Cell Re Selection and Handover Parameters Specification

HUAWEI

Prepared by: ETISALAT MS section HUAWEI Radio Network Planning Department 2004-02-15

3G-2G Cell Reselection and Handover Parameters Specification

CONTENT 1. 3G to 2G cell reselection parameters specification ...................................................................... 3 2. 3G to 2G handover parameters specification ............................................................................... 6

Confidential

2 of 12


1. 3G to 2G cell reselection parameters specification Parameters

Value

Meaning

Qoffset1sn

-3

-3dB

Min RX level

-58

-115dBm

Hysteresis 1

2

4dB

Inter-RAT cell reselection threshold

3

6dB

Reselection delay time

0

7.68S

Min quality level

-18

-18dB

Step 1: 3G measure Ec/Io < Inter-RAT cell resele ction threshold + Min quality level Step 2: GSM Rxlev measurement value > Min RX level Step 3: GSM Rxlev measurement value – Qoffset1sn > 3G RSCP measurem ent value + Hysteresis1

Step 4: Reselection delay time Step 5: Trigger 3G to 2G reselection

Parameters specification: Step1: 3G measure Ec/Io < Inter-RAT cell reselection threshold + Min quality level 3G measure Ec/Io: the measurement Ec/Io value in 3G serving cell.

Inter-RAT cell reselection threshold : Threshold for inter-RAT cell reselection. When the quality (CPICH Ec/Io measured by UE) of the serving cell is lower than the threshold plus Min quality level of the cell, the inter-RAT cell reselection procedure will be started.

Value range :

-16

~

10.

Physical value range:

-32

~

20 ;

step: 2.

Physical unit : dB.

: Minimum required quality level corresponding to the CPICH Ec/Io. UE Min quality level can camp on the cell only when the CPICH Ec/Io measured is larger than the value of this parameter; it will affect the call setup success rate .

Value range : Physical unit :

Confidential

-24

~

0.

dB.

3 of 12


Step 2: GSM Rxlev measurement value > Min RX level GSM Rxlev measurement value : the measurement BCCH Rxlev value in GSM cell. Min RX level: Minimum required Rxlev value of the GSM neighboring cell.

Value range :

~

-13.

Physical value range :

-115

Physical unit :

-58

~

-25;

step: 2.

dBm.

Step 3: GSM Rxlev measurement value – Qoffset1sn > 3G RSCP measurement value + Hysteresis1 GSM Rxlev measurement value: the measurement BCCH Rxlev value in GSM cell.

3G RSCP measurement value: the measurement RSCP value in 3G servi ng cell.

Qoffset1sn : Offset for GSM Rxlev measurement value. It is used for cell reselection process. The greater the value is, the less is the probability of reselecting the GSM neighboring cell Value range: Physical unit:

-50 ~ 50. dB.

Hysteresis 1: Hysteresis for 3G RSCP measurement value. It is used for cell reselection process. The greater the value is, the less is the probability of reselecting the GSM neighboring cell Value range :

0 ~ 20

Physical value range : Physical unit :

0

~

40;

step: 2.

dB.

Step 4: Reselection delay time Reselection delay time: If the signal quality of a GSM neighbor cell is better than the 3G serving cell (satisfied the step 3) during the specified time of this parameter, the UE will reselect the neighbor cell. It is used to avoid ping -pong reselection between different cells

Value range : Physical unit : Confidential

0 ~ 31 second. 4 of 12


The actual value of reselection delay time setting is depended on the DRX cycle length coefficient. DRX cycle length coefficient : Used by UE to calculate the DRX cycle length of the CN domain. Value range :

6 ~ 9.

Recommendation value :

8.

