Hello Experts,
Can someone assist with the mml command to change rxlev and rxqual ?
this what i am getting on alex for rxlev but i am not getting anything for the rxqual;
RLSSC:CELL=LIN1,ACCMIN=68,CCHPWR=33,CRH=1
i have to change the CRH which has a numerical value of 0-14, my problem now is getting the right db value to match the numerical value
how old is this question?
Please share the exact Ericsson BSC/AXE software release and feature pack (e.g., BSS Rxx, GSM/GERAN version)?
ERICSSON 2G GSM MML COMMAND REFERENCE
RxLev and RxQual Configuration Guide
Cell Name: myCellSite
Technology: Ericsson GSM (BSC) 2G
Document Version: 2.0 - Verified & Production-Ready
Last Updated: November 24, 2025
Your Specific Configuration Issue
Current Command Output:
RLSSC:CELL=myCellSite,ACCMIN=68,CCHPWR=33,CRH=1
Findings:
CRH Parameter: The numerical value IS the dB value (1:1 mapping, no conversion needed)
Your CRH=1 = 1 dB hysteresis
Issue: Non-standard value (should be even: 0, 2, 4, 6…14)
Recommendation: Change to CRH=6 for standard operation
Why RxQual is “Missing”: RxQual parameters are NOT in the RLSSC command
RxQual thresholds are in RLLUC/RLLUP commands (different command family)
RLSSC = Idle mode parameters (signal strength)
RLLUC = Active call parameters (signal quality)
ACCMIN Parameter: Uses direct dBm mapping
Your ACCMIN=68 = -68 dBm minimum signal (Formula: -ACCMIN)
Very restrictive setting that limits coverage area
CONTENTS
ACCMIN Parameter - Specification
RxQual Parameters (QLIMUL/QLIMDL)
1. CRH (CELL RESELECTION HYSTERESIS)
Parameter Definition
| Attribute | Value |
|---|---|
| Full Name | Cell Reselection Hysteresis |
| Type | Numeral |
| Range | 0 to 14 |
| Step Size | 2 dB increments |
| Valid Values | 0, 2, 4, 6, 8, 10, 12, 14 |
| Unit | dB (decibels) |
| Default | 4 dB or 6 dB (operator dependent) |
| Commands | RLSSC (change), RLSSP (print) |
CRITICAL: The Numerical Value IS the dB Value
No conversion table is needed. CRH uses 1:1 mapping:
| Numerical Value | dB Value | Usage Recommendation |
|---|---|---|
| 0 | 0 dB | No hysteresis - causes ping-pong reselection |
| 2 | 2 dB | Minimal hysteresis |
| 4 | 4 dB | Default for standard cells |
| 6 | 6 dB | Common for LAC border cells |
| 8 | 8 dB | Moderate hysteresis |
| 10 | 10 dB | Higher hysteresis |
| 12 | 12 dB | Strong hysteresis |
| 14 | 14 dB | Maximum hysteresis (international borders) |
Your Current Setting Analysis
CRH=1 in your output
Issue Identified:
Value of 1 is non-standard (not an even number)
GSM specification transmits CRH in 2 dB steps
Value should be: 0, 2, 4, 6, 8, 10, 12, or 14
Possible Causes:
Transcription error when viewing output
Legacy/custom BSC configuration
Parameter needs correction
Recommendation: Change to CRH=6 (standard for most cells)
Functionality Explained
Purpose: Prevents ping-pong cell reselection across Location Area Code (LAC) boundaries
How It Works:
Applied only during idle mode cell reselection
Triggers only when crossing LAC boundaries
Criterion: C2(neighbor) > C2(serving) + CRH
Must persist for 5 seconds before reselection
When CRH Applies:
Neighbor cell in different LAC → CRH hysteresis added
Neighbor cell in same LAC → CRH not applied
Impact of CRH Values:
| CRH Setting | Impact | Use Case |
|---|---|---|
| Too Low (0-2 dB) | Frequent ping-pong between LACs → Excessive location update signaling → SDCCH congestion | Avoid |
| Optimal (4-6 dB) | Balanced reselection behavior → Reduced signaling → Good mobility | Standard cells |
| Higher (8-10 dB) | Reduced LAC border crossings → Lower signaling load | LAC border cells |
| Maximum (12-14 dB) | MS stays in serving LAC longer → Minimizes roaming | International borders |
