Contents1. CALL DROP DEFINITION and MEASUREMENT POINTS ............................................................................................................ 2 2. CALL DROP COUNTERS ................................................................................................................................................................ 3 2.1 CALL DROP COUNTERS RELATIONS ....................................................................................................................................... 3 2.2 CALL DROP COUNTERS DEFINITIONS .................................................................................................................................... 4 2.3 CALL DROP COUNTERS INCREMENT LOGIC .......................................................................................................................... 4 3. CALL DROP TROUBLESHOOTING ................................................................................................................................................. 5 3.1 CALL DROP CAUSE ANALYSIS ................................................................................................................................................ 5 3.2 CALL DROP REASONS for GENERAL CALL DROP TYPES ......................................................................................................... 6 3.3 TROUBLESHOOT STEPS FOR CALL DROP ............................................................................................................................... 6 3.3.1 PARAMETER PROBLEMS ................................................................................................................................................ 6 3.3.2 PATH BALANCE PROBLEMS ............................................................................................................................................ 7 3.3.3 COVERAGE GAPS PROBLEMS ......................................................................................................................................... 8 3.3.4 QUALITY and INTERFERENCE PROBLEMS .................................................................................................................... 11 3.3.5 MISSING NEIGHBOR PROBLEMS .................................................................................................................................. 15 failure of decoding HANDOVER DETECTION and HANDOVER COMPLETE message. this item is measured in the source cell. when the target cell AM/CM net-drive fails (due to timeout or negative acknowledgement). In Intra-BSC handover procedure. TCH is seized as traffic channel. outgoing BSC handover initiated and the timer for the source cell to wait for CLEAR COMMAND message from MSC expires (T8 expires). TCH call drop rate=TCH call drops / Successful TCH seizures (all) Measurement points of TCH Drop are showed in below sketch. excluding the source cell for directed retry. TCH serves as traffic channel. measures the item when the timer for the source cell to wait for Inter Clear Request with cause value HANDOVER COMPLETE from the target cell expires. The resource of the lower_priority call will be preempted by the higher_priority call if MSC and BSC both support preemption. the target cell sends Inter Clear Request to the source cell when the timer for the target cell to wait for HANDOVER COMPLETE from MS expires. in this case this item is measured in the source cell. TCH serves as traffic channel. In assignment procedure and handover procedure. which will cause call drop. In the case that MS reverses to the original channel after intra BSC handover fails. in this case. the source cell. CALL DROP DEFINITION and MEASUREMENT POINTS Generally TCH Drop Formula is like below. In intra-BSC handover procedure.1. In this case this item is measured in the source cell. the target cell sends Inter Clear Request to source cell. BSC receives ERROR INDICATION message from BTS. . TCH serves as traffic channel. In Intra-BSC handover procedure. BSC receives CONNECT FAILURE INDICATION message from BTS. incoming BSC handover initiated and the timer for the target cell to wait for HANDOVER COMPLETE message expires. which will cause call drop. This item is measured when the RSL link of the TRX that the call is using disconnects. the source cell first releases the terrestrial connection but the AM/CM re-net-drive fails (due to timeout or negative acknowledgement). CALL DROP