Basic KPIs Definition Based on Huawei Counters

Basic KPIs Definition Based on Huawei counters

Document reference: OP-090904- 1

Written by: S. Badie Mohammadi

Introduction: ........................................................................................................................................................................................ 3 BSS basic KPIs .................................................................................................................................................................................... 3 1.1 CSSR: Call Setup Success Rate .................................................................................................................................................. 4 1.2 CDR: Call Dropped Rate ............................................................................................................................................................ 4 1.3 SDASR: SDCCH Access Success Rate....................................................................................................................................... 5 1.4 TASSFAIL: TCH Assignment Failure ........................................................................................................................................ 5 1.5 TCH Blocking (Excluding HO) .................................................................................................................................................. 6 1.6 TCH blocking (including HO) .................................................................................................................................................... 7 1.7 TCH RF LOSS .......................................................................................................................................................................... 7 1.8 Outgoing Ho Success Rate.......................................................................................................................................................... 7 1.9 SDCCH Blocking Rate ............................................................................................................................................................... 8 1.10 TCH MHT ................................................................................................................................................................................ 8 1.11 No. of Dropped calls ................................................................................................................................................................. 9 1.12 No. Of calls .............................................................................................................................................................................. 9 1.13 SDCCH Traffic ........................................................................................................................................................................ 9 1.14 SDCCH MHT........................................................................................................................................................................... 9 1.15 Available SDCCH Channels ................................................................................................................................................... 10 1.16 SDCCH Dropped Rate............................................................................................................................................................ 10 1.17 TCH/F Carried Traffic ............................................................................................................................................................ 10 1.18 TCH/H Carried Traffic ........................................................................................................................................................... 10 1.19 Available Full Rate Channels.................................................................................................................................................. 11 1.20 Available Half Rate Channels ................................................................................................................................................. 11 1.21 Dedicated TCH/F ................................................................................................................................................................... 11 2. Conclusion ..................................................................................................................................................................................... 11 3. References: .................................................................................................................................................................................... 12


Introduction: Network performance analysis has very important role in optimization, planning and network expansion, which could be analyzed based on following inputs: a) Drive Tests b) System measurements c) Counters and defined KPIs (Key Performance Indicator). Each of the mentioned input has advantages and disadvantages. Counters and KPIs are able to give the fastest and most comprehensive analysis but they are based on statistic analysis, therefore there should be enough samples to make them accurate. Besides it depends on how the vendor defined the counters and how much they can cover the requirements. Counters are normally accumulator, which changes by occurrence of an event or receiving a message, for example, Handover command. KPI is a counter or a formula, which deploys different counters, to show performance of a process in network for example Call Setup process or carried traffic. There could be a lot of counters and KPIs in network. Therefore defining basic KPIs is mandatory and the other KPIs and counters will be deployed on demand. In this document the basic KPIs, which are needed to analyze BSS elements performance, will be introduced.

BSS basic KPIs Counters normally are the number of occurrence of an event or message. Therefore counters can’t show performance of an event or process. KPIs are almost mentioned in rate, which can give a good sense about how much the process is succeeded or failed. BSS is most important part of mobile network, which is facing users directly. Thus the highly performing BSS elements can satisfy users. Hereunder the basic BSS KPIs based on Huawei equipment counters, have been defined.


1.1 CSSR: Call Setup Success Rate CSSR shows how many of generated calls are successful in a cell, BSC or network. Call Setup process includes originated, terminated, emergency and direct retried calls but not handed over calls. Call setup process starts by user request by sending RACH and ends by seizing TCH. The formula for CSSR is as follow: No. of successfully seized TCH in call setup process CSSR = 100 × No. SDCCH Attempts for calls And the formula based on Huawei counters:  Successful TCH Seizure for call   Successful SDCCH Seizures (all )    ⋅  CSSR = 100 ×   Attempted TCH Seizure for call   Attempted SDCCH Seizures (all )  It can be seen clearly that this formula is not accurate because there is no counter to show the number of SDCCH seizure attempts for calls. References: TCH Measurement Function and SDCCH measurement Function

1.2 CDR: Call Dropped Rate This KPI shows how many of calls are dropped. It includes handed over calls. CDR formula: No. of dropped calls CDR = 100 × No. of calls And the formula based on Huawei counters: CDR = TCH Call drop rate


Or CDR = 100 ×

TCH drop call Successful TCH Seizures (all )

Reference: TCH Measurement Function.

1.3 SDASR: SDCCH Access Success Rate User seizes SDCCH channels for different purposes such as call setup process, Location Update, SMS and so on. This KPI shows how many users could seize SDCCH successfully. The formula:

SDASR = 100 ×

No. of Successfully seized SDCCH No. of SDCCH Seizure attempt − outgoing SDCCH HO Attempt + inco min g SDCCH HO Attempt

The formula based on Huawei counters: SDASR = 100 ×

Successful SDCCH seizures + Successful SDCCH seizures for SDCCH busy Attempted SDCCH seizures (all )

References: BSC Measurement Function, TCH Measurement Function Note: “Attempted SDCCH seizures” includes HO attempted as well.

1.4 TASSFAIL: TCH Assignment Failure This KPI calculates how many TCH assignments fail due to different causes excluding those attempts, which are meeting blocking on resources.


