Panduan Singkat Problem RTWP
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Prepared by SME Team
01 July 2013
Pengukuran RTWP RTWP adalah salah satu kriteria pengukuran kualitas uplink channel
RTWP : Received Total Wideband Power (UE signal + UL interference) Dikenal juga sebagai UL RSSI (Received Signal Strength Indicator) RTWP = Measured RTWP - GAIN Faktor2 yang mempengaruhi RTWP: Air-interface signal (RTWP aktual yang diterima antenna) Feeder connection (RTWP aktual yang masuk ke TRX board) Internal parameter settings di TRX module (GAIN)
Note:
Apabila terdapat external amplification unit (e.g TMA), GAIN dari perangkat ini harus dimasukkan dalam perhitungan, sebagai channel attenuation.
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Setting standar untuk Attenuation di RX Branch Cek keberadaan perangkat dual band combiner di site :
No Combiner Site = 0
MO Parameter ID Parameter Name NE MML Command Meaning
RxBranch ATTEN Attenuation NodeB MOD RXBRANCH Indicates the attenuation of the RX channel of the RRU. NO NO None None
IsKey Mandatory Feature ID Feature Name
With Combiner Site = max 3 dB (GUI value 6)
Note : Ada 2 tipe dual band combiner yg digunakan di HCPT, yaitu Kathrein & Fingu.
Value Type GUI Value Range Enumeration Number/Bit Unit Actual Value Range Default Value Recommended Value
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Interval values 0~60 Not involved 0.5dB 0~30 0 When the TMA is not used, this parameter needs to be set to 0. When the 12 dB TMA is not used, this parameter needs to be set to 4 dB to 11 dB. When the 24 dB TMA is not used, this parameter needs to be set to 11 dB to 22 dB.
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Problem Umum RTWP and Penyebabnya Problem Type Problem Uplink Channel
Problem Capacity
Problem Location
Related Problem
Description
Air-interface channel
External interference
Space characteristics: regional external interference dan site interference Time characteristics: intermittent interference dan continuous interference Signal characteristics: inter-system interference
Antenna channel
Plumbing issues
Inter modulation interference, incorrect antenna dan feeder connection, faulty di antenna and feeder components dikarenakan poor antenna and feeder quality
Intra-TRX channel
Incorrect configurations
RF channel configurations : berefek ke RTWP di semua carrier dalam RF channel termasuk channel attenuation configuration, interconnection mode, distributed sector, and single-antenna/dual-antenna mode Carrier configurations: berefek ke RTWP di carrier tersebut termasuk initial RTWP value and desensitization intensity
Hardware failure
Hardware failure di RF module termasuk RF Unit Hardware Fault
Service capacity problems
Akibat dari heavy traffic, version upgrade, feature deployment, interference antar neighboring cells
Air-interface channel
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Metode untuk Menemukan Problematic RTWP Cell Pilih counter Vs.MinRTWP karena counter in yang paling objektif di antara 3 RTWP counters (Vs.MinRTWP, Vs.MeanRTWP, Vs.MaxRTWP) Ambil low hour (3 AM) sebagai periode pengamatan Ambil nilai minimum Vs.MinRTWP dalam 7 hari di minggu yang sama Taruh threshold >-90 dBm untuk menyusun cell list
Contoh distribusi permasalahan RTWP yang ditemukan di network
Source:
Presentation title in footer
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01 July 2013
Cara Mengecek Configuration Problem dengan MML Command
Parameter
MML
Impact Range
Check Point or Recommended Value
RF channel attenuation value
DSP RXBRANCH
Sector
Diset berdasarkanTMA installation and feeder connection. Umumnya, channel attenuation value = TMA gain-feeder loss
RTWP Initial RTWP value
DSP RXBRANCH
Cell
Typical setting adalah 0.
RF desensitization value
LST RRU
Sector
Typical setting adalah 0.
Cell desensitization intensity
DSP DESENS
Cell
Typical setting adalah 0.
Interconnection mode
LST SEC
Sector
Diset berdasarkan physical connections and cek juga apakah hardware connection dalam kondisi normal
Cell mode
LST SEC
Sector
Diset berbeda2 untuk single-antenna, dual-antenna, distributed scenarios
TMA gain value
DSP TMASUBUNIT
Sector
Diset sesuai denganTMA specifications atau settable value.
TMA mode
DSP TMASUBUNIT
Sector
Umumnya, TMA mode adalah Normal.
Current status on the antenna port
DSP ANTENNAPORT
Sector
Umumnya, power switch ON.