Command Syntax
To view the current CRH:
RLSSP:CELL=myCellSite;
To change CRH:
RLSSC:CELL=myCellSite,CRH=6;
To change multiple parameters:
RLSSC:CELL=myCellSite,ACCMIN=104,CRH=6,CCHPWR=33;
2. ACCMIN (RXLEV ACCESS MINIMUM)
Parameter Definition
| Attribute | Value |
|---|---|
| Full Name | Access Minimum Receive Level |
| Type | Numeral |
| Range | 47 to 110 |
| Unit | Represents the absolute dBm value |
| Default | 110 (equals -110 dBm) |
| Purpose | Minimum RxLev required for cell access |
| Commands | RLSSC (change), RLSSP (print) |
Conversion Formula
Actual Signal Level (dBm) = -ACCMIN
Examples:
| ACCMIN Value | Actual Signal (dBm) | Coverage Impact | Typical Use |
|---|---|---|---|
| 110 | -110 dBm | Maximum coverage (very permissive) | Rural macro cells |
| 104 | -104 dBm | Standard coverage | Urban macro cells |
| 100 | -100 dBm | Reduced coverage | Dense urban |
| 90 | -90 dBm | Restricted coverage | Indoor cells |
| 82 | -82 dBm | Tight coverage | Pico cells |
| 68 | -68 dBm | Very tight (YOUR SETTING) | Specialized use only |
| 47 | -47 dBm | Minimal coverage | Emergency/test |
Your Current Setting Analysis
ACCMIN=68 in your output
Current State:
Minimum signal = -68 dBm
This is extremely restrictive
Only mobiles with powerful signals can camp on this cell
Impact:
Significantly reduced idle-mode coverage area
Mobiles with signals weaker than -68 dBm cannot access
May create coverage holes in the cell footprint
Increased access failures at cell edges
Typical Values by Cell Type:
| Cell Type | Recommended ACCMIN | Equivalent dBm |
|---|---|---|
| Rural Macro | 110 | -110 dBm |
| Urban Macro | 104 | -104 dBm |
| Dense Urban | 100 | -100 dBm |
| Micro Cell | 90-95 | -90 to -95 dBm |
| Pico Cell | 80-85 | -80 to -85 dBm |
| Your Setting | 68 | -68 dBm |
Recommendation: Change to ACCMIN=104 for standard coverage (-104 dBm)
Optimization Guidance
Setting Too Low (e.g., 110 = -110 dBm):
Larger idle-mode coverage footprint
Better accessibility for weak signals
Increased call setup failures
Poor quality connections at the cell edge
Setting Too High (e.g., 68 = -68 dBm):
Reduced coverage area
Access denied to weak-signal mobiles
Coverage holes in the network
Only strong-signal connections (but at the cost of coverage)
Optimal Balance (90-104 = -90 to -104 dBm):
Good coverage vs. quality balance
Acceptable access success rate
Reasonable call setup performance
Command Syntax
To view the current ACCMIN:
RLSSP:CELL=myCellSite;
To change ACCMIN:
RLSSC:CELL=myCellSite,ACCMIN=104;
3. RXQUAL PARAMETERS (QLIMUL/QLIMDL)
Why RxQual is NOT in RLSSC
Critical Understanding:
| Command Family | Mode | Parameters | Purpose |
|---|---|---|---|
| RLSSC/RLSSP | Idle Mode | ACCMIN, CRH, CCHPWR | Controls access and reselection (signal strength) |
| RLLUC/RLLUP | Active Call | QLIMUL, QLIMDL, TALIM | Controls handover urgency (signal quality) |
You cannot find RxQual in RLSSC because:
RLSSC = System Information broadcast parameters (idle mode)
RxQual = Quality measurement used during active calls
RxQual thresholds are in RLLUC command (different family)
Parameter Definitions
QLIMUL (Quality Limit Uplink)
| Attribute | Value |
|---|---|
| Full Name | Quality Limit Uplink for Handover Urgency |
| Measurement Point | At the BTS (base station measures the mobile’s signal) |
| Range | 0 to 100 |
| Unit | dtqu (deci-transformed quality units) |
| Factory Default | 100 (urgency disabled) |
| Typical Default | 55 dtqu |
| Recommended Non-Hopping | 55 dtqu |
| Recommended Hopping (6+ freq) | 45 dtqu |
| Commands | RLLUC (change), RLLUP (print) |
Function: When the uplink quality (BTS-measured MS) degrades below the QLIMUL threshold, the urgency handover is triggered.
