobile network. The purpose of handover is

to ensure that a UE in CELL_DCH state is served continuously when it moves.

Based on the frequencies of the source and target cells, handover includes the

following three types:

Intra-frequency handover

Inter-frequency handover

Inter-system handover

Figure 7-1 shows the handover types supported by UMTS.

Intra-frequencyhandover

Inter-frequencyhandover

Intra-frequencysoft handover

Intra-frequencyhard handover

Inter-frequency handoverbased on coverage

Inter-frequency handoverbased on load

3G-2G handover

Compressed mode(based on UE capability)

3G-2G handoverbased on coverage

3G-2G handoverbased on load

Intra-UMTS handover

Inter-RAT handover

Figure 7-1 Handover types supported by UMTS

7.1.2 Intra-Frequency Handover

Intra-frequency handover includes two types: intra-frequency soft handover and intra-

frequency hard handover. Figure 7-2 shows the difference between them. In this

example, the UE is moving from cell 1 to cell 2.


1


Cell 1 Cell 2

Cell 1

Cell 1

Cell 2

Cell 2

Cell 1 Cell 2

(CPICH Ec/N0) (CPICH Ec/N0)

Intra-frequency hard handover

Intra-frequency soft handover

Figure 7-2 Difference between intra-frequency soft and hard handovers

In intra-frequency soft handover, a new connection is set up between the UE and cell

2 while the connection between UE and cell 1 is still maintained. In this case, the UE

keeps the connections to cells 1 and cell 2 at the same time. After the condition of

disconnection is met, the UE disconnects with cell 1.

In intra-frequency hard handover, the UE disconnects with cell 1 before setting up a

connection to cell 2.

Intra-frequency soft handover is more commonly used than intra-frequency hard

handover, which is used only in some special scenarios, for example, when there is

no Iur interface between two RNCs.

7.1.3 Inter-Frequency Handover

From the view of UE, inter-frequency handover is as the same as intra-frequency

hard handover. The old connection is released before a new connection is set up for

both the cases.

Inter-frequency handover can increase the resource utilization efficiency by solving

the following two problems:

Coverage problem generated when the UE moves

Load problem in a multi-frequency network

For details, see Chapter 8 "Inter-Frequency Handover".

7.1.4 Inter-System Handover

Inter-system handover refers to the handover between different systems, such as

UMTS and GSM, which use different radio access technologies (RAT).

Inter-system handover may be due to coverage limitation or load limitation of 3G

system.


2


For details, see Chapter 9 "Inter-System Handover".

7.1.5 Parameter Setting Modes

The parameter setting modes are as follows:

RNC-oriented parameter setting is applied in the system on RNC level to

setting default system parameters and most cell parameters. This mode can

reduce the parameter setting workload.

Cell-oriented parameter setting is applied in the system on Cell level to setting

parameters for each cell. After a cell-oriented parameter is set, the same

parameters on RNC level becomes invalid in this cell.

Table 7-1 lists the parameters applicable to the two setting modes.

Table 7-1 RNC-oriented parameters and cell-oriented parameters

Item RNC-Oriented parameter Cell-Oriented parameter

Common

parameters

Common handover

parametersCell common handover parameters

Intra-frequency

parameters

Intra-frequency handover

algorithm parameters

Cell intra-frequency handover


Intra-frequency neighboring cell

parameters

Inter-frequency

parameters

Inter-frequency coverage

handover algorithm

parameters

Inter-frequency non-

coverage handover


Cell inter-frequency coverage

handover algorithm parameters

Cell inter-frequency non-coverage


Inter-frequency neighboring cell

parameters

Inter-system

parameters

Inter-system coverage

handover algorithm

parameters

Inter-system non-

coverage handover


Cell inter-system coverage


Cell inter-system non-coverage


Inter-system neighboring cell

parameters


3


7.1.6 Terms and abbreviations

I. Terms

Term Description

BE service Best effort service, that is, interactive service or background service

Ec/No Ratio of energy per chip to noise spectrum density

Ping-pong

effect

Frequent handovers between cells due to changes in signal quality or

improper parameter settings

II. Abbreviations

Abbreviation Full Spelling

ALCAP Access Link Control Application Part

3G 3rd Generation

3GPP 3rd Generation Partnership Project

CN Core Network

DL Downlink

DRNC Drift RNC

DS-CDMA Direct-Sequence Code Division Multiple Access

FDD Frequency Division Duplex

HHO Hard Handover

HO Handover

IE Information Element

MS Mobile Station

PC Power Control

RL Radio Link

RNC Radio Network Controller

RRM Radio Resource Management

SHO Soft Handover


4


Abbreviation Full Spelling

SIR Signal to Interference Ratio

SRNC Serving RNC

TPC Transmit Power Control

UE User Equipment

UL Uplink

UTRAN UMTS Terrestrial Radio Access Network

WCDMA Wideband Code Division Multiple Access

7.2 Availability

7.2.1 Network Elements Required

The intra-frequency handover procedure depends on the cooperation of the UE, the

NodeB, and the RNC. Table 7-2 shows the Network Elements (NEs) required for

intra-frequency handover.

Table 7-2 NEs required for intra-frequency handover

UE NodeB RNCMSC

ServerMGW SGSN GGSN HLR

√ √ √ – – – – –

Note:

–: not required

√: required

Note:

This chapter describes only the availability of the NodeB and the RNC.

7.2.2 Software Releases

Table 7-3 describes the versions of the RAN products that support the intra-frequency

handover.


5


Table 7-3 RAN products and related versions

Product Version

RNC BSC6800 V100R002 and later releases

NodeB

DBS3800 V100R006 and later releases

BTS3812A V100R005 and later releases

BTS3812E V100R005 and later releases

7.3 Impact

7.3.1 On System Performance

Intra-frequency soft handover provides seamless connection services for mobile

users, however, it occupies more downlink resources and transport resources.

By controlling of the number of UEs involved in intra-frequency soft handover, the

consumption of resource can be controlled.

Figure 7-3 shows the extra resources required for intra-frequency soft handover

compared with intra-frequency hard handover.

RNC

NodeB NodeB

Extra uplink channel is requiredin selection combination in RNC

Extra downlink channel is required inmaximum ratio combination in UE

UE

Figure 7-3 Extra resources required in intra-frequency soft handover (with two

channels)


6


7.3.2 On Other Features

For more information about the relationship between inter-frequency handover and

other handover, see section7.1 "Introduction to Handover"

7.4 Technical Description

7.4.1 Intra-frequency Handover Configuration Model

The configuration model for Intra-frequency Handover is as show in Figure 7-4.

CellClassGlobalParaClass

RNC

RadioClass

INTRAFREQHO .Class

CELLINTRAFREQHO .Class

Intra-freq Measure Quantity

Intra-freq meas L3 filter coeff

CS service 1A event relative threshold

PS service 1A event relative threshold

1A hysteresis

1A event trigger delay time

CS service 1B event relative threshold

PS service 1B event relative threshold

1B hysteresis

1B event trigger delay time

1C hysteresis

1C event trigger delay time

Max number of cell in active set

1D hysteresis[dB]

1D event trigger delay time

Weighted factor

Cell offset[dB]

Min quality THD for SHO

HOCOMM .Class

1B event trigger delay time

1F event absolute EcNo threshold

1F event absolute RSCP threshold

1F hysteresis

1F event trigger delay time

Figure 7-4 Intra-frequency Handover configuration model

7.4.2 Overview of Intra-Frequency Handover

I. Intra-Frequency Soft Handover

Intra-frequency soft handover includes three types:

Intra-NodeB soft handover, including softer handover


7


Intra-RNC and inter-NodeB soft handover

Inter-RNC soft handover

Table 7-1 lists the differences between soft handover and softer handover.