The formula: TASSFAIL = 100 ×

No. Failed TCH Assignment Attempts for calls (exclude blocking ) TCH Assignment Attempts (exclude HO)

The formula based on Huawei counters:

TASSFAIL = 100 ×

TCH Seizure Failures for call − TCH Seizure Failures for call ( No radio resource) Attempted TCH Seizures for call

References: TCH Measurement Function Note: There should be different reasons for TCH assignment failure, which can be separated by causes.

1.5 TCH Blocking (Excluding HO) This KPI shows how many calls face blocking when they are generated (MOC, MTC and emergency calls and so on). This KPI doesn’t include blocking in HO process because handover has lower priority and user can stay with existing server. Formula: TCH Blocking = 100 ×

Generated calls which are facing blocking No. of call attempts

And the formula based on Huawei Counters: TCH Seizure Failures for call ( No radio resource) TCH Blocking = 100 × Attempted TCH Seizures for call


1.6 TCH blocking (including HO) It is the same as previous KPI but this counter includes HO attempts to show the effect of blocking in Ho procedure. The formula: TCH Blocking (including HO) = 100 ×

TCH Assignment attempts which are facing blocking No. of TCH Assignment attempts

The formula based on Huawei counters: TCH Blocking (including HO) = 100 ×

Attempted TCH Seizures meeting a TCH blocked state Attempted TCH Seizures (all )

And predefined KPI in Huawei OMC: TCH blocking rate (including handover) % References: TCH measurement Function

1.7 TCH RF LOSS To calculate how many calls dropped due to RF problems (interference, low signal level and so on), this KPI has been defined. Huawei predefined KPI: TCH RF Loss Rate % References: TCH Measurement Function

1.8 Outgoing Ho Success Rate This KPI shows how many outgoing HO attempts are successful. If the incoming HO attempts are included in formula, the HO attempts are considered 2 times. Therefore we are just focusing on outgoing handovers. The formula:


Successful outgoing HO Attempted outgoing HO And based on Huawei counters: Successful outgoing int ernal int er cell handovers + Successful outgoing int erBSC int er cell handovers Outgoing HSR = 100 × Attempted outgoing int ernal int er cell handovers + Attempted outgoing int erBSC int er cell handovers Ougoing HSR = 100 ×

References: Inter-cell handover measurement Function.

1.9 SDCCH Blocking Rate It shows how many attempts in accessing SDCCH channels, meet blocking. Huawei predefined KPI: SDCCH Blocking Rate % References: SDCCH Measurement Function, BSC Measurement Function

1.10 TCH MHT TCH Mean Holding Time is the average time that each TCH is busy. The formula: TCH MHT= And the formula based on Huawei counters:

TCH MHT =

3600 × (TCHF traffic volume (excluding very eary assignment) (ERL) + TCHH traffic volume (excluding very eary assignment) (ERL)) Successful TCH seizures (all )


1.11 No. of Dropped calls It shows the amount of dropped calls. Huawei Counter: TCH Call Drop References: BSC Measurement Function, TCH Measurement Function

1.12 No. Of calls Total number of generated or handed over calls in cell. Huawei Counter: Successful TCH seizures (all) References: TCH Measurement Function

1.13 SDCCH Traffic Carried traffic by SCCH channels. Huawei counter: SDCCH traffic volume (excluding very early assignment) (ERL) References: SDCCH Measurement.

1.14 SDCCH MHT SDCCH Mean Holding Time means the average busy time for each SDCCH channel. Formula: 3600 × SDCCH Traffic SDCCH MHT = No. Of SDCCH Connections And the formula based on Huawei counters:


3600 × SDCCH traffic volume (excluding very early assignment) (ERL Successful SDCCH Seizures(all ) References: SDCCH Measurement Function. SDCCH MHT =

1.15 Available SDCCH Channels Number of available SDCCH channels. Huawei counter: Available SDCCHs References: SDCCH Measurement Function.

1.16 SDCCH Dropped Rate The rate of dropped SDCCH connections. Huawei counter: SDCCH Call Drop Rate % References: SDCCH Measurement Function.

1.17 TCH/F Carried Traffic Carried traffic on available full rate channels. Huawei counter: TCHF traffic volume (excluding very eary assignment) (ERL)

1.18 TCH/H Carried Traffic Carried traffic on available half rate channels. Huawei counter: TCHH traffic volume (excluding very eary assignment) (ERL)


1.19 Available Full Rate Channels The number of available Full rate channels. Please note that differs from equipped channels. Huawei counters: Available TCHF

1.20 Available Half Rate Channels The number of available half rate channels. Please note that differs from equipped channels. Huawei counters: Available TCHH

1.21 Dedicated TCH/F It means the number of TCH/F when there are no half rate channels. The formula based on Huawei counters: Available TCHH Dedicated TCH/F = Available TCHF + 2

2. Conclusion • • • • • •

Counters analysis is the fastest and comprehensive way to analyze the network elements’ performance. Counters analysis is based on statistics. Therefore enough samples would be needed. The basic KPIs have been defined to cover the requirements. Defined Call Setup Success Rate is not accurate. The basic KPIs could be calculated at cell and BSC busy hour or could be averaged over a block of hours. Extra counters and KPIs could be used on demand or further analysis.


3. References: 1) M900/M1800 Base Station Controller, Traffic Statistic Manual Manual Version T2-031616-20030113-C-4.00 Product Version V300R002


Basic KPIs Definition Based on Huawei Counters

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