GSM OPTIMIZATION HANDBOOK 06/10/22 1/38
Nov 24, 2015
Radio Network Optimisation Handbook
GSM OPTIMIZATION
HANDBOOK
1.Introduction32.Support Arrangement43.Optimisation Team Structure54.Bad Perfromance FisH Bone diagram65.Information Preparation76.General Optimisation Proceedure87.Alarm Analysis98.Statistics Investigation Procedure109.Drive Test129.1.Drive Test Reminder129.2.Drive Test Log Investigation Consideration1210.Frequeny Planning1310.1.BCCH and BSIC planning criteria1310.2.Frequency Assignment Criteria1310.3.Frequency Retune Procedure1411.Add Neighbor Criteria1412.High Rise Building Coverage1513.Maximum System Configuration1514.HDPC Setting Template1714.1.TX Power and Power Control1714.2.Handover2014.3.Multiband2214.4.Miscellaneous2215.Tools Available2416.Problem Root Cause2516.1.High SDCCH Blocking2516.2.High TCH Blocking2616.3.SDCCH Access Failure Rate2716.4.Handover Failure & Loss2816.5.MSC Connection Rate 2916.5.SDCCH and TCH RF Loss3016.6.Power Control3116.7.Handover Problem3116.8.Others32
1. Introduction
Teamwork, listen to order, cycle time reduction and follow procedure are critical to every successful optimisation.
Below is the optimisation flow chart:
2. Support Arrangement
3. Optimisation Team Structure
Job Function
BSS Controller
- Understand fully on BTS maintenance, BSS configuration
Alarm Monitoring,
- Monitor daily alarm
Statistics Monitoring
- Investigate problem from statistics
D.B. & Feature Controller
- Check database and monitor feature deployment process
Drive Test Log Investigator
- Investigate problem from drive test log
4. Bad Perfromance FisH Bone diagram
Example of each major problems:
a. Database Setting improper HOPC settings
b. Neighbor wrong external neighbors BCCH or BSIC values, missing neighbor
c. Coverage weak, highly overlapped, improper antenna downtilt and orientation
d. External Interference microwave, repeater, faulty alarm
e. Calculation incorrect statistics equations
f. Cable Connection no/cross connection
g. Statistics Pegging and Collection SW problem on statistics pegging, or retrieval
h. Capacity lack of TRCU, improper channel configuration, lack of RSL, MTL links
i. Frequency Plan co-channel, adj-channel, improper BSIC planning
j. Software bug
k. Hardware wrong cable connection, faulty combiner and filter, PCM link down
l. Network Topology bad site location selection, redundant site deployed
m. Signaling Improper cause value and message sequence
n. Mobile faulty mobile in term of signaling or frequency hopping capability
o. Documentation wrong feature/parameter usage description
5. Information Preparation
6. General Optimisation Proceedure
7. Alarm Analysis
Below lists some important alarms that we focus,
a. Critical and major alarm
b. Alarms affect voice quality like MSI, KSW, RXCDR, DRIM, DRI
c. GCLK affects HO
d. Link alarms affect site availability and voice quality
e. XBL alarm affects acknowledgement of OOS CIC
8. Statistics Analysis Procedure
Statistics Tree Diagram
Firstly, we need to understand account teams and customer performance equation.