Table 7-1 Differences between soft handover and softer handover

Item Softer Handover Soft Handover

Scenario

When the UE is in the overlapped

cell coverage area of two adjacent

sectors of a BS

When the UE is in the

coverage intersection of the

two sectors of two cells

Uplink signal Using maximum-ratio combination Using selection combination

Downlink

signalUsing maximum-ratio combination

Using maximum-ratio

combination

Resource

usageOccupying less Iub bandwidth

Occupying more Iub

bandwidth

Specially for softer combination function of NodeB, there is a switch Softer handover

combination indication switch to adjust the decision rules for softer combination.

If it's set to "MAY", the NodeB can decide whether to do softer combination (the

softer combination can be done for the radio links in different cells in the same

NodeB).

If it's set to "MUST", the NodeB is forced to do softer combination for the radio

links in different cells.

If it's set to "MUST NOT", the NodeB is not allowed to do softer combination.

Caution:

It is highly recommended that it is switched to the default setting "MAY" for optimized

radio network performance. Any adjustment to this switch should be under strict

consideration or special reason.


8


Parameter name Softer handover combination indication

switch

Parameter ID DIVCTRLFIELD

GUI range MAY, MUST, MUST_NOT

Physical range& unit MAY, MUST, MUST_NOT

Default value MAY

Optional / Mandatory Optional

MML command SET HOCOMM

Description:

The indicator for the NodeB to do softer combination.

If it's set to "MAY", the NodeB can decide whether to do softer combination (the

softer combination can be done for the radio links in different cells in the same

NodeB).

If it's set to "MUST", the NodeB is forced to do softer combination for the radio

links in different cells.

If it's set to "MUST NOT", the NodeB is not allowed to do softer combination.

II. Intra-Frequency Hard Handover

Intra-frequency hard handover does not rely on the Iur interface and it utilize fewer

transmission resources.

Intra-frequency hard handover is used in either of the following scenarios:

No Iur interface between RNCs

In this case soft handover between RNCs is unavailable.

Iur interface congestion

In this case soft handover between RNCs is also unavailable.

High-speed BE service

For the high-speed BE service, intra-frequency hard handover could be used to

save downlink capacity, compared with soft handover.

Failure in intra-frequency soft handover while intra-frequency hard handover

allowed


9


When intra-frequency soft handover is failed due to capacity congestion problem of

the target cell, intra-frequency hard handover could be tried with lower service bits

rate.

7.4.3 Handover Procedure

After the UE transits to CELL_DCH connected mode, for example, during active calls,

the RNC sends the MEASUREMENT CONTROL message to ask the UE to take

measurement and report measurement event result. The message contains event

thresholds, hysteresis value, event trigger delay time, and neighboring cell list. Upon

receipt of the event reported from the UE, the RNC makes a handover decision and

performs a corresponding handover procedure.

There are the following three phases in a handover procedure:

Measurement phase

Decision phase

Execution phase

Figure 7-5 shows the handover procedure. (measurement quantity set to CPICH

Ec/No)

Decision phase

Execution phase

Measurement phase

Yes

NoAre handover criteria satisfied?

Perform a handover and update relative parameters

Measure the CPICH Ec/N0 of the serving cell andits neighboring cells as well as the relative timedifference between the cells

Figure 7-5 Handover procedure

7.4.4 Measurement Phase

In the measurement phase, the UE takes measurement according to the

MEASUREMENT CONTROL message received from the RNC. The UE sends related

measurement reports to the RNC according to the rules defined in the

MEASUREMENT CONTROL message when the event triggering conditions are met.


10


I. Measurement Quantity

The Ec/No of a common pilot channel is the default measurement quantity for intra-

frequency handover. The measurement quantity of intra-frequency measurement can

be also chosen to RSCP by setting the parameter of Intra-freq Measure Quantity.

Parameter name Intra-freq Measure Quantity

Parameter ID IntraFreqMeasQuantity

GUI range CPICH_Ec/No, CPICH_RSCP

Physical range& unit None

Default value CPICH_Ec/No


MML command SET INTRAFREQHO / ADD CELLINTRAFREQHO /

MOD CELLINTRAFREQHO

Description:

Measurement quantity used in intra-frequency measurement.

II. Measurement Model and Layer 3 Filter Coefficient

Before judging a measurement event and sending the measurement report, the UE

performs layer 3 filtering for the measurement value.

Figure 7-6 shows the measurement model defined in 3GPP 25.302, illustrating the

location of layer 3 filtering in the procedure of measurement.

Layer 1filtering

Layer 3filtering Evaluation of

reporting criteria

A B C

C '

Parameters Parameters

D

Figure 7-6 Measurement model in the WCDMA system

Figure 7-6 shows the measurement points in the model, where:

A is the measurement value at the physical layer.

B is the measurement value after layer 1 filtering at the physical layer. The value

goes form the physical layer to a higher layer.


11


C is a measurement after processing in the layer 3 filter.

C' is another measurement value.

D is measurement report information (message) sent on the radio or Iub

interface.

Parameters of the left include the filter coefficient for L3 filtering, while Parameter

of the right include the configurations for the measurement reports.

The Intra-freq meas L3 filter coeff parameter is the filter coefficient for the intra-

frequency measurement value. The measurement values (B) at the physical layer that

are measured at different times are weighted by the L3 filter coefficient. The filtering

of layer 3 measurement values is controlled by a higher layer. The filtered value (C)

can apply to event report and periodic report (D).

The filtered measurement value is calculated with the following formula:

nnn MaFaF 1)1(

Where:

Fn is the new measurement value after filtering.

Fn-1 is the last measurement value after filtering.

Mn is the latest measurement value from the physical layer.

= 1/2(k/2) (k is set to Intra-freq meas L3 filter coeff)

When is set to 1, that is, k = 0, no layer 3 filtering is performed.

Parameter name Intra-freq meas L3 filter coeff

Parameter ID FilterCoef

GUI range D0, D1, D2, D3, D4, D5, D6, D7, D8, D9, D11, D13,

D15, D17, D19

Physical range& unit 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 13, 15, 17, 19

Default value D3



MOD CELLINTRAFREQHO

Description:

The intra-frequency measurement L3 filter coefficient. The greater this value is set,

the greater the smoothing effect and the higher the anti fast fading capability are,

but the lower the signal change tracing capability is.


12


III. Measurement Events

In intra-frequency handover, the UE reports measurement results to the RNC through

reporting events. The involved events are as follows:

Table 7-1 Measurement events of intra-frequency handover

Event Description

1A

The PCPICH quality of the cells in the monitored set enters the reporting

range. This indicates that the quality of a cell is close to the quality of the

best cell or the active set. A relatively high combined gain can be

achieved when the cell is added to the active set.

1B

The PCPICH quality of the cells in the active set leaves the reporting

range. This indicates that the quality of a cell is much worse than the

quality of the best cell or the active set. The cell should not stay in or join

the active set.

1C

A non-active primary CPICH becomes better than an active primary

CPICH. This indicates that the quality of a cell is close to the quality of

the best cell or the active set. In addition, the number of cells in the active

set has reached the maximum value allowed. The cell replaces the worst

cell in the active set; thus achieving a higher combined gain.

1D Event of the change of the best cell

The relative thresholds of event 1A and event 1B are separately set for the CS

services and PS services.

