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    KPI's Analysis

    Uploaded by

    Amin Muhammed
    1) The document defines key performance indicators (KPIs) such as SDCCH congestion, TCH congestion, CSSR, HOSR, and CDR that are used to judge the performance of a cellular network. 2) SDCCH congestion is calculated as the ratio of SDCCH assignment failures to SDCCH requests, and can be caused by issues with capacity or availability of SDCCH channels. TCH congestion is similarly defined. 3) CSSR accounts for failures in both SDCCH and TCH assignments, and factors in SDCCH call drop rates. HOSR is the ratio of successful handovers to total handover requests.

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    Attribution Non-Commercial (BY-NC)
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    KPI's Analysis

    Uploaded by

    Amin Muhammed
    229 views43 pages
    1) The document defines key performance indicators (KPIs) such as SDCCH congestion, TCH congestion, CSSR, HOSR, and CDR that are used to judge the performance of a cellular network. 2) SDCCH congestion is calculated as the ratio of SDCCH assignment failures to SDCCH requests, and can be caused by issues with capacity or availability of SDCCH channels. TCH congestion is similarly defined. 3) CSSR accounts for failures in both SDCCH and TCH assignments, and factors in SDCCH call drop rates. HOSR is the ratio of successful handovers to total handover requests.

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    1) The document defines key performance indicators (KPIs) such as SDCCH congestion, TCH congestion, CSSR, HOSR, and CDR that are used to judge the performance of a cellular network. 2) SDCCH congestion is calculated as the ratio of SDCCH assignment failures to SDCCH requests, and can be caused by issues with capacity or availability of SDCCH channels. TCH congestion is similarly defined. 3) CSSR accounts for failures in both SDCCH and TCH assignments, and factors in SDCCH call drop rates. HOSR is the ratio of successful handovers to total handover requests.

    Copyright:

    Attribution Non-Commercial (BY-NC)
    Download as PPTX, PDF, TXT or read online from Scribd
    Download as pptx, pdf, or txt
    229 views43 pages

    KPI's Analysis

    Uploaded by

    Amin Muhammed
    1) The document defines key performance indicators (KPIs) such as SDCCH congestion, TCH congestion, CSSR, HOSR, and CDR that are used to judge the performance of a cellular network. 2) SDCCH congestion is calculated as the ratio of SDCCH assignment failures to SDCCH requests, and can be caused by issues with capacity or availability of SDCCH channels. TCH congestion is similarly defined. 3) CSSR accounts for failures in both SDCCH and TCH assignments, and factors in SDCCH call drop rates. HOSR is the ratio of successful handovers to total handover requests.

    Copyright:

    Attribution Non-Commercial (BY-NC)
    Download as PPTX, PDF, TXT or read online from Scribd
    Download as pptx, pdf, or txt
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    Contents

    1) Introduction

    2) Main KPIs
    3) SDCCH congestion 4) TCH congestion 5) CSSR 6) HOSR

    7) CDR
    8) Useful information

    Introduction
    Firstly, we must differentiate between 4 words:

    Introduction
    1) Counter:

    It is the counters in the BSC that counts every


    event in the layer 3 messages.
    Such as : K3012B Call Drops in TCH Handovers (Traffic Channel), (ET02) TCH CDR Per Cell & K3016:Configured TCHs

    Introduction
    2) KPI:
    It is the combination of some counters in a

    certain formula to help in judging the network


    performance .
    Such as: CDR, HOSR & TCH congestion

    Introduction
    3) Parameter:
    It is the item in the BSC to be adjusted to have a

    switch, threshold or an interval


    Such as: CRO, Concentric circles HO allowed & UtoO traffic HO allowed.

    Introduction
    4) Algorithm:
    It is a group of commands controlling a certain

    process.
    Such as: HO algorithm, Power control algorithm & Direct retry algorithm.

    Main KPIs
    To judge a network we have 5 main KPIs:

    SDCCH congestion

    TCH congestion

    CSSR

    HOSR

    CDR

    SDCCH Congestion

    SDCCH congestion
    1) SDCCH congestion:

    Total No. of SDCCH assignment failures(Due to congestion) Total No. of SDCCH requests

    SDCCH congestion
    SDCCH congestion may be due to:

    A) Capacity

    No. of required SDCCHs > Configured SDCCHS

    B) Availability

    No. of Available SDCCHs Configured SDCCHS

    SDCCH congestion
    Incase of Capacity problem & TCH congestion=0 the solution will be:
    Static SD: Traffic in BH > Available capacity Expansion (Static or Dynamic SDCCH)

    Dynamic SD: Congestion is due to sudden increase in SD requests

    Load sharing

    Sharing the load with neighboring cells using both CRO & PBGT parameters

    SDCCH congestion
    Incase of Capacity problem & TCH congestion0 the solution will be:
    Enabling Dynamic SDCCH if TCH & SD congestion are not in the same time Expansion

    Physical expansion is needed if TCH & SD congestion are in the same time

    Load sharing

    Sharing the load with neighboring cells using both CRO & PBGT parameters

    SDCCH congestion
    Incase of availability :

    Checking alarms on the cell

    Checking alarms on neighboring cells

    TCH Congestion

    TCH congestion

    No. of TCH assignment failures due to congestion (Stable state + HO)


    No. of TCH assignment requests(Stable state + HO)

    TCH congestion
    SDCCH congestion may be due to:

    A) Capacity

    No. of required TCHs > Configured TCHS

    B) Availability

    No. of Available TCHs Configured TCHS

    TCH congestion
    Incase of Capacity problem the solution will be:
    Enabling HR Expansion (Static or Dynamic SDCCH) Remove useless SDs & Packet TSs Add new TRX