Problem Identification from Statistics
1. per carrier on HW, external interference, channel interference, coverage
a. PATH_BALANCE for faulty hardware (Every 3 days)b. IOI for external interference and bad channel assignment (Every Day)c. BER for external interference and bad channel assignment (Every Day)d. TCH_RF_LOSS for faulty hardware and bad channel assignment (Every Day)e. CHAN_REQ_FAIL_ROLL for faulty hardware and BCCH and SDCCH coverage footprint difference (Every Day)2. per cell on usage
a. AVAILABLE_TCH and AVAILABLE_SDCCH (Every Day)b. BUSY_SDCCH_MAX, SDCCH Blocking for faulty hardware (Every Day)c. SDCCH_CONGESTION and BUSY_SDCCH_MEAN for phantom RACH (Weekly)d. BUSY_TCH_MAX, TCH Blocking for faulty hardware (Every Day)e. OK_ACC_PROC_SUC_RACH for sleeping cell (Every Day)f. No TOTAL_CALL, OUT_INTRA_BSS_ATMPT, OUT_INTER_BSS_ATMPT (Every Day)g. CONN_REFUSED { - IMSI_DETACH} for CIC blocking (Weekly)h. cell without any statistics for OOS cell (Every Day)3. per cell on dual band mobile usage
a. MA_ACCESS_BY_TYPE (Weekly)b. MS_TCH_USAGE_BY_TYPE (Weekly)4. per cell on Cipher Mode
a. CIPHER_MODE_FAIL (Weekly)5. per cell on loading
a. BSS GPROC loading mean 70% (Weekly)b. MSC Processor Loading and Subscriber (Weekly)c. RSL TX, RX Utilisation mean 25% (Weekly)d. MTL TX, RX Utilisation mean 20% (Weekly)e. Pages per second (Weekly)
f. ALLOC_SDCCH, ALLOC_SDCCH_FAIL ,OK_ACC_PROC relationship (Weekly)g. HO per call (Weekly)6. per cell on paging
a. PCH_PAGE_Q_DISCARD (Weekly)7. per cell for BCCH and BSIC planning
a. INV_EST_CAUSE_RACH and BAD_HO_REFNUM_MS (Weekly)8. per cell inter-BSS HO monitoring
a. OUT_INTER_BSS_MS_FAIL + OUT_INTER_BSS_MS_LOST = HP_MSC_REQ_FAIL (not include blocking) (Weekly)b. OUT_INTER_BSS_MS_ATMPT = HO_MSC_REQ_FAIL + HO_MSC_REQ_OK (Weekly)Below all are daily task:
9. evaluate target
a. calculate system total call, total loss, ho loss, rf loss, drop call%
b. calculate how many total loss reduction is required to achieve the goal
c. do (b) again for other statistics
10. select worst cells and BSCs
d. pick worst 20 cells and worst 5 BSCs
11. per cell on TCH Assignment
a. CONN_REQ_TO_MSC
b. MA_REQ_FROM_MSC, CONN_REFUSED { - IMSI_DETACH}, if CONN_REFUSED is high, MSC procedure is required.
c. MA_CMD_TO_MS_BLKD, MA_CMD_TO_MS
d. MA_FAIL_FROM_MS, MA_COMPLETE_TO_MSC (same as TOTAL_CALL)
12. per cell on HO Cause
a. OUT_HO_CAUSE
13. per cell on HO Failure
a. OUT_INTRA_BSS_HO_FAIL, OUT_INTER_BSS_HO_FAIL, IN_INTRA_BSS_HO_FAIL and IN_INTER_BSS_MS_NO_SEIZE for ho failues
14. per cell on TCH_RF_LOSS, SD_RF_LOSS, HO Loss
a. TCH_RF_LOSS, OUT_INTRA_BSS_HO_REQ, OUT_INTRA_BSS_HO_ATMPT, OUT_INTER_BSS_HO_REQ, OUT_INTER_BSS_HO_ATMPT
b. SD_RF_LOSS and HO_LOSS relationship on cell coverage
c. OUT_INTER_BSS_HO_LOSTMS, OUT_INTRA_BSS_HO_LOSTMS, OUT_INTRA_CELL_HO_LOSTMS
For hardware fix, it usually takes 3 days to fix, hence we suggest to review those statistics every 3 days. For system loading and usage, we will visit them once in a week.
Weekly and every 3 days statistics should be reviewed when that corrective action is done.
Special Request
For growth planning per cell on blocked call setup, we can use ALLOC_TCH_FAIL HO_FAIL_NO_RESUORCES_INTRA_BSS - HO_FAIL_NO_RESUORCES_INTER_BSS - HO_FAIL_NO_RESUORCES_INTRA_CELL to estimate expanded network total calls.
For coverage analysis and improve MSC connection rate, we can use per LAC ACCESS_PER_RACH PAGING_RESPONSE. Difference tells us how many no page reponses.
9. Drive Test
9.1. Drive Test Reminder
i. prepare cell definition file
ii. 2mins per call
iii. 10-15mins per log file
iv. force to appropriate band (GSM only, DCS only or Dual)
v. mark benchmark route per log file in map
vi. mark on maps about (a) drop call (b) weak coverage (c) lot of rxquality (d) bad coverage
vii. fill in drive test problem sheet
9.2. Drive Test Log Investigation Consideration
General TEMS Log Investigation Concern
1. check undecoded BCCH this affects RF loss and creates log of ping pong handover
2. decoded neighbor but no handover is attempted due to missing neighbor or incorrect external neighbor path
3. focus on drop call and rxqual greater than 4 for non-hopping, 5 for hopping for at least 4 seconds
4. look for handover failure investigation target cell assigned ARFCN/MA from ASSIGNMENT COMMAND and HANDOVER COMMAND
5. mark down weak coverage area, no dominant server, say less than 85dBm
6. mark down highly overlapped area
Besides, be careful that when you see a decoded cell, that cell is not definitely a neighbor of serving, it can be due to serving cell having a neighbor which has same BCCH as decoded cell.