IV. Triggering of Event 1A

Event 1A is triggered on the basis of the following formula:

),2/(10)1(1010 111

aaBest

N

iiNewNew HRLogMWMLogWCIOLogM

A

Where:

MNew is the measurement value of the cell in the reporting range.

CIONew is Cell offset of the cell in the reporting range. It is set for the neighboring

cell.

W is the weighted value. The total quality of the best cell and the active set is

weighted by the Weighted factor parameter.

Mi is the measurement value of the cell in the active set.

MBes is the measurement value of the best cell in the active set.


13


R1a is the reporting range or the relative threshold of soft handover. The

threshold parameters of the CS and PS services are CS service 1A event

relative threshold, PS service 1A event relative threshold respectively.

H1a is 1A hysteresis, the hysteresis value of event 1A.

Parameter name CS service 1A event relative threshold

Parameter ID IntraRelThdFor1ACS

GUI range 0 - 29

Physical range & unit 0 - 14.5; step: 0.5 (dB)

Default value 6



MOD CELLINTRAFREQHO

Description:

The CS service relative threshold of the event 1A. It is easier to trigger event 1A if

the value is greater. It is harder to trigger event 1A if the value is small.

Parameter name PS service 1A event relative threshold

Parameter ID IntraRelThdFor1APS

GUI range 0–29

Physical range & unit 0–14.5; step: 0.5 (dB)

Default value 6



MOD CELLINTRAFREQHO

Description:

The PS service relative threshold of the event 1A. It is easier to trigger event 1A if

the value is large. It is harder to trigger event 1A if the value is small.


14


Parameter name 1A hysteresis

Parameter ID Hystfor1A

GUI range 0 - 15

Physical range & unit 0 - 7.5; step: 0.5 (dB)

Default value 0



MOD CELLINTRAFREQHO

Description:

The hysteresis value of the event 1A. This parameter value is related to the slow

fading characteristic. The greater this value is set, the less ping-pong effect and

misjudgment can be caused. However, in this case, the event cannot be triggered

in time.

Figure 7-7 shows the triggering of event 1A. Default parameter values are used.

Th1A = (CPICH Ec/No of the best cell in the active set - Reporting range for 1A),

where reporting range for 1A equals CS service 1A event relative threshold or PS

service 1A event relative threshold.

If the signal quality of a cell not in the active set is higher than Th1A for a certain time

1A event trigger delay time (Time to trigger in the figure), the UE reports event 1A,

as shown in Figure 7-7.

If Weighted factor > 0,

Th1A = (General signal quality of all cells in the active set - Reporting range for

1A),.


15


Time to trigger

Event 1A is triggered

B

A

CPICH Ec/N0

Time

C

Reportingrange

Figure 7-7 Triggering of event 1A

where the meanings of the curves marked with letters are as follows:

A: signal quality curve of the best cell in the active set

B: signal quality curve of a cell in the monitoring set

C: Th1A curve


16


Parameter name 1A event trigger delay time

Parameter ID TrigTime1A

GUI range D0, D10, D20, D40, D60, D80, D100, D120, D160,

D200, D240, D320, D640, D1280, D2560, D5000

Physical range & unit 0, 10, 20, 40, 60, 80, 100, 120, 160, 200, 240, 320, 640,

1280, 2560, 5000 (ms)

Default value D320



MOD CELLINTRAFREQHO

Description:

The trigger delay time of the event 1A. This parameter value is related to the slow

fading characteristic. The greater this parameter is set, the smaller the

misjudgment probability, but the lower the response speed of the event to the

measured signal changes.

V. Triggering of Event 1B

Event 1B is triggered on the basis of the following formula:

),2/(10)1(1010 111

bbBest

N

iiOldOld HRLogMWMLogWCIOLogM

A

Where:

MOld is the measurement value of the cell that becomes worse

CIOOld is Cell offset of the cell in the reporting range. It is set for the neighboring

cell.

W is the weighted value. The total quality of the best cell and the active set is

weighted by the Weighted factor parameter.

Mi is the measurement value of the cell in the active set.

MBest is the measurement value of the best cell in the active set.

R1b is the reporting range or the relative threshold of soft handover. The

threshold parameters of the CS and PS services are CS service 1B event

relative threshold, PS service 1B event relative threshold respectively.

H1b is 1B hysteresis, the hysteresis value of event 1B.


17


Parameter name CS service 1B event relative threshold

Parameter ID IntraRelThdFor1BCS

GUI range 0–29


Default value 12



MOD CELLINTRAFREQHO

Description:

The CS service relative threshold of the event 1B.It is easier to trigger event 1B if

the value decreases. It is harder to trigger event 1B if the value increases.

Configuration Rule and Restriction:

The value of IntraRelThdFor1BCS should be larger than that of

IntraRelThdFor1ACS.

Parameter name PS service 1B event relative threshold

Parameter ID IntraRelThdFor1BPS

GUI range 0–29


Default value 12



MOD CELLINTRAFREQHO

Description:

The PS service relative threshold of the event 1B. It is easier to trigger event 1B if

the value decreases. It is harder to trigger event 1B if the value increases.


18


Configuration Rule and Restriction:

The value of IntraRelThdFor1BPS should be larger than that of

IntraRelThdFor1APS.

Parameter name 1B hysteresis

Parameter ID Hystfor1B

GUI range 0–15


Default value 0



MOD CELLINTRAFREQHO

Description:

The hysteresis value of the event 1B. This parameter value is related to the slow



in time.

Figure 7-8 shows the triggering of event 1B. Default parameter values are used.

Th1B= (CPICH Ec/No of the best cell in the active set - Reporting range for 1B),

where reporting range for 1B equals CS service 1B event relative threshold or PS

service 1B event relative threshold.

If the signal quality of a cell in the active set is lower than Th1B for a certain time 1B

event trigger delay time (Time to trigger in the figure), the UE reports event 1B, as

shown in Figure 7-8.

If Weighted factor > 0,

Th1B = (General signal quality of all cells in the active set - Reporting range for

1B)


19


Time to trigger

Event 1B is trigged

B

A

CPICH Ec/N0

Time

C Reporting range

Figure 7-8 Triggering of event 1B



B: signal quality curve of a cell in the monitoring set

C: Th1B curve


20


Parameter name 1B event trigger delay time

Parameter ID TrigTime1B


D200, D240, D320, D640, D1280, D2560, D5000


1280, 2560, 5000 (ms)

Default value D640



MOD CELLINTRAFREQHO

Description:

The trigger delay time of the event 1B. This parameter value is related to the slow

fading characteristic. The greater this value is set, the smaller the misjudgment

probability, but the lower the response speed of the event to the measured signal

changes.

VI. Triggering of Event 1C

Event 1C is triggered on the basis of the following formula:

,2/1010 1cInASInASNewNew HCIOLogMCIOLogM

Where:

MNew is the measurement value of the cell in the reporting range.

CIONew is Cell offset of the cell in the reporting range.

MInAS is the measurement value of the worst cell in the active set.

CIOInASis Cell offset of the worst cell in the active set.

H1c is 1C hysteresis, the hysteresis value of event 1C.


21


Parameter name 1C hysteresis

Parameter ID Hystfor1C

GUI range 0–15


Default value 8



MOD CELLINTRAFREQHO

Description:

The hysteresis value of the event 1C. This parameter value is related to the slow



in time.

Figure 7-9 shows the triggering of event 1C. Default parameter values are used.

Th1C= (CPICH Ec/No of the worst cell in the active set + Hysteresis/2),

where Hysteresis equals 1C hysteresis.