COUNTERS 2.2.1 CALL DROP COUNTERS RELATIONS Call Drop has a set of counters which related to each other like below schema CM33 CM33C CM332 CM330 CM331 H3027Ca CM3300 CM3301 CM3302 H3028Ca H3127Ca M3100A M3101A M3102 H3128Ca M3100B M3101B M3202 H3327Ca M3100C M3101C M3200A M3101D M3200B M3101E M3200C M3201A M3201B M3201C M3201D M3201E H3328Ca CM333 CM334 CM335 . when uudecoded SACCH occurs.3 CALL DROP COUNTERS INCREMENT LOGIC Radio Link Timeout increasing and decreasing in below sequence. it sends ERROR INDICATION with cause unsolicited DM response (0x05) to BSC. Also if ERROR INDICATION message sent to BSC. it sends ERROR INDICATION with cause sequence error (0x07). Unsolicited DM Response : If BTS gets unexpected DM Frame. At the end if BTS still could not get acknowledge for I Frame.2 CALL DROP COUNTERS DEFINITIONS These Call Drop counters meaning are below. it repeats sending I Frame for N200+1 times.2. Sequence Error : If BTS gets I and S Frames not in correct order. M3100C or M3200C are incremented according to suitable channel type (TCHF or TCHH). M3100B or M3200B are incremented according to suitable channel type (TCHF or TCHH). CM330 CM33C Call Drops on Radio Interface in Stable State (Traffic Channel) CM3300 Call Drops on Traffic Channel in Stable State (Error Indication) CM3301 Call Drops on Traffic Channel in Stable State (Connection Failure) Call Drops on Radio Interface (Traffic Channel) CM3302 CM33 Call Drops on Traffic Channel H3027Ca H3028Ca Call Drops on Radio H3127Ca Interface in Handover CM331 State (Traffic H3128Ca Channel) H3327Ca H3328Ca CM332 CM333 CM334 CM335 Call Drops on Traffic Channel in Stable State (Release Indication) Failed Internal Intra-Cell Handovers (TimerExpired) (TCHF) (TrafficChannel) Failed Internal Intra-Cell Handovers (TimerExpired) (TCHH) (TrafficChannel) Number of Unsuccessful Outgoing Internal Inter-CellHandovers (Timer Expired)(TCHF) Number of Unsuccessful Outgoing Internal Inter-CellHandovers (Timer Expired)(TCHH) Failed Outgoing External Inter-Cell Handovers (T8 Expiry)(TCHF) (Traffic Failed Outgoing External Inter-Cell Handovers (T8 Expiry)(TCHH) (Traffic M3100A M3100B M3100C M3200A M3200B M3200C M3101A M3101B M3101C M3101D M3101E M3201A M3201B M3201C M3201D M3201E M3102 M3202 Call Call Call Call Call Call Call Call Call Call Call Call Call Call Call Call Call Call Drops due to ERR IND Received on TCHF (Traffic Channel) in Stable State (T200 Expired) Drops due to ERR IND Received on TCHF (Traffic Channel) in Stable State (Unsolicited DM Response) Drops due to ERR IND Received on TCHF (Traffic Channel) in Stable State (Sequence Error) Drops due to ERR IND Received on TCHH (Traffic Channel) in Stable State (T200 Expired) Drops due to ERR IND Received on TCHH (Traffic Channel) in Stable State (Unsolicited DM Response) Drops due to ERR IND Received on TCHH (Traffic Channel) in Stable State (Sequence Error) Drops due to CONN FAIL Received on TCHF (Traffic Channel) in Stable State (Radio Link Failure) Drops due to CONN FAIL Received on TCHF (Traffic Channel) in Stable State (HO Access Failure) Drops due to CONN FAIL Received on TCHF (Traffic Channel) in Stable State (OM Intervention) Drops due to CONN FAIL Received on TCHF (Traffic Channel) in Stable State (Radio Resource Unavailable) Drops due to CONN FAIL Received on TCHF (Traffic Channel) in Stable State (Other Causes) Drops due to CONN FAIL Received on TCHH (Traffic Channel) in Stable State (Radio Link Failure) Drops due to CONN FAIL Received on TCHH (Traffic Channel) in Stable State (HO Access Failure) Drops due to CONN FAIL Received on TCHH (Traffic Channel) in Stable State (OM Intervention) Drops due to CONN FAIL Received on TCHH (Traffic Channel) in Stable State (Radio Resource Unavailable) Drops due to CONN FAIL Received on TCHH (Traffic Channel) in Stable State (Other Causes) Drops due to REL IND Received on TCHF (Traffic Channel) Drops due to REL IND Received on TCHH (Traffic Channel) Call Drops Due to No MR from MS for a Long Time (Traffic Channel) Call Drops due to Abis Terrestrial Link Failure (Traffic Channel) Call Drops due to Equipment Failure (Traffic Channel) Call Drops due to Forced Handover (Traffic Channel) 2. If CONECTION FAILURE message sent to BSC. RLT decreased by one. As seen. T200 expired : If BTS could not receive any acknowledge message to send I Frame till T200 expired. If RLT becomes zero than Radio Link will be released. It is calculated continuously for both uplink and downlink. . reasons like. M3100A or M3200A are incremented according to suitable channel type (TCHF or TCHH). it sends ERROR INDICATION with cause of timer T200 expired (N200+1) times (0x01) to BSC. decoded SACCH occurs increased by two. 4 6.1 0. OM Intervention.0 9. M3201D and M3201E are incremented. 