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    RAN14.0

    Capacity Monitoring Guide

    Issue 02

    Date 2012-06-30

    HUAWEI TECHNOLOGIES CO., LTD.

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    Issue 02 (2012-06-30) Huawei Proprietary and Confidential

    Copyright © Huawei Technologies Co., Ltd.

    i

    Copyright © Huawei Technologies Co., Ltd. 2012. All rights reserved.

    No part of this document may be reproduced or transmitted in any form or by any means without priorwritten consent of Huawei Technologies Co., Ltd.

    Trademarks and Permissions

    and other Huawei trademarks are trademarks of Huawei Technologies Co., Ltd.

    All other trademarks and trade names mentioned in this document are the property of their respectiveholders.

    Notice

    The purchased products, services and features are stipulated by the contract made between Huawei andthe customer. All or part of the products, services and features described in this document may not bewithin the purchase scope or the usage scope. Unless otherwise specified in the contract, all statements,

    information, and recommendations in this document are provided "AS IS" without warranties, guarantees orrepresentations of any kind, either express or implied.

    The information in this document is subject to change without notice. Every effort has been made in thepreparation of this document to ensure accuracy of the contents, but all statements, information, andrecommendations in this document do not constitute a warranty of any kind, express or implied.

    Huawei Technologies Co., Ltd.

    Address: Huawei Industrial Base

    Bantian, Longgang

    Shenzhen 518129

    People's Republic of China

    Website: http://www.huawei.com

    Email: [email protected]

    http://www.huawei.com/mailto:[email protected]:[email protected]://www.huawei.com/

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    RAN14.0

    Capacity Monitoring Guide About This Document

    Issue 02 (2012-06-30) Huawei Proprietary and Confidential

    Copyright © Huawei Technologies Co., Ltd.

    ii

    About This Document

    PurposeTraffic on a mobile telecommunications network, especially a new network, increases by the

    day. To support the increasing traffic, more and more resources are required, such as signaling

    processing resources, transmission resources, and air interface resources.

    If any type of network resource is insufficient, user experience is affected (for example, the

    call drop rate increases). This means that real-time resource monitoring, timely resourcebottleneck detection, and proper network expansion are critical to good user experience on a

    mobile telecommunications network. This document describes how to monitor usage ofvarious network resources, locate network resource bottlenecks, and perform network

    expansion in a timely manner.

    Guidelines provided in this document are applicable to BSC6900 and BTS3900 series base

    stations, but can only be used as references for RNCs and NodeBs of earlier versions.

    AudienceThis document is intended for network maintenance personnel.

    Organization

    This document consists of the following chapters.

    Chapter Description

    1 Network Resource

    Monitoring Methods

    Describes basic concepts associated with network resources, including definitions

    and monitoring activities.

    2 Network Resource

    CountersDescribes various network resources.

    3 HSPA Related

    ResourcesDescribes how to monitor network resources when HSPA is enabled.

    4 Diagnosis of Problems

    Related to NetworkResources

    Provides fault analysis and locating methods that experienced WCDMA network

    maintenance personnel can use to handle network congestion or overload eventsefficiently.

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    iii

    Chapter Description

    5 Counter Definitions Lists all performance counters mentioned in the other chapters. These counters

    help in monitoring network resources and designing resource analyzing

    instruments.

    Change History

    Changes between document issues are cumulative. Therefore, the latest document issue

    contains all changes made in previous issues.

    02 (2012-06-30)

    This is the second commercial release of RAN 14.0.

    Compared with issue 01 (2012-04-30), this issue incorporates the following changes:

      Update the formula for calculating CE usage, replace the NodeB counter with RNCCounter.

      Add MPU part.

      Adjust SPU,DPU,Interface board threshold.

      Adjust the document structure.

    01 (2012-04-30)

    This is the first commercial release of RAN 14.0.

    Compared with issue Draft A (2012-02-15), this issue optimizes the description.

    Draft A (2012-02-15)

    This is the draft for RAN14.0.

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    RAN14.0

    Capacity Monitoring Guide Contents

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    iv

    Contents

    About This Document .................................................................................................................... ii 

    1 Network Resource Monitoring Methods ................................................................................. 1 

    1.1 Network Resource Introduction .......................................................... ............................................................. 1 

    1.2 Resource Monitoring Procedure .......................................................... ............................................................. 3 

    2 Network Resource Counters ....................................................................................................... 5 

    2.2 SPU CPU Load ................................................................................................................................................ 5 

    2.3 MPU CPU Load ................................................................................. .............................................................. 6 

    2.4 DPU DSP Load ................................................................................................................................................ 7 

    2.5 Interface Board Load ................................................................ ................................................................ ........ 7 

    2.6 Uplink Load ..................................................................................................................................................... 7 

    2.7 Downlink Load .............................................................. ................................................................. .................. 9 

    2.8 CE Usage ............................................................ ................................................................ .............................. 9 

    2.9 OVSF Code Usage ....................................................................................... .................................................. 10 

    2.10 Iub Bandwidth .................................................................................................................. ............................ 12 

    2.11 Common Channels ...................................................... ................................................................ ................. 12 

    2.12 NodeB CPU Load ........................................................................................................................................ 13 

    2.13 Main processing and transmission unit (WMPT/UMPT) CNBAP Load .............. ....................................... 13 

    3 HSPA Related Resources ........................................................................................................... 15 

    3.1 HSDPA ............................................................... ................................................................ ............................ 15 

    3.1.1 Power Resources ............................................................. ................................................................ ...... 15 

    3.1.2 Code Resources ............................................................... ................................................................ ...... 16 

    3.2 HSUPA ............................................................... ................................................................ ............................ 17 

    3.2.1 CE Resources ....................................................... ................................................................ ................. 17 

    3.2.2 RTWP ........................................................ ................................................................ ............................ 17 

    4 Diagnosis of Problems Related to Network Resources ....................................................... 18 

    4.1 Call Blocks in the Basic Call Flow ................................................................................................................ 18 

    4.2 Call Congestion Counters ......................................................... .............................................................. ........ 20 

    4.2.1 Performance Counters Associated with Paging Loss ........................................................... ................. 20 

    4.2.2 Performance Counters Associated with RRC Congestion Rates ........................................................... 20 

    4.2.3 Performance Counters Associated with RAB Congestion Rates........................................................... 21 

    4.3 Signaling Storms and Solutions .......................................................... ........................................................... 22 

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    4.4 Resource Analysis ......................................................... ................................................................. ................ 24 

    4.4.2 CE Resource Consumption Analysis ......................................................................... ........................... 26 

    4.4.3 Code Resource Usage Analysis ............................................................ ................................................. 29 

    4.4.4 Iub Resource Analysis ................................................................ ........................................................... 29 

    4.4.5 Power Resource Analysis ........................................................... ........................................................... 30 

    4.4.6 SPU CPU Usage Analysis .......................................................... ........................................................... 31 

    4.4.7 DPU DSP and Interface Board CPU Usage Analysis .......................... ................................................. 33 

    4.4.8 PCH Usage Analysis ..................................................................................................................... ........ 33 

    4.4.9 FACH Usage Analysis .............................. ................................................................. ........................... 34 

    5 Counter Definitions .................................................................................................................... 36 

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    RAN14.0

    Capacity Monitoring Guide 1 Network Resource Monitoring Methods

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    1 Network Resource Monitoring MethodsThere are two methods of monitoring system resources and detecting resource bottlenecks:

      Prediction-based monitoring: This is a proactive approach wherein various networkresources are monitored simultaneously.