If the signal quality of a cell not in the active set is higher than Th1C for a certain time

1C event trigger delay time (Time to trigger in the figure), the UE reports event 1C,



22


TimeEvent 1C is triggered

CPICH Ec/N0

A

B

C

D

Hysteresis/2

E

Time to trigger

Figure 7-9 Triggering of event 1C



B: signal quality curve of a cell in the active set

C: signal quality curve of the worst cell in the active set

D: signal quality curve of a cell in the monitoring set

E: Th1C curve


23


Parameter name 1C event trigger delay time

Parameter ID TrigTime1C

GUI range D0, D10, D20, D40, D60, D80, D100, D120, D160, D200,

D240, D320, D640, D1280, D2560, D5000


1280, 2560, 5000 (ms)

Default value D640



MOD CELLINTRAFREQHO

Description:

The trigger delay time of the event 1C. This parameter value is related to the slow



changes.

Note:

UE reports the event IC for qualified cells after the number of the cells in the active

set reaches the maximum supported value. The maximum number of the active set

cells Max number of cell in active set can be configured on cell level. At present,

the maximum supported number of the cells in the active set supported is 6.


24


Parameter name Max number of cell in active set

Parameter ID MaxCellInActiveSet

GUI range 1–6

Physical range & unit 1–6

Default value 3



MOD CELLINTRAFREQHO

Description:

The maximum number of cells in active set.

VII. Triggering of Event 1D

Event 1D

Where:

MNotBest is the measurement value of a cell that is not on the list of the best cells.

CIONotBest is the cell offset of a cell that is not on the list of the best cells. The

offset is not used.

MBest is the measurement value of the best cell in the active set.

CIONotBest is the cell offset of the best cell. The offset is not used.

H1d is 1D hysteresis, the hysteresis value of event 1D.


25


Parameter name 1D hysteresis[dB]

Parameter ID Hystfor1D

GUI range 0–15


Default value 8



MOD CELLINTRAFREQHO

Description:

The hysteresis value of the event 1D. This parameter value is related to the slow



in time.

Figure 7-10 shows the triggering of 1D. Default parameter values are used.

Th1D= (CPICH Ec/No of the best cell in the active set + Hysteresis/2)

where Hysteresis equals 1D hysteresis.

If the signal quality of a cell not in the active set is higher than Th1D for a certain time

1D event trigger delay time (Time to trigger in the figure), the UE reports event 1D,


TimeEvent 1D is triggered

CPICH Ec/N0

A

B

Hysteresis/2

C Time to trigger

Figure 7-10 Triggering of event 1D


26




B: signal quality curve of a cell in the active set or the monitoring set

C: Th1D curve

Parameter name 1D event trigger delay time

Parameter ID TrigTime1D


D200, D240, D320, D640, D1280, D2560, D5000


1280, 2560, 5000 (ms)

Default value D640



MOD CELLINTRAFREQHO

Description:

The trigger delay time of the event 1D. This parameter value is related to the slow



changes.

VIII. Triggering of Event 1F

Event 1F is triggered on the basis of the following formula:

Where:

MOld is the measurement value of the cell that becomes worse

T1f is an absolute threshold. The threshold parameters for different intra-

frequency measurement quantity are set to 1F event absolute EcNo threshold,

1F event absolute RSCP threshold respectively.

H1f is 1F hysteresis, the hysteresis value of event 1F.

If the signal quality of a cell not in the active set is worse than T1f - H1f/2 for a certain

time 1F event trigger delay time, the UE reports event 1F.


27


Parameter name 1F event absolute EcNo threshold

Parameter ID INTRAABLTHDFOR1FECNO

GUI range -24 ~0

Physical range& unit -24 ~0; step: 1 (dB)

Default value -24



MOD CELLINTRAFREQHO

Description:

The absolute EcNo threshold of the event 1F.It is easier to trigger event 1F if the

value increases.It is harder to trigger event 1F if the value decreases.

Parameter name 1F event absolute RSCP threshold

Parameter ID INTRAABLTHDFOR1FRSCP

GUI range -115~25

Physical range& unit -115~25; step: 1 (dB)

Default value 8



MOD CELLINTRAFREQHO

Description:

The absolute RSCP threshold of the event 1F.It is easier to trigger event 1F if the

value increases.It is harder to trigger event 1F if the value decreases.


28


Parameter name 1F hysteresis

Parameter ID Hystfor1D

GUI range 0–15


Default value 8



MOD CELLINTRAFREQHO

Description:

The hysteresis value of the event 1D. This parameter value is related to the slow



in time.

Parameter name 1F event trigger delay time

Parameter ID TRIGTIME1F


D200, D240, D320, D640, D1280, D2560, D5000

Physical range& unit 0, 10, 20, 40, 60, 80, 100, 120, 160, 200, 240, 320, 640,

1280, 2560, 5000 (ms)

Default value D640



MOD CELLINTRAFREQHO

Description:

The trigger delay time of the event 1F. This parameter value is related to the slow

fading characteristic. The greater this parameter is set, the smaller the

misjudgment probability, but the lower the response speed of the event to the

measured signal changes.


29


IX. Parameters

The following table lists the critical parameters of the measurement events for intra-

frequency handover.

The related MML Commands are as follows:

SET INTRAFREQHO

ADD CELLINTRAFREQHO

MOD CELLINTRAFREQHO

Event Parameter NameDefault

Value

Physical

ValueUnit

1A CS service 1A event relative threshold 6 3 dB

PS service 1A event relative threshold 6 3 dB

1A hysteresis 0 0 dB

1A event trigger delay time D320 320 ms

1B CS service 1B event relative threshold 12 6 dB

PS service 1B event relative threshold 12 6 dB

1B hysteresis 0 0 dB

1B event trigger delay time D640 640 ms

1C 1C hysteresis 8 8 dB

1C event trigger delay time D640 640 ms

1D 1D hysteresis 8 4 dB

1D event trigger delay time D640 640 ms

1F 1F event absolute EcNo threshold -24 -24 dB

1F event absolute RSCP threshold -115 -115 dBm

1F hysteresis 8 4 dB

1F event trigger delay time D640 640 ms

The following table describes the other parameters.


30


Parameter name Weighted factor

Parameter ID Weight

GUI range 0–20

Physical range & unit 0–2; step: 0.1

Default value 0



MOD CELLINTRAFREQHO

Description:

This parameter is used to define the soft handover relative threshold based on the

measured value of each cell in the active set. The greater this parameter is set, the

higher the soft handover relative threshold. When this value is set as 0, the soft

handover relative threshold is only for the best cell in the active set.

Parameter name Cell offset[dB]

Parameter ID CellIndividalOffset

GUI range -20–20

Physical range & unit -10–10; step: 0.5 (dB)

Default value 0


MML command ADD INTRAFREQNCELL / MOD INTRAFREQNCELL

Description:

Offset of cell CPICH measurement value. The sum of this parameter value and the

actual measured value is used in UE event evaluation. In handover algorithms, this

parameter is used for moving the border of a cell. It is configured according to the

actual environment.


31


7.4.5 Decision Phase and Execution Phase

After receiving the intra-frequency measurement report from the UE, the RNC

decides whether to go to the execution phase, depending on the information in the

report. Intra-frequency handover procedures will be described in sections 7.4.6 ,

7.4.7 7.4.8 , 7.4.9 , and 7.4.10 .

Table 7-1 lists the functions of events in decision phase and execution phase.

Table 7-1 Functions of events in intra-frequency handover

Event Soft Handover Hard Handover

1A

Deciding to initiate an addition of a cell.