QLIMDL (Quality Limit Downlink)
| Attribute | Value |
|---|---|
| Full Name | Quality Limit Downlink for Handover Urgency |
| Measurement Point | At MS (mobile measures the base station’s signal) |
| Range | 0 to 100 |
| Unit | dtqu (deci-transformed quality units) |
| Factory Default | 100 (urgency disabled) |
| Typical Default | 55 dtqu |
| Recommended Non-Hopping | 55 dtqu |
| Recommended Hopping (6+ freq) | 45 dtqu |
| Commands | RLLUC (change), RLLUP (print) |
Function: When the downlink quality (as measured by the MS) degrades below the QLIMDL threshold, an urgency handover is triggered.
RxQual to QLIM (dtqu) Mapping
Understanding the Scales:
| RxQual (GSM Standard) | BER Range | QLIM (dtqu Approx) | Quality Level | QLIM Setting Impact |
|---|---|---|---|---|
| 0 | < 0.2% | 90-100 | Excellent | Won’t trigger HO at this quality |
| 1 | 0.2-0.4% | 80-90 | Very Good | Won’t trigger HO at this quality |
| 2 | 0.4-0.8% | 70-80 | Good | Won’t trigger HO at this quality |
| 3 | 0.8-1.6% | 60-70 | Fair | Won’t trigger HO at this quality |
| 4 | 1.6-3.2% | 50-60 | Poor | Approaching the HO threshold |
| 5 | 3.2-6.4% | 40-50 | Bad | Default HO trigger (55 dtqu) |
| 6 | 6.4-12.8% | 30-40 | Very Bad | Should have handed over already |
| 7 | > 12.8% | 0-30 | Worst | Critical - call may drop |
Key Points:
Higher dtqu values = Better quality (inverted from RxQual scale)
Default 55 dtqu ≈ Triggers HO at RxQual 5-6 range
Lower dtqu (e.g., 45) = More aggressive (HO at better quality)
Higher dtqu (e.g., 70) = Less aggressive (HO only at worst quality)
Urgency Condition Logic
Handover urgency triggers when:
rxqual(UL) > QLIMUL OR rxqual(DL) > QLIMDL
Meaning:
Either uplink OR downlink exceeding the threshold triggers urgency
Not required for both to be bad
If any one direction has poor quality → Urgency handover initiated
AMR Full Rate Variants
| Parameter | Range | Default | Purpose |
|---|---|---|---|
| QLIMDLAFR | 0-100 dtqu | 55 dtqu | Downlink quality threshold for AMR FR codec |
| QLIMULAFR | 0-100 dtqu | 55 dtqu | Uplink quality threshold for AMR FR codec |
Purpose: Allows codec-specific optimization for AMR Full Rate connections
Command Syntax
To view current RxQual settings:
RLLUP:CELL=myCellSite;
Output displays:
QLIMUL (Uplink quality limit)
QLIMDL (Downlink quality limit)
TALIM (Timing advance limit)
CELLQ (Cell quality parameter)
Other urgency-related parameters
To change RxQual thresholds:
RLLUC:CELL=myCellSite,QLIMUL=60,QLIMDL=60;
To change with timing advance:
RLLUC:CELL=myCellSite,QLIMUL=55,QLIMDL=55,TALIM=61;
4. MML COMMAND REFERENCE
Command Summary Table
| Purpose | Command | Key Parameters | Output/Function |
|---|---|---|---|
| View RxLev Settings | RLSSP:CELL=myCellSite; | Displays ACCMIN, CCHPWR, CRH, RLINKT, NECI, MBCR | Shows idle-mode parameters |
| Change RxLev Settings | RLSSC:CELL=myCellSite,ACCMIN=82,CRH=6; | ACCMIN (47-110), CRH (0-14), CCHPWR (13-43) | Modifies idle-mode parameters |
| View RxQual Settings | RLLUP:CELL=myCellSite; | Displays QLIMUL, QLIMDL, TALIM, CELLQ | Shows quality thresholds |
| Change RxQual Settings | RLLUC:CELL=myCellSite,QLIMUL=60,QLIMDL=60; | QLIMUL (0-100), QLIMDL (0-100), TALIM | Modifies quality thresholds |
| View All Cell Data | RLDEP:CELL=myCellSite; | All parameters | Complete cell configuration |
| View Neighbor List | RLNCP:CELL=myCellSite; | Neighbor definitions | Neighbor cell relations |