    You can monitor usage of a network resource (for example, the downlink transmit power of a

    cell), predict the resource usage trend and impacts, and determine whether to perform networkexpansion after comparing the detected resource usage with a preset upper threshold. After

    detecting that usage of a resource is higher than its upper threshold for a long time (forexample, a cell remains overloaded during busy hours for several consecutive days), you cansplit the cell or add carriers for network expansion. This approach, which applies to daily

    resource monitoring, is easy to implement and can be used to determine high-load cells andRNCs. This chapter describes the procedure for monitoring network resources.

    NOTE

     For details on network resources, see chapter 2 "Network Resource Counters." For details on

    HSPA-associated resources, see chapter 3 "HSPA Related Resources."

      Problem-driven analysis: When a network performance counter deteriorates (for example,calls are dropped), a thorough analysis is performed. This method is applicable to

    analysis upon network congestion. This method requires more analysis instruments andskills than the prediction-based monitoring method, but can use the current system and

    eliminates the need for an immediate network expansion. For details on this method, see

    chapter 4 "Diagnosis of Problems Related to Network Resources."

    NOTE 

    In addition to the preceding two methods, other methods may also be used by network maintenance

    engineers for system problem analysis.

    1.1 Network Resource Introduction

    The network resources that can be monitored are as follows:

      SPU: indicates the signaling processing unit on an RNC. An RNC supports various typesof SPUs. SPUs process air interface signaling and manage transport resources. They arethe most likely network resource bottleneck.

      MPU: indicates the main control processing unit on an RNC. It manages control-plane

    resources, user-plane resources, and transport resources. If provided on an SPUb board,

    the MPU subsystem may be overloaded.

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      DPU: indicates the user-plane processing unit on an RNC. It distributes user-planeservice data. With rapid development of mobile broadband (MBB), more and more DPU

    resources are consumed. There is a high possibility that the preset DPU resource

    capability cannot meet the requirements for the rapid development.

     

    Received total wideband power (RTWP): indicates the total wideband power received bya base station within a bandwidth (namely, the uplink load generated due to the receiver

    noise, external radio interference, and uplink traffic). This is a counter for measuringuplink load, similar to the received signal strength counter (RSSI) in the CDMA system.

    RSSI is a downlink load measurement, indicating the total channel power received by a

    UE.

      Transmitting carrier power (TCP): indicates the full-carrier power transmitted by a celland is a counter for monitoring downlink load. This counter value is limited by the

    maximum transmission capability of the power amplifier at a NodeB.

      Channel element (CE): indicates the baseband processing resource. CEs are managedand shared at the NodeB level. For a new network, this counter has a small start value to

    lower capital expenditure (CAPEX). Generally, CEs are the most likely resource

    bottleneck that results in network congestion.  Orthogonal variable spreading factor (OVSF): indicates the downlink OVSF code

    resource. For a cell, only one OVSF code tree is available in the downlink direction.

      Iub interface resource: On an IP transport network, uplink and downlink Iub interface

    bandwidth can be dynamically adjusted for both NodeBs and RNCs. Generally, transportresource bottlenecks do not result from insufficient capacities of interface boards but

    from low bandwidth available on the IP transport network.

      Paging channel (PCH): The PCH usage is directly related to the LAC area plan and PCHstate transition. PCH overload will cause a decrease in the paging success ratio.

      Random access channel (RACH) and forward access channel (FACH): The RACH andFACH carry signaling and some user-plane data. RACH/FACH overload will cause a

    decrease in access success ratio and affect user experience.  Main processing and transmission unit(WMPT/UMPT): The main processing and

    transmission unit performs site transmission, signaling, and system management. CPU

    overload of the WMPT will cause a decrease in system processing capabilities, therefore

    affecting NodeB-related KPIs.

    Figure 1-1 Allocation of radio resources that can be monitored

    http://3ms.huawei.com/term/docMaintain/termOperate.do?method=listTermAndDefinition&f_id=20090723000327&fd_id=25090&node_id=1-9&searchType=fulltext&searchValue=CAPEX&caseSensitive=&language_t=cnhttp://3ms.huawei.com/term/docMaintain/termOperate.do?method=listTermAndDefinition&f_id=20090723000327&fd_id=25090&node_id=1-9&searchType=fulltext&searchValue=CAPEX&caseSensitive=&language_t=cn

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    1.2 Resource Monitoring Procedure

    This section describes the resource monitoring procedure. This procedure is easy toimplement and is applicable to most scenarios.

    For a newly constructed network, you can monitor only one resource. Once detecting that this

    resource exceeds its upper threshold, check whether other resources exceed their upperthresholds.

      If yes, the cell or NodeB is overloaded. Perform network expansion.

      If no, the cell or NodeB is not necessarily overloaded. In this case, network expansion isnot mandatory and the problem can be solved by other adjustments or optimizations.

    For example, the CE usage is more than 70% but the usages of other resources such as RTWP,

    TCP, and OVSF codes are within their allowed ranges. In this case, CE resources are

    insufficient but the cell is not overloaded. To solve the problem in this example, configurelicenses allowing more CEs or add baseband processing boards, instead of performing

    network expansion immediately.

    Figure 1-2 Resource monitoring flowchart

    As shown in Figure 1-2, an SPU is overloaded if its CPU usage is 50% to 60%, regardless of

    other resource usages.

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    This flowchart is applicable to most resource monitoring scenarios, except when the systemoverload is due to an unexpected event, but not a service increase. Unexpected events are not

    considered in this flowchart.

    Causes for unexpected events can be located based on their association with various resource

    bottlenecks. For details on how to locate a resource-related problem, see chapter 4 "Diagnosisof Problems Related to Network Resources."

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    RAN14.0

    Capacity Monitoring Guide 2 Network Resource Counters

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    2 Network Resource CountersVarious counters are defined to represent the resource usage or load of a UTRAN system. Inaddition, upper thresholds for these counters are predefined.

    Identifying the busy hour is a key to accurate counter analysis. There are various methods ofidentifying the busy hour. The simplest one is to take the hour when the most resources are

    consumed as the busy hour.