For event 1A, the UE can report multiple cells

in one measurement report in compliance

with the related protocol. These cells are on

the list of the triggered event, and they are

sequenced from the highest to the lowest cell

quality according to measurement quantity.

For the cells on the list, a radio link can be

added if the number of cells in the active set

does not reach the maximum allowed value;

no action is taken if the number of cells in the

active set has reached the specified value.

–

1B

Deciding to initiate a deletion of a cell.

When event 1B is triggered, the RNC decides

whether to remove the link when there is

more than one radio link in the active set; the

RNC takes no action if there is only one radio

link in the active set.

–

1C

Deciding to initiate a change of the worst cell.

When event 1C is triggered, the UE reports

the event-triggered list that contains good

cells and the cells to be replaced, and

sequences the cells from the highest to the

lowest quality according to measurement

quantity.

After receiving the event-triggered list from

the UE, the RNC replace the bad cells in the

active set with the good cells on the list.

–


32


Event Soft Handover Hard Handover

1D

Deciding to initiate a change of the best cell

or a reconfiguration of measurement control.

In compliance with the related protocol, event

1D can only report one event-triggered cell.

The cell can be in the active set or in the

monitored set.

The cells in the monitored set must be added

to the active set. If the number of cells in the

active set has reached the specified value, a

cell whose quality is the worst in the active

set will be replaced by the best cell reported

by the UE.

Deciding to initiate an

intra-frequency hard

handover when the

reported cell is triggered

by event 1D and the

conditions for intra-

frequency hard handover

are met.

When receiving event 1F, the RNC will decide to try a blind handover to inter-

frequency cell if a blind handover neighboring cell is available.

When receiving event 1A, event 1C, and event 1D, the RNC adds the target cells to

the active set only when the CPICH Ec/Io of the target cells is higher than the

absolute threshold Min quality THD for SHO.

Parameter name Min quality THD for SHO

Parameter ID SHOQualmin

GUI range -24–0

Physical range & unit -24–0 (dB)

Default value -16



MOD CELLINTRAFREQHO

Description:

Minimum quality threshold for soft handover.


33


7.4.6 Signaling Procedure for Intra-Frequency Soft Handover intra-NodeB

Figure 7-11 shows the procedure for a softer handover when the UE moves from one

cell to another cell.

CN

SRNC

NodeB

CELL1

CN

SRNC

NodeB

CN

SRNC

NodeB

CELL2 CELL1 CELL2 CELL1 CELL2

(1) (2) (3)

Figure 7-11 Procedure for softer handover

The connections involved in softer handover procedure change as follows:

1) Before the softer handover, only cell 1 has connection with the UE.

2) During the softer handover, both cell 1 and cell 2 have connections with the UE.

3) After the softer handover, only cell 2 has connection with the UE. The cell 1 is

removed from the active set by the network.

Figure 7-1 shows the signaling procedure for softer handover.


34


1. Radio Link Addition Request

2. Radio Link Addition Response

UE NodeB

3. DCCH : Active Set Update Command ( RL Addition )

4. DCCH : Active Set Update Complete

SRNC

Decision to setup new RL

Start RX

Start TX

Decision to delete old RL

5. DCCH : Active Set Update Command ( RL Deletion )


Stop RX and TX

7. Radio Link Deletion Request

8. Radio Link Deletion Response

Figure 7-1 Signaling procedure for softer handover

In Figure 7-1, steps 1) to 4) set up a new connection; steps 5) to 8) release the old

connection.

The signaling procedure is as follows:

1) After the SRNC makes a soft handover decision according to the measurement

report of the UE, it sends the NodeB a Radio Link Addition Request message.

2) The NodeB configures its physical channel in the target cell and starts to receive

the signal from the UE to achieve UL synchronization. It sends the SRNC a

Radio Link Addition Response message, notifying whether the radio link is

combined. Then the NodeB starts DL transmission.

3) The SRNC sends the UE an Active Set Update (Radio Link Addition) message

on DCCH.

4) The UE responds with an Active Set Update Complete message.

5) The SRNC decides to release the old radio link. The SRNC sends the UE an

Active Set Update (Radio Link Deletion) message on DCCH.


35


6) The UE responds an Active Set Update Complete message.

7) The SRNC sends the NodeB a Radio Link Deletion Request message.

8) The NodeB releases the radio resource and reports that the old link is released

through an NBAP message, Radio Link Deletion Response.

7.4.7 Signaling Procedure for Intra-Frequency Soft Handover Inter- NodeB

Figure 7-1 shows the procedure for inter-NodeB soft handover within an RNC when

the UE moves from one cell to another cell.

CN

SRNC

CN CN

SRNC

NodeB1 NodeB2 NodeB1 NodeB2

SRNC

NodeB1 NodeB2

(1) (2) (3)

Figure 7-1 Procedure for inter-NodeB soft handover within an RNC

The connections involved in inter-NodeB soft handover within an RNC are as follows:

1) Before the soft handover, only NodeB 1 connects with the UE.

2) During the soft handover, both NodeBs connect with the UE.

3) After the soft handover, only NodeB 2 connects with the UE. The active set of

NodeB 1 is removed by the network.

Figure 7-1 shows the signaling procedure for inter-NodeB soft handover within an

RNC.


36


1. Radio Link Setup Request

2. Radio Link Setup Response

UE NodeB2

6. DCCH : Active Set Update ( RL Addition )


SRNC NodeB1


Start RX

Start TX


8. DCCH : Active Set Update Command ( RL Deletion )


10. Radio Link DeletionRequest

11. Radio Link DeletionResponse

Stop RX and TX

3.ALCAP Iub data transport barer setup

4.Downlink Synchronization

5.Uplink Synchronization

12.ALCAP Iub data transport barer release

Figure 7-1 Signaling procedure for inter-NodeB soft handover within an RNC

In Figure 7-1, NodeB 1 is source NodeB and NodeB 2 is target NodeB. Steps 1 to 7

set up a new connection. Steps 8 to 12 release the old connection.


1) After the SRNC decides to set up a new radio link in a cell of NodeB 2, it sends

NodeB 2 a Radio Link Setup Request message.

2) NodeB 2 configures its physical channel, starts to receive the signal from the UE

to achieve UL synchronization, and then sends the SRNC a Radio Link Setup

Response message.

3) The SRNC sets up an ALCAP DATA IUB Transport Bearer between the SRNC

and NodeB 2 to bear the new connection.

4) The SRNC sends NodeB 2 the Downlink Synchronization frame through the new

ALCAP Data Iub Transport Bearer.


37


5) NodeB 2 sends the SRNC the Uplink Synchronization frame through the new

ALCAP Data Iub Transport Bearer. Then NodeB 2 starts DL transmission.

6) The SRNC sends the UE an Active Set Update (Radio Link Addition) message

on DCCH.

7) The UE responds an RRC message, Active Set Update Complete.

8) The SRNC decides to release the old radio link. The SRNC sends the UE an

Active Set Update (Radio Link Deletion) message on DCCH.

9) The UE deactivates the old DL reception and responds with an RRC message,

Active Set Update Complete.

10) The SRNC sends NodeB 1 an NBAP message, Radio Link Deletion Request.

NodeB 1 stops UL reception and DL transmission.

11) NodeB 1 releases the radio resource and reports that the radio link is released


12) The SRNC initiates the release of Iub Data Transport Bearer through ALCAP.

7.4.8 Inter-RNC Soft Handover

Figure 7-1 shows the procedure for inter-RNC soft handover.

