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Dear All can any one tell me whats the difference between SI TYPE 5 and SI TYPE 5ter?
As far as i have read SI TYPE 5 carries BCCH information of neighbors cells from the same band as the serving cell, and SI TYPE 5ter carries BCCH information of neighboring cells from the other band.
Tell me if i am right or wrong about it as i have a question which i will put if i am right about this concept.
Thanks for your help
Hi Asif,
You are right! 5ter=neighbours from 1800 MHz.Shoot your question !
Rex, beware 🙂 it’s 1800MHz list, if you’re in a 900 cell. But it’s 900MHz neighbour list if you’re curently in a 1800MHz cell.
(((headache)))Hi all,
Pix do you mean that
BCCH of one cell on 900 and neighbour on 1800….and vice versa
If yes then that is strange.
If no..please explain the (((headache)))??
Regards
MKTAsif..
SI 5 for 900 BCCH
SI 5ter for 1800 BCCH.MKT
Headache, because the explanation gives a headache so early in the morning
If the serving cell with BCCH in 900MHZ, then SI5 contains cells from 900MHz band.
If the serving cell with BCCH in 1800MHZ, then SI5 contains cells from 1800MHz band.
If the serving cell with BCCH in 900MHZ, then SI5ter contains cells from 1800MHz band.
If the serving cell with BCCH in 1800MHZ, then SI5ter contains cells from 900MHz band.
Thank you all.
I am having a problem i hav a DCS only site (i.e it has BCCH on 1800 and no 900 TRX) Its not making outgoing handovers.
During the Drive test i have found that its SI 5 contains a strange thing which i am posting below.
MS1
System Information Type 5Time: 13:22:52.18
Frame number: 61147634L2 Header (Hex) : 0x00 0x00 0x03 0x03 0x49
Skip indicator : 0
Protocol discriminator : (6) Radio resources management messages
Message type : 29
Neighbour Cell Description
EXT IND : (0) The information element carries the complete BA
BA IND : 0
1024 Range
Channels : 63 64 65 66 68 69 70 71 72 73 74 75 77 78 79 622Header dump (Hex):
EB 00 19 00 00 00 04 19 00 01
17 00 00 03 03 49Message dump (Hex):
06 1D 80 47 FE 81 3F 7F 80 80
FF FF FF FC 08 15 00 7FNow if you see the BA list in this message its containing Frequencies from 900 + 1800 also there is no SI 5ter message, which is against the standard as the standard say :-
SI 5 : one band
SI 5ter: other bandI have drive tested some other DCS only sites, they are not showing this discrepecy and are working fine.
Can any tell whats the problem? why is the message like this? is there any parameter that controls this?
Thanks.
I’m going to propose an idea which doesn’t sound great at all… Basically, I’d say the neighbour list in this cell is “bugged”.
could you add another 1800 neighbor cell, and see if it appears in the list?
The 900 neighbours are defined in the OMC-R, aren’t they?
If it does’t improve, then I would reset the OMU.
Idle mode is also showing discrepency.
We know that SI type 2 contains BA list (ARFCN’s) from the same band as the serving cell,
i.e
if Serving cell is 900: SI type 2 contain 900 Frequencies
if Serving cell is 1800: SI type 2 contain 1800 Frequencies
SI type 2ter contains frequencies from the other band i.e
if Serving cell is 900: SI type 2ter contain 1800 Frequencies
if Serving cell is 1800: SI type 2ter contain 900 Frequencies
and SI Type 2bis is used if SI type 2 is incomplete.
Below are the SI messages received during Drive test. and clearly they show stuff that is against what the standard says(may be i hav lack of knowledge about the standard, in that case you people can correct me)
#############################
MS2
System Information Type 2Time: 13:19:00.70
Frame number: 24659997ARFCN : 624 (GSM 1800)
L2 Pseudo Length : 22
Skip indicator : 0
Protocol discriminator : (6) Radio resources management messages
Message type : 26
Neighbour Cell Description
EXT IND : (1) The information element carries only a part of the BA
BA IND : 1
1024 Range
Channels : 63 64 65 66 68 69 70 71 72 73 74 75 77 78 79
NCC permitted
NCC permitted values : 0 1 2 3 4 5 6 7
RACH control parameters
Max retransmission : (2) Maximum 4 retransmissions
Tx-integer : (7) 10 slots used
Cell bar access : (0) Not barred
Call reestablishment : (1) Not allowed
Access control
Emergency Call allowed : (0) All MSs
Barred classes :Header dump (Hex):
E6 00 1B 00 00 00 04 1B 00 01
19 02 70 59Message dump (Hex):
06 1A B0 47 FD 81 3F BF 80 C0
FF FF FF FC 08 10 20 40 FF 9D
00 00
##################################************************
MS2
System Information Type 2bisTime: 13:19:03.48
Frame number: 24660703ARFCN : 624 (GSM 1800)
L2 Pseudo Length : 21
Skip indicator : 0
Protocol discriminator : (6) Radio resources management messages
Message type : 2
Neighbour Cell Description
EXT IND : (1) The information element carries only a part of the BA
BA IND : 1
1024 Range
Channels : 622 624
RACH control parameters
Max retransmission : (2) Maximum 4 retransmissions
Tx-integer : (7) 10 slots used
Cell bar access : (0) Not barred
Call reestablishment : (1) Not allowed
Access control
Emergency Call allowed : (0) All MSs
Barred classes :
rest
spareHeader dump (Hex):
E6 00 1B 00 00 00 04 1B 00 01
19 02 70 55Message dump (Hex):
06 02 B2 70 FF 00 00 00 00 00
00 00 00 00 00 00 00 00 9D 00
00 2B
**********************************SI Type 2ter is not received :S
Help me out!!!
Atually its a two sector site. the second sector is also 1800 and has the same problem, both sectors are added as neighbors to each other but not handovers between them.
yes neighbors are defined in the OMCR.
What do you mean by resetting the OMU?
i will add an other 1800 neigbhor and see what happens and share the finding here.
Asif,
which vendor are you using?
OMU is the SUM card, in alcatel systems.
There is definitely a non-standard behaviour in this cell… that’s why i’m assuming the brain of this cell is … out of his mind ! (SUM card = brain…)
for more info about SI messages..
we are using Nokia system
Asif,
Pix is correct in saying that the “Brain of BTS” might not be working properly.
In NOKIA systems..the brain of BTS is
BOIA CARD.You check the ALARM in BSC for this BTS.
If you are observing HANDOVER FAILURES for this BTS in drive tests and also from the reports then…
ask the BTS engineer to ensure the correct value of DAC in BOIA.
Incorrect setting of DAC in case of Nokia BTS can result handover failures irrespective of the definitions in BSC.Iam not remembering exactly but the alarm description is somewhat like
DIFFERENCE IN FREQUENCY REFERENCE BETWEEN BTS AND PCM.
Regards…
MKT i will check for the alarms, but one thing to add: there are no handovers so no handover failures
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