    Table 2-1 RNC resources and threshold

    Resources Type Counter Monitoring

    Threshold

    SPU CPU VS.XPU.CPULOAD.MEAN 50%

    MPU CPU VS.XPU.CPULOAD.MEAN 50%

    DPU DSP Load VS.DSP.UsageAvg 60%

    Interface Board CPU

    LoadVS.INT.CPULOAD.MEAN 50%

    Interface Board

    Forwarding LoadVS.INT.TRANSLOAD.RATIO.MEAN 70%

    2.2 SPU CPU LoadSPUs process all the air interface signaling and transmission interface signaling. They are theboards most likely to be overloaded due to signaling storms.

    If SPUs are overloaded, new messages are discarded and new call requests are rejected. Thiswill affect end user experience.

    The load indicator of SPUs is their CPU usage. A Huawei RNC can house multiple SPUs.Each SPUa board contains four CPUs (each represents a subsystem). Each SPUb board

    contains eight CPUs.

    A Huawei RNC automatically shares and balances its load between CPUs. If an SPU is

    overloaded, add SPUs as required.

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    The mean SPU resource usage (SPU CPU load) is indicated by the counterVS.XPU.CPULOAD.MEAN expressed in percentage.

    It is recommended:

     

    If the SPU CPU usage is over 50% in the busy hour for three consecutive days in oneweek, add SPUs as required.

      If the SPU CPU usage is over 60% in the busy hour for three consecutive days in one

    week, take emergency expansion measures.

    Figure 2-2 SPU Threshold

    2.3 MPU CPU LoadMPU is a resource manager which take charge of resource allocation of SPU, DPU and

    interface board for UE call.

    Physically, it corresponds to subsystem 0 on a certain SPUa/SPUb.

    The MPU CPU load is indicated by the counter VS.XPU.CPULOAD.MEAN and the mean

    MPU CPU load is expressed as a percentage.

    It is recommended that 50% be used as the monitoring threshold. If any one MPU CPU load

    is over 50% for a specified period, adjust the resources between MPUs or add more MPU.Huawei provides professional services to accomplish the adjustment.

    The maximum 5 MPU can be defined in per subrack.

    How to find the MPU? Execute the MML “DSP BRD” and check if one SPUa or SPUb’s subsystem 0

    “Logic function type = RUCP” , if Yes, it is MPU. Or check the RNC configuration files to find

    “ADD BRD”, for example:

    ADD BRD: SRN=0, BRDCLASS=XPU, BRDTYPE=SPUb, LGCAPPTYPE=RUCP, SN=0;

    LGCAPPTYPE=RUCP indicates the subsystem 0 of the SPU is MPU.

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    2.4 DPU DSP LoadThe performance of a DPU is measured by its DSP usage. An RNC can house multiple DPUboards. Each DPUb or DPUe board contains several DSPs.

    Load on an RNC can be dynamically balanced between all its DSPs. The DPU resource usage

    (the DSP load) is indicated by the counter VS.DSP.UsageAvg (the mean DSP load expressedin percentage).

    It is recommended that the average DPU DSP usage be not higher than 60%. If the DPU DSPusage is higher than 60% in the busy hour for three consecutive days in one week, expand theDPU capacity.

    2.5 Interface Board Load

    The interface board performance is measured by its CPU usage (for forwarding load orsession load). An RNC can house several interface boards. If an interface board is overloaded,re-allocate the load to other interface boards or add an interface board.

    The interface board resource usage is indicated by the following counters:

      VS.INT.CPULOAD.MEAN: mean CPU usage of an interface board, which is expressedin percentage.

      VS.INT.TRANSLOAD.RATIO.MEAN: mean forwarding load of an interface board,

    which is expressed in percentage.

      Session load = VS.INT.CFG.INTERWORKING.NUM/Number of session setup or

    release times x 60 x SP

    where

      VS.INT.CFG.INTERWORKING.NUM: indicates the number of call setup attempts on an

    interface board.

      SP: indicates the measurement period, expressed in minutes.

      Number of session setup or release times (per second): 500 for a single-core interfaceboard (1000 for the GOUa and FG2a) and 5000 for a multi-core interface board.

    It is recommended that you expand the interface board capacity if the mean CPU usage or thesession load is higher than 50% or the forwarding load is higher than 70% for three

    consecutive days in one week.

    2.6 Uplink LoadIn a CDMA system, the radio performance of a cell is limited by the received noise. This

    means that the total received noise (or total received power) in a cell can be used to measurethe uplink cell capability.

    In a WCDMA system, the RTWP value minus the cell background noise is the noise increasethat results from a service increase. The noise increase (%) represents the uplink service

    increase. For example, a 3 dB noise increase corresponds to 50% uplink load and a 6 dB noise

    increase corresponds to 75% uplink load.

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    Generally, the total uplink received bandwidth is 5 MHz and the background noise is  – 106dBm. For the relationship between RTWP, noise increase, and uplink load, see Figure 2-3. 

    Figure 2-3 Relationship between RTWP, noise increase, and uplink load

    Generally, the uplink load threshold is 75% and the corresponding RTWP is smaller than  – 100dBm. The corresponding equivalent number of users (ENU) ratio should be smaller than 75%

    if the power-based admission decision is based on algorithm 2 (the algorithm for the ENU).

    If the RTWP value is larger than  – 100 dBm, the cell is overloaded in the uplink direction.

    Generally, if a cell is overloaded or the RTWP value is too large, the cell coverage decreases,live service quality declines, or new service requests are rejected.

    Huawei RNCs support the following RTWP and ENU counters:

      VS.MeanRTWP: mean RTWP in a cell (unit: dBm)

      VS.MinRTWP: minimum RTWP in a cell (unit: dBm)

      VS.RAC.UL.EqvUserN: uplink mean ENU on all dedicated channels in a cell

      UlTotalEqUserNum: maximum ENU that is configured by the ADD UCELLCACcommand.

    UL ENU Ratio = VS.RAC.UL.EqvUserNum/UlTotalEqUserNum

    In some areas, the background noise increases to more than  – 106 dBm due to otherinterference or hardware faults (for example, poor quality of antennas or feeder connectors).

    In this case, the VS.MinRTWP counter value (RTWP when the cell carries no traffic) isconsidered the background noise.

    If the VS.MinRTWP value is larger than  – 100 dBm or smaller than  – 110 dBm in the idle hourfor three consecutive days in one week, there are hardware faults or external interference.

    Locate and rectify the faults.

    Normally, VS.MeanRTWP is used as the cell capacity indicator. If the VS.MeanRTWP value

    is higher than  – 100 dBm (corresponding to a 6 dB noise increase or 75% load) or the uplinkENU ratio is higher than 75% in the busy hour for two or three days in one week, the cell isregarded as heavily loaded.