Note: (a) Focus on new site database
(b) Due to CCB, no SFH can be deployed
(c) Dedicated ARFCN/MA is different from BCCH
(d) After Assignment and Handover, the cell ID may not be updated yet due to serious rxquality at DL.
10. Frequeny Planning
10.1. BCCH and BSIC planning criteria
a. Cells have same BCCH and BSIC that increases TEMS log review troublesome.
b. Nearby cells have same BCCH:BSIC with ARFCN:BSIC.
c. Nearby cells have adjacent BCCH with ARFCN and same BSIC.
10.2. Frequency Assignment Criteria
Non-hopping Case
Hopping Case for non-BCCH
BCCH in hopping case is same as the non-hopping case.
10.3. Frequency Retune Procedure
Frequencies can be grouped into 5 types, they are:-
a. same site co- and adj-channel to BCCH
b. adjacent site co- and adj-channel to BCCH
c. adjacent site co-channel to ARFCN
d. same site co-channel to ARFCN
e. same site adj-channel to ARFCN
f. adjacent site adj-channel to ARFCN
g. others ARFCN
Priority of ARFCN retune is from g. to e. for fix and BBH, from g. to d. for SFH. If no available ARFCN can be found, site planning need to be reviewed.
Besides, 400k separation is required for CCB.
58, 70 shouldnt be used for BCCH.
MCell generates UL interference on channel 50 and 56.
11. Add Neighbor Criteria
In general, LOS and 2nd Round Interferer will be added as neighbor; however, for 3rd Round, this is very network dependant. field knowledge is required to make the decision.
12. High Rise Building Coverage
Introduce high rise building coverage must make sure to have good street coverage.
High Rise Building provide high level (likely above 8th floor) high rise building coverage
Macro provide low floors and street level coverage
Micro provide street level and indoor coverage
13. Maximum System Configuration
It is important to understand how system grows from phase to phase. It can be described in 3 phases.
Phase 1: Only macro layer, antenna located at tower top with small downtilt. Antenna uses large vertical beam-width.
Phase 2: Start to introduce micro layer, and increase macro cell downtilt and lower macro cell height of macro antenna.
Phase 3: Introduce high rise building coverage to office building and hotel. Before deploying this kind of coverage, street level coverage MUST be strong enough (likely more than 75dBm) to protect interference from high rise building coverage.
For a mature network which its system rxlevel has reach average 75dBm, it is time for us to deploy SFH to expand system capacity.
14. HDPC Setting Template
14.1. TX Power and Power Control
TX Power
ParameterCurrent
SettingSuggest SettingReason
max_tx_ms
max_tx_bts
Downlink Power Control due to Level
ParameterCurrent
SettingSuggest SettingReason
decision_alg_num
bts_power_control_allowed
bts_p_con_ack (TIMER)
bts_p_con_interval (TIMER)
pow_inc_step_size
pow_red_step_size
rxlev_dl_pc, hreqave
rxlev_dl_pc, hreqt
decision_1_dl_rxlev_av_p
l_rxlev_dl_p
u_rxlev_dl_p
decision_1_n1
decision_1_p1
decision_1_n2
decision_1_p2
Downlink Power Control due to Quality
ParameterCurrent
