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HUAWEI TECHNOLOGIES CO., LTD.

www.huawei.com

Huawei Confidential

Security Level:2014/1/4

Handover

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Content

Purpose

Process

Step by Step

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Purpose

Movement Continuity Cell

Interference Quality Channel

Traffic Congestion Border / Layer

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Process

MeasurementsMS

BTS

DL Level serving cell

DL Quality serving cell

DL Level neighbor cells

UL Level

UL Quality

Timing advanceMeasurement reporting MS BTS

MR preprocessing

Penalty processing

Cell Ranking

Handover Judgement

BA2 table

BCCH

BSICBSC

/BTS

Module number

cell number

CGI

Adjacent cell Relation Table

Cell Description Table

External Cell Description Table

BSC Target cell list

Handover execution

MS

BTS

BSC

MSC

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Step by Step

Measurements

Measurement reporting

MR preprocessing

Penalty processing

Cell Ranking

Handover Judgement

Handover execution

RXQUAL: Function of BER(Defined by GSM 05.08)

RXLEV: Average per SACCH period

Mapped as RXLEV value

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FULL-- Averaging 100 TCH bursts

(except the four idle frames in the four 26-multiframes)

SUB-- Averaging 12 bursts

(four SACCH bursts and eight TCH bursts in specific position)

Measurements

Measurement reporting

MR preprocessing

Penalty processing

Cell Ranking

Handover Judgement

Handover execution

Step by Step

SUB DTX

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MRMR

MR MRMR

Measurementreport No. n

Measurement rNo. n+4

ContinuousMR

flow

Measurements

Measurement reporting

MR preprocessing

Penalty processing

Cell Ranking

Handover Judgement

Handover execution

Interpolate ---- Add MR when missing

Filter----Average several continuous MR

MRMR MRMR MR MR

Continuous MR

flow

Step by Step

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Measurements

Measurement reporting

MR preprocessing

Penalty processing

Cell Ranking

Handover Judgement

Handover execution

Step by Step

Penalty Time

Penalty Level

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Measurements

Measurement reporting

MR preprocessing

Penalty processing

Cell Ranking

Handover Judgement

Handover execution

M rulereceived signal level generate candidate cell list

DL RXLEV >= Min DL Power on HO Candidate Cell+ Min Access Level Offset

UL RXLEV >= Min DL Power on HO Candidate Cell+ Min Access Level Offset

SS_UPn = MS_PWRn Ln

Ln = BSTXPWRn - SS_DOWNn

If the cell is overflowed, then the cell should be removed from the candidate cell list

K rulereceived signal level rank candidate cell list

For serving cell: K=0

For a neighbor 2G cell:

K = BCCH signal level of neighbor cellTCH signal level of serving cellKIAS;

16 bit rankingcalculate 16 bit value and rank

Step by Step

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Measurements

Measurement reporting

MR preprocessing

Penalty processing

Cell Ranking

Handover Judgement

Handover execution

Step by Step

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Intra-BSC Handover Signaling process

MS MSBTS1 BTS2BSC MSC

Measurement Report from MS

Channel_Active

Channel_Active ACK

HANDOVER COMMAND

Handover Access

Handover_DetectPHY INFO

First SABM

Establish_IND

PHY INFO

Handover Complete

Handover_Performed

Measurements

Measurement reporting

MR preprocessing

Penalty processing

Cell Ranking

Handover Judgement

Handover execution HO-REQUIRED

HO-REQUEST

Step by Step

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TA Handover

Trigger Condition

TA value of serving cell TA Threshold

Candidate Cell

The serving cell is removed.

The co-site neighbor cells that meet the following conditions are removed:

TA Thresholdof the neighbor cell

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Interference Handover Interference HO Allowed = Yes

Trigger Condition

Uplink/Downlink receive quality of the serving cell A

AMR call: A isRXQUAL1 (n=1);RXQUA_n+RXLEVOff(2n12)

Non-AMR call: A isRXQUA_n (1n12)

Candidate Cell

IfIntracell HO Allowed =YESthen the serving cell can be the target cell.

Rxlev neighbor cell Inter-layer HO Threshold +Inter-layer HO Hysteresis of neighbor cell

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BQ Handover BQ HO Allowed = Yes

Trigger Condition

Uplink receive quality of the serving cell UL Qual. Threshold

Downlink receive quality of the serving cell DL Qual. Threshold

Candidate Cell

RXLEV of neighbor cell > RXLEV of serving cell + Inter-cell Handover Hysteresis BQ HO MarginIf the number of candidate cells is 1, then the above condition for the neighbor cell is unnecessary.

If Intracell HO Allowed =YES, and the candidate cell list keeps only the serving cell. Assignment priority:

different frequency bands > different frequencies set > different TRXs > different timeslots

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Edge Handover Fringe HO Allowed = Yes

Trigger Condition

Rxlev on uplink/downlink TCH of serving cell < Edge HO UL/DL RX_LEV Threshold ;

Meet the P/N criterion

Candidate Cell

Remove the serving cell from the candidate cell list

16-bit sequence number of neighbor cell is less than the number of the serving cell.

Rxlev on BCCH of neighbor cell > Rxlevel on DL TCH of serving cell + Inter-cell HO

Hysteresis

Meet the P/N criterion.

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Layer Handover Layer HO Allowed = Yes

Cell Layer

Cell Priority

Trigger Condition & Candidate Cell

The priority level of the neighbor cell is higher than the serving cell.

Rxlev of neighbor cell >Inter-layer HO Threshold+Inter-layer HO Hysteresis.

Meet the P/N criterion

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PBGT Handover PBGT HO Allowed = Yes

Trigger Condition

The neighbor cell has the same hierarchy as the serving cell at the same layer.

The neighbor cell met the following formula

SS_DLs_f indicates the receive level of the downlink TCH in the serving cell after filtering.

SS_DLi_f indicates the receive level of the BCCH in neighbor cell i after f iltering and penalty.

Poff_DLs_f indicates the offset of the transmit power of the BTS on the downlink after the filtering in the serving

cell to the maximum transmit power on the TCH. The step is 2 dB.

Pms_i indicates the maximum transmit power of the MS in neighbor cell i. It is related to the frequency band for

neighbor cell i. Generally, GSM900/850, GSM1800, and GSM1900 correspond to different transmit power.

Pms_s indicates the maximum transmit power of the MS in the serving cell. It is related to the frequency band for

the serving cell. Generally, GSM900/850, GSM1800, and GSM1900 correspond to different transmit power.

Meet the P/N criterion

PBGT Handover Threshold is toward the neighbor cell, and its value range is 0-127 Candidate Cell

The candidate cells are the neighbor cells with the smallest 16-bit sequence number.

_ _ _ __ _ 2i f s f s_f ms i ms sSS DL SS DL Poff_DL P P Margin