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    When the cell is heavily loaded, perform capacity expansion operations such as adding acarrier or increasing the UlTotalEqUserNum values.

    2.7 Downlink LoadThe downlink capacity of a cell is limited by its total available transmit power, which isdetermined by the base station amplifier and by software settings.

    When the downlink power is exhausted, the following may occur:

      The cell coverage decreases.

      The data throughput decreases.

      The service quality declines.

      New call requests are rejected.

    The amount of consumed downlink power in a cell is not only related to cell traffic (or load),but also related to the user's location and the cell coverage. The larger the cell coverage and

    the farther the user is located from the cell, the more power is consumed. The heavier the

    traffic in a cell, the more power is consumed.

    In a WCDMA system, TCP is defined to measure the downlink total transmit power. For

    Huawei RNCs, four TCP-associated counters are defined:

      VS.MeanTCP: mean carrier transmit power in a cell

      VS.MaxTCP: maximum carrier transmit power in a cell

      VS.MinTCP: minimum carrier transmit power in a cell

      VS.MeanTCP.NonHS: mean downlink carrier transmit power for non-HSDPA in a cell

    VS.MeanTCP is used as the downlink load indicator. If VS.MeanTCP is constantly higher

    than 85% VS.MaxTCP, the cell is overloaded in the downlink direction.

    Some live UTRAN networks use hierarchical cell structures with multiple frequency layers.The downlink power settings and the corresponding downlink TCP thresholds vary by carrier.

    For example,

      If the maximum TCP value is 20 W (43 dBm), the downlink TCP threshold is 17 W (42.3

    dBm).

      If the maximum TCP value is 40 W (46 dBm), the downlink TCP threshold is 34 W (45.3dBm).

    If VS.MeanTCP or VS.MaxTCP exceeds 85% of its threshold in the busy hour for threeconsecutive days in one week, the cell is regarded as heavily loaded in the uplink direction.

    Perform capacity expansion operations such as adding a carrier.

    2.8 CE Usage

    CE resources are baseband resources in a NodeB. One CE is the resources consumed by a12.2 kbit/s voice call. If a new call arrives but there are not enough CEs (not enough basebandprocessing resources), the call will be blocked.

    CE resources are managed and shared at the NodeB level (note that 850 MHz and 1900 MHz

    cells cannot share CEs with each other, because the cells belong to different license groups).

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    In a WCDMA cell, data from different users is distinguished based on code division and alluser data is transmitted over the same frequency almost at the same time. OVSF codes

    provide perfect orthogonality, minimizing interference between data from different users.

    Figure 2-4 shows an OVSF code tree.

    Figure 2-4 OVSF code tree

    A maximum spreading factor (SF) of 256 is supported.

    For a cell, only an OVSF code tree is available, with sibling codes orthogonal to each otherbut not with their parent or child codes. As a result, once a code is allocated to a user, neither

    its parent nor child code can be allocated to any other user. The total OVSF resources arelimited. If available OVSF codes are insufficient to implement the desired QoS, a new callrequest may be rejected.

    An OVSF code tree can be divided to four codes (SF = 4), 8 codes (SF = 8), 16 codes (SF =

    16), or 256 codes (SF = 256). This means that code resources with various SFs can be

    considered N x equivalent SF = 256 codes. For example, one SF = 8 code is equivalent tothirty-two SF = 256 codes. Based on this equivalence mapping, the OVSF code usage for a

    user or a cell can be calculated.

    A Huawei RNC monitors the average code usage of an OVSF code tree based on the number

    of occupied equivalent SF = 256 codes. The average code usage of an OVSF code tree isindicated by the VS.RAB.SFOccupy counter.

    OVSF code usages are defined as follows:

      OVSF_Utilization = VS.RAB.SFOccupy/256

      DCH_OVSF_Utilization = DCH_OVSF_CODE/256

    where

    DCH_OVSF_CODE = ( + ) x 64 +( + ) x 32 + ( +

    ) x 16 + ( + ) x 8 +( + ) x 4 + ( +

    ) x 2 + ( + )

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    A threshold (such as 70%) can be defined for DCH_OVSF_Utilization to judge whether a cellruns out of OVSF codes. If OVSF code resources are insufficient in the busy hour for three

    consecutive days in one week, perform capacity expansion operations such as adding a carrier

    or splitting the cell.

    2.10 Iub BandwidthIub bandwidth needs to be monitored. Based on transport media, Iub transport is classifiedinto ATM transport and IP transport.

    On either an ATM or IP transport network, Huawei RNCs and NodeBs can monitor theaverage uplink/downlink load. You can learn the Iub bandwidth usage by comparing the

    average uplink/downlink load and the total Iub bandwidth.

    On an ATM transport network, Huawei RNCs and NodeBs can dynamically adjust thebandwidth allowed for each user based on the service QoS requirements and user priorities,

    and use reverse pressure to increase Iub bandwidth usage efficiency. On an IP transportnetwork, however, Huawei RNCs can use only upper-layer (RLC layer, for example)

    measures to prevent packet loss over an Iub interface.

    If calls are frequently rejected due to too many users accessing the network, the Iubbandwidth may be insufficient. If so, increase Iub interfaces as required.

    For an IP transport network, it is recommended that you do not monitor Iub bandwidth duringthe implementation phase of the prediction-based monitoring method.

    2.11 Common ChannelsCapacities of common channels, such as PCHs and FACHs, are configurable. If PCH orFACH capacities are insufficient, messages may be lost.

    A PCH is used to transport paging messages.

    An FACH is used to transport user signaling and a small amount of user data to a UE that is inCELL_FACH state.

    Common channel analysis needs to be conducted based on monitoring of both PCHs andFACHs. A paging message may be lost if the PCH usage is too high. Paging messages are

    broadcast across an entire LAC. Therefore, improper LAC planning will contribute to highPCH usage. Two major sources contribute to FACH traffic: PS service state transition and

    RRC signaling traffic.

    Based on the default configurations for Huawei RNCs, the PCH usage and FACH usage arecalculated as follows:

      PCH usage = VS.UTRAN.AttPaging1/( x 60 x 5/0.01)

      Usage of an FACH carried on a non-standard SCCPCH = VS.CRNCIubBytesFACH.Tx x

    8/[(60 x x 168 x 1/0.01) x VS.PCH.Bandwidth.UsageRate x 6/7 + [60 x x360 x 1/0.01) x (1- VS.PCH.Bandwidth.UsageRate x 6/7)]

    where,

    VS.PCH.Bandwidth.UsageRate =

     /( x SP x 60.0)

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      Usage of an FACH carried on a standard SCCPCH = VS.CRNCIubBytesFACH.Tx x8/(60 x x 360 x 1/0.01)

    In the preceding formulas, SP indicates the measurement period in seconds.