SettingSuggest SettingReason
decision_alg_num
bts_power_control_allowed
bts_p_con_ack (TIMER)
bts_p_con_interval (TIMER)
pow_inc_step_size
pow_red_step_size
rxqual_dl_pc, hreqave
rxqual_dl_pc, hreqt
rxqual_dl_pc, qual_weight
decision_1_dl_rxqual_av_p
l_rxqual_dl_p
u_rxqual_dl_p
decision_1_n3
decision_1_p3
decision_1_n4
decision_1_p4
w_qual
Uplink Power Control due to Level
ParameterCurrent
SettingSuggest SettingReason
decision_alg_num
ms_power_control_allowed
ms_p_con_ack
ms_p_con_interval
pow_inc_step_size
pow_red_step_size
rxlev_ul_pc, hreqave
rxlev_ul_pc, hreqt
decision_1_ul_rxlev_av_p
l_rxlev_ul_p
u_rxlev_ul_p
decision_1_n1
decision_1_p1
decision_1_n2
decision_1_p2
Uplink Power Control due to Quality
ParameterCurrent
SettingSuggest SettingReason
decision_alg_num
ms_power_control_allowed
ms_p_con_ack
ms_p_con_interval
pow_inc_step_size
pow_red_step_size
rxqual_ul_pc, hreqave
rxqual_ul_pc, hreqt
rxqual_ul_pc, qual_weight
decision_1_ul_rxqual_av_p
l_rxqual_ul_p
u_rxqual_ul_p
decision_1_n3
decision_1_p3
decision_1_n4
decision_1_p4
w_qual
Data and Hopping Quality Power Control
ParameterCurrent
SettingSuggest SettingReason
data_qual_flag
l_rxqual_dl_p_data
l_rxqual_ul_p_data
hop_qual_enabled
l_rxqual_dl_p_hopping
l_rxqual_ul_p_hopping
Standard MS HO Power, MS Ho Power Level based on Path Loss Calculations (GSR3)
ParameterCurrent
SettingSuggest SettingReason
handover_power_level
use_derived_ho_power01Reduce MS UL power and interference
Optimised Power Control (GSR4)
ParameterCurrent
SettingSuggest SettingReason
dyn_step_adj
dyn_step_adj_fmpr
pow_inc_step_size_dl
pow_inc_step_size_ul
pow_red_step_size_dl
pow_red_step_size_ul
Oscillation Prevention for MS Power Control
ParameterCurrent
SettingSuggest SettingReason
mspwr_alg
Rapid MS Power Down
ParameterCurrent
SettingSuggest SettingReason
rpd_pwr_down
rpd_period (TIMER)
rpd_trigger
rpd_offset
14.2. Handover
Inter-cell HandoverParameterCurrent
SettingSuggest SettingReason
inter_cell_handover_allowed
Intra-cell Handover
ParameterCurrent
SettingSuggest SettingReason
intra_cell_handover_allowed
ho_ack (TIMER)
hop_count
hop_count_ timer
Uplink Quality
ParameterCurrent
SettingSuggest SettingReason
ul_rxqual_ho_allowed
rxqual_ul_ho, hreqave
rxqual_ul_ho, hreqt
rxqual_ul_ho, qual_weight
rxqual_ul_ho, qual_pwr_flag
rxqual_ul_ho, qual_margin
rxqual_ul_ho, adj_qual_margin
decision_1_ul_rxqual_av_h
l_rxqual_ul_h
u_rxqual_ul_h
decision_1_n6
decision_1_p6
w_qual
Uplink Interference
ParameterCurrent
SettingSuggest SettingReason
interfer_ho_allowed
rxlev_ul_ho, hreqave
rxlev_ul_ho, hreqt
rxlev_ul_ho, qual_margin
rxlev_ul_ho, adj_qual_margin
decision_1_ul_rxlev_av_ih
u_rxlev_ul_ih
decision_1_n7
decision_1_p7
Downlink Quality
ParameterCurrent
SettingSuggest SettingReason
dl_rxqual_ho_allowed
rxqual_dl_ho, hreqave
rxqual_dl_ho, hreqt
rxqual_dl_ho, qual_weight
rxqual_dl_ho, qual_pwr_flag
rxqual_dl_ho, qual_margin
rxqual_dl_ho, adj_qual_margin
decision_1_dl_rxqual_av_h
l_rxqual_dl_h
u_rxqual_dl_h
decision_1_n6
decision_1_p6
w_qual
