answer_handover and power control practice

8/13/2019 Answer_handover and Power Control Practice

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Document Title Security Level

2010-11-09 HUAWEI Confidential Page1, Total4

1. Handover practice

There are three cells in one BSC: CELL A/CELL B/CELL C

The setting of parameter as follow:

Cell name Band Cell

layer

Inter-layer

HO Threshold

Inter-layer

Hysteresis

Edge HO DL Rx-LEV

Threshold

PBGT HO Threshold Inter-cell

Hysteresis

Cell A GSM900 3 25 3 25 68 5

Cell B GSM900 3 25 3 25 68 5

Cell C GSM1800 2 20 3 20 68 4

And the signal level as follow, please sort the cell and list the possible normal HO Typefor example the 1st line

No.

Serving

cell

Neighbor

cell 1

Neighbor

cell 2

Rx-LEV

(serving)

Rx-LEV

(neighbor1)

Rx-LEV

(neighbor2) Cell ranking Possible HO Type

1 A C B -87 -86 -81 CBA Edge HOCell C

2 B C A -84 -88 -81 BAC No Handover

3 A C B -75 -74 -69 CBA Layer HOCell C

4 B C A -75 -89 -69 ABC PBGT HOCell A

5 C A B -89 -80 -83 CAB No Handover

2. Power control practice

Step1: Calculate the adjustment based on level= [actual receiving level (upper threshold + lower threshold)/2]

Minus (-) means increase output power, positive (+) means decrease output power.

Step 2: Then compare with the adjustable step size of actual quality bandand choose small one.

This is the expected adjustment based on level,


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Step 3:Then compare the actual quality with threshold of quality.

If > lower threshold, increase power,

if < upper threshold, decrease power.

Otherwise no need.

Step 4:The expected adjustment based on quality is equal to the adjustable step size for power control by quality.

Step 5:Then according to the general judgment get the final result.

Given conditions:

The uplink receiving level is -85dBm, the quality is level 4.

Data configuration is as follows:

Uplink signal level upper threshold: -60dBm,

uplink signal level lower threshold: - 80dBm.Uplink signal upper quality threshold: level 0.

Uplink signal lower quality threshold: level 2.

The adjustable step size of quality band 0 is 16dB, of quality band 1 is 8dB, and of quality 2 is 4 dB.

The adjustable step size for power control by quality is 4dB.

Question:What will be the uplink stable receiving level after power control?

Step1: Calculate the adjustment based on level= [actual receiving level (upper threshold + lower threshold)/2]

Minus (-) means increase output power, positive (+) means decrease output power.

Answer: the adjustment based on level = [-85-(-60+(-80))/2]= -15

It means increase output power 15dB

Step 2: Compareadjustment based on levelwith the adjustable step size of actual quality bandand choose small one.


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This is the expected adjustment based on level,

Answer: band 0 corresponding to Rx quality is 0

band 1 corresponding to Rx quality is 1 or 2

band 2 corresponding to Rx quality is 3 or more than 3

now the quality is 4, means band 2, the adjustment step size of quality band 2 is 4dB

15dB and 4dB , choose the small one , so the expected adjustment based on level is increase 4dB

Step 3:Then compare the actual quality with threshold of quality.

If > lower threshold, increase power,

if < upper threshold, decrease power.

Otherwise no need.

Answer: the actual quality is 4 and the Uplink signal upper quality threshold is level 0.

Uplink signal lower quality threshold is level 2. so > lower threshold, increase power,Step 4:The expected adjustment based on quality is equal to the adjustable step size for power control by quality.

Answer: The adjustable step size for power control by quality is 4dB.

So expected adjustment based on quality is increase power 4dB

Step 5:Then according to the general judgment get the final result.

Answer :the expected adjustment based on level is increase 4dB

the expected adjustment based on quality is increase power 4dB

according to the principle of judgment as follow, (the red one), the final result is increase power 4dB

Rxlev & RxQual one side need adjust, base it needed

Rxlev & Rxqual adjust to same direction, choose the MAX value of them

Rxlev & Rxqual adjust to contrary direction, Rxlev need raise then raise; Rxlev need lower then no action


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answer_handover and power control practice

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