    Idle mode: CRO & Direct Retry(DR) Load sharing Dedicated mode: Incoming & outgoing PBGT HO & load HO

    TCH congestion
    Incase of availability :

    Available Configured

    Checking alarms on the cell

    Available = Configured

    With sudden increase in traffic then check alarms on neighboring cells

    CSSR

    CSSR

    1-

    Total No. of TCH assignment failures Total No. of TCH assignment requests Total No. of SDCCH failures

    (1 - Total No. of SDCCH requests )


    (1 - SDCCH call drop)

    CSSR
    For TCH assignment failure, it includes: 1) Radio problems 2) BSS problems 3) Congestion problems

    CSSR
    For SD drop rate, it is affected by:
    1) Poor coverage

    2) UL-DL imbalance
    3) High Interference (Internal or External)

    4) Cross connection
    For SD congestion, it was discussed in the previous slides

    HOSR

    HOSR

    Total No. of successful HOs (Incoming + Outgoing + Intracell) Total No. of HO requests (Incoming + Outgoing + Intracell)

    HOSR
    HO purposes:

    Mobility Sustain calls Save MS & BTS power

    HOSR
    We may classify HOs according to:

    Network Architecture Intra BSC: Intra-cell Inter-cell Intra-site Inter-site

    Synchronization Synchronous Asynchronous

    Radio Normal (Better cell/PBGT) Emergency (BQ/Edge/TA/ Interference/Sudden level drop) Performance (Load/Layer/ Level/ Fast moving) Concentric (UtoO/OtoU)

    HOSR
    For PBGT HO:

    RxLevel RxLevel (neighbour) (serving)


    For BQ HO:

    Max of (PBGT HO threshold, PBGT HO hystersis)

    RxLevel RxLevel (neighbour) (serving)


    For Interference HO:

    PBGT HO threshold

    BQ HO threshold

    RxLevel (serving) Quality (serving)

    RxLevel threshold BQ threshold

    Interference HO has lower priority than BQ HO because there is no condition on the target cell level

    HOSR
    For Layer HO: (4) Umbrella (3) Macro (2) Micro (1) Pico

    RxLevel Layer HO (Higher priority) threshold

    Hystersis

    This level is the min. level required for the higher priority cell to trigger layer HO There is no PBGT HO between 2 cells in different layers

    Entering higher layer cell is by layer HO & exiting is by Edge HO

    HOSR
    For Edge HO:

    If UL Edge HO RxLevel threshold OR DL Edge HO RxLevel threshold is satisfied


    For Load HO:

    If Load HO threshold on source AND Load HO threshold on target cells are satisfied
    For TA HO:

    TA (serving)

    TA HO threshold

    It is the logical way to overcome overshooting

    HOSR
    For MS fast moving HO:

    It is done by increasing the ranking of higher layer & prevent HO to lower layer
    For Sudden power drop HO:

    It is done in the BSC by comparing values of successive measurement reports. It is disabled in Huawei network
    For Level HO:

    It is disabled in Huawei network

    HOSR
    HO Algorithm: MR

    MR preprocessing

    Penalty application

    Basic ranking (16-Bit)

    HO decision

    HOSR

    1
    TA HO

    HO Priorities:

    BQ HO

    2 3 4 5
    Load HO Sudden RxLevel drop HO

    Interference HO

    Edge HO

    6 7
    Layer/Level HO

    PBGT HO

    8 9 10
    MS fast moving HO
    Concentric HO

    HOSR
    To Analyze HOSR it is divided to:

    Intra cell HO failures


    Incoming HO failures Outgoing HO failures

    HOSR
    Intracell HO failures may be

    OtoU
    Congestion on underlaid Underlaid Interference Alarms Faulty EGSM TRXs or DDPUs Path Imbalance

    UtoO
    Congestion on overlaid Faulty DCS TRXs or DDPUs Path Imbalance Alarms Wrong DCS electric tilt

    HOSR
    Incoming HO failures may be due to

    Congestion Failed TCH seizures due to busy TCHs Failed Incoming HO failures

    BSS Alarms Faulty TRXs or combiners Path imbalance

    Radio External Interference Internal Interference Configuration problem

    HOSR
    Outgoing HO failures may be due to

    To one cell
    Problem in the neighbour cell

    To all cells
    Revise counters requests

    HOSR
    To analysze outgoing HO requests: 1) Quality requests >>> Level requests UL Quality requests >>> DL Quality requests DL Quality requests >>> UL Quality requests 2) Strenth requests >>> Remaining counters UL Strenth requests >>> Remaining counters DL Strenth requests >>> Remaining counters Path Imbalance (UL limited) Path Imbalance (DL limited) or HW problem

    External Interference
    Internal Interference

    HOSR

    3) UL, DL quality & strenth requests >>> PBGT requests Poor coverage area

    Ideally, the majority of requests must be PBGT requests

    CDR

    CDR

    Total No. of dropped calls (Stable state + HO)


    No. of successful TCH assignments (Stable state + HO)

    CDR
    Call drops may be due to

    Error indication Incase of bad radio conditions if the BTS does not receive the correct frame & T200 timer expired N200+1 times the call drops

    Connection Failure Incase MS does not decode SACCH or the BTS does not decode MR until RLT expires(=32 in DL & 24 in UL) the call drops

    Release Indication The MS send a disconnection message to the BTS

    CDR
    Call drop reasons: 1) Poor coverage 2) Interference 3) Missing neighbors

    4) Outgoing HO failures
    5) Congestion on underlaid 6) Overshooting 7) Path imbalance 8) Configuration problems 9) Alarms

    Thank You

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