Downlink Interference
ParameterCurrent
SettingSuggest SettingReason
interfer_ho_allowed
rxlev_dl_ho, hreqave
rxlev_dl_ho, hreqt
rxlev_dl_ho, qual_margin
rxlev_dl_ho, adj_qual_margin
decision_1_dl_rxlev_av_ih
u_rxlev_dl_ih
decision_1_n7
decision_1_p7
Uplink Level
ParameterCurrent
SettingSuggest SettingReason
ul_rxlev_ho_allowed
rxlev_ul_ho, hreqave
rxlev_ul_ho, hreqt
decision_1_ul_rxlev_av_h
l_rxlev_ul_h
u_rxlev_ul_h
deicion_1_n5
decision_1_p5
Downlink Level
ParameterCurrent
SettingSuggest SettingReason
dl_rxlev_ho_allowed
rxlev_dl_ho, hreqave
rxlev_dl_ho, hreqt
decision_1_dl_rxlev_av_h
l_rxlev_dl_h
u_rxlev_dl_h
decision_1_n5
decision_1_p5
Distance
ParameterCurrent
SettingSuggest SettingReason
ms_distance_allowed
rel_tim_adv, hreqave
rel_tim_adv, hreqt
decision_1_tim_adv_av_alg
ms_max_range
decision_1_n8
decision_1_p8
poor_initial_assignment
timing_advance_period (TIMER)Define the interval between timing advance changes
Power Budget
ParameterCurrent
SettingSuggest SettingReason
pwr_handover_allowed
rxlev_dl_ho, hreqave
rxlev_dl_ho, hreqt
surround_cell, hreqave
decision_1_pbgt_rxlev_av_h
decision_1_ncell_rxlev_av_h_calc
max_tx_ms (serving cell)
ms_tx_pwr_max_def (internal neighbor default)
ms_tx_pwr_max_cell (external neighbor)
use_neighbor_pbgt_hreqave1
Data and Hopping Quality Handover Control
ParameterCurrent
SettingSuggest SettingReason
data_qual_flag
l_rxqual_dl_h_data
l_rxqual_ul_h_data
hop_qual_enabled
l_rxqual_dl_h_hopping
l_rxqual_ul_h_hopping
14.3. Multiband
Multiband Handover
ParameterCurrent
SettingSuggest SettingReason
mb_preference
phase2_classmark_ allowed
early_classmark_sending
early_classmark_delay
interband_ho_allowed
band_preference
band_preference_mode
multiband_reporting
14.4. Miscellaneous
Criteria 1
ParameterCurrent
SettingSuggest SettingReason
rxlev_min_def5rxlev_min_def (internal neighbor default)
rxlev_min_cell5rxlev_min_cell (external neighbor)
Criteria 2
ParameterCurrent
SettingSuggest SettingReason
ho_margin_def4,5
Neighboring Cell Processing
ParameterCurrent
SettingSuggest SettingReason
ncell_pro0
disuse_cnt_hreqave0
ho_only_max_pwr1
neighbor_journal0
worse_neighbor_ho0
Alternative Processing of Rxqual Measurements
ParameterCurrent
SettingSuggest SettingReason
alt_qual_proc00Quality Band Unit
Broadcast Control Channel Allocation (BA) Reinitialization
ParameterCurrent
SettingSuggest SettingReason
ba_alloac_proc1
Missing ReportParameterCurrent
SettingSuggest SettingReason
missing_rpt00Waiting for the actual data
Handover Timer
ParameterCurrent
SettingSuggest SettingReason
handover_recongnized_period
bssmap_t7
Link Disconnection
ParameterCurrent
SettingSuggest SettingReason
radio_link_timeout
rr_t3109
link_about_to_fail
link_fail
full_pwr_rfloss
15. Tools Available
COP Event Counting Tool, Call Trace Product, Generic Look Up, Cell Analysis Tool 2
TEMS and Safco
K1103
Web Statisitcs
NetPlan
BSS Database
GEP
16. Problem Root Cause
16.1. High SDCCH Blocking
16.2. High TCH Blocking
16.3. SDCCH Access Failure Rate
Note: SDCCH blocking is excluded.