CN CN

NodeB1

SRNC DRNC

NodeB3 NodeB1

SRNC DRNC

NodeB3

(1) (2)

NodeB2 NodeB2

Figure 7-1 Procedure for inter-RNC soft handover

The connections involved in inter-RNC soft handover change as follows:

1) The UE has set up connections with NodeB 1 and NodeB 2.

13) After the SRNC makes a soft handover decision, it sets up the connection from

NodeB 3 to the UE through another RNC, and releases the connection between

NodeB 1 and UE.

During the soft handover, the Iur interface connection exists between SRNC and

DRNC.

Figure 7-1 shows the signaling procedure for inter-RNC soft handover.


38


UE NodeB3 DRNC SRNC NodeB1

Decision to setup new RLand release old RL

1.Radio Link Setup Request

2.Radio Link Setup Request

Start RX

3.Radio Link Setup Response

4.Radio Link Setup Response

5. ALCAP Iub Data Transport Bearer Setup ALCAP Iur Bearer Setup

6. Downlink Synchronization

7. Uplink Synchronization

8. DCCH: Active Set Update

[Radio Link Addition & Deletion]


10. Radio Link Deletion Request

Stop RX and TX

11. Radio Link Release Response

12. ALCAP Iub Data Transport Bearer Release

Figure 7-1 Signaling procedure for inter-RNC soft handover

In Figure 7-1, NodeB 1 is the source NodeB; NodeB 3 is the target NodeB. Steps 1 to

7 set up a new connection. Steps 8 to 12 release the old connection.


1) After the SRNC makes a soft handover decision, it sends the DRNC an RNSAP

message, Radio Link Setup Request, to request the DRNC to allocate radio

resource.

14) If the needed resource is available, the DRNC sends the NodeB an NBAP

message, Radio Link Setup Request.

15) NodeB 3 allocates radio resource as requested, and reports that the resource

allocation succeeds through an NBAP message, Radio Link Setup Response.

16) The DRNC sends the SRNC an RNSAP message, Radio Link Setup Response.

17) The SRNC initiates the setup of Iur/Iub Data Transport Bearer through ALCAP.

This request includes the AAL2 Binding Identity, used to bind the Iub Data

Transport Bearer to DCH.


39


18) The SRNC sends NodeB 3 the Downlink Synchronization frame through the new

ALCAP Data Iub Transport Bearer.

19) NodeB 3 sends the SRNC the Uplink Synchronization frame through the new

ALCAP Data Iub Transport Bearer. Then NodeB 2 starts DL transmission.

20) The SRNC sends the UE an Active Set Update (Radio Link Addition & Deletion)

message on DCCH.

21) The UE deactivates the old and new DL receptions and responds with an RRC

message, Active Set Update Complete.

22) The SRNC sends NodeB 1 an NBAP message, Radio Link Deletion Request.

NodeB 1 stops UL reception and DL transmission.

23) NodeB 1 releases the radio resource and reports that the radio link is released


24) The SRNC initiates the release of Iub Data Transport Bearer through ALCAP.

7.4.9 Signaling Procedure for Intra-Frequency Hard Handover

Figure 7-1 shows the procedure for intra-frequency hard handover when a UE moves

from NodeB 1 to NodeB 2 in an RNC.

CN

SRNC

NodeB1 NodeB2 NodeB1 NodeB2

CN

SRNC

(1) (2)

Figure 7-1 Intra-frequency hard handover (intra-RNC, inter-NodeB)

Before the handover, the UE connects to NodeB 1. After the handover, the UE

connects to NodeB 2. Figure 7-2 shows the signaling procedure.


40


1. Radio Link Setup Request

2. Radio Link Setup Response

UE

NodeB2

SRNC

NodeB1

Decision to setup newRL

Decision to delete oldRL

8. Radio Link DeletionRequest

9.Radio Link Deletion Response

Stop RX andTX

4.Downlink Synchronization

5.Uplink Synchronization

UE NodeB2 SRNC NodeB1



Stop RX and TX

Start RX

Start TX

3. ALCAP Iub Data Transport Bearer Setup

10.ALCAP Iub Data Transport Bearer Release

6. DCCH : Physical Channel Reconfiguration

7. DCCH : Physical Channel Reconfiguration Complete

Figure 7-2 Signaling procedure for intra-frequency hard handover (intra-RNC, inter-NodeB)

In Figure 7-2, NodeB 1 is the source NodeB; and NodeB 2 is the target NodeB. Steps

1 to 7 set up a new connection. Steps 8 to 10 release the old connection.

The specific signaling procedure is as follows:

1) The SRNC decides to set up a radio link in a cell of NodeB 2, and sends a Radio

Link Setup Request message to NodeB 2.

25) NodeB 2 configures its physical channel, starts to receive UE signals for UL

synchronization, and then sends a Radio Link Setup Response message to the

SRNC.

26) The SRNC sets up an ALCAP Iub Data Transport Bearer to bear the new

connection between the SRNC and NodeB 2.

27) The SRNC sends a Downlink Synchronization frame to NodeB 2 through the

new bearer.


41


28) NodeB 2 sends an Uplink Synchronization frame to the SRNC through the new

bearer.

29) NodeB 2 starts downlink transmission.

30) The SRNC sends an RRC message Physical Channel Reconfiguration to the UE

through DCCH.

31) The UE responds with an RRC Physical Channel Reconfiguration Complete.

32) The SRNC sends an NBAP message Radio Link Deletion Request to NodeB 1.

33) NodeB 1 stops uplink reception and downlink transmission.

34) NodeB 1 releases radio resources and then sends an NBAP message Radio

Link Deletion Response.

35) The SRNC initiates the release of the ALCAP Iub Data Transport Bearer through

ALCAP protocol.

7.4.10 Signaling Procedure for Intra-Frequency Hard Handover Between RNCs

Figure 7-1 shows the intra-frequency hard handover when a UE moves from NodeB

1 in one RNC to a NodeB 2 in another RNC.

(1) (2)

CN

NodeB1 NodeB2

SRNC DRNC

CN

NodeB1 NodeB2

SRNC DRNC

Figure 7-1 Intra-frequency hard handover between RNCs

Before the handover, the UE sets up a connection to NodeB 1. After the handover, the

UE sets up a connection to NodeB 2.

Figure 7-2 shows the signaling procedure for intra-frequency hard handover between

RNCs.


42


UE NodeB2 DRNC SRNC NodeB1

Decision to setup new Radio Link

1.Radio Link Setup

Requset2.Radio Link Setup Requset

Start Rx

3.Radio Link SetupResponse

Response

4.Radio Link Setup

5. ALCAP Iub Data Transport Bearer Setup

6. ALCAP Iur Data Transport Bearer Setup

7.Radio Link Restore

Indicate8.Radio Link

Restore Indicate

9. Downlink Synchronization

Start Tx

11. DCCH: Physical Channel Reconfiguration

10. Uplink Synchronization

12. DCCH: Physical Channel Reconfiguration Complete13. Radio Link Deletion

Request

Stop Rx and Tx

14. Radio Link DeletionResponse

15.ALCAP Iub Data Transport Bearer Release

Figure 7-2 Procedure for intra-frequency hard handover between RNCs

As shown in Figure 7-2, NodeB 1 is the source NodeB and NodeB 2 is the target

NodeB. In steps 1–11, a new connection is set up. In steps 12–14, the old connection

is released.

The specific procedure is as follows:

1) SRNC decides to set up a radio link in a cell of NodeB 2, and sends a Radio Link

Setup Request message to DRNC.

36) DRNC sends a Radio Link Setup Request message to NodeB 2.


