Accessibility Trobleshooting

Accessibility troubleshooting Accessibility is the ability to successfully establish a radio connection for a requested QOS. Accessibility includes below KPIs.           

CS RRC PS RRC Speech RAB Video(CS64) RAB R99(PS) RAB HSDPA RAB EUL RAB E2E CS E2E PS E2E HS E2E EUL

Following steps helps in CS/PS RRC and Speech/Video/R99/HS/EUL RAB degradation troubleshooting. 1.

Identification of CS/PS RRC affecting cells by CS/PS RRC failures = CS/PS RRC attempts – CS/PS RRC success.

2.

CS/PS RRC failure causes can be identified by  MP load rejections (pmNoRejRrcConnMpLoadC) due to high MP load  Admission control (DeniedAdmDlPwr, DeniedAdmDlChnlCode, DeniedAdmDlHw, DeniedAdmUlHw) due to resource unavailability  Transport NW/Node blockings (pmNoRrcConnReqBlockTnCs, pmNoRrcConnReqBlockTnPs, pmNoRrcConnReqBlockNodeCs, pmNoRrcConnReqBlockNodePs) due to transport network congestion Identification of Speech/Video/R99/HS/EUL RAB affecting cells by Speech/Video/R99/HS/EUL RAB failures = Speech/Video/R99/HS/EUL RAB attempts – Speech/Video/R99/HS/EUL RAB success.  pmNoRabEstablishAttempt.Speech  pmNoRabEstablishSuccess.Speech  pmNoRabEstablishAttempt.Cs64  pmNoRabEstablishSuccess.Cs64  pmNoRabEstAttemptPsIntNonHs  pmNoRabEstSuccessPsIntNonHs  pmNoRabEstablishAttempt.PacketInteractiveHs  pmNoRabEstablishSuccess.PacketInteractiveHs  pmNoRabEstablishAttempt.PacketInteractiveEul  pmNoRabEstablishSuccess.PacketInteractiveEul

3.

4.

Speech/Video/R99/HS/EUL RAB failure causes can be identified by  Admission control (LackDlPwr, LackDlChnlCode, LackDlHwBest, LackUlHwBest, LackDlHw, LackUlHw, ExceedConnLimit, LackDlAse, LackUlAse) due to resource unavailability  Transport NW/Node blockings (pmNoRabEstBlkNodePsIntNonHsBest, pmNoRabEstBlkNodePsStrNonHsBest, pmNoRabEstBlockNodeCs57Best, pmNoRabEstBlockNodeCs64Best, pmNoRabEstBlockNodePsIntHsBest, pmNoRabEstBlockNodePsStrHsBest, pmNoRabEstBlockNodeSpeechBest, pmNoRabEstBlockTnCs57, pmNoRabEstBlockTnCs57Best, pmNoRabEstBlockTnCs64, pmNoRabEstBlockTnCs64Best, pmNoRabEstBlockTnPsIntHs, pmNoRabEstBlockTnPsIntHsBest, pmNoRabEstBlockTnPsIntNonHs, pmNoRabEstBlockTnPsIntNonHsBest, pmNoRabEstBlockTnPsStreamHsBest, pmNoRabEstBlockTnPsStrHs, pmNoRabEstBlockTnPsStrNonHs, pmNoRabEstBlockTnPsStrNonHsBest, pmNoRabEstBlockTnSpeech, pmNoRabEstBlockTnSpeechBest) due to transport network congestion

Admission Control: Admission control blockings represents the resource congestion.    

Power congestion Code congestion UL/DL CE congestion UL/DL ASE congestion

Power congestion: Observations can be 1.

2. 3. 4. 5. 6.

Check the power parameter discrepancy.  If Cell has 40W license, @NodeB end, maxDlPowerCapability should be 460 and maxTotalOutputPower should be 40. @RNC end, maximumTransmissionPower should be 460  pwrAdm and pwrOffset parameter values can be verified Check primaryCpichPower discrepancy. Check for alarms. Check for licenses. Check the propagation delay. Check the cell fluctuations (auto downtime and manual downtime).

