141139871 Huawei RNC Capacity Dimension

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Huawei RNC dimensioning

Text of 141139871 Huawei RNC Capacity Dimension

  • Huawei RNC Capacity dimension

    Huawei Copyright 2005.

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    Capacity dimensionPrinciple for capacity dimensionInput from operator( Total subscribers in network, traffic model)RNC capacity limitation( Erl, Throughput,BHCA)Number of WRBSSubscribers per WRBSNodebs per WRBSSubscribers per Nodeb If Nodebs per WRBS >100Radio Network dimension

    Huawei Copyright 2005.

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    Traffic Model Parameters Traffic Model from Vodafone

    Traffic ParameterValueBHCA CS per sub0.6BHCA total per sub0.9CS Voice per sub/BH16,2mErlCS Data per sub/BH1,1mErlCS Video Telephony call duration/BH135secCS call duration/BH135secRel.99 PS per sub/BH580bpsTotal PS per sub/BH1160bpsTimer for CH switching (DCH/FACH)600-800msec

    Location update rate sub/BH2.2Ratio of soft/softer HO/BH0.8:0.2Proportion of HO/BH30%Handover times/call/BH (inter/intra RNC SHO)7,0 times/callPS CH switching4.0 times/callCell update/PSCall 3 times/callRatio of UL : DL (Rel.99/HSDPA)1:3.6

    Huawei Copyright 2005.

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    LimitationLimiting factor : throughput capacity60Mbps/ WRBSLimiting factor : BHCA capacity75,000/ WRBSLimiting factor : NodeB capacity100 NodeB/ WRBSLimiting factor : Cell capacity300 NodeB/ WRBS120Mbps / 60Mbps = 2e.g.2 WRBS60,000 / 75,000 = 0.8e.g.1 WRBS150 / 100 = 1.5e.g.2 WRBS400 / 300 = 1.3e.g.2 WRBS

    Huawei Copyright 2005.

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    RNC Dimension 2*63 channalized E1sVF CALL PROFILE DATAS

    Huawei Copyright 2005.

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    RNC Capacity LimitationThere define a relationship between CS Erlang and throughput as follows: 1 CS Erlang = 16kbps throughput. The relation comes from the processing consuming in WFMRb board. CS Erlang and CS ThroughputFor each RNC subrack : CS throughput + PS throughput 20k Subs in RNC121

    Erlangs for each Nodeb from counters

    Nodeb to SPU map( worse SPU 40 nodeb among 87)

    The cpu load is 8% for common task if the traffic load is 0

    Cpu load with 275 Erlangs=40% at BH and limit is 80% => the SPU can handle 275*(80-8)/(40-8)=618 Erlangs => If 618/87=7 Erlangs per nodeB => a SPU can handle 550/7=78Nodeb

    Erlangs per SPU=600*40/87=275 Erl

    600Erl

    Huawei Copyright 2005.

    BHCA total per sub1.2+0.18+1 = 2.38/ 1.2+0.18+0.3 = 1.68