43


37) NodeB 2 configures its physical channel, and starts to receive UE signals for UL

synchronization, and then sends the Radio Link Setup Response message to

the DRNC

38) DRNC sends the Radio Link Setup Response message to SRNC.

39) SRNC sets up an ALCAP Iub Data Transport Bearer to bear the new connection

to NodeB 2.

40) SRNC sets up an ALCAP Iur Data Transport Bearer to bear the connection to

DRNC.

41) NodeB 2 sends a Radio Link Restore Indicate message to DRNC.

42) DRNC sends the Radio Link Restore Indicate to SRNC.

43) SRNC sends a Downlink Synchronization frame to NodeB.

44) NodeB 2 the Uplink Synchronization frame to SRNC. NodeB 2 starts downlink

transmission.

45) SRNCRRC sends a Physical Channel Reconfiguration message to UE through

DCCH.

46) UE reponds with a RRC message Physical Channel Reconfiguration Complete.

47) SRNC sends an NBAP message Radio Link Deletion Request to NodeB 1.

NodeB 1 stops its uplink receiving and downlink transmitting.

48) NodeB 1 releases the radios resources, and reports the success of release

through a NBAP message Radio Link Deletion Response.

49) SRNC initiates the release of the Iub Data Transport Bearer through the ALCAP.

7.5 Capabilities

One UE can support up to 6 radio links in the active set.

7.6 Implementation

7.6.1 Enabling Intra-Frequency Handover

I. Hardware Installation

This feature does not need extra hardware.

II. Software Installation

This feature does not need extra software.


44


III. Data Configuration

To configure the parameters for the intra-frequency handover, perform the following

steps:

Execute the SET CORRMALGOSWITCH command to configure connection oriented

algorithm switch in the RNC. The corresponding parameter is Handover Algorithm

Switch, turn on the following switches:

Intra-frequency soft handover: SOFT_HANDOVER_SWITCH

Intra-frequency hard handover:

INTRA_FREQUENCY_HARD_HANDOVER_SWITCH

Execute the ADD/MOD INTRAFREQNCELL command to add or modify intra-

frequency neighboring cells

Execute the SET HOCOMM command to configure RNC oriented intra-frequency

handover algorithm common parameters.

Execute the LST INTRAFREQHO command to query whether the RNC oriented

intra-frequency handover algorithm common parameters are reasonable.

If reconfiguration is required, execute the SET INTRAFREQHO command to adjust

the RNC oriented intra-frequency handover algorithm common parameters.

Execute the ADD/MOD CELLINTRAFREQHO command to add or modify cell

oriented intra-frequency handover measurement algorithm parameters.

Note:

The configuration priority of cell oriented intra-frequency handover parameters is

higher than that of RNC oriented intra-frequency handover algorithm parameters.

IV. Verification of the Enabled Feature

Execute the LST CORRMALGOSWITCH command to query the current state of

intra-frequency handover switch. The intra-frequency handover is enabled when intra-

frequency soft handover switch and intra-frequency hard handover switch are turned

on in the parameter Handover Algorithm Switch.

V. Examples

//The example of enabling intra-frequency soft handover

//(1)Set cell 100 of RNC 9 as an intra-frequency neighboring cell of cell

1.


45


ADD INTRAFREQNCELL: CELLID=1, RNCID=9, NCELLID=100, READSFNIND=READ,

CELLINDIVIDALOFFSET=0, CELLSFORBIDDEN1A=AFFECT, CELLSFORBIDDEN1B=AFFECT,

QOFFSET1SN=0, QOFFSET2SN=0, TPENALTYHCSRESELECT=D0;

//(2)Set RNC connection oriented handover algorithm switch to turn on

intra-frequency soft handover switch.

SET CORRMALGOSWITCH:

HoSwitch=SOFT_HANDOVER_SWITCH-1;

//(3)Execute the LST CORRMALGOSWITCH command to query whether the intra-

frequency soft handover is enabled.

LST CORRMALGOSWITCH: LstFormat=VERTICAL;

//The output results show that the state of the soft handover switch is

ON.

//The example of enabling intra-frequency hard handover


1.





intra-frequency hard handover switch.


HoSwitch= INTRA_FREQUENCY_HARD_HANDOVER_SWITCH-1;


frequency hard handover is enabled.


//The output results show that the state of the hard handover switch is

ON.

//The example of enabling intra-frequency soft handover and intra-

frequency hard handover


1.





intra-frequency soft handover switch and intra-frequency hard handover

switch.


HoSwitch=SOFT_HANDOVER_SWITCH-1&INTRA_FREQUENCY_HARD_HANDOVER_SWITCH-1;


46



frequency handover is enabled.


//The output results show that the state of the soft handover switch and

intra-frequency hard handover switch are ON.

7.6.2 Reconfiguring Intra-Frequency Handover Parameters

Note:

The Intra-frequency handover parameters of the RNC side are reconfigured on the

RNC LMT.

I. Parameter Reconfiguration on the RNC Side.

The commands for reconfiguring intra-frequency handover algorithm parameters on

RNC side includes the following two categories:

Table 7-1 shows the commands for reconfiguring RNC oriented intra-frequency

handover algorithm parameters.

Table 7-2 shows the commands for reconfiguring cell oriented intra-frequency

handover algorithm parameters.

Table 7-1 Commands for reconfiguring RNC oriented intra-frequency handover


Function Command

Reconfigure intra-frequency

handover algorithm switch:

[handover algorithm switch]

parameter:

Soft handover switch

Intra-frequency hard handover

switch

Detected set cells join active

set algorithm switch

Set intra-

frequency

handover

algorithm switch

SET

CORRMALGOSWITCH

List intra-

frequency

handover

algorithm switch

LST

CORRMALGOSWITCH

Reconfigure intra-frequency

handover algorithm parameters:

Softer handover combining

indication switch

Set RNC oriented

intra-frequency

handover

algorithm common

parameters

SET HOCOMM


47


Function Command

BE service handover speed

decision threshold

DRNC soft handover initial

power offset

Indicating soft handover

branch delay difference

threshold

List RNC oriented

intra-frequency

handover

algorithm common

parameters

LST HOCOMM

Reconfigure RNC oriented intra-

frequency handover

measurement algorithm

parameters

Set RNC oriented

intra-frequency

handover

measurement

algorithm

parameters

SET INTRAFREQHO

List RNC oriented

intra-frequency

handover

measurement

algorithm

parameters

LST INTRAFREQHO

Table 7-2 Commands for reconfiguring cell oriented intra-frequency handover


Function Command

Reconfigure cell

oriented intra-

frequency handover

algorithm

parameters

Add cell oriented intra-

frequency handover algorithm

parameters

ADD

CELLINTRAFREQHO

Modify cell oriented intra-


parameters

MOD

CELLINTRAFREQHO

List cell oriented intra-


parameters

LST CELLINTRAFREQHO

Remove cell oriented intra-


parameters

RMV

CELLINTRAFREQHO


48


Function Command

Reconfigure intra-

frequency

neighboring cell

Add intra-frequency

neighboring cellADD INTRAFREQNCELL

Modify intra-frequency

neighboring cellMOD INTRAFREQNCELL

List intra-frequency

neighboring cellLST INTRAFREQNCELL

Remove intra-frequency

neighboring cellRMV INTRAFREQNCELL

Note:

The priority of cell oriented intra-frequency handover algorithm parameters is higher

that of the RNC oriented intra-frequency handover algorithm parameters.

II. Parameter Reconfiguration on the NodeB Side

None.