    The basic principles for evaluating PCHs are as follows:  If paging messages are not re-transported, 5% of them will be lost when the PCH usage

    reaches 60%. It is recommended that you troubleshoot this message loss or replan theLAC.

      If paging messages are re-transported once or twice, 1% of them will be lost when the

    PCH usage reaches 70%. It is recommended that you troubleshoot this message loss orreplan the LAC.

    The basic principle for evaluating FACHs is as follows:

    If the FACH usage reaches 70%, it is recommended that you optimize specific policies or

    parameters, or add FACHs as required.

    2.12 NodeB CPU Load

    Main control and transmission board, baseband boards, and extension transmission boards are

    most likely to be overloaded on a network with many smart terminals. When the CPU on anyof the preceding boards is overloaded, the signaling message discard ratio increases and new

    call requests are rejected.

    The signaling performance of these boards is measured by their mean CPU usage

    (VS.BRD.CPULOAD.MEAN) expressed in percentage.

    It is recommended that you perform capacity expansion (such as splitting the correspondingNodeB or adding a NodeB) if VS.BRD.CPULOAD.MEAN is greater than 60% in the busyhour for three consecutive days in one week.

    2.13 Main processing and transmission unit(WMPT/UMPT) CNBAP Load

    The main processing and transmission unit processes signaling messages and manages the

    resources for other boards.

    If the main processing and transmission unit is overloaded, a radio link fails to be set up or noresponse to a radio link setup request is received. This decreases KPIs, such as success ratiosof RRC and RAB setup. For Huawei NodeBs, control NBAP (CNBAP) is used to assess the

    main processing and transmission unit processing capacity.

    CNBAP usage

    where

      VS.IUB.AttRLSetup: number of Iub interface RL establishment requests for a cell

      VS.IUB.AttRLAdd: number of Iub interface RL addition requests for a cell

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      VS.IUB.AttRLRecfg: number of Iub interface RL reconfiguration requests for a cell

      SP: indicates the measurement period, expressed in minutes.

      CNBAP capacity of a NodeB: depends on the main processing and transmissionunit/WBBP board configuration.

    If the CNBAP usage is higher than 60% in the busy hour for three consecutive days in one

    week, the main processing and transmission unit is becoming overloaded. Add a baseband

    board or an extension transmission board, or split the NodeB.

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    3 HSPA Related ResourcesHigh Speed Packet Access (HSPA) includes High Speed Downlink Packet Access (HSDPA)and High Speed Uplink Packet Access (HSUPA). HSDPA and HSUPA functionalities are partof the WCDMA standard. HSPA uses technologies such as fast scheduling, adaptive

    modulation, and hybrid automatic repeat request (HARQ) to transport data at high speed.

    HSPA carries PS data. As conversational services are prioritized over PS data, HSPA uses

    system resources only after conversational services are served. This chapter looks into how toefficiently use the system resources by means of HSPA without changing the existing pattern

    for resource allocation.

    3.1 HSDPA

    3.1.1 Power ResourcesFigure 3-1 illustrates how the downlink transmit power of a cell is allocated. The dashed line

    indicates the total downlink transmit power of a cell.

    Figure 3-1 Dynamic power resource allocation

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    Power for CCH: This portion of power is allocated to common transport channels (CCHs) of

    the cell such as the broadcast channel, pilot channel, and paging channel.

    Power margin: This portion of power is not allocated. The power margin is reserved to ensurethat the system can remain stable even if the UE position or environment changes.

    Power for DPCH: This portion of power is allocated to real-time services (voice and videocalls) and PS R99 services, and varies with the number and locations of users. RNCs and UEs

    can adjust power for DPCH based on the power control algorithm.

    Power for HSPA: This portion of power is allocated to HSDPA and is calculated as follows:

    HSDPA user power = Maximum cell transmit power  –  (Power for CCH + Power margin +Power for DPCH)

    HSPA power schedulers are designed primarily to make the most of available power.

    In an HSDPA-enabled cell, TCP is still monitored to see if the system is overloaded in thedownlink. TCP thresholds for this cell are the same as those for a cell without HSDPA. With

    HSDPA, downlink power overload affects HSDPA performance before it affects

    conversational services.

    3.1.2 Code Resources

    HSDPA can share code resources with real-time services. The system can dynamically

    reallocate OVSF codes to HSDPA services and real-time services based on OVSF codeallocation settings (such as the number of codes reserved only for HSDPA and the number of

    codes that can be shared). These settings can be changed online based on the network plan.

    When HSDPA is enabled, OVSF code resources are monitored the same way as when HSDPA

    is not enabled. Note that a high OVSF usage can be reduced by adjusting OVSF codeallocation settings (such as the number of codes reserved only for HSDPA and the number of

    codes that can be shared).

    Figure 3-2 OVSF code sharing

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    3.2 HSUPA

    3.2.1 CE Resources

    HSUPA channels are dedicated channels, and resource consumption of HUSPA services ismeasured by CE. UL CEs are shared between R99 services and HSUPA services.

    HSUPA improves user experience and uplink throughput, but also consumes more uplink CE

    overhead for hybrid automatic repeat requests (HARQ) and soft handovers. This means thatuplink CE resources may become a system bottleneck. Therefore, uplink CE usage needs to

    be monitored when HSUPA is enabled.

    Huawei NodeBs support dynamic HSUPA CE management.

    3.2.2 RTWP

    Similar to HSDPA, which is designed to make the most of the downlink power, HSUPA is

    designed to make the most of uplink capacity margin. HSUPA is always authorized to senddata until the RTWP rises to 6 dBm.

    HSUPA provision increases uplink data throughput but also consumes a large amount ofuplink RTWP, which is monitored in the same way regardless of whether HSUPA isprovisioned. If RTWP overload occurs, rates of HSUPA services must be lowered to ensure

    QoS of conversational services.

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    4 Diagnosis of Problems Related toNetwork Resources

    The preceding chapters describe the basic methods of monitoring network resources. Thesemethods can be used to resolve most problems caused by high resource usage. In certainscenarios, further analysis is required to determine whether high resource usage is caused by a

    traffic increase or other exceptions.

    This chapter describes how to diagnose problems related to network resources. This chapter is

    intended for experts who have a deep understanding of WCDMA networks.

    4.1 Call Blocks in the Basic Call Flow

    When network resources are running out, KPIs related to system accessibility are most likelyto be affected first.

    Figure 4-1 shows the basic call flowchart where possible block and failure points are marked.For details about the call flow, see 3GPP TS 25.931.

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    Figure 4-1 Call flowchart where possible block and failure points are marked

    The call flow, which uses a mobile-terminated call as an example, is described as follows:

    Step 1  The CN sends a paging message to the RNC.

