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Cell Planning

Viewing 15 posts - 166 through 180 (of 184 total)
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  • #37438 Reply
    Tomar
    Guest

    Hi Daniel, may be this basic definition could help you (from some documentation):
    A TDMA frame consist of eight timeslots or physical channels. Each timeslot
    has a length of 0.577 ms. The length of a TDMA frame is therefore 4.615 ms.
    A 26-TDMA multi-frame is defined as a succession of 26 TDMA frames, and
    corresponds to exactly 120 ms (26 x 4.615ms) cycle used for the TCH/F and
    TCH/H.
    A 51-TDMA multi-frame is defined as a succession of 51 TDMA frames, and
    corresponds to a 235 ms (51 x 4.615ms) cycle.
    A Super-frame is a succession of 51 x 26 TDMA frames (6.12 sec). This is
    the smallest cycle for which the organization of all channels is repeated,
    because of these smallest common denominators.
    A Hyper-frame is a succession of 2048 x 51 x 26 TDMA frames (3 h, 28 min,
    53 sec & 760 ms). It is a numbering period and determines all the cycles in the
    transmission of the radio path. The frame number in the hyper-frame (absolute
    TDMA frame number) is e.g. the smallest cycle used for frequency hopping
    and ciphering.
    We have seen that a physical channel is defined by a frequency and a timeslot
    number. We have also seen that a physical channel can be used to carry various
    logical channels. At any point in time, the MS must know on which logical channel to
    send to the BTS and which logical channel is being sent from the BTS. For example
    the timeslot allocated to a user is usually used for traffic (TCH) but sometimes is used
    for signalling (either FACCH or SACCH). The MS and BTS must know when to
    send/receive each of these logical channels.
    In order to achieve this, sequences of logical channels are defined. They are called
    ‘multi-frames’. There are two types of multi-frames. The traffic channel multi-frame is
    26-TDMA frames long, and the BTS signalling multi-frame is 51 TDMA frames long.
    Each multi-frame can have different combinations of logical channels depending on
    the configuration of the BTS.

    #37439 Reply
    Promod
    Guest

    Is their anybody ready to explain about LMRG,QMRG,NX,PX and PBGT? I would like to know the appications of these parameters in simple explaination..pls help me out.
    What is the NECI value? I hope this will help out when you have AMR HR in the network which will support the all classes of the mobile.

    pls suggest me…

    #37440 Reply
    gabary
    Guest

    Hi all
    if we want to make a dual band RBS 2206 with one sector 900 had 8 TRU and the another sector 1800 had 4 TRU in the same direction .. the question is we can assign one BCCH for these two sector ?? , because of it is no possible for two sector to be in the same direction with 2 BCCH .

    #37441 Reply
    Promod
    Guest

    When u have the TCH availability is low in the perticular cell, will it going to affect the DCR and HSR in the network? If it affect can anybody give me the reason for the same.

    In some cells we have very good DCR and in some cells the DCR is worst can anybody give the reason?

    Ex:TCH availabilyt is 27% and DCR is 1.3 and HSR is 97.23, The worst is cell DCR id 7.6 and HSR is 78.34
    for the same TCH availability.

    #37442 Reply
    PROMOD
    Guest

    Nobody is ready to anwser my question? pls somebody have help me out? From past 3 days i am asking queries nobody is reply>

    Pls help me out..

    #37443 Reply
    Partha
    Guest

    Hi Promod,
    TCH Availability will not affect DCR(if u mean Drop Call rate).
    But it may affect HSR(Handover Success rate) depending on how many neighbours are trying to handover to this cell(assuming this is the better cell for the incoming handover).

    #37444 Reply
    PROMOD
    Guest

    1.can i know the reason why it is getting reduced? Is it due to hardware issue or due to some other reason?

    2.Why it will affect the HSR due to low TCH availability even though there is no congestion and no hardware alarm?

