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System info type 5 and 5ter

Viewing 15 posts - 1 through 15 (of 16 total)
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  • #56348 Reply
    Asif
    Guest

    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

    #56349 Reply
    Rex
    Guest

    Hi Asif,
    You are right! 5ter=neighbours from 1800 MHz.

    #56350 Reply
    Pix
    Guest

    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)))

    #56351 Reply
    MKT
    Guest

    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
    MKT

    #56352 Reply
    MKT
    Guest

    Asif..

    SI 5 for 900 BCCH
    SI 5ter for 1800 BCCH.

    MKT

    #56353 Reply
    Pix
    Guest

    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.

    #56354 Reply
    Asif
    Guest

    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 5

    Time: 13:22:52.18
    Frame number: 61147634

    L2 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 79 622

    Header dump (Hex):
    EB 00 19 00 00 00 04 19 00 01
    17 00 00 03 03 49

    Message dump (Hex):
    06 1D 80 47 FE 81 3F 7F 80 80
    FF FF FF FC 08 15 00 7F

    Now 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 band

    I 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.

    #56355 Reply
    Pix
    Guest

    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.

    #56356 Reply
    Asif
    Guest

    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 2

    Time: 13:19:00.70
    Frame number: 24659997

    ARFCN : 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 59

    Message 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 2bis

    Time: 13:19:03.48
    Frame number: 24660703

    ARFCN : 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
    spare

    Header dump (Hex):
    E6 00 1B 00 00 00 04 1B 00 01
    19 02 70 55

    Message 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!!!

    #56357 Reply
    Asif
    Guest

    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.

    #56358 Reply
    asif
    Guest

    What do you mean by resetting the OMU?

    i will add an other 1800 neigbhor and see what happens and share the finding here.

    #56359 Reply
    Pix
    Guest

    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..

    http://www.scribd.com/doc/4353979/GSM-System-Information-4

    #56360 Reply
    asif
    Guest

    we are using Nokia system

    #56361 Reply
    MKT
    Guest

    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…

    #56362 Reply
    Asif
    Guest

    MKT i will check for the alarms, but one thing to add: there are no handovers so no handover failures

Viewing 15 posts - 1 through 15 (of 16 total)
Reply To: Reply #56359 in System info type 5 and 5ter
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