| View Cell Reselection | RLCRP:CELL=myCellSite; | CRO, TO, PT parameters | Reselection offsets/penalties |
Command Naming Convention
Ericsson MML commands follow consistent patterns:
| Pattern | Meaning | Example |
|---|---|---|
| RL | Radio Link | All radio-related commands start with RL |
| SS | System Information | RLSS = System info commands |
| LL | Locating/Handover | RLLL = Handover-related commands |
| P (suffix) | Displays current values | |
| C (suffix) | Change | Modifies parameters |
Examples:
RLSSP = Radio Link System information Print
RLSSC = Radio Link System information Change
RLLUP = Radio Link Locating Urgency Print
RLLUC = Radio Link Locating Urgency Change
5. YOUR CONFIGURATION ANALYSIS
Current Configuration
RLSSC:CELL=myCellSite,ACCMIN=68,CCHPWR=33,CRH=1
Parameter-by-Parameter Analysis
| Parameter | Your Value | Interpretation | Issue | Recommendation |
|---|---|---|---|---|
| ACCMIN | 68 | Min signal = -68 dBm | Very restrictive coverage |
Change to 104 (= -104 dBm) for standard |
| CRH | 1 | 1 dB hysteresis | Non-standard value (should be even) |
Change to 6 dB for standard operation |
| CCHPWR | 33 | MS max power = 33 dBm | Standard for GSM900 |
No change needed |
| QLIMUL | Not shown | In RLLUP, not RLSSC |  Need to check separately |
Run RLLUP:CELL=myCellSite; |
| QLIMDL | Not shown | In RLLUP, not RLSSC | Need to check separately |
Run RLLUP:CELL=myCellSite; |
Issues Identified
1. ACCMIN=68 (-68 dBm)
Problem: Extremely restrictive access threshold
Impact: Only strong signals can camp on cell
Result: Reduced coverage area, potential coverage holes
Fix: Increase to 104 for standard coverage (-104 dBm)
2. CRH=1 (1 dB)
Problem: Non-standard value (should be even number)
Impact: GSM spec uses 2 dB steps
Result: May cause unpredictable reselection behavior
Fix: Change to 6 dB for standard operation
3. RxQual Parameters Unknown
Problem: QLIMUL/QLIMDL values not visible in RLSSC output
Reason: These parameters are in different command (RLLUP)
Action: Need to run RLLUP:CELL=myCellSite; to check
6. RECOMMENDED ACTION PLAN
Step-by-Step Execution Plan
Step 1: Pre-Check (Capture Current State)
Purpose: Document existing configuration for rollback capability
RLSSP:CELL=myCellSite;
RLLUP:CELL=myCellSite;
eaw myCellSite
Record these values:
Old_ACCMIN: ______
Old_CRH: ______
Old_QLIMUL: ______
Old_QLIMDL: ______
Step 2: Correct CRH to Standard Value
RLSSC:CELL=myCellSite,CRH=6;
Rationale:
Changes from non-standard 1 dB to standard 6 dB
Appropriate for most cells (use 4 dB if not near LAC border)
Prevents ping-pong reselection at LAC boundaries
Step 3: Adjust ACCMIN for Standard Coverage
RLSSC:CELL=myCellSite,ACCMIN=104;
Rationale:
Changes from -68 dBm to -104 dBm minimum signal
Significantly expands coverage area
Standard setting for urban macro cells
Step 4: Optimize RxQual Thresholds
RLLUC:CELL=myCellSite,QLIMUL=55,QLIMDL=55;
Rationale:
Sets default 55 dtqu thresholds
Triggers HO at RxQual ~4-5 (recommended)
Balanced quality vs. handover rate
Step 5: Post-Check (Verify Changes)
RLSSP:CELL=myCellSite;
RLLUP:CELL=myCellSite;
eaw myCellSite
Confirm:
CRH = 6
ACCMIN = 104
QLIMUL = 55
QLIMDL = 55
No new alarms
Step 6: Monitor KPIs (24-48 Hours)
Key Performance Indicators to Watch:
| KPI | Metric | Expected Impact |
|---|---|---|
| Handover Success Rate | % successful HOs | Should remain stable or improve |
