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

Threshol

d

Inter-

layer

Hysteresi

s

Edge HO

DL Rx-

LEV

Threshol

d

PBGT HO

Threshol

d

Inter-cell

Hysteresi

s

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 Type（ for

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 C→B→AEdge HO→Cell C

2 B C A -84 -88 -81 B→A→C No Handover

3 A C B -75 -74 -69 C→B→ALayer HO→Cell C

4 B C A -75 -89 -69 A→B→CPBGT HO→Cell A

5 C A B -89 -80 -83 C→A→B No Handover

2. Power control practice

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

actual receiving level ]

Positive (+) value means increase output power, minus (-) value means decrease

output power,

Increase power base on RxLev, the adjustment step is set as Min(|(upper threshold

+ lower threshold)/2 - actual receiving level|, MAX Up Adj. PC Value by RX_LEV).

Decrease power base on RxLev, the adjustment step is set as Min(|(upper

threshold + lower threshold)/2 - actual receiving level|,. MAX Down Adj. PC Value

of Quality Zone).

This is the expected adjustment based on level,

Step 2: Then compare the actual quality with threshold of quality.

If >= lower threshold, increase power. RxLev + MAX Up Adj. PC Value by Qual. <

UL/DL RX_LEV Upper Threshold, applying power control; Otherwise, no power

control, to avoid ping-pong power control may occur.

if < upper threshold, decrease power. RxLev– MAX Down Adj. PC Value by Qual. >

UL/DL RX_LEV Lower Threshold, applying power control; Otherwise, no power

control, to avoid ping-pong power control may occur.

Otherwise no require of power control.

Step 3: General judgment

Step 4: 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 zone 0 is 16dB, of quality zone 1 is 8dB, and

of quality zone 2 is 4 dB.

Max Up Adj. PC Value by RxLev: 16dB

MAX Up Adj. PC Value by Qual.: 8dB

MAX Down Adj. PC Value by Qual.: 4dB

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

Answer:

Step1: the adjustment based on level = [(-60+(-80))/2-(-85)]= 15

It means increase output power 15dB

Choose Min(15dB, MAX Up Adj. PC Value by RX_LEV (16dB))

Actually adjust power 15dB base on RxLev

Step 2: the actual quality is 4 > Uplink signal lower quality threshold: level 2.

So increase power with MAX Up Adj. PC Value by Qual.: 8dB

Step 3: Both RxLev and RxQual require increasing power, so choose the

maximum value. The result is take the 15dB as the power control step.

Step 4: RxLev after power control = -85dBm + 15dB = -70dBm