3.0 0.0 7.0 0.1 0.0 0. All of Error Indication drops occurs in T200 expired.0 0.0 99.1 0. Radio Resource Unavailable and Other Causes.0 34. one of the M3101A. we should focus on T200 expired drops.0 Sum of M3100A:Ca l l Drops due to ERR IND Recei ved on TCHF (Tra ffi c Cha nnel ) i n Stabl e State (T200 Expi red)(times ) Sum of M3100B:Ca l l Drops due to ERR IND Recei ved on TCHF (Tra ffi c Cha nnel ) i n Stabl e State (Uns ol i ci ted DM Res pons e)(times ) Sum of M3100C:Ca l l Drops due to ERR IND Recei ved on TCHF (Tra ffi c Cha nnel ) i n Stabl e State (Sequence Error)(times ) Sum of M3200A:Ca l l Drops due to ERR IND Recei ved on TCHH (Tra ffi c Cha nnel ) i n Stabl e State (T200 Expi red)(times ) Sum of M3200B:Ca l l Drops due to ERR IND Recei ved on TCHH (Tra ffi c Cha nnel ) i n Stabl e State (Uns ol i ci ted DM Res pons e)(times ) Sum of M3200C:Ca l l Drops due to ERR IND Recei ved on TCHH (Tra ffi c Cha nnel ) i n Stabl e State (Sequence Error)(times ) 4554 0 1 392 0 0 92. M3201A.0 0. % 90. M3101B.2 100.0 0.7 65.1 100.0 0.9 0.0 . M3101D. According to reason and suitable channel type.2 of Radio Interface Drops occurs in Stable State.1 CALL DROP CAUSE ANALYSIS For troubleshooting. As seen in one day total drop numbers.0 0.0 Sum of M3101A:Ca l l Drops due to CONN FAIL Recei ved on TCHF (Tra ffi c Cha nnel ) i n Stabl e State (Ra di o Li nk Fa i l ure)(times ) Sum of M3101B:Ca l l Drops due to CONN FAIL Recei ved on TCHF (Tra ffi c Cha nnel ) i n Stabl e State (HO Acces s Fa i l ure)(times ) Sum of M3101C:Ca l l Drops due to CONN FAIL Recei ved on TCHF (Tra ffi c Cha nnel ) i n Stabl e State (OM Intervention)(times ) Sum of M3101D:Ca l l Drops due to CONN FAIL Recei ved on TCHF (Tra ffi c Cha nnel ) i n Stabl e State (Ra di o Res ource Una va i l a bl e)(times ) Sum of M3101E:Ca l l Drops due to CONN FAIL Recei ved on TCHF (Tra ffi c Cha nnel ) i n Stabl e State (Other Ca us es )(times ) Sum of M3201A:Ca l l Drops due to CONN FAIL Recei ved on TCHH (Tra ffi c Cha nnel ) i n Stabl e State (Ra di o Li nk Fa i l ure)(times ) Sum of M3201B:Ca l l Drops due to CONN FAIL Recei ved on TCHH (Tra ffi c Cha nnel ) i n Stabl e State (HO Acces s Fa i l ure)(times ) Sum of M3201C:Ca l l Drops due to CONN FAIL Recei ved on TCHH (Tra ffi c Cha nnel ) i n Stabl e State (OM Intervention)(times ) Sum of M3201D:Ca l l Drops due to CONN FAIL Recei ved on TCHH (Tra ffi c Cha nnel ) i n Stabl e State (Ra di o Res ource Una va i l a bl e)(times ) Sum of M3201E:Ca l l Drops due to CONN FAIL Recei ved on TCHH (Tra ffi c Cha nnel ) i n Stabl e State (Other Ca us es )(times ) 9079 6 0 0 0 468 0 0 0 0 95.0 Sum of H3027Ca :Fa i l ed Sum of H3028Ca :Fa i l ed Sum of H3127Ca :Fa i l ed Sum of H3128Ca :Fa i l ed Sum of H3327Ca :Fa i l ed Sum of H3328Ca :Fa i l ed 1 4 1472 97 2 0 0.0 Interna l Intra -Cel l Ha ndovers (Ti mer Expi red) (TCHF) (Tra ffi c Cha nnel )(times ) Interna l Intra -Cel l Ha ndovers (Ti mer Expi red) (TCHH) (Tra ffi c Cha nnel )(times ) Outgoi ng Interna l Inter-Cel l Ha ndovers (Ti mer Expi red) (TCHF) (Tra ffi c Cha nnel )(times ) Outgoi ng Interna l Inter-Cel l Ha ndovers (Ti mer Expi red) (TCHH) (Tra ffi c Cha nnel )(times ) Outgoi ng Externa l Inter-Cel l Ha ndovers (T8 Expi red) (TCHF) (Tra ffi c Cha nnel )(times ) Outgoi ng Externa l Inter-Cel l Ha ndovers (T8 Expi red) (TCHH) (Tra ffi c Cha nnel )(times ) Sum of CM332:Call Drops due to No MRs from MS for a Long Time (Traffic Channel)(times) Sum of CM333:Call Drops due to Abis Terrestrial Link Failure (Traffic Channel)(times) Sum of CM334:Call Drops due to Equipment Failure (Traffic Channel)(times) Sum of CM335:Call Drops due to Forced Handover (Traffic Channel)(times) 2 0 45 7 100.3 93. M3201B. All of Connection Failure drops occurs in Radio Link Failure. Get stats for all call drop counters for a period. If Multi Frame link established and BTS gets DICS Frame from MS.0 Sum of CM331:Call Drops on Radio Interface in Handover State (Traffic Channel)(times) 1576 100. M3201C. So generally. M3101C.1 0.9 0.0 Sum of M3102:Ca l l Drops due to REL IND Recei ved on TCHF (Tra ffi c Cha nnel )(times ) Sum of M3202:Ca l l Drops due to REL IND Recei ved on TCHH (Tra ffi c Cha nnel )(times ) 5 0 100. HO Access Failure.8 0.0 0.3 0. Drop counters Values Level 1 Level 2 Level 3 Level 4 Sum of CM33:Call Drops on Traffic Channel(times) Sum of CM33C:Call Drops on Radio Interface (Traffic Channel)(times) Sum of CM330:Call Drops on Radio Interface in Stable State (Traffic Channel)(times) Sum of CM3300:Call Drops on Traffic Channel in Stable State (Error Indication)(times) 16135 16081 14505 4947 100.0 4. than BTS sends RELEASE INDICATION to BSC according to suitable channel type.2 0. % 99.0 Sum of CM3301:Call Drops on Traffic Channel in Stable State (Connection Failure)(times) 9553 100.9 in Connection Failure.0 0.In Uplink.0 90.7 of drops occurs in Radio Interface. CALL DROP TROUBLESHOOTING 3.9 0. Radio Link Failure drops. if BTS could not decode SACCH then it sends to BSC CONNECTION FAILURE message with reasons Radio Link Failure. % 34.1 of Stable Drops occurs in Error Indication and % 65.0 Sum of CM3302:Call Drops on Traffic Channel in Stable State (Release Indication)(times) 5 100. first thing to do search about what kind of drops occurs generally.0 0. M3101E. Also Failed Outgoing Internal Inter-Cell Handovers (Timer Expired) drops are should be touched. TCH/F Uplink DTX. Missing Neighbor Relations. PT. These would affect general quality of serving cell. Equipment Failure drops caused by HW problems and Forced Handover drops caused by OM Intervention. In Call Control Parameter set. BS-PA-MFRAMS. Wrong cell to cell neighbor parameters or timers. TCH/F Use Downlink DTX. T200 SACCH SDCCH. T200 SDCCH. T3111. These would affect service area of cell. Quality or Interference problems. Coverage gaps. e should he k ge eral para eters of this ell a d also this ell’s eigh or ells. In Idle Mode Parameter set. CRO. T200 SDCCH SAPI3. T200 FACCH/F. T3107. 3. HW Fault or Installation faults. T3122 should be checked. Cell Priority. MAX TA. AFR Radio Link Timeout. AFR SACCH Multi-Frames. SACCH Multi-Frames.2 CALL DROP REASONS for GENERAL CALL DROP TYPES Other drops like Abis Terrestrial Link Failure drop caused by Transmission Link broken. Cell IUO Type. Wrong or missing neighbor definitions. T7. Direct Retry. the reasons are. N200 . Coverage gaps. T3101. T3103C. AHR Radio Link Timeout. LAC. T3212. Parameter definition and OSS problems. Encryption Algorithm. Also for other big percent of drop cause Failed Outgoing Internal Inter-Cell Handovers (Timer Expired). In Basic Attributes Parameter set. UL PC Allowed. TCH/H Downlink DTX should be checked. These drops should be handled by separately. T3121. Quality or Interference problems. HW Faults or Installation faults. AHR SACCH Multi-Frames. If cell is a border cell or have external definitions in other BSCs or RNCs. TCH/H Uplink DTX. DL PC Allowed. MS MAX Retrans. Cells general parameters like. N200 of Establish. Unbalanced Path Losses. CRH. T200 FACCH/H. TO. N200 of Release. These would affect general quality of serving cell. RXLEV_ACCESS_MIN. T3103A. PI. For these two general drop cause Radio Link Timeout and T200 Expired.3 TROUBLESHOOT STEPS FOR CALL DROP 3. T200 SACCH TCH SAPI0. Radio Link Timeout. T200 SACCH TCH SAPI3.1 PARAMETER PROBLEMS First of all for a pro le ati ell. In Other Attributes Parameter set. MS_TXPWR_MAX_CCH. Layer of Cell.3. STIRC Allowed. Use LAPDm N200.3. the reasons are. All external definitions should be checked also. Paging Times. Cell Extension Type. T8. NCC Permitted should be checked. T3109. You should keep in mind that.of SACCH. TA HO Allowed. It is TRX based. it would affect path balance. TRX Power parameters differences.HO Allowed should be checked. hysteresis and thresholds between cells would affect HO performance between these cells. Intracell HO Allowed. BQ HO Allowed. MR. Power Level.3. No Dl Mr. Pathloss Ho. HW Problems. These differences generally points out. These would affect deciding faster or slower of HO. RXU definitions. N200 of SDCCH. N200 of FACCH/Full rate should be checked. Also Cell to Cell neighbor definitions should be checked. Power Type parameters would decide maximum TRX output power.DL Path Loss. Load HO Allowed. Co-BSC/MSC Adj. On left these counters are shown. Send mode and Receive mode definitions problems. More samples less than 3 means there is a DL Path Loss problem more samples greater than 8 means there is a UL Path Loss problem. PBGT HO Allowed. So it is expected to be all samples in 6 ideally. Also if there is a Power difference between TRXs of cells. These would affect HO performance and decision of serving cell. 6 means difference is zero. Concentric Circles HO Allowed. . Rx_Level_Drop HO Allowed. 