Recommendations can be 1. 2. 3. 4. 5. 6.

pwrAdm can be increased from 75 to 85. 40W license upgrade. Higher SF admission can be restricted. Ex: sf8Adm, sf4AdmUl, sf16Adm, sf8AdmUl… Physical optimization. Alarm clearance. License loading.

7. 8. 9.

Power parameter discrepancy clearance. primaryCpichPower can be reduced. New site can be recommended if power congestion still exists after the above all steps implementation.

Code congestion: Observations can be 1. 2. 3. 4. 5. 6.

Check the dlCodeAdm parameter discrepancy. Check primaryCpichPower discrepancy. Check for alarms. Check for licenses. Check the propagation delay. Check the cell fluctuations (auto downtime and manual downtime).

Recommendations can be 1. 2. 3. 4. 5. 6. 7. 8.

dlCodeAdm can be increased from 70 to 85. Higher SF admission can be restricted. Ex: sf8Adm, sf4AdmUl, sf16Adm, sf8AdmUl… Physical optimization. Alarm clearance. License loading. dlCodeAdm parameter discrepancy clearance. primaryCpichPower can be reduced. New site can be recommended if Code congestion still exists after the above all steps implementation.

UL/DL CE congestion: Observations can be 1. 2. 3. 4. 5. 6. 7.

Check the dlHwAdm and ulHwAdm parameter discrepancy. Check primaryCpichPower discrepancy. Check for alarms. Check for licenses. Check for DUW discrepancy. Check the propagation delay. Check the cell fluctuations (auto downtime and manual downtime).

Recommendations can be 1. 2. 3. 4. 5. 6. 7. 8.

Physical optimization. UL/DL CE license upgrade (128/256 to 256/384 on DUW20). If site has DUW10, DUW to be upgraded to DUW20. If site is RBS3000, RAX/TX board addition. Higher SF admission can be restricted. Ex: sf8Adm, sf4AdmUl, sf16Adm, sf8AdmUl… Alarm clearance. License loading. dlHwAdm/ulHwAdm parameter discrepancy clearance. primaryCpichPower can be reduced. New site can be recommended if CE congestion still exists after the above all steps implementation.

Transport NW/Node blockings: Observations can be 1. 2. 3.

Transport NW/Node blocking counters pegging. High IubHsLimiting Ratio. Check for alarms.

Recommendations can be 1. 2. 3. 4.

ATM path/port discrepancy clearance (VLAN definitions). E1 expansion. Alarm clearance. Transport network - ATM to IP conversion.

For HS and EUL RAB failures following can be checked in addition to above. 1.

2. 3.

@NodeB end, licenseCapacityNumHsdpaUsers, licenseStateNumHsdpaUsers, maxNumHsdpaUsers, licenseCapacityNumEulUsers, licenseStateNumEulUsers, maxNumEulUsers parameter discrepancy can be checked. Discrepancy can be cleared. @RNC end, hsdpaUsersAdm, eulServingCellUsersAdm and eulServingCellUsersAdmTti2 can be checked. Discrepancy can be cleared. @NodeB end, available UL/DL CE can be checked. Discrepancy can be cleared.

For E2E KPIs, CS/PS System NAS releases can be checked as shown below.

UL RSSI: UL RSSI represents the UL interference. For UL RSSI, following steps helps in troubleshooting. 1. 2. 3. 4. 5. 6.

Check and clear VSWR alarm. Check cell overshooting or NBR overshooting into the cell’s serving area. Check and define missing neighbors. Check Feeder/Jumper/HW connections. Check configuration and recreate the site. Check and clear obstructions in antenna main lobe or reorient antenna.

*For sudden degradation of any KPI, Cold Restart can be preferred as preliminary action.