[anshuman]

-> The broadcast control channel (BCCH) is a point to multipoint, unidirectional (downlink) channel used in the Um Interface of a GSM cellular standard.

-> The BCCH carries a repeating pattern of system information messages that describe the system related Information (CGI Info, Neighbouring cell Info- arfcn, Power level info etc.).

I know only this much, is there any other functions?
If it is not a right place to ask any begginer-level-querries, may be very small for you guys, then please let me know and I’ll stop.

[asje]

Broadcast Control Channel (BCCH)
The Broadcast Control Channel is transmitted by the BTS at all times. The RF carrier
used to transmit the BCCH is referred to as the BCCH carrier. The information carried
on the BCCH is monitored by the MS periodically (at least every 30 secs), when it is
switched on and not in a call.
Broadcast Control Channel (BCCH) – Carries the following information (this is only a
partial list):

Location Area Identity (LAI).

List of neighbouring cells which should be monitored by the MS.

List of frequencies used in the cell.

Cell identity.

Power control indicator.

DTX permitted.

Access control (for example, emergency calls, call barring).

CBCH description.
The BCCH is transmitted at constant power at all times, and its signal strength is
measured by all MS which may seek to use it. “Dummy” bursts are transmitted to ensure
continuity when there is no BCCH carrier traffic.

[ajay rajput]

dear pix
please tel me how to calculate max traffic beare by per trx or per chennal of trx

[gaurav]

what are the uses of different frequencies in bcch whose bandwidth is 200khz. what are its uses when we go for drive test

[ASIF KHAN]

hello everybody, i am working on my final year project of BS and i want to know ARFCN through AT commands. i am using siemens mobile phone A60. the commands i have tried to get ARFCN are
AT^SMONC
AT^MONI
AT^MONP
but i am getting ERROR. can anybody please help me, as its urgent.
thank you.

[TELECOM ENGINEER]

After reading yur all deta i ca,nt understand about BCCH missing. how can we solve this problam by a easy method ?

[vijay]

broad cast control channel

for 200khz it uses 1-12 channels,these channels are used for different frequency planning in a cell site

proper planning is used to avoid interference

in drivetest it is used for checking signal quality level i think so

[Ayat]

Hello

in our network , we have counter with name Cell down .. it represents “””This counter counts how long the cell is interrupted on BCCH.
When the confirmation message (tGetCellDownTimeAck.wResult)
of cell’s interruption duration obtained from database is true, the
counter records the measurement value”” as i know we define BCCH in trx0 , so when we lost the BCCH , the cell will be completely stopped .. but when check from the PM system ia have found large #f cell have this counter =3600 sec in BH and they have high traffic ..could you help me

[pix]

Ayat,

This counter indicates whether the cell is available for traffic or not. It is as simple as that. You may have other counters which provide availability per TRX (trx avaiability).
If trx3 is down, the rest of the cell remains available.
If cell is not available, then trx0 is not transmitting bcch, then your counter is stepped.

Now, based on the values you are seeing, it looks like the value “3600” indicates that the cell is indeed available.
You should check the values for a cell which is apparently “down” or “locked”, and see if they increase or decrease.

I suspect they decrease..? You gotta try… If all your cells are “Up”, consider locking a cell artificially for 30mn 😉

Regards
pix

[Ayat]

Hi again pix

yes i understood what yoy had explained but i can not find that in PM data .. 3600 that means the cell is out during whole hour. check the data below and help me to explain ..

BTS NAME Cell down time Cell Down Time (%) Number of invalid access requests TCH total traffic number (erl) SDCCH total traffic number (erl) TRX Equipment Availability Rate Number of TRXs Number of healthy TRXs
Site001-3 3,600.00 100.00% 0 0 0 0.000 1 0
Site8-3 3,600.00 100.00% 0 0 0 0.000 2 0
Site8-1 3,600.00 100.00% 0 0 0 0.000 2 0
Site9-2 3,600.00 100.00% 0 0 0 0.000 2 0
Site9-1 3,600.00 100.00% 0 0 0 0.000 2 0
Site10D-1 3,600.00 100.00% 0 19.5619 1.2542 100.000 8 8
Site11-3 3,600.00 100.00% 0 44.2714 11.4383 100.000 4 4
Site12-3 3,600.00 100.00% 0 20.4394 3.5419 100.000 4 4
Site13-2 3,234.00 89.83% 0 0.3147 0.0606 0.000 4 0
Site13-1 3,234.00 89.83% 0 0.0383 0.0972 0.000 4 0
Site14-3 2,808.00 78.00% 0 0.7689 0.2628 0.000 4 0
Site14-2 2,808.00 78.00% 0 0.6839 0.1689 0.000 4 0
Site15-2 2,676.00 74.33% 0 0.1908 0.1503 0.000 4 0
Site16-3 2,509.00 69.69% 0 7.0811 1.0378 25.000 4 1
Site17-1 1,917.00 53.25% 0 1.7358 0.1736 50.000 4 2
Site17-2 1,916.00 53.22% 0 0.4414 0.1453 50.000 4 2
Site17-3 1,913.00 53.14% 0 0.5025 0.1469 50.000 5 2.5
Site18-3 1,913.00 53.14% 0 3.9008 0.8436 50.000 4 2
Site18-2 1,912.00 53.11% 0 7.2083 1.255 50.000 4 2

[Ayat]

Hi,,,

I have found 2 cases
case#1 High cell down time % with High Trx avalibilty and High traffic … no alram

Case#2 zero TCH traffic and zero Trx avalibilty and high cell down time % in case with arlarm cell interuption

cell down time =3600 in an hour that means that cell is out of service full hour.

[pix]

hi ayat,

ok, i understood :

Site10D-1
Site11-3
Site12-3

are the crazy ones.

I have no explanation for that , it looks like a counter issue.

[Ayat]

Hi

thanks Pix as usual no helping for our vendor to confirm that ..

but i have more question ..

I have checked some cells with cell interruption alarm , these cells have problem with trx that contains BCCH channel for long time .. i am thinking , can we reconfigure channels to transfer BCCH to onther trx.??

[pix]

yes, that should be possible, but it would be strange if that was the issue.

typically, you just lock the TRX that is carrying the BCCH. That should automatically (?) push the BCCH onto another TRX. I can’t be sure on your system though, but it’s easy to try.

It’s a pity your vendor is not more interested in your issues. Can’t you “short-circuit” your primary local support and contact higher up support team ?

Regards
Pix

[Ayat]

Hi pix thanks

They are zte ,, and I have to push them to check that .. At least as reminder boz currently we are in Ms period , thanks god it is almost finish

[Author]

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