16.4. Handover Failure & Loss
MSC Connection Rate
16.5. SDCCH and TCH RF Loss
16.6. Power Control
Sudden Power Drop
1. Incorrect call clearing timer setting
2. Faulty hardware
Slow Power Control
1. ho_only_max_pwr is turned on
2. Bad xx_p_con_ack and xx_p_con_interval
Power Control Window
1. Any external interference
2. Frequency planning technique
3. Speed of power down and up
4. Street or indoor coverage
16.7. Handover Problem
Ping Pong Handover
1. Bad radio calibration
2. Hardware fault
3. Negative handover allowed
4. Quality handover without turning on qual_pwr flag
5. Especially air combing, one of TX, RX antenna is blocked by building
Negative Handover
1. Neighbor journal
2. qual_margin_flag=0
3. Bad radio calibration between BCCH and non-BCCH
4. Turn on ho_magrin_rxqual feature with default value
No and Delay Handover
1. Inappriorate hreqave, hreqt and N & P voting
2. Negative handover margin
3. Improper setting on handover_recognised_period and bssmap_t7
4. Improper HO algorithm (Type 4, 6)
5. Blocking
16.8. Others
Low Erlang Usage
1. Inappropriate C1, C2 and handover criteria
High Rxqual
1. Adjacent site interference
2. Same site MAIO assignment problem
3. High internal same site hit rate
4. External interference like cordless phone, alarm, BTS hardware
Undecode BSIC
1. GCLK shift
2. BCCH interfered
Spurious Coverage
1. Coverage optimization
2. TA control
Killed Paging
1. Too many access grant block reserved
2. Location area too large
No Paging After Mobile is on certain time period
1. MSC Location Update Timer < BSS Location Update Timer
No Call Setup
1. LACI is different between BSS and MSC
2. Cell BAR
Immediate Assignment Reject
1. NO SDCCH
Monthly performance meeting to identify optimisation targets.
Start optimisation
PEG discuss with account teams to identify optimisation targets.
Engineers perform brief audit in Beijing to understand REAL situation
Optimisation Flow
Contractor prepares optimisation information
in Beijing
9. Radio Calibration
PEG Arrangement
OMC Engineer arrives local office to setup data collection platform
8. HW (DRCU, Filter) Fault
6. Excessive TA
5. UL Interference
External check night line IOI
High cell site
High UL Path Loss
Co. or adj. channel interference
4. HW Problem, check per carrier chan_req_ms_fail stats. or check alarm
3. Link balance, DB power setting
2. Path Balance, BCCH is OK bat SD carrier not OK
1. Phantom RACH, check any same ARFCN and BSIC
LOW SDCCH ACCESS SUCCESS RATE
12. Inappropriate congestion HO setting
11. Increase of single or dualband MSs.
Y
N
N
Y
Y
N
Reduce ho margin and enable congestion relief
Site reconfiguration
8. check adjacent cell busy_tch_max, if the busy_tch_max-8>configured TCH
10. Add radio to cell without
adding new cabinet
9. Coverage hole and improper DT & orientation
Find neighbors which has high
in_intra_bss_ho_return in_inter_bss_ho_seize then
check its fp
7. If SD has no blocking. May reconfigure channels or enable channel reconfiguration feature
6. Check any co-located or close
micro-cell,see whether traffic
offload is possible by optismisig
DB
END
5. check out_intra_bss_no_return and out_inter_bss_ho_return, it is high
4. Long timer setting
intra_BSS HO_rrt3103
channel release_rrt3109
3. Its GCLK SHIFT causes neighbors bsic undecoded
2. Missing Neighbor or incorrect Neighbor BSIC
1. Any neighbors BCCH interfered
Find faulty TS From BER Stats or check alarm
BUSY_TCH_MAX
=MAX_CONFIGURED_TCH
HIGH TCH BLOCKING
Y
Y
Y
Y
N
N
N
N
Neighbors tx power reduced
No TCH BLOKING, ENABLE CHANNEL RE CONFIGUPATION
FP, Neighobr and Coverage
LAC BORDER REDESIGN check t3121
Network Topology
Database, Interference & Capacity
Capacity
Hardware
TEMS Log & FP. mainly on
Undecoded BCCH
Missing Neighbor
HO Failure
Incorrect External Neighbor
Weak Coverage
High Overlapping
use non-dominant server
by ARFCN retune, neighor change and coverage
Statistics & DB. mainly on
SDCCH Access Failure
CSFR
Drop Call
TCH_RF_Loss
HO_Loss
HO_Failure
by ARFCN retune, neighor change and coverage
Network Topology Problem due to no available ARFCN is found by:
Site Replacement
Coverage Optimisation
Capacity Dimensioning
Solve Blocking by:
BCCH Optimisation
Neighor Optimisation
Add Radio
Site Reconfiguration
Add Site
Antenna Refinement
Suggest Better Database Setting (Channel Reconfiguration, Standard HOPC, Blocking Timer , Congestion Relief)
Capture External Interference
Frequency Retune for high IOI, BER and TCH_RF_LOSS
Audit External Neighbor
Improper ARFCN:BSIC Planning
GPROC loading
RSL & MTL Usage
Hardware Fix (Sleeping Cell, OOS TCU, OOS TS
Path Balance Issue, Faulty TCU from TCH_RF_Loss Issue)
GCLK shift and frequent Phase Lock Loop failure from Alarm
Network Audit from
Alarm
Statistics
Database
Check customer statistics equations
Data Preparation & NetPlan Information Correction
Data Collection & Check Local Office NetPlan Information
Statistics Monitoring
Alarm Monitoring
Drive Test Log Investigator
D.B. & Feature Controller
Team Leader
2 days
2 days
2 days
12 days
1 day
Check neighbor in_intra_BSS_ho_return and in_inter_bss_ho_Seize, if high, Check neighbors fp
END
Is out_INTRA_BSS_HO_RETURN AND out_INTER_BSS_HO_RETURN A LOT?