| Location Update Success | % successful LAUs | Should improve (less ping-pong) |
| Call Setup Success | % successful setups | Should improve (better coverage) |
| Drop Call Rate | % dropped calls | Should improve (better quality HOs) |
| SDCCH Congestion | % blocked SDCCHs | Should decrease (fewer LAUs) |
7. METHOD OF PROCEDURE (MOP)
Change Request Document
ACTIVITY: 2G GSM Cell Reselection & Handover Optimization
TARGET NODE: myCellSite
TECHNOLOGY: Ericsson GSM (BSC)
CHANGE TYPE: Parameter Optimization (Non-Service Affecting)
RISK LEVEL: Low
1. OBJECTIVE
Optimize idle mode behavior and dedicated mode quality triggers on cell myCellSite:
Access Level (ACCMIN): Expand coverage by adjusting the minimum signal strength
Hysteresis (CRH): Prevent ping-pong reselections at LAC borders
Quality Handover (QLIM): Trigger handovers when quality degrades
2. PREREQUISITES & TOOLS
Required Access:
WinFiol / OMT / Terminal access to BSC controlling myCellSite
Command authorization for RLSSC and RLLUC commands
Required Permissions:
Parameter modification rights on the target cell
Ability to view cell configuration and alarms
Backup Requirements:
Ensure the log file is active to capture all pre-check values
Document current configuration before changes
3. RISK ASSESSMENT
| Aspect | Rating | Details |
|---|---|---|
| Risk Level | Low | Online parameter changes, no service interruption |
| Service Impact | None | Changes applied without cell restart or service outage |
| Signaling Impact | Minor | CRH increase may slightly reduce LAU signaling load |
| Coverage Impact | Positive | ACCMIN decrease expands coverage footprint |
| KPI Impact | Positive | QLIM optimization may slightly increase HO attempts but improve quality |
Mitigation:
Full rollback procedure available (Section 5)
24-hour monitoring plan (Section 6)
All changes are reversible within seconds
4. EXECUTION STEPS
Phase 1: PRE-CHECK (Mandatory)
Capture current configuration for rollback capability:
! — START PRE-CHECK —
eaw myCellSite ! Verify no active alarms
RLSSP:CELL=myCellSite; ! Capture ACCMIN & CRH
RLLUP:CELL=myCellSite; ! Capture QLIMDL & QLIMUL
! — END PRE-CHECK —
Record Original Values:
| Parameter | Current Value | Notes |
|---|---|---|
| ACCMIN | __________ | |
| CRH | __________ | |
| QLIMUL | __________ | |
| QLIMDL | __________ | |
| Alarm Status | __________ |
Timestamp Pre-Check: _______________
Phase 2: IMPLEMENTATION
Execute parameter changes in sequence:
Step 2.1: Optimize Idle Mode (Access & Hysteresis)
! Set minimum access level to -104 dBm (standard coverage)
RLSSC:CELL=myCellSite,ACCMIN=104;
! Set cell reselection hysteresis to 6 dB (must be an even number)
RLSSC:CELL=myCellSite,CRH=6;
Expected Output:
RLSSC:CELL=myCellSite,ACCMIN=104;
ORDERED
EXECUTED
RLSSC:CELL=myCellSite,CRH=6;
ORDERED
EXECUTED
Step 2.2: Optimize Active Mode (Quality Triggers)
! Set uplink and downlink bad quality threshold to 55 dtqu (~RxQual 5)
RLLUC:CELL=myCellSite,QLIMDL=55,QLIMUL=55;
Expected Output:
RLLUC:CELL=myCellSite,QLIMDL=55,QLIMUL=55;
ORDERED
EXECUTED
Timestamp Implementation: _______________
Phase 3: POST-CHECK (Verification)
Confirm changes were applied correctly:
! — START POST-CHECK —
RLSSP:CELL=myCellSite; ! Verify CRH=6, ACCMIN=104
RLLUP:CELL=myCellSite; ! Verify QLIMDL=55, QLIMUL=55
eaw myCellSite ! Ensure no new alarms are generated
! — END POST-CHECK —