3. Timer. Fringe HO Allowed. Power Fine Tune. UtoO Traffic HO Allowed. MS Fast Moving HO Allowed.Preprocessing. Penalty Allowed. In Handover Data Parameter set. Formula is UL Path Loss. Intracell F-H HO Allowed. Quick Handover Enable. so we could see unbalanced TRX or have an opinion about feeder connections. Level HO Allowed. By counter meaning. if there is a TMA installation in sector path balance would shift to 1 or in use of PBT (Power Boost Technology) path balance would shift to 11 because of power changes. These would affect deciding time of drop events. N200 of FACH/Half rate. Cross-connections of feeder between sectors.2 PATH BALANCE PROBLEMS COUNTER NUMBER S462A S462B S462C S462D S462E S462F S462G S462H S462I S462J S462K COUNTER NAME Number of MRs (Uplink-and-Downlink Number of MRs (Uplink-and-Downlink Number of MRs (Uplink-and-Downlink Number of MRs (Uplink-and-Downlink Number of MRs (Uplink-and-Downlink Number of MRs (Uplink-and-Downlink Number of MRs (Uplink-and-Downlink Number of MRs (Uplink-and-Downlink Number of MRs (Uplink-and-Downlink Number of MRs (Uplink-and-Downlink Number of MRs (Uplink-and-Downlink Balance Level Balance Level Balance Level Balance Level Balance Level Balance Level Balance Level Balance Level Balance Level Balance Level Balance Level = = = = = = = = = = = 1)(times) 2)(times) 3)(times) 4)(times) 5)(times) 6)(times) 7)(times) 8)(times) 9)(times) 10)(times) 11)(times) Path Balance is a statistic considering Uplink Path Loss and Downlink Path Loss. In TRX definitions. Enable. Also the parameters related with Watch Time/Valid Time should be checked. Interference HO Allowed. TCHF Re ei e Le el Measure e t per TRX . ers of MRs ased o TA per TRX ou ters are sho These counters are MR samples in each TA based on TRX. HW Check should be done. TCHH Re ei e Le el Measure e t per TRX easure e t sets should e used. COUNTER NUMBER S4400A S4401A S4402A S4403A S4404A S4405A S4406A S4407A S4408A S4409A S4410A S4411A S4412A S4413A S4414A S4415A S4416A S4417A S4418A S4419A S4420A S4421A S4422A S4423A S4424A S4425A S4426A S4427A S4428A S4429A S4430A S4432A S4434A S4436A S4438A S4440A S4445A S4450A S4455A S4463A COUNTER NAME Num ber of MRs (TA = 0)(tim es ) Num ber of MRs (TA = 1)(tim es ) Num ber of MRs (TA = 2)(tim es ) Num ber of MRs (TA = 3)(tim es ) Num ber of MRs (TA = 4)(tim es ) Num ber of MRs (TA = 5)(tim es ) Num ber of MRs (TA = 6)(tim es ) Num ber of MRs (TA = 7)(tim es ) Num ber of MRs (TA = 8)(tim es ) Num ber of MRs (TA = 9)(tim es ) Num ber of MRs (TA = 10)(tim es ) Num ber of MRs (TA = 11)(tim es ) Num ber of MRs (TA = 12)(tim es ) Num ber of MRs (TA = 13)(tim es ) Num ber of MRs (TA = 14)(tim es ) Num ber of MRs (TA = 15)(tim es ) Num ber of MRs (TA = 16)(tim es ) Num ber of MRs (TA = 17)(tim es ) Num ber of MRs (TA = 18)(tim es ) Num ber of MRs (TA = 19)(tim es ) Num ber of MRs (TA = 20)(tim es ) Num ber of MRs (TA = 21)(tim es ) Num ber of MRs (TA = 22)(tim es ) Num ber of MRs (TA = 23)(tim es ) Num ber of MRs (TA = 24)(tim es ) Num ber of MRs (TA = 25)(tim es ) Num ber of MRs (TA = 26)(tim es ) Num ber of MRs (TA = 27)(tim es ) Num ber of MRs (TA = 28)(tim es ) Num ber of MRs (TA = 29)(tim es ) Num ber of MRs (TA = 30 or 31)(tim es ) Num ber of MRs (TA = 32 or 33)(tim es ) Num ber of MRs (TA = 34 or 35)(tim es ) Num ber of MRs (TA = 36 or 37)(tim es ) Num ber of MRs (TA = 38 or 39)(tim es ) Num ber of MRs (TA = 40 to 44)(tim es ) Num ber of MRs (TA = 45 to 49)(tim es ) Num ber of MRs (TA = 50 to 54)(tim es ) Num ber of MRs (TA = 55 to 63)(tim es ) Num ber of MRs (TA greater than 63)(tim es ) elo . 