END
Lot of location Update?
Coverage Hole
Neighbor Cell Outage or own cell carrier outage (l carrier can have max 2 SD)
Review OK_ACC_PROC like CM_SERVICE_REQ_CALL, PAGE_RESPONSE,LOCATION UPDATE
Missing Neighbor or incorrect neighbor DB Path, TOTAL_CALL/ALLOC_TCH may be used
Start optimisation and skill transfer and acquisition
Best engineering arrangement arrives at local office
All engineers return to Beijing to derive plan
PEG arrives local office to discuss the optimisation plan with Account Team and Customer
PEG derives optimisation plan
PEG audits network in Beijing
PEG prepares INFORMATION FOR OPTIMISTION
Account Team supplies required information
Check Neighbor BCCH being Interfered
May due to Phantom RACH and HO access burst, check any same ARFCN and BSIC
Path Imbalance (SDCCH not on BCCH carrier)
SD_MEAN_HOCDING TIME CONVERGES to T3101
Find faulty TS from BER stats or check alarm
Frequency
Plan
Software
Hardware
Capacity
Network Topology
Bad Performance
Calculation
External
Interference
Database
Setting
Coverage
Neighbor
Statistics Pegging and Retrieval
3rd Round Interferer
2nd Round Interferer
LOS interferer
serving cell
No
Yes
Satisfactory Result?
Data Collection
Optimisation
Complete
Data Preparation
Data Analysis
ACTION
serving cell
MONITORING
BSS Controller
2 days
2 days
BUSY_SD_MAX
=MAX CONFIGUREDSD
HIGH SD BLOCKING
co-channel
adjacent channel
adjacent
channel
co-channel
cant be co- or adj-cahannel
serving cell
6. Handover_power_level is max?
3. MSC Problem
7. HO failure
- Check target cell fp
5. HO Failure
- Incorrect External Neighbor Database
4. Bad fp or external Interference -find % of UL/DL Quality by out_ho_cause
2. Short rr_t3103
7. Proper setting on ms_txpwr_max_cch and ms_txpwr_max_def
8. MSC Connection Refused (MTL Congested)
6. Cipher Mode Fail
5. Infrequent Location Update
4. TCH BLOCKING
3. SD RF loss
2. Coverage Hole
1. Paging Overflow Causing Discard
Low MSC Connection Rate
Y
N
Check neighbor in_intra_bss_ho_return and in_inter_bss_ho_seize if high, check neighbor(s fp
END
9. Is out_intra_bss_ho_return
and out_inter_bss_ho_return
a lot?
8. Poor HDPC setting
7. SD RF LOSS
Inconsistent coverage
Not enough overlapping
No SDCCH HO
5. Coverage hole, check UL Path Loss
Missing Neighbor, usually by drive test or trace-call
Neighbor Blocking
-check (OUT_INTRA_BSS_HO_REQ_OUT_INTRA_BSS_HO_ATTEMPT)
or (OUT_INTER_BSS_REQ_TO_MSC_OUT_TNETER_BSS_HO_ATTEMPT)
and check neighbor(s ALLOC_TCH_FAIL
2. Hardware
(a)Path balance
-idea is 108;(120 (serious UL Path Loss)
;(100 (serious DL Path Loss)
(b)Radio
-check per carrier RF loss stats
(c) Neighbor cell outage
(d) GCLK SHIFT
a. Neighbors BCCH Interfered
b. External Interference
c. Use guard band
d. Use AMPS frequency
High SD & TCH RF LOSS
Micro
Macro
High Rise Building
9. Call clearing timer (t3109