How to calculate the reselection delay time by DRX cycle length coefficient. Refer to 3GPP 25.133

Formula:

E.g.

n

DRX cycle length = 2 * 10ms

If DRX cycle length coefficient = 8 then 8

DRX cycle length = 2 * 10ms = 2560ms=2.56s Then use table below to get the resele ction time and number of DRX c ycles (defined by 3GPP)

DRX cycle length [s] 0.08 0.16 0.32 0.64 1.28 2.56 5.12

TmeasureGSM [s] (number of DRX cycles) 2.56 (32) 2.56 (16) 5.12 (16) 5.12 (8) 6.4 (5) 7.68 (3) 10.24 (2)

Step 5: Trigger 3G to 2G reselection

Confidential

5 of 12


2. 3G to 2G-Handover parameters specification Parameters

Value

Meaning

Cell individual offset

0

0

GSM RSSI threshold

15

-95dB

Hysteresis

2

1dB

Inter-RAT handover trigger time

1000

1S

Filter coefficient

UU_FC4

7

Report interval

UU_RILE_1

1S

Inter-freq measure start RSCP threshold

-95

-95dBm

Inter-freq measure end RSCP threshold

-90

-90dBm

2D Hysteresis

6

3dB

2F Hysteresis

6

3dB

2D trigger time

640

0.64S

2F trigger time

640

0.64S

Step 1: 3G RSCP measurement value = < Inter-freq measure start RSCP threshold - 2D Hysteresis/2 Step 2: Filter coefficient Step 3: Report interval Step 4: GSM Rxlev measurement value + Cell individual offset >= GSM RSSI threshold + Hysteresis/2 Step 5: Inter-RAT handover trigger time Step 6: Trigger Inter-RAT handover

Parameters specification: Step1: 3G RSCP measurement value = < Inter-freq measure start RSCP threshold – 2D Hysteresis/2 3G RSCP measurement value: the measurement RSCP value in 3 G serving cell.

Inter-freq measure start RSCP threshold : UE will report 2D event and then RNC will send signal to start CM and inter-frequency measurement when the measured value is lower than this threshold.

Value range : Confidential

-115

~

-25 6 of 12


Physical unit :

dBm

2D Hysteresis: Hysteresis value of the 2D event. This parameter value is related to the slow fading characteristic. The greater this parameter is valued, the less ping-pong and misjudgment can be caused. However, in this case, the event cannot be t riggered in time.

Value range :

0 ~ 29


0 ~ 14.5 with the step size of 0.5

dB

2D event refer to 3GPP 25.331 Triggering condition Equation 1:

QUsed T Used 2d H 2d / 2 The variables in the formula are defi ned as follows: QUsed is the quality estimate of the used frequency. TUsed 2d is the absolute threshold that applies for the used frequency and event 2d. H2d is the hysteresis parameter for the event 2d.

Leaving triggered state condition Equation 2:

QUsed T Used 2d H 2d / 2 The variables in the formula are defined as follows: QUsed is the quality estimate of the used frequency. TUsed 2d is the absolute threshold that applies for the used frequency and event 2d. H2d is the hysteresis parameter for the event 2d.

2D trigger time: 2D event trigger delay time. This parameter value is related to the slow fading characteristic. The greater this parameter is valued, the less the misjudgment probability is. However, the response speed of the event to the me asurement signal change becomes lower.

Value range: D0, D10, D20, D40, D60, D80, D100, D120, D160, D200, D240, D320, D640, Confidential

7 of 12


D1280, D2560 and D5000

Physical value range: 0, 10, 20, 40, 60, 80, 100, 120, 160, 200, 240, 320, 640, 1280, 2560 and 5000

Physical unit :

ms

Inter-freq measure end RSCP threshold : UE will report 2F event and then RNC will send signal to stop CM and inter-frequency measurement when the measured value is higher than this threshold.


-115

~

-25

dBm

2F Hysteresis: Hysteresis value of the 2F event. This parameter value is related to the slow fading characteristic. The greater this parameter is valued, the less ping-pong and misjudgment can be caused. However, in this case, the event cannot be tri ggered in time.

Value range :

0 ~ 29


0 ~ 14.5

with the step size of

0.5

dB

2F event refer to 3GPP 25.331 Triggering condition: Equation 1:

QUsed T Used 2 f H 2 f / 2 The variables in the formula are defi ned as follows: QUsed is the quality estimate of the used frequenc y. TUsed 2f is the absolute threshold that applies for the used freq uency and event 2f. H2f is the hysteresis parameter for the event 2f.

Leaving triggered state condition: Equation 2:

QUsed T Used 2 f H 2 f / 2

Confidential

8 of 12


The variables in the formula are defined as follows: QUsed is the quality estimate of the used frequency. TUsed 2f is the absolute threshold that applies for the used freq uency and event 2f. H2f is the hysteresis parameter for the event 2f.