3.There are sample stats of TRX based path balance statistic. As seen on the left for TRX1343 there is a Uplink path loss problem. .3. Radio Li k Failure Measure e t ased o TA per TRX .3 COVERAGE GAPS PROBLEMS For finding coverage gaps. Nu Nu ers of MRs ased o TA per TRX . As seen in below graph. cells have some overshooting and coverage gaps. ou ters are . COUNTER NUMBER COUNTER NAME S4400B Ra di o Li nk Fa i l ures (TA = 0)(ti mes ) S4401B Ra di o Li nk Fa i l ures (TA = 1)(ti mes ) S4402B Ra di o Li nk Fa i l ures (TA = 2)(ti mes ) S4403B Ra di o Li nk Fa i l ures (TA = 3)(ti mes ) S4404B Ra di o Li nk Fa i l ures (TA = 4)(ti mes ) S4405B Ra di o Li nk Fa i l ures (TA = 5)(ti mes ) S4406B Ra di o Li nk Fa i l ures (TA = 6)(ti mes ) S4407B Ra di o Li nk Fa i l ures (TA = 7)(ti mes ) S4408B Ra di o Li nk Fa i l ures (TA = 8)(ti mes ) S4409B Ra di o Li nk Fa i l ures (TA = 9)(ti mes ) S4410B Ra di o Li nk Fa i l ures (TA = 10)(ti mes ) S4411B Ra di o Li nk Fa i l ures (TA = 11)(ti mes ) S4412B Ra di o Li nk Fa i l ures (TA = 12)(ti mes ) S4413B Ra di o Li nk Fa i l ures (TA = 13)(ti mes ) S4414B Ra di o Li nk Fa i l ures (TA = 14)(ti mes ) S4415B Ra di o Li nk Fa i l ures (TA = 15)(ti mes ) S4416B Ra di o Li nk Fa i l ures (TA = 16)(ti mes ) S4417B Ra di o Li nk Fa i l ures (TA = 17)(ti mes ) S4418B Ra di o Li nk Fa i l ures (TA = 18)(ti mes ) S4419B Ra di o Li nk Fa i l ures (TA = 19)(ti mes ) S4420B Ra di o Li nk Fa i l ures (TA = 20)(ti mes ) S4421B Ra di o Li nk Fa i l ures (TA = 21)(ti mes ) S4422B Ra di o Li nk Fa i l ures (TA = 22)(ti mes ) S4423B Ra di o Li nk Fa i l ures (TA = 23)(ti mes ) S4424B Ra di o Li nk Fa i l ures (TA = 24)(ti mes ) S4425B Ra di o Li nk Fa i l ures (TA = 25)(ti mes ) S4426B Ra di o Li nk Fa i l ures (TA = 26)(ti mes ) S4427B Ra di o Li nk Fa i l ures (TA = 27)(ti mes ) S4428B Ra di o Li nk Fa i l ures (TA = 28)(ti mes ) S4429B Ra di o Li nk Fa i l ures (TA = 29)(ti mes ) S4430B Ra di o Li nk Fa i l ures (TA = 30 or 31)(ti mes ) S4432B Ra di o Li nk Fa i l ures (TA = 32 or 33)(ti mes ) S4434B Ra di o Li nk Fa i l ures (TA = 34 or 35)(ti mes ) S4436B Ra di o Li nk Fa i l ures (TA = 36 or 37)(ti mes ) S4438B Ra di o Li nk Fa i l ures (TA = 38 or 39)(ti mes ) S4440B Ra di o Li nk Fa i l ures (TA = 40 to 44)(ti mes ) S4445B Ra di o Li nk Fa i l ures (TA = 45 to 49)(ti mes ) S4450B Ra di o Li nk Fa i l ures (TA = 50 to 54)(ti mes ) S4455B Ra di o Li nk Fa i l ures (TA = 55 to 63)(ti mes ) S4463B Ra di o Li nk Fa i l ures (TA grea ter tha n 63)(ti mes ) Radio Li k Failure Measure e t ased o TA per TRX shown on the left. There are COUNTER NUMBER S4100A S4101A S4102A S4103A S4104A S4105A S4106A S4107A S4110A S4111A S4112A S4113A S4114A S4115A S4116A S4117A S4120A S4121A S4122A S4123A S4124A S4125A S4126A S4127A S4130A S4131A S4132A S4133A S4134A S4135A S4136A S4137A S4140A S4141A S4142A S4143A S4144A S4145A S4146A S4147A S4150A S4151A S4152A S4153A S4154A S4155A S4156A S4157A S4160A S4161A S4162A S4163A S4164A S4165A S4166A S4167A S4170A S4171A S4172A S4173A S4174A S4175A S4176A S4177A 8 ou ter for each RxLevel between 0- COUNTER NAME Number of MRs on Uplink TCHF (Receive Level Rank 0 and Receive Quality Rank 0)(times) Number of MRs on Uplink TCHF (Receive Level Rank 0 and Receive Quality Rank 1)(times) Number of MRs on Uplink TCHF (Receive Level Rank 0 and Receive Quality Rank 2)(times) Number of MRs on Uplink TCHF (Receive Level Rank 0 and Receive Quality Rank 3)(times) Number of MRs on Uplink TCHF (Receive Level Rank 0 and Receive Quality Rank 4)(times) Number of MRs on Uplink TCHF (Receive Level Rank 0 and Receive Quality Rank 5)(times) Number of MRs on Uplink TCHF (Receive Level Rank 0 and Receive Quality Rank 6)(times) Number of MRs on Uplink TCHF (Receive Level Rank 0 and Receive Quality Rank 7)(times) Number of MRs on Uplink TCHF (Receive Level Rank 1 and Receive Quality Rank 0)(times) Number of MRs on Uplink TCHF (Receive Level Rank 1 and Receive Quality Rank 1)(times) Number of MRs on Uplink TCHF (Receive Level Rank 1 and Receive Quality Rank 2)(times) Number of MRs on Uplink TCHF (Receive Level Rank 1 and Receive Quality Rank 3)(times) Number of MRs on Uplink TCHF (Receive Level Rank 1 and Receive Quality Rank 4)(times) Number of MRs on Uplink TCHF (Receive Level Rank 1 and Receive Quality Rank 5)(times) Number of MRs on Uplink TCHF (Receive Level Rank 1 and Receive Quality Rank 6)(times) Number of MRs on Uplink TCHF (Receive Level Rank 1 and Receive Quality Rank 7)(times) Number of MRs on Uplink TCHF (Receive Level Rank 2 and Receive Quality Rank 0)(times) Number of MRs on Uplink TCHF (Receive Level Rank 2 and Receive Quality Rank 1)(times) Number of MRs on Uplink TCHF (Receive Level Rank 2 and Receive Quality Rank 2)(times) Number of MRs on Uplink TCHF (Receive Level Rank 2 and Receive Quality Rank 3)(times) Number of MRs on Uplink TCHF (Receive Level Rank 2 and Receive Quality Rank 4)(times) Number of MRs on Uplink TCHF (Receive Level Rank 2 and Receive Quality Rank 5)(times) Number of MRs on Uplink TCHF (Receive Level Rank 2 and Receive