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Alarm2 yang Terkait dengan Problem RTWP No.
Alarm Name
1
ALM-26522 RF Unit RX Channel RTWP/RSSI Unbalanced
2
ALM-26521 RF Unit RX Channel RTWP/RSSI Too Low
3
ALM-26532 RF Unit Hardware Fault
4
ALM-26752 ALD Hardware Fault
5
ALM-26758 TMA Running Data and Configuration Mismatch
6
ALM-26755 TMA Bypass
7
ALM-26757 RET Antenna Running Data and Configuration Mismatch
8
ALM-26541 ALD Maintenance Link Failure
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1. ALM-26522 RF Unit RX Channel RTWP/RSSI Unbalanced Triggering condition: Apabila perbedaan antara RTWP main RX channel dana RTWP diversity RX channel melebihi 10 dB. Suggested handling procedure:
Antara main dan diversity channels, salah satu memiliki high RTWP dan lainnya normal. Clear alarm sesuai prosedur troublosehooting high RTWP.
Main dan diversity channel memiliki high RTWP dan perbedaan keduanya melebihi 10 dB. Clear alarm sesuai prosedur troublosehooting high RTWP.
Antara main dan diversity channels, salah satu memiliki low RTWP dan lainnya normal. Clear alarm sesuai prosedur troublosehooting high RTWP.
2. ALM-26521 RF Unit RX Channel RTWP/RSSI Too Low Triggering cause: Apabila RTWP/RSSI RX channel di RF unit kurang dari -144 dBm. Suggested handling procedure:
Salah satu di antara main dan diversity channel memiliki low RTWP. Clear alarm sesuai prosedur troublosehooting low RTWP.
Diversity channel memiliki low RTWP. Untuk indoor site, diversity channel umumnya tidak dikoneksikan ke antena. Apabila kedua RF modules berada di kabinet yang sama, RF interconnection mode bisa di-disable.
Main channel memiliko low RTWP. Untuk indoor site, RX dan TX channels terpisah akibatnya tidak ada uplink signal di main channel.
3. ALM-26532 RF Unit Hardware Fault Triggering cause: RF channel atau RX channel kemungkinan faulty, berakibat ke abnormal RTWP. Suggested handling procedure: Lakukan soft dan hard reset RF module, cek apakah alarm hilang. Jika tidak, ganti RF module
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4. ALM-26752 ALD Hardware Fault Triggering Cause: TMA gain invalid. Suggested handling procedure: Replace TMA.
5. ALM-26758 TMA Running Data and Configuration Mismatch Triggering cause: TMA gain inconsistent dengan configuration, berakibat ke abnormal uplink TMA gains and RTWP problems. Suggested handling procedure: Reset gain TMA atau working mode TMA.
6. ALM-26755 TMA Bypass Triggering cause: TMA gain is invalid. Suggested handling procedure: Cek apakah TMA faulty. Jika ya, replace TMA. Jika tidak, set working mode TMA ke normal mode.
7. ALM-26757 RET Antenna Running Data and Configuration Mismatch Triggering cause: Tilt angle antenna inconsistent dengan configuration. Suggested handling procedure: Reset tilt angle antenna terkait.
8. ALM-26541 ALD Maintenance Link Failure Triggering Cause: TMA maintenance links disconnected.
Suggested handling procedure: Cek TMA. Apabila maintenance links TMA tidak dapat di-restore, coba replace TMA.
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Cara Melakukan Pengecekan RTWP dengan LMT (sisi RNC) RTWP Real Time
User Number di Cell
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Cara Melakukan Pengecekan RTWP dengan LMT (sisi Node-B)
Petunjuk Setting
RTWP Real Time
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Cell RTWP Tracing
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Contoh RX Scanning melalui Node-B LMT (WRFU locked, prosedur penyelidikan External Interference)
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Contoh UL Measurement Result Menggunakan Spectrum Analyzer (+ Drive Test, prosedur penyelidikan External Interference)
00 = -100.4 dBm
300 = -131.4 dBm
900 = -132.2 dBm
600 = -125.7 dBm
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Contoh skenario trial selama troubleshooting RTWP
Sector 2 WRFU Board
A
B Jumper
Combiner
C
D Feeder
Antenna
Sector 3 WRFU Board
W
X Jumper
Combiner
Y
Untuk mengecek Board and Combiner, swap titik B dan X lalu cek ulang nilai RTWP
Untuk mengecek Combiner, swap titik C dan Y lalu cek ulang nilai RTWP
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Z Feeder
Antenna
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01 July 2013