    Step 2  Upon receipt of the paging message, the RNC broadcasts the message on a PCH. If the PCHis congested, the RNC may drop the message. See block point #1.

    Step 3  The UE cannot receive the paging message or fails to connect to the network. See failurepoint # 2.

    Step 4  After receiving the paging message, the UE sends an RRC connection request to the RNC.

    Step 5  If the RNC is congested when receiving the RRC connection request, the RNC may drop therequest. See block point #3.

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    Step 6  If the RNC receives the RRC connection request and does not drop it, the RNC determineswhether to accept or reject the request. The request may be rejected due to insufficient

    resources. See block point #4.

    Step 7  If the RNC accepts the request, the RNC instructs the UE to set up an RRC connection. The

    RRC connection setup may fail, the UE does not receive the instruction, or the UE receivesthe message but finds the configuration information to be incorrect. See failure points #5 and#6.

    Step 8  After the RRC connection is set up, the UE sends NAS messages to negotiate with the CNabout service setup. If the CN determines to set up a service, the CN sends an RABassignment request to the RNC.

    Step 9  The RNC accepts or rejects the RAB assignment request based on the resource usage on theRAN side. See block point #7.

    Step 10  If the RNC accepts the RAB assignment request, the RNC initiates an RB setup process.During the process, the RNC sets up transmission resources over the Iub interface by setting

    up a radio link (RL) to the NodeB, and sets up channel resources over the Uu interface bysending an RB setup message to the UE. A failure may occur in the RL or RB setup process.See failure points #8 and #9.

    4.2 Call Congestion CountersAs shown in Figure 4-1, call congestion may occur during paging, RRC connection setup, or

    RAB establishment.

    The following describes performance counters and KPIs associated with call congestion rates.

    For details about call congestion counters, see chapter 5 "Counter Definitions." You can also

    refer to the BSC6900 UMTS Performance Counter Reference and 3900 Series WCDMANodeB Performance Counter Reference.

    4.2.1 Performance Counters Associated with Paging Loss

    RNC-level and cell-level performance counters can be used to measure paging loss rates:

      Paging loss (RNC)

    Counters indicating that RNC-level paging loss ratio are caused by Iu-interface flowcontrol, CPU overload, or RNC-level PCH congestion: VS.RANAP.CsPaging.Loss and

    VS.RANAP.PsPaging.Loss

    Iu-interface paging loss ratio (RNC) = [(VS.RANAP.CsPaging.Loss +

    VS.RANAP.PsPaging.Loss)/(VS.RANAP.CsPaging.Att + VS.RANAP.PsPaging.Att)] x100%

      Paging loss (Cell)

    Counter indicating that paging requests are discarded due to cell-level PCH congestion:VS.RRC.Paging1.Loss.PCHCong.Cell

    Iu-interface paging loss ratio (cell) =(VS.RRC.Paging1.Loss.PCHCong.Cell/VS.UTRAN.AttPaging1) x 100%

    4.2.2 Performance Counters Associated with RRC CongestionRates

    RRC congestion rates are associated with:

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      Insufficient uplink power resources: VS.RRC.Rej.ULPower.Cong

      Insufficient downlink power resources: VS.RRC.Rej.DLPower.Cong

      Insufficient uplink CE resources: VS.RRC.Rej.UL.CE.Cong

      Insufficient downlink CE resources: VS.RRC.Rej.DL.CE.Cong

      Insufficient uplink Iub bandwidth resources: VS.RRC.Rej.ULIUBBand.Cong

      Insufficient downlink Iub bandwidth resources: VS.RRC.Rej.DLIUBBand.Cong

      Insufficient downlink code resources: VS.RRC.Rej.Code.Cong

      Number of RRC requests: VS.RRC.AttConnEstab.Sum

    The following is the formula for calculating the paging loss ratio:

    Vs.RRC.Block.Rate = Total RRC Rej/VS.RRC.AttConnEstab.Sum x 100%

    Where

    Total RRC Rej = < VS.RRC.Rej.ULPower.Cong > + < VS.RRC.Rej.DLPower.Cong > +

    < VS.RRC.Rej.UL.CE.Cong > + < VS.RRC.Rej.DL.CE.Cong > +

    < VS.RRC.Rej.ULIUBBand.Cong > + < VS.RRC.Rej.DLIUBBand.Cong > +

    < VS.RRC.Rej.Code.Cong >

    4.2.3 Performance Counters Associated with RAB CongestionRates

    RAB congestion rates are associated with:

      Insufficient power resources

    −  VS.RAB.FailEstabCS.ULPower.Cong

    −  VS.RAB.FailEstabCS.DLPower.Cong

    −  VS.RAB.FailEstabPS.ULPower.Cong

    −  VS.RAB.FailEstabPS.DLPower.Cong

      Insufficient uplink CE resources

    −  VS.RAB.FailEstabCS.ULCE.Cong

    −  VS.RAB.FailEstabPS.ULCE.Cong

      Insufficient downlink CE resources

    −  VS.RAB.FailEstabCs.DLCE.Cong

    −  VS.RAB.FailEstabPs.DLCE.Cong  Insufficient downlink code resources

    −  VS.RAB.FailEstabCs.Code.Cong

    −  VS.RAB.FailEstabPs.Code.Cong

      Insufficient downlink Iub bandwidth resources

    −  VS.RAB.FailEstabCS.DLIUBBand.Cong

    −  VS.RAB.FailEstabCS.ULIUBBand.Cong

    −  VS.RAB.FailEstabPS.DLIUBBand.Cong

    −  VS.RAB.FailEstabPS.ULIUBBand.Cong

     Number of RAB setup requests: VS.RAB.AttEstab.Cell

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    The following is the formula for calculating the call congestion ratio:

    VS.RAB.Block.Rate = Total number of congestions due to the preceding

    causes/VS.RAB.AttEstab.Cell

    4.3 Signaling Storms and SolutionsIn busy hours, a smart terminal makes about 10 more call attempts than a common terminalper call. The additional call attempts generate massive signaling exchange and occupy a large

    amount of signaling processing resources of the RNC and NodeB on the control plane.

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    Figure 4-2 Process for analyzing signaling storms

    Table 4-1 provides solutions to signaling storms. These solutions attempt to reduce signalingloads so that the network capacity does not need to be expanded immediately.

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    Table 4-1 Signaling storm causes and solutions

    UE Behavior UE Type Solution

    No signaling connection

    release indication (SCRI)

    Nokia, Samsung, or

    Motorola feature phones

    Enable the Cell_PCH function to decrease signaling

    services for these terminals.

    SCRI without values

    indicating causesiPhone (R6) Enable the enhanced fast dormancy (EFD) function for

    RNCs and add international mobile equipmentidentities (IMEIs) of terminals to the whitelist.