Quality Rank 6)(times) Number of MRs on Uplink TCHF (Receive Level Rank 2 and Receive Quality Rank 7)(times) Number of MRs on Uplink TCHF (Receive Level Rank 3 and Receive Quality Rank 0)(times) Number of MRs on Uplink TCHF (Receive Level Rank 3 and Receive Quality Rank 1)(times) Number of MRs on Uplink TCHF (Receive Level Rank 3 and Receive Quality Rank 2)(times) Number of MRs on Uplink TCHF (Receive Level Rank 3 and Receive Quality Rank 3)(times) Number of MRs on Uplink TCHF (Receive Level Rank 3 and Receive Quality Rank 4)(times) Number of MRs on Uplink TCHF (Receive Level Rank 3 and Receive Quality Rank 5)(times) Number of MRs on Uplink TCHF (Receive Level Rank 3 and Receive Quality Rank 6)(times) Number of MRs on Uplink TCHF (Receive Level Rank 3 and Receive Quality Rank 7)(times) Number of MRs on Uplink TCHF (Receive Level Rank 4 and Receive Quality Rank 0)(times) Number of MRs on Uplink TCHF (Receive Level Rank 4 and Receive Quality Rank 1)(times) Number of MRs on Uplink TCHF (Receive Level Rank 4 and Receive Quality Rank 2)(times) Number of MRs on Uplink TCHF (Receive Level Rank 4 and Receive Quality Rank 3)(times) Number of MRs on Uplink TCHF (Receive Level Rank 4 and Receive Quality Rank 4)(times) Number of MRs on Uplink TCHF (Receive Level Rank 4 and Receive Quality Rank 5)(times) Number of MRs on Uplink TCHF (Receive Level Rank 4 and Receive Quality Rank 6)(times) Number of MRs on Uplink TCHF (Receive Level Rank 4 and Receive Quality Rank 7)(times) Number of MRs on Uplink TCHF (Receive Level Rank 5 and Receive Quality Rank 0)(times) Number of MRs on Uplink TCHF (Receive Level Rank 5 and Receive Quality Rank 1)(times) Number of MRs on Uplink TCHF (Receive Level Rank 5 and Receive Quality Rank 2)(times) Number of MRs on Uplink TCHF (Receive Level Rank 5 and Receive Quality Rank 3)(times) Number of MRs on Uplink TCHF (Receive Level Rank 5 and Receive Quality Rank 4)(times) Number of MRs on Uplink TCHF (Receive Level Rank 5 and Receive Quality Rank 5)(times) Number of MRs on Uplink TCHF (Receive Level Rank 5 and Receive Quality Rank 6)(times) Number of MRs on Uplink TCHF (Receive Level Rank 5 and Receive Quality Rank 7)(times) Number of MRs on Uplink TCHF (Receive Level Rank 6 and Receive Quality Rank 0)(times) Number of MRs on Uplink TCHF (Receive Level Rank 6 and Receive Quality Rank 1)(times) Number of MRs on Uplink TCHF (Receive Level Rank 6 and Receive Quality Rank 2)(times) Number of MRs on Uplink TCHF (Receive Level Rank 6 and Receive Quality Rank 3)(times) Number of MRs on Uplink TCHF (Receive Level Rank 6 and Receive Quality Rank 4)(times) Number of MRs on Uplink TCHF (Receive Level Rank 6 and Receive Quality Rank 5)(times) Number of MRs on Uplink TCHF (Receive Level Rank 6 and Receive Quality Rank 6)(times) Number of MRs on Uplink TCHF (Receive Level Rank 6 and Receive Quality Rank 7)(times) Number of MRs on Uplink TCHF (Receive Level Rank 7 and Receive Quality Rank 0)(times) Number of MRs on Uplink TCHF (Receive Level Rank 7 and Receive Quality Rank 1)(times) Number of MRs on Uplink TCHF (Receive Level Rank 7 and Receive Quality Rank 2)(times) Number of MRs on Uplink TCHF (Receive Level Rank 7 and Receive Quality Rank 3)(times) Number of MRs on Uplink TCHF (Receive Level Rank 7 and Receive Quality Rank 4)(times) Number of MRs on Uplink TCHF (Receive Level Rank 7 and Receive Quality Rank 5)(times) Number of MRs on Uplink TCHF (Receive Level Rank 7 and Receive Quality Rank 6)(times) Number of MRs on Uplink TCHF (Receive Level Rank 7 and Receive Quality Rank 7)(times) . it could be said that in that TA area there is a coverage problem. COUNTER NUMBER S4100B S4101B S4102B S4103B S4104B S4105B S4106B S4107B S4110B S4111B S4112B S4113B S4114B S4115B S4116B S4117B S4120B S4121B S4122B S4123B S4124B S4125B S4126B S4127B S4130B S4131B S4132B S4133B S4134B S4135B S4136B S4137B S4140B S4141B S4142B S4143B S4144B S4145B S4146B S4147B S4150B S4151B S4152B S4153B S4154B S4155B S4156B S4157B S4160B S4161B S4162B S4163B S4164B S4165B S4166B S4167B S4170B S4171B S4172B S4173B S4174B S4175B S4176B S4177B COUNTER NAME Number of MRs on Downlink TCHF (Receive Level Rank 0 and Receive Quality Rank 0)(times) Number of MRs on Downlink TCHF (Receive Level Rank 0 and Receive Quality Rank 1)(times) Number of MRs on Downlink TCHF (Receive Level Rank 0 and Receive Quality Rank 2)(times) Number of MRs on Downlink TCHF (Receive Level Rank 0 and Receive Quality Rank 3)(times) Number