III. Parameter Reconfiguration Verification

To verify the parameter reconfiguration, perform the following steps:

50) Execute LST CORRMALGOSWITCH command to query the reconfigured intra-

frequency handover algorithm switch.

51) Execute LST HOCOMM command to query the reconfigured RNC oriented

handover algorithm common parameters.

52) Execute LST INTRAFREQHO command to query the reconfigured RNC oriented

intra-frequency handover measurement algorithms parameters.

53) Execute LST INTRAFREQNCELL command to query the reconfigured intra-

frequency neighboring cells information.

54) Execute LST CELLINTRAFREQHO command to query the reconfigured cell

oriented intra-frequency handover measurement algorithm parameters.

IV. Examples

//Reconfigure RNC oriented handover algorithm common parameters.

//(1)List RNC oriented handover algorithm common parameters.

LST HOCOMM: LstFormat=VERTICAL;

//(2)Set RNC oriented handover algorithm common parameters.


49


SET HOCOMM: DivCtrlField=MAY, BeBitRateThd=D384, DrncShoInitPwrPo=16,

ShMdcLegDelayThresh=20, D2HTimerLen=3;

//(3)Execute the LST HOCOMM command to list whether RNC oriented handover

algorithm common parameters are reconfigured.

LST HOCOMM: LstFormat=VERTICAL;

//The output results show that intra-frequency handover common parameters

are reconfigured.

//Reconfigure RNC oriented intra-frequency handover measurement algorithm

parameters.

//(1)List RNC oriented intra-frequency handover measurement algorithm

parameters.

LST INTRAFREQHO: LstFormat=VERTICAL;

//(2)Set RNC oriented intra-frequency handover measurement algorithm

parameters.

SET INTRAFREQHO: FilterCoef=D3, IntraFreqMeasQuantity=CPICH_EC/NO,

PeriodMRReportNumfor1A=D16, ReportIntervalfor1A=D4000,

IntraAblThdFor1FEcNo=-18, IntraAblThdFor1FRSCP=-115, Hystfor1A=0,

Hystfor1B=0, Hystfor1C=8, Hystfor1D=8, Hystfor1F=8, Weight=0,

TrigTime1A=D320, TrigTime1B=D640, TrigTime1C=D640, TrigTime1D=D640,

TrigTime1F=D640, SHOQualmin=-16, MaxCellInActiveSet=3;

//(3)Executer the LST INTRAFREQHO command to query whether RNC oriented

intra-frequency handover measurement algorithm parameters are

reconfigured.

LST INTRAFREQHO: LstFormat=VERTICAL;

//The output results show that intra-frequency handover measurement

algorithm parameters are reconfigured.

//Reconfigure intra-frequency neighboring cell information.

//(1)List intra-frequency neighboring cell information.

LST INTRAFREQNCELL: CellId=200, RncId=2, LstFormat=VERTICAL;

//(2)Add cell 100 of RNC 2 as an intra-frequency neighboring cell of cell

200.

ADD INTRAFREQNCELL: CellId=200, RncId=2, NCellId=100, ReadSFNInd=NOT_READ,

CellIndividalOffset=0, CellsForbidden1A=AFFECT, CellsForbidden1B=AFFECT,

SIB11Ind=TRUE, IdleQoffset1sn=0, IdleQoffset2sn=0, SIB12Ind=FALSE,

TpenaltyHcsReselect=D0;

//(3)Execute the LST INTRAFREQNCELL command to query whether intra-

frequency neighboring cell information is added.

LST INTRAFREQNCELL: CellId=200, RncId=2, NCellId=100, LstFormat=VERTICAL;

//The output results indicate that intra-frequency neighboring cell

information is added.


50


7.6.3 Disabling Intra-Frequency Handover

I. Method of Disabling Intra-Frequency Handover

To disable the intra-frequency handover, execute the SET CORRMALGOSWITCH

command to turn off the intra-frequency handover switch.

II. Verification of the Disabled Feature

Execute the LST CORRMALGOSWITCH command to query the current state of

intra-frequency handover switch. The intra-frequency handover is disabled when

intra-frequency soft handover switch and intra-frequency hard handover switch are

turned off in the parameter Handover Algorithm Switch.

III. Examples

//Disable intra-frequency soft handover.

//(1)Disable intra-frequency soft handover.

HoSwitch=SOFT_HANDOVER_SWITCH-0;

//(2)Execute LST CORRMALGOSWITCH command to query whether intra-frequency

soft handover is disabled.


//The output results show that the state of soft handover switch is OFF.

//Disable intra-frequency hard handover.

//(1)Disable intra-frequency hard handover.

HoSwitch=INTRA_FREQUENCY_HARD_HANDOVER_SWITCH-0;


hard handover is disabled.


//The output results show that the state of hard handover switch is OFF.

//Disable intra-frequency soft handover and intra-frequency hard handover.

//(1)Disable intra-frequency soft handover and intra-frequency hard

handover.


HoSwitch=SOFT_HANDOVER_SWITCH-0&INTRA_FREQUENCY_HARD_HANDOVER_SWITCH-0;


handover is disabled.


//The output results show that soft handover switch and intra-frequency

hard handover switch are OFF.


51


7.7 Maintenance Information

7.7.1 MML Commands

Table 7-1 shows the MML commands related to intra-frequency handover.

Table 7-1 MML commands related to intra-frequency handover

Command Description

SET CORRMALGOSWITCH Set intra-frequency handover algorithm switch

ADD INTRAFREQNCELL Add intra-frequency neighboring cell

SET HOCOMMSet RNC oriented handover algorithm common

parameter

SET INTRAFREQHOSet RNC oriented intra-frequency handover

measurement algorithm parameter

MOD CELLINTRAFREQHOModify cell oriented intra-frequency handover

measurement algorithm parameter

7.7.2 Alarms

None.

7.7.3 Counters

Table 7-1 lists the counters of soft handover.

Table 7-2 Counters of soft handover

Counter Description

Measurement Object ->

Measurement Family ->

Measurement Unit

VS.RRC.MrRpt.1ANumber of Event 1A

Measurement Reports

CELL -> MEASR ->

MEASR.REORT.CELL

VS.RRC.MrRpt.1BNumber of Event 1B

Measurement Reports

CELL -> MEASR ->

MEASR.REORT.CELL

VS.RRC.MrRpt.1CNumber of Event 1C

Measurement Reports

CELL -> MEASR ->

MEASR.REORT.CELL


52


Counter Description

Measurement Object ->

Measurement Family ->

Measurement Unit

VS.RRC.MrRpt.1DNumber of Event 1D

Measurement Reports

CELL -> MEASR ->

MEASR.REORT.CELL

VS.SHO.AddTime

Mean Delay of Soft

Handover Radio Link

Addition

CELL -> SHO ->

SHO.CELL

VS.SHO.AS.1Average Number of UEs

with One RLRNC -> SHO -> SHO.RNC

VS.SHO.AS.2Soft

Average Number of UEs

with Two RLs

Uncombined

RNC->SHO->SHO.RNC

VS.SHO.AS.2SofterAverage Number of UEs

with Two RLs CombinedRNC->SHO->SHO.RNC

VS.SHO.AS.3Soft2Softer

Average Number of UEs

with Three RLs and Two

Combined

RNC->SHO->SHO.RNC

7.8 References

3GPP, 25.331 "RRC Protocol Specification"

3GPP, 25.931 " UTRAN Functions, Examples on Signalling Procedures"

Yue Chen, “Soft Handover Issues in Radio Resource Management for 3G

WCDMA”, Doctor Degree Dissertation, September 2003


53

07 intra frequency handover

Documents