HO PARAMETER

promod,

could you write down some QoS Stats about your cells ? (only relevant qos stats, not all indicators)

if you’re having UL HO on one cell (not on all the network), you might want to check your BTS hardware (TRX faulty, probably)

2.ALSO WE HAVE A PROBLEM IN THE BSC BORDERS.THE STATS SHOWS THE 100% FAILURES EVEN THOUGH U DIFINE IN BOTHWAYS.

As i was having problem with INTER MSC and INTER BSC problem has been resolved after difining the LAC in the MSC level. So i thank for everybody giving the solution.

I would like to know what changes to be done in the below mentioned power control parameters due to the level HO problem.

POWER CTRL ENABLED ……… Y POWER CONTROL INTERVAL ….. 02 s
BS TX PWR MIN ….PEAK PWR – 30 dB BS TX PWR MAX ….PEAK PWR – 00 dB
BS TX PWR MAX1X00 PEAK PWR – 00 dB
POWER INCR STEP SIZE ……. 4 dB POWER RED STEP SIZE …….. 2 dB
POWER DECR LIMIT BAND 0 …. 38 dB POWER DECR LIMIT BAND 1 …. 38 dB
POWER DECR LIMIT BAND 2 …. 38 dB POWER DECR QUAL FACTOR ….. 1
ALA ENABLED ……………. N MIN INT BETWEEN ALA …….. 10 s
POWER LIMIT ALA ………… 6 dB

PC AVERAGING LEV DL WINDOW SIZE ………… 04 WEIGHTING …. 1
PC AVERAGING LEV UL WINDOW SIZE ………… 04 WEIGHTING …. 1
PC AVERAGING QUAL DL WINDOW SIZE ………… 01 WEIGHTING …. 1
PC AVERAGING QUAL UL WINDOW SIZE ………… 01 WEIGHTING …. 1

PC UPPER THRESHOLDS QUAL DL RX QUAL .. < 0.2% PX .. 16 NX .. 16 PC UPPER THRESHOLDS QUAL UL RX QUAL .. < 0.2% PX .. 16 NX .. 16 PC LOWER THRESHOLDS QUAL DL RX QUAL .. 0.8% - 1.6% PX .. 03 NX .. 04 PC LOWER THRESHOLDS QUAL UL RX QUAL .. 0.8% - 1.6% PX .. 03 NX .. 04 PC LOWER THRESHOLDS QUAL144 RX QUAL .. 0.8% - 1.6% PX .. 03 NX .. 04 PC UPPER THRESHOLDS LEV DL RX LEVEL .. - 68 dBm PX .. 01 NX .. 01 PC UPPER THRESHOLDS LEV UL RX LEVEL .. - 72 dBm PX .. 01 NX .. 01 PC LOWER THRESHOLDS LEV DL RX LEVEL .. - 80 dBm PX .. 01 NX .. 01 PC LOWER THRESHOLDS LEV UL RX LEVEL .. - 84 dBm PX .. 01 NX .. 01 PC UPPER THRESHOLDS DL RX QUAL AMR HR .. < 0.2% PC UPPER THRESHOLDS UL RX QUAL AMR HR .. < 0.2% PC LOWER THRESHOLDS DL RX QUAL AMR HR .. 0.8% - 1.6% PC LOWER THRESHOLDS UL RX QUAL AMR HR .. 0.8% - 1.6% Regards, Promod

Please find the below mentioned QOS report for your reference.

Date Segment ID 2G Network Availability / SDCCH Availability (ava_4) Availability / TCH Availability (ava_1d) Blocking / TCH Blocking (blck_8d) CSR Call Congestion / SDCCH Blocking (blck_5a) DCR Intensity / Average TCH Traffic, erlang (trf_12a) Successful Ratio / Incoming HO Success (hsr_18) Successful Ratio / Outgoing HO Success (hsr_19) TCH Sucess Assignment
4-Jan-07 58 B24_16231 100.00 100.00 0.00 99.44 949 0.00 1.42 0.46 63.80 90.74 97.59
5-Jan-07 58 B24_16231 100.00 100.00 0.00 99.40 1041 0.00 1.82 0.49 59.79 85.64 98.41
7-Jan-07 58 B24_16231 100 99.99836 0 99.54709 1269 0 1.667825 0.798752 59.72696 89.5 98.02905
8-Jan-07 58 B24_16231 100 100 0 99.54445 1061 0 1.982554 0.576971 64.51613 88.74459 97.86382
9-Jan-07 58 B24_16231 100 100 0 99.7032 1197 0 1.212553 0.777284 66.66667 88.83929 99.09502
10-Jan-07 58 B24_16231 100 100 0 99.45479 1300 0 1.51715 0.612849 60.10782 76.84887 98.91186
11-Jan-07 58 B24_16231 100 100 0 98.41598 1373 0 1.344743 0.959566 60.3211 91.41914 97.63948

hello promod,

Thanks for the qos report.

Unfortunately i didn’t manage to match the headers (indicators names) with the columns (indicators values).

Ok, what you could try to do :

1) HO THRESHOLDS LEV UL RX LEVEL ………… -102 dBm

2a) PC UPPER THRESHOLDS LEV UL RX LEVEL .. – 80 dBm PX .. 01 NX .. 01

2b) PC LOWER THRESHOLDS LEV UL RX LEVEL .. – 90 dBm PX .. 01 NX .. 01

1) Your UL threshold is way too high, sorry i didn’t notice that earlier. Those thresholds will force to trigger a UL HO eventhough the level is still within an acceptable range.

2a & 2b ) Those settings I’m proposing are not mandatory, but currently the power control is forcing the mobiles to emit with a strong power : it decreases the battery life (= less potential traffic !!) and it is always better to decrease the MS power (potential health concerns…)

Check out the call drop rate after changes, and in case of higher CDR, increase those thresholds by 2dB step increments.

In my opinion, you might also be in an area which is not covered well enough, which is the reason why there is no “power budget” handover, but only handovers based on level thresholds

Regards,
Pix

1- the window size is the number of measures averaged in order to get a “smoothed-out” value. This “averaged” value is compared to the threshold.
For instance, window size for PC LEVEL = 4 means :
RX LEV (t=1) = -60
RX LEV (t=2) = -62
RX LEV (t=3) = -61
RX LEV (t=4) = -63

At t=4, the AV-RX-LEV = -61.5 dBm. This value will be cmpared to the threshold UPPER PC LEV and LOWER PC LEV.

2- i learnt about Px and Nx long time ago, but since they are not modifiable, i forgot about them. I didn’t ask you to change these values though… just keep the current values.

3-
if av_rx_lev > upper pc lev threshold, then the Tx Power of the MS will be increased.
if av_rx_lev < lower pc lev threshold, then the Tx Power of the MS will be decreased. i hope it helps.. i suggest you have a look through 3GPP specifications regarding GSM algorithms if you need additional details.

Dear Pix,

Yes i got the some more improvement in the network on DCR after implementing the your parameters.So thanks for your input sir.

1.I would like know how the HO margin of LMRG,PBGT and QMRG works in the network?

2.You have given the ex: of PC level,same like this i would like to know the window side size uplink level and downlink level works?

3.I would like to know about RLT?

Regards,
Promod

PARAHO ,

yes, if a mobile receives a signal (rxlev) of less than -100dBm, it is way too low. Most of the time it will lead to a dropped call.

PROMOD ,

i’m glad it works better now.

i think it is now time for you to learn about parameters and radio optimization 🙂 i can’t explain you everything via internet.. you’d rather ask your vendor some documents about radio optimization, radio parameters and handover procedures.

good luck !