of MRs on Downlink TCHF (Receive Level Rank 0 and Receive Quality Rank 4)(times) Number of MRs on Downlink TCHF (Receive Level Rank 0 and Receive Quality Rank 5)(times) Number of MRs on Downlink TCHF (Receive Level Rank 0 and Receive Quality Rank 6)(times) Number of MRs on Downlink TCHF (Receive Level Rank 0 and Receive Quality Rank 7)(times) Number of MRs on Downlink TCHF (Receive Level Rank 1 and Receive Quality Rank 0)(times) Number of MRs on Downlink TCHF (Receive Level Rank 1 and Receive Quality Rank 1)(times) Number of MRs on Downlink TCHF (Receive Level Rank 1 and Receive Quality Rank 2)(times) Number of MRs on Downlink TCHF (Receive Level Rank 1 and Receive Quality Rank 3)(times) Number of MRs on Downlink TCHF (Receive Level Rank 1 and Receive Quality Rank 4)(times) Number of MRs on Downlink TCHF (Receive Level Rank 1 and Receive Quality Rank 5)(times) Number of MRs on Downlink TCHF (Receive Level Rank 1 and Receive Quality Rank 6)(times) Number of MRs on Downlink TCHF (Receive Level Rank 1 and Receive Quality Rank 7)(times) Number of MRs on Downlink TCHF (Receive Level Rank 2 and Receive Quality Rank 0)(times) Number of MRs on Downlink TCHF (Receive Level Rank 2 and Receive Quality Rank 1)(times) Number of MRs on Downlink TCHF (Receive Level Rank 2 and Receive Quality Rank 2)(times) Number of MRs on Downlink TCHF (Receive Level Rank 2 and Receive Quality Rank 3)(times) Number of MRs on Downlink TCHF (Receive Level Rank 2 and Receive Quality Rank 4)(times) Number of MRs on Downlink TCHF (Receive Level Rank 2 and Receive Quality Rank 5)(times) Number of MRs on Downlink TCHF (Receive Level Rank 2 and Receive Quality Rank 6)(times) Number of MRs on Downlink TCHF (Receive Level Rank 2 and Receive Quality Rank 7)(times) Number of MRs on Downlink TCHF (Receive Level Rank 3 and Receive Quality Rank 0)(times) Number of MRs on Downlink TCHF (Receive Level Rank 3 and Receive Quality Rank 1)(times) Number of MRs on Downlink TCHF (Receive Level Rank 3 and Receive Quality Rank 2)(times) Number of MRs on Downlink TCHF (Receive Level Rank 3 and Receive Quality Rank 3)(times) Number of MRs on Downlink TCHF (Receive Level Rank 3 and Receive Quality Rank 4)(times) Number of MRs on Downlink TCHF (Receive Level Rank 3 and Receive Quality Rank 5)(times) Number of MRs on Downlink TCHF (Receive Level Rank 3 and Receive Quality Rank 6)(times) Number of MRs on Downlink TCHF (Receive Level Rank 3 and Receive Quality Rank 7)(times) Number of MRs on Downlink TCHF (Receive Level Rank 4 and Receive Quality Rank 0)(times) Number of MRs on Downlink TCHF (Receive Level Rank 4 and Receive Quality Rank 1)(times) Number of MRs on Downlink TCHF (Receive Level Rank 4 and Receive Quality Rank 2)(times) Number of MRs on Downlink TCHF (Receive Level Rank 4 and Receive Quality Rank 3)(times) Number of MRs on Downlink TCHF (Receive Level Rank 4 and Receive Quality Rank 4)(times) Number of MRs on Downlink TCHF (Receive Level Rank 4 and Receive Quality Rank 5)(times) Number of MRs on Downlink TCHF (Receive Level Rank 4 and Receive Quality Rank 6)(times) Number of MRs on Downlink TCHF (Receive Level Rank 4 and Receive Quality Rank 7)(times) Number of MRs on Downlink TCHF (Receive Level Rank 5 and Receive Quality Rank 0)(times) Number of MRs on Downlink TCHF (Receive Level Rank 5 and Receive Quality Rank 1)(times) Number of MRs on Downlink TCHF (Receive Level Rank 5 and Receive Quality Rank 2)(times) Number of MRs on Downlink TCHF (Receive Level Rank 5 and Receive Quality Rank 3)(times) Number of MRs on Downlink TCHF (Receive Level Rank 5 and Receive Quality Rank 4)(times) Number of MRs on Downlink TCHF (Receive Level Rank 5 and Receive Quality Rank 5)(times) Number of MRs on Downlink TCHF (Receive Level Rank 5 and Receive Quality Rank 6)(times) Number of MRs on Downlink TCHF (Receive Level Rank 5 and Receive Quality Rank 7)(times) Number of MRs on Downlink TCHF (Receive Level Rank 6 and Receive Quality Rank 0)(times) Number of MRs on Downlink TCHF (Receive Level Rank 6 and Receive Quality Rank 1)(times) Number of MRs on Downlink TCHF (Receive Level Rank 6 and Receive Quality Rank 2)(times) Number of MRs on Downlink TCHF (Receive Level Rank 6 and Receive Quality Rank 3)(times) Number of MRs on Downlink TCHF (Receive Level Rank 6 and Receive Quality Rank 4)(times) Number of MRs on Downlink TCHF (Receive Level Rank 6 and Receive Quality Rank 5)(times) Number of MRs on Downlink TCHF (Receive Level Rank 6 