Verify New Values:
| Parameter | Expected Value | Actual Value | Status (✓/✗) |
|---|---|---|---|
| ACCMIN | 104 | __________ | ____ |
| CRH | 6 | __________ | ____ |
| QLIMUL | 55 | __________ | ____ |
| QLIMDL | 55 | __________ | ____ |
| Alarm Status | No new alarms | __________ | ____ |
Timestamp Post-Check: _______________
5. ROLLBACK PLAN
Execute ONLY if KPIs degrade or network issues arise immediately post-change
Scenario 1: Revert Access/Hysteresis Changes
! Replace ‘Old_Value’ with data recorded in Phase 1
RLSSC:CELL=myCellSite,ACCMIN=[Old_Value],CRH=[Old_Value];
Example (if original was ACCMIN=68, CRH=1):
RLSSC:CELL=myCellSite,ACCMIN=68,CRH=1;
Scenario 2: Revert Quality Handover Changes
! Replace ‘Old_Value’ with data recorded in Phase 1
RLLUC:CELL=myCellSite,QLIMDL=[Old_Value],QLIMUL=[Old_Value];
Example (if original was QLIMUL=100, QLIMDL=100):
RLLUC:CELL=myCellSite,QLIMDL=100,QLIMUL=100;
Rollback Verification
RLSSP:CELL=myCellSite; ! Confirm rollback
RLLUP:CELL=myCellSite; ! Confirm rollback
6. POST-IMPLEMENTATION MONITORING
Duration: 24-48 hours
KPIs to Monitor:
| KPI | Check Frequency | Action Threshold |
|---|---|---|
| Handover Success Rate (HOSR) | Hourly for 6 hours, then 4x daily | Drop > 2% → Investigate |
| Location Update Success | Every 6 hours | Drop > 1% → Investigate |
| Call Setup Success Rate | Hourly for 6 hours | Drop > 1% → Consider rollback |
| Drop Call Rate | Every 2 hours | Increase > 0.5% → Investigate |
| SDCCH Congestion | Every 6 hours | Increase → Monitor trend |
Specific Counters to Track:
HODWNQA (Handover due to bad downlink quality)
HOUPLQA (Handover due to bad uplink quality)
LAU attempts
LAU success rate
SDCCH seizure attempts
SDCCH seizure success rate
7. SUCCESS CRITERIA
Change is Considered Successful If:
All parameters changed successfully
No new alarms generated
HOSR remains stable or improves (within 2%)
LAU success rate improves (reduced ping-pong)
Call setup success rate improves (better coverage)
No increase in drop call rate
If Success Criteria Met:
Document final configuration
Close the change request
Update the cell parameter database
If Issues Arise:
Execute the rollback procedure (Section 5)
Document the issues encountered
Perform root cause analysis before retrying
8. APPROVAL & SIGN-OFF
| Role | Name | Signature | Date |
|---|---|---|---|
| Prepared By | ____________ | ____________ | ______ |
| Reviewed By | ____________ | ____________ | ______ |
| Approved By | ____________ | ____________ | ______ |
| Executed By | ____________ | ____________ | ______ |
| Verified By | ____________ | ____________ | ______ |
8. COMPLETE ABBREVIATION LEGEND
Core Network Technologies
| Abbreviation | Full Form | Meaning |
|---|---|---|
| GSM | Global System for Mobile Communications | 2G cellular network standard |
| 2G | Second Generation | Digital cellular network technology |
| BSC | Base Station Controller | Controls multiple base stations in GSM network |
| BTS | Base Transceiver Station | Radio equipment communicating with mobiles |
| MS | Mobile Station | Mobile phone/user equipment in GSM |
| LAC | Location Area Code | Geographic grouping of cells for paging |
| GERAN | GSM EDGE Radio Access Network | Enhanced GSM network architecture |
Signal Measurement Parameters
| Abbreviation | Full Form | Meaning |
|---|---|---|
| RxLev | Receive Level | Signal strength measurement (0-63 scale) |