2F trigger time: 2F event trigger delay time. This parameter value is related to the slow fading characteristic. The greater this parameter is valued, the less the misjudgment probability is. However, the response speed of the event to the me asurement signal change becomes lower.

Value range: D0, D10, D20, D40, D60, D80, D100, D120, D160, D200, D240, D320, D640, D1280, D2560 and D5000

Physical value range: 0, 10, 20, 40, 60, 80, 100, 120, 160, 200, 240, 320, 640, 1280, 2560 and 5000

Physical unit :

Confidential

ms

9 of 12


RSCP

2D Trigger time

-100dBm

Send 2D event to RNC

2D Hysteresis/2

2D threshold

Start 2D measurement 2D Hysteresis/2

Stop 2D measurement

Start 2F measurement 2F Trigger time

Send 2F event to RNC

2F Hysteresis/2

2F threshold

2F Hysteresis/2

Stop 2F measurement -85dBm Time

Step 2: Filter coefficient Filter coefficient: Inter-RAT measurement L3 filter coefficient, the greater this parameter is valued, the stronger smoothing effect can be caused to the signal and the greater anti-slow fading ability can be possessed. However, the signal change tracing abilit y becomes weaker.

Value range : D0, D1, D2, D3, D4, D5, D6, D7, D8, D9, D11, D13, D15, D17, D19. Physical value range : 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 13, 15, 17, 19. Filter coefficient

0

1

2

3

4

5

6

7

8

9

11

Iterative report

1

2

3

5

7

10

15

21

30

42

85

Step 3: Report interval Report interval: Time interval in which UE reports the inter-RAT measurement results to RNC periodically. Confidential 12

10 of


Value range: D250, D500, D1000, D2000, D3000, D4000, D6000, D8000, D12000, D16000, D20000, D24000, D28000, D32000, D64000.

Physical value range: 250, 500, 1000, 2000, 3000, 4000, 6000, 8000, 12000, 16000, 20000, 24000, 28000, 32000, 64000.

Physical unit :

ms.

Step 4: GSM Rxlev measurement value + Cell individual offset >= GSM RSSI threshold + Hysteresis/2 GSM Rxlev measurement value : the measurement BCCH Rxlev value in GSM cell.

GSM RSSI threshold : Requirement for the BCCH Rxlev of GSM cell in the inter-RAT handover. Cell individual offset: It is used in inte r-RAT handover decision process. The greater the value is, the more is the probability of handover to the GSM cell. Value range : Physical unit :

-50 ~ 50. dB.

Hysteresis: It decides whether to trigger the GSM handover decision together with the GSM RSSI threshold. The value can be decreased to some degree in areas with less shadow fading, and

increased in a reas with more shadow shading . Value range :

0 ~ 15.


0~7.5;

step: 0.5.

dB.

Reference 3GPP 25.331 Triggering conditions: Equation 1:

M Other RAT CIOOther RAT T Other RAT H / 2 The variables in the formula are defined as follows: MOther RAT is the measurement quantity for the cell of the other system. Confidential 12

11 of


CIOOther RAT is the cell individual offset for the cell of the other system. TOther RAT is the absolute threshold that applies for the other system in that measurement. H is the hysteresis parameter for inter-RAT handover

Leaving triggered state conditions: Equation 2:

M Other RAT CIOOther RAT T Other RAT H / 2 The variables in the formula are defi ned as follows: MOther RAT is the measurement quantity for the cell of the other system. M Other RAT is expressed in dBm. CIOOther RAT is the cell individual offset for the cell of the other system. TOther RAT is the absolute threshold that applies for the other system in that measurement. H is the hysteresis parameter for inter-RAT handover

Step 5: Inter-RAT handover trigger time Inter-RAT handover trigger time: The inter-RAT handover to GSM procedure will be started if the GSM BCCH Rxlev always satisfies the inter-RAT handover decision (step 4) during the specified period of this parameter.


0 ~ 64000.

Step: 1

ms

Step 6: Trigger Inter-RAT handover

Confidential 12

12 of

Cell Re Selection and Handover Parameters Specification

Recommend Documents