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Frequency Hopping System

Viewing 15 posts - 31 through 45 (of 118 total)
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  • 19th September 2005 at 04:19 #41297
    M.Thyagarajan
    Guest

    hi,

    if you don’t want any complications u should go for 1X1 . As 1X3 requires a bit of planning it needs to be done carefully.

    regards
    M.Thyagarajan

    19th September 2005 at 04:39 #41298
    Wilibrordus Herbowo
    Guest

    but we still to consider MAIO + HSN management, to avoid MAIO + HSN interference.

    thanks

    19th September 2005 at 11:57 #41299
    M.Thyagarajan
    Guest

    maio plan is straight forward as it depends on the trx configuration.

    HSN is easy to plan as we have 63 in number

    20th September 2005 at 04:12 #41300
    Gunjan
    Guest

    CAN SOMEBODY EXPLAIN ME HOW DOES SYNTHSIZER FREQUENCY HOPPING WORKS OR WHERE CAN I FIND DOCUMENTS ON THE INTERNET

    20th September 2005 at 05:37 #41301
    more
    Guest

    hi gunjan
    in synthisizer hop there is tuning process to order TRX transmit in different freq through wide band combiner,becuse the freq is tuned over diff freq (wide BW).so there is one link from TRX to one combiner and tuning link.
    Considering this the other methodology is base band hop (switching the TRX to different number of combiner, any combiner transimit on individual permanent frequency).

    20th September 2005 at 05:46 #41302
    jood
    Guest

    when we need to specify synth freq hopping we say SFH yxk. just like 1×1, 1×2, 2×2.
    so y number for what??
    k number for what ??
    is it for MAIO, or no of MA, OR WHAT ????
    regards

    21st September 2005 at 05:12 #41303
    wilibrordus herbowo
    Guest

    1×2 mean number of sites and number if cell.

    1 = number site
    2 = number of cells.

    MAIO is in the MA LIST. (choose 1)
    HSN = 0 – 64

    24th September 2005 at 06:12 #41304
    jood
    Guest

    Hi Wilibrordus(thanks)
    Hi all
    Kindly,I wonder what is the minimum no of freq allocated for hopping pattern (MA).to get efficent interference reduction at 900MHZ(in/out door). is it 10freq or less.
    thanks in advance

    27th September 2005 at 16:42 #41305
    BOBOO
    Guest

    hi Guys,

    The BBH : The number of hopping frequency is equal to the number of TRX

    Advantage :
    the more TRX you have, better it is to avoid interference
    BBH coud be handle by RTC combiner. This combiner could combine 6 DRX with 3dB insertion loss. BS_TxPower_max with RTC is greater than BS_TXPowerMax with Hybrid combiner (SFH case).
    I’ve got good results with BBH with Nokia

    Drawbacks :
    If you have only 2 DRX pe rsector, it’s not enough to avoid interference (go to SFH).

    SFH : The number of hopping frequency depends to the MAL, MAIO.

    Advantage :
    if you have 2 TRX by sector, you could hope with all frequency contained on the MAL to avoid interference.

    Drawbacks :
    Only Hybrid combiner could handle SFH. This kind of combiner, combine only 4 DRX with 3 dB of insertion loss. If you set more DRX your insertion loss shift from 3 to 6 dB. Decrease of BS_TX_Power_max. maybe, it doesn’t matter in urban dense area.

    I hope I could help anyone.

    Regards

    BOBOO

    28th September 2005 at 06:42 #41306
    jood
    Guest

    Hi all
    what about Co filling on synthesizer is it allowed me to hop on other TSs in BCCH freq, OR WHAT ????

    30th September 2005 at 12:03 #41307
    Nishant
    Guest

    Hi Everybody,
    Can anyone explain me the baseband and synthesized frequency hopping with respect to sectors and what is MAO,MAIO and HSN ?hOW IT PLAYS IT,S ROLE IN FREQUENCY HOPPING?????

    4th October 2005 at 09:50 #41308
    Boboo
    Guest

    Hi all,
    I found an exemple in SFH with nortel. I hope it wiil be clear.

    MA: Mobile Allocation (list of hopping frequencies for a TRX)
    MAIO: Mobile Allocation Index Offset between 0 and (Nb of Freq in MA – 1).
    F1: BCCH frequency
    HSN : Hopping Sequence Number

    TS 0 1 2 3 4 5 6 7
    TDMA 0 F1 F1 F1 F1 F1 F1 F1 F1
    TDMA 1 MA0 MA0 MA0 MA0 MA0 MA0 MA0 MA0 MAIO = 0
    TDMA 2 MA0 MA0 MA0 MA0 MA0 MA0 MA0 MA0 MAIO = 2
    TDMA 3 MA0 MA0 MA0 MA0 MA0 MA0 MA0 MA0 MAIO = 4

    TDMA 0 is mapping on TRX 0
    TDMA 1 is mapping on TRX 1
    TDMA 2 is mapping on TRX 2
    TDMA 3 is mapping on TRX 3

    So there is 4 TRX. TDMA0 don’t hop because it’s the TDMA with BCCH. BCCH equal to F1.

    MA is the same for all TRX. 1,2,3,4,5,6,7,8,9 for exemple.

    TDMA 1 hop with the frequency in the MA without offset(MAIO). So It’s 1,2,3,4,5,6,7,8,9,
    TDMA 2 hop with the frequency in the MA with an offset equal to 2. So it’s 3,4,5,6,7,8,9,1,2,
    TDMA 3 hop with the frequency in the MA with an offset equal to 2. So it’s 3,4,5,6,7,8,9,1,2
    Etc …
    In this case the HSN is equal to 0. the hopping sequency is not a random sequence.

    It’s an pedagogic exemple. It’s just a way to understand how does it work. According to my experience, there are one HSN & on MAIO by sector. So You could apply this strategy on site level if you implement the same MA by sector with different HSN & MAIO

    I hope it’s a bit more clear

    Regards

    Boboo.

    5th October 2005 at 08:35 #41309
    wilibrordus herbowo
    Guest

    assume = no Guardband

    we have channel freq 1 – 50
    1-29 channel is for BCCH
    30 – 50 channel is for Hop channel

    S1 MA LIST = 30 – 36
    S2 MA LIST = 37 – 43
    S3 MA LIST = 44 – 50

    those 7 channel called MA LIST.
    exp : configuration 3/3/3
    for TRX1 = BCCH
    for MAIO2 = 30
    for MAIO3 = 32
    for MAIO4 = 34

    etc…

    maybe it can help you

    5th October 2005 at 09:21 #41310
    M.Thyagarajan
    Guest

    It is stupid not to have any guard band.This can lead to a lot of quality problems if implemented.

    From 30 to 50 we have 21 hopping freq which can give you 10 hopping freq so we can have 5+4+4 as max configuration

    Same is the case with 31 to 50 with 20 hopping channels

    5th October 2005 at 13:20 #41311
    z
    Guest

    Hi Ravi,

    Hows ur planning going on…..

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