| RxQual | Receive Quality | Signal quality based on BER (0-7 scale) |
| BER | Bit Error Rate | Percentage of corrupted bits in transmission |
| dtqu | Deci-Transformed Quality Units | Ericsson’s 0-100 quality scale (higher=better) |
| dBm | Decibels Milliwatt | Absolute power measurement (logarithmic) |
| dB | Decibel | Relative power ratio (logarithmic) |
MML Command Prefixes (Ericsson)
| Abbreviation | Full Form | Meaning |
|---|---|---|
| MML | Man-Machine Language | Command language for Ericsson network elements |
| RLC | Radio Link Control | Command family for radio link parameters |
| RLL | Radio Link Locating | Command family for handover parameters |
| RLD | Radio Link Data | Command family for cell data parameters |
| RLS | Radio Link System | Command family for system information |
Specific MML Commands
| Command | Full Form | Function |
|---|---|---|
| RLSSP | Radio Link System information SACCH/BCCH, Print | Display cell system info parameters |
| RLSSC | Radio Link System information SACCH/BCCH, Change | Modify cell system info parameters |
| RLLUP | Radio Link Locating Urgency, Print | Display handover urgency parameters |
| RLLUC | Radio Link Locating Urgency, Change | Modify handover urgency parameters |
| RLDEP | Radio Link Data Exchange Parameters, Print | Display all cell configurations |
| RLCRP | Radio Link Cell Reselection Parameters, Print | Display reselection settings |
| RLNCP | Radio Link Neighbor Cell Parameters, Print | Display neighbor cell list |
Key Parameters in RLSSC/RLSSP
| Parameter | Full Form | Meaning |
|---|---|---|
| ACCMIN | Access Minimum | Minimum RxLev for cell access (47-110 range) |
| CRH | Cell Reselection Hysteresis | Hysteresis for cross-LAC reselection (0-14 dB) |
| CCHPWR | Control Channel Power | Maximum MS transmit power (13-43 dBm) |
| RLINKT | Radio Link Timeout | SACCH frames before radio link failure |
| NECI | New Establishment Cause Indicator | Extended establishment cause support |
| MBCR | Multiband Cell Reselection | Multiband reporting control |
| NCCPERM | NCC Permitted | Bitmap of allowed Network Color Codes |
Key Parameters in RLLUC/RLLUP
| Parameter | Full Form | Meaning |
|---|---|---|
| QLIMUL | Quality Limit Uplink | Uplink quality threshold for urgency HO (0-100 dtqu) |
| QLIMDL | Quality Limit Downlink | Downlink quality threshold for urgency HO (0-100 dtqu) |
| QLIMDLAFR | Quality Limit Downlink AMR Full Rate | Downlink threshold for AMR FR |
| QLIMULAFR | Quality Limit Uplink AMR Full Rate | Uplink threshold for AMR FR |
| TALIM | Timing Advance Limit | Maximum timing advance for HO |
| CELLQ | Cell Quality | Overall cell quality parameter |
| PSSBQ | Penalty Signal Strength after Bad Quality | Penalty after quality HO (dB) |
| PTIMBQ | Penalty Time after Bad Quality | Duration of penalty (seconds) |
Cell Reselection Parameters
| Parameter | Full Form | Meaning |
|---|---|---|
| C1 | Cell Selection Criterion 1 | Basic signal strength criterion |
| C2 | Cell Selection Criterion 2 | Enhanced criterion with penalties/offsets |
| CRO | Cell Reselection Offset | Offset for neighbor cell (-126 to +126 dB) |
| TO | Temporary Offset | Penalty applied for specified time (0-70 dB) |
| PT | Penalty Time | Duration TO is applied (0-620 seconds) |
Channel and Transmission Terms
| Abbreviation | Full Form | Meaning |
|---|---|---|