    R8 terminals with SCRI

    carrying values

    indicating causes

    iPhone4 (after R6) Enable the R8 FD function for RNCs and add terminal

    IMEIs to the whitelist.

    4.4 Resource AnalysisFigure 4-3 illustrates the general troubleshooting process for resource usage issues.

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    Figure 4-3 General troubleshooting process

    Generally, an abnormal KPI initiates a troubleshooting process. Determining the top N cells

    that may have problems facilitates follow-up troubleshooting.

    It is recommended to analyze accessibility KPIs to identify the system bottleneck that causesaccess congestion.

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    Figure 4-4 Key points for bottleneck analysis

    4.4.2 CE Resource Consumption Analysis

    Cells under one NodeB share CEs. Common channels have reserved CE resources and

    signaling is carried on a channel accompanying the DCH. Therefore, CCHs and signaling areconsidered not to consume CEs.

    Table 4-2 Number of CEs consumed by different services

    Service Type Number of ConsumedCEs on the Uplink

    Number of ConsumedCEs on the Downlink

    AMR 12.2 kbit/s 1 1

    CS 64 kbit/s 3 2

    PS 64 kbit/s 3 2

    PS 128 kbit/s 5 4

    PS 144 kbit/s 5 4

    PS 384 kbit/s 10 8

    SF32 (HSUPA) 1 N/A

    SF16 (HSUPA) 

    2 N/A

    SF8 (HSUPA) 4 N/A

    SF4 (HSUPA) 8 N/A

    2*SF4 (HSUPA) 16 N/A

    2*SF2 (HSUPA) 32 N/A

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    Service Type Number of ConsumedCEs on the Uplink

    Number of ConsumedCEs on the Downlink

    2*SF2+2*SF4 (HSUPA) 48 N/A

    2xM2+2xM4 64 N/A

    NOTE 

    CE usage in Table 4-2 assumes that the signaling radio bearer (SRB) over HSUPA feature is enabled. If

    the SRB is carried on an R99 DCH independently, an extra CE is consumed by the SRB. Therefore, add

    one CE to the number listed in Table 4-2. 

    HSDPA services do not consume downlink R99 CEs. HSUPA services and R99 services shareuplink CEs.

    CE congestion or routine CE usage monitoring may trigger CE resource analysis.

    If the CE resource usage is higher than a preset threshold for a period of time or CE

    congestion occurs, the CE resources are insufficient and must be increased to ensure systemstability.

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    Figure 4-5 Process for analyzing CE resource consumption

    Cells belonging to the same NodeB share CEs and CE resources consumed by a NodeB mustbe manually calculated.

    Check whether CE resource congestion occurs in a resource group or an entire site. If CEresource congestion occurs in a resource group, reallocate CEs between resource groups. If

    CE resource congestion occurs in an entire site, perform site capacity expansion and

    reconfigure CEs as required.

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    4.4.3 Code Resource Usage Analysis

    Huawei RNCs can reserve codes (for example, five SF = 16 codes) for HSDPA services. If

    fixed codes are reserved for HSDPA services, code congestion may occur under high traffic.

    The only solution to code congestion is to add carriers or split sectors.

    In some scenarios, massive signaling exchange on the network occupies a large amount of

    codes, causing code congestion, power congestion, or CPU overload. In these scenarios,identify root causes and rectify faults rather than expanding capacity.

    If code congestion occurs, operators can perform the following operations before expandingcapacity:

      Decrease the maximum number of PS RABs.

      Enable code-based load reshuffling (LDR).

      Decrease the minimum number of codes reserved for HSDPA services.

      Activate the license for dynamic code allocation on the NodeB.

    Thresholds for the preceding code congestion-related operations must be set based on

    operators' requirements for services quality.

    4.4.4 Iub Resource Analysis

    NOTE 

    After IP RAN is introduced, Iub resources no longer need to be monitored. This section is retained to

    provide a complete solution so that operators can compare solutions provided by different vendors.

    If insufficient Iub bandwidth causes congestion, check the Iub bandwidth usage.

    If the Iub bandwidth usage remains higher than 80% for a certain period, it can be determinedthat the Iub bandwidth is insufficient.

    If no more Iub resources are available or the issue is not urgent, decrease PS activity factorsso the system admits more users. The activity factor, which is the ratio of actual bandwidth

    occupied by a user to the allocated bandwidth, is used to estimate the real bandwidth neededin admission. The activity factor can be set on a per-NodeB basis. The default activity factoris 70% for voice services and 40% for PS BE services.

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    Figure 4-6 Process for analyzing Iub resources

    4.4.5 Power Resource Analysis

    Power congestion occurs if RTWP and TCP values are larger than preset thresholds.

    If downlink power congestion occurs, enable the LDR and OLC function.

    If uplink power is restricted, check whether any interference exists.

    In most cases, interference rather than traffic increase causes uplink power restriction.

    If RTWP is larger than  – 97 dBm over a period of time, analyze root causes and troubleshoot

    the problem.

    For high RTWP caused by high traffic (instead of signaling storms):

      Workaround: Enable the LDR and OLC functions.

      Solution: Add carriers or split cells.

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    Figure 4-7 Process for analyzing power resources

    Adding carriers is the most efficient solution to insufficient uplink power. If no more carriersare available, add more sites or tilt down antennas to spit cells.

    4.4.6 SPU CPU Usage Analysis

    Among all RNC CPUs, SPU CPUs are the most likely resources to cause system bottlenecksbecause smart terminals often cause signaling storms on networks.

    If the SPU CPU usage is higher than the SPU CPU alarming threshold, RNCs will enable the

    flow control function to discard some RRC setup or paging requests. Ensure that the CPUusage is not higher than the SPU CPU alarming threshold.

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    Figure 4-8 Process for analyzing SPU CPUs

    If the SPU CPU usage is higher than 50%, advise customers to add SPU boards. If SPU CPUusage is higher than 60%, add SPU boards immediately.

    Check whether SPU subsystem loads are balanced. If they are unbalanced, adjust load sharingthresholds so that subsystems share loads evenly.

    In addition, identify root causes for the high CPU usage.

    If signaling storms occur, check whether system configurations are correct or the transmission

    link is interrupted. If high traffic causes the high CPU usage, add SPU boards to expand

    capacity.

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    4.4.7 DPU DSP and Interface Board CPU Usage Analysis

    If the DPU DSP or interface board CPUs are overloaded, the RNC will drop some user data.

    The DPU DSP and interface board loads must be monitored closely.

    Figure 4-9 Process for analyzing DPU DSP and interface board CPU usage

      If the DPU DSP or interface board CPU usage is higher than 60%, add DPU boards or

    interface boards.  Add hardware for capacity expansion if traffic increase or unbalanced transmission

    causes the high loads.

    4.4.8 PCH Usage Analysis

    In most cases, PCHs are overloaded because a LAC area covers too many cells.