    #37445 Reply
    Boreau
    Guest

    Hi,

    I actually got a tems investigation 7.0 and I would like to change rxqual parameters.
    i tried with info element sbut it’s not working

    thx

    #37446 Reply
    pix
    Guest

    hello boreau,

    i’m not familiar with TEMS 7.0 (only 6.1), but it should be fairly identical to the 6.1… so what you’re doing is correct.

    why not send an email to TEMS directly ? you must be entitled to some support after having purchased it ?

    #37447 Reply
    Gito Prastomo
    Guest

    Hi Boreau,

    Try to export to Map Info then modify with thematic, if you experience problem with info element..

    BR
    Gito

    #37448 Reply
    Tanvir
    Guest

    Att. PIX,

    Would you please explain me in details about cell planning and the steps of frequency planning. What r the trade offs. And the most important is Optimization.

    I am really in need of these features.

    waiting for reply.
    Tanvir

    #37449 Reply
    kr
    Guest

    hi everybody

    why do we use AMR ?
    (Is it a funda to increase the call carrying capacity or to increase the signal strength as it gives an improvement of around S/N = 4-6 dB.)

    Is it implemented specifically with Tch half rate ?
    what is the difference if implemented with Tch HR of FR?

    #37450 Reply
    Pix
    Guest

    Hello KR,

    AMR is not a feature itself, it is more like the availability to use different codecs, rather than just EFR, FR or HR.

    You have two features associated :
    codec adaptation : within a same channel rate (FR or HR), it is possible to change the codec, in order to increase or decrease the protection of the speech. When changing from one codec to another, the call remains in the same timeslot. It is not a Handover.

    channel adaptation : depending on the C/I and the cell load, the BSC can order to make a HO from FR to HR (good quality, loaded cell) or from HR to FR (bad quality and cell with less load).

    FR to HR : the call performs a HO from a FR timeslot to a HR timeslot, in order to gain space. Since the C/I is good, the speech quality is not affected by this HO.

    HR to FR : other way around 🙂

    The codec adaptation… maybe i should explain more in details :
    you have a subset of codecs for HR timeslots and another subset of codecs for FR timeslots. So you can apply codec adaptation for HR calls only, FR calls only or BOTH.
    At the same time, the codec on the UL path and the codec at the DL path can be different. Each path is handled separately.

    Ok… enough :))
    Regards,

    #37451 Reply
    kant
    Guest

    hi pix , tomar n vanderlay
    could u pls look into my qestion

    How many TRX can be connected in one E1?
    each TRX needs 2 E1 time slots ( 64*2= 128 kbps )
    each TRX needs needs 16 kbps for signalling , so 4 TRX can fit in 1 E1 time slot
    so for 4/4/4 configuration 24 E1 time slots for actual voice traffic and 3 E1 time slots for signalling.
    0 time slot for synchronization and 16th time slot for O&M link .

    So, 24+3+2 = 29 time slots are occupied . We are left with only 3 E1 time slots . I can put one more TRX , again occupying 2 E1 time slots and the last one for signalling out of which 48 kbps is still free.
    So , all in all we can connect 13 TRX at max with 1:4 multiplexing .

    But , I have connected 14 TRX in one E1 in Nortel System .
    And at the most we can connect 15 TRX in one E1 with LAPD concentrated mode 2 .

    But I could not justify more than 13 TRX in one E1 logically.
    pls explain.

    1. What is 1:4 mulitplexing ?
    2. What is 1:1 multiplexing in which we can at max 10 TRX at max( correct me if wrong )
    3. What is LAPD concentrated mode 2?
    4. Is it important that only 16th E1 time slot should be given for O& M link ?

    #37452 Reply
    kr
    Guest

    hi pix

    thanks for the ansr
    m sorry if i irritated u ….. the expression i got from ur last words Ok…. Enough !

    AMR is an audio data compression scheme. We have 14 modes of codec….. 8 for FR channel and 6 for HR channel …..i got it

    but my question is why do we implement it ?
    To increase the weak signal ( robustness of the n/w as it provides improvement upto S/N = 4-6 dB )
    To increase the call carrying capacity as it increases or decreases the data rate using appropriate codecs depending upon the RF conditions …. as u told link adaptation …..

Viewing 15 posts - 166 through 180 (of 184 total)
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