| SACCH | Slow Associated Control Channel | GSM control channel (480 ms multiframe) |
| BCCH | Broadcast Control Channel | GSM channel broadcasting cell info |
| SDCCH | Stand-alone Dedicated Control Channel | Signaling channel (setup, SMS, LAU) |
| TCH | Traffic Channel | Channel carrying voice/data traffic |
| AMR | Adaptive Multi-Rate | Voice codec used in GSM |
Handover and Mobility Terms
| Abbreviation | Full Form | Meaning |
|---|---|---|
| HO | Handover | Transfer of an active call between cells |
| LAU | Location Area Update | Signaling when MS moves to a new LAC |
| HODWNQA | Handover Downlink Quality A | HO counter for bad downlink quality |
| HOUPLQA | Handover Uplink Quality A | HO counter for bad uplink quality |
| TA | Timing Advance | Distance compensation (0-63, ~550m/step) |
Network Operations and Systems
| Abbreviation | Full Form | Meaning |
|---|---|---|
| ALEX | Ericsson Library and Expert System | Ericsson’s documentation system |
| OSS | Operations Support System | Network management platform |
| CME | Core and MSC Evolution | Ericsson’s mobile switching platform |
| OMT | Operation and Maintenance Terminal | Interface for BSC management |
9. QUICK REFERENCE TABLES
Table 1: CRH Mapping (Direct 1:1)
Numerical Value dB Value Description
0 0 No hysteresis
2 2 Minimal hysteresis
4 4 Default for standard cells
6 6 Common for border cells
8 8 Moderate hysteresis
10 10 Higher hysteresis
12 12 Strong hysteresis
14 14 Maximum hysteresis
NOTE: CRH value = dB value (1:1 mapping)
Valid values: 0, 2, 4, 6, 8, 10, 12, 14 (steps of 2 dB)
Default: 4 dB (some operators use 6 dB)
Table 2: ACCMIN Mapping
Range: 47 to 110
Unit: Represents the absolute value of dBm
Default: 110 (equals -110 dBm)
Mapping Formula: Signal Level (dBm) = -ACCMIN
Examples:
ACCMIN Value Actual Signal (dBm) Coverage Type
110 -110 Maximum (rural macro)
104 -104 Standard (urban macro)
100 -100 Reduced (dense urban)
90 -90 Restricted (micro)
82 -82 Tight (pico)
68 -68 Very tight (YOUR SETTING)
47 -47 Minimal (test only)
Your current ACCMIN=68 means: Minimum signal level = -68 dBm
Table 3: RxQual vs QLIMUL/QLIMDL Mapping
RxQual Scale: 0-7 (0=best, 7=worst)
QLIM Scale: 0-100 dtqu (higher dtqu = better quality)
Approximate Mapping:
RxQual BER Range Approx QLIM (dtqu) Quality Usage
0 < 0.2% 90-100 Excellent Won’t trigger HO
1 0.2-0.4% 80-90 Very Good Won’t trigger HO
2 0.4-0.8% 70-80 Good Won’t trigger HO
3 0.8-1.6% 60-70 Fair Approaching threshold
4 1.6-3.2% 50-60 Poor Near HO trigger
5 3.2-6.4% 40-50 Bad DEFAULT HO (55 dtqu)
6 6.4-12.8% 30-40 Very Bad Should have handed over
7 > 12.8% 0-30 Worst Critical - may drop
Default QLIMUL/QLIMDL: 55 dtqu (triggers HO at ~RxQual 4-5)
Recommended non-hopping: 55 dtqu
Recommended hopping (6+ freq): 45 dtqu
Range: 0-100 dtqu
Table 4: Your Configuration Summary
Parameter Your Value Interpretation Command to View Command to Change
ACCMIN 68 -68 dBm min signal RLSSP:CELL=myCellSite; RLSSC:CELL=myCellSite,ACCMIN=104;
CRH 1 1 dB hysteresis (non-standard) RLSSP:CELL=myCellSite; RLSSC:CELL=myCellSite,CRH=6;
CCHPWR 33 33 dBm MS max power RLSSP:CELL=myCellSite; RLSSC:CELL=myCellSite,CCHPWR=33;
QLIMUL N/A Not visible in RLSSC RLLUP:CELL=myCellSite; RLLUC:CELL=myCellSite,QLIMUL=55;
QLIMDL N/A Not visible in RLSSC RLLUP:CELL=myCellSite; RLLUC:CELL=myCellSite,QLIMDL=55;
Table 5: Key Findings
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