    Replan LAC areas to resolve the PCH overload issue.

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    Figure 4-10 Process for analyzing PCH usage

    4.4.9 FACH Usage Analysis

    Usually no FACH congestion will occur if the UE state transition switch is turned off.

    However, the UE state transition switch is turned on by default to transfer low traffic servicesto FACHs. This saves radio resources but increases traffic on FACHs.

    Two solutions are available for resolving the FACH congestion issue:

      Decrease values of PS inactive timers to transfer PS services to the CELL_PCH or IDLEstate and set up RRC connections on DCHs instead of FACH if DCH resources are

    sufficient.

      Add an SCCPCH to carry FACHs

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    Figure 4-11 Process for analyzing FACH usage

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    5 Counter DefinitionsCounter Name Counter Definition

    CongestionCounter

    Call drop ratio Vs.Call.Block.Rate (custom) Vs.RRC.Block.Rate +

    (/( +)) x

    Vs.Rab.Block.Rate

    RRC congestion

    ratio

    Vs.RRC.Block.Rate (custom) ( +

    + +

    + + +

    )/

    RAB congestion

    ratioVs.RAB.Block.Rate (custom) ( +

    + +

    + + +

    +

    + +

    + +

    + +)/VS.

    RAB.AttEstab.Cell

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    Counter Name Counter Definition

    Call attempts VS.RAB.AttEstab.Cell (custom) ( + +

    + +

    +

    )

    Usage Counter

    Power UsageCounter

    R99_TCP_Utiliz

    ation_RatioVS.MeanTCP.NonHS VS.MeanTCP.NonHS/Configured_Total_Cell_T

    CP (43 dBm or 46 dBm)

    Total_TCP_Utili

    zation_Ratio

    VS.MeanTCP VS.MeanTCP/Configured_Total_Cell_TCP

    Max UL RTWP VS.MaxRTWP VS.MaxRTWP

    Mean UL RTWP VS.MeanRTWP VS.MeanRTWP

    Min UL RTWP VS.MinRTWP VS.MinRTWP

    UL ENU ratio VS.RAC.UL.EqvUserNum VS.RAC.UL.EqvUserNum/UlTotalEqUserNum

    IUB UsageCounters

    IUB BW usage NODEB_Throughput (custom)

    NODEB_Trans_Cap (custom)

    NODEB_Throughput/NODEB_Trans_Cap

    NODEB_Trans_

    CapVS.IPDLTotal.1

    VS.IPDLTotal.2

    VS.IPDLTotal.3

    VS.IPDLTotal.4

    (VS.IPDLTotal.1 + VS.IPDLTotal.2 +

    VS.IPDLTotal.3 + VS.IPDLTotal.4)

    NODEB_Throug

    hputNODEB_Throughput_DL (custom)

    NODEB_Throughput_UL (custom)

    MAX(NODEB_Throughput_DL,

    NODEB_Throughput_UL)

    NODEB_Throug

    hput_DLVS.IPDLAvgUsed.1

    VS.IPDLAvgUsed.2VS.IPDLAvgUsed.3

    VS.IPDLAvgUsed.4

    (VS.IPDLAvgUsed.1 + VS.IPDLAvgUsed.2 +

    VS.IPDLAvgUsed.3 + VS.IPDLAvgUsed.4)

    NODEB_Throug

    hput_ULVS.IPULAvgUsed.1

    VS.IPULAvgUsed.2

    VS.IPULAvgUsed.3

    VS.IPULAvgUsed.4

    (VS.IPULAvgUsed.1 + VS.IPULAvgUsed.2 +

    VS.IPULAvgUsed.3 + VS.IPULAvgUsed.4)

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    Counter Name Counter Definition

    PCH/FACHUsage Counter

    PCH usage VS.UTRAN.AttPaging1 VS.UTRAN.AttPaging1/(60 x 60 x 5/0.01)

    FACH usage VS.CRNCIubBytesFACH.Tx

    VS.PCH.Bandwidth.UsageRate

    (1) Utilization of FACH carried on

    non-standalone SCCPCH

    FACH Utility Ratio =

    VS.CRNCIubBytesFACH.Tx x 8/((60 x x

    168 x 1/0.01) x VS.PCH.Bandwidth.UsageRate x6/7 + (60 x x 360 x 1/0.01) x (1-VS.PCH.Bandwidth.UsageRate x 6/7))

    where,

    VS.PCH.Bandwidth.UsageRate =

     /( x SP x

    60.0)

    (2) Utilization of FACH carried on standaloneSCCPCH

    FACH Utility Ratio =

    VS.CRNCIubBytesFACH.Tx x 8/(60 x x360 x 1/0.01)

    OVSF UsageCounter

    OVSF usage VS.RAB.SFOccupy VS.RAB.SFOccupy

    OVSF usability

    ratioVS.RAB.SFOccupy.Ratio VS.RAB.SFOccupy/256

    DCH OVSF ratio DCH_OVSF_Utilization [( + )

    x 64 + ( +) x 32 +

    ( +

    ) x 16 +( +

    ) x 8 +( +

    ) x 4 +

    ( +) x 2 +

    ( +

    )]/256

    CPU UsageCounter

    SPU usage VS.XPU.CPULOAD.MEAN VS.XPU.CPULOAD.MEAN

    MPU usage VS.XPU.CPULOAD.MEAN VS.XPU.CPULOAD.MEAN

    DPU usage VS.DSP.UsageAvg VS.DSP.UsageAvg

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    Counter Name Counter Definition

    INT CPU Load

    VS.INT.CPULOAD.MEAN

    VS.INT.TRANSLOAD.RATIO.MEAN

    VS.INT.CPULOAD.MEAN

    VS.INT.TRANSLOAD.RATIO.MEAN

    NodeB CPUusage

    VS.BRD.CPULOAD.MEAN VS.BRD.CPULOAD.MEAN

    Credit UsageCounter

    UL_CE_MEAN

    _RATIO

    VS.NodeB.ULCreditUsed.Mean

    VS.LC.ULCreditUsed.Mean

    VS.LC.DLCreditUsed.Mean

    if VS.NodeB.ULCreditUsed.Mean>0

    Sum_AllCells_of_NodeB(VS.NodeB.ULCreditU

    sed.Mean /2) / MIN(NodeB License UL CE

    Number, NodeB Physical UL CE Capacity)

    else

    Sum_AllCells_of_NodeB(VS.LC.ULCreditUsed.Mean/2) / MIN(NodeB License UL CE Number,

    NodeB Physical UL CE Capacity)

    DL_CE_MEAN

    _REMAIN

    Sum_AllCells_of_NodeB(VS.LC.DLCreditUsed.Mean) / MIN(NodeB License DL CE Number,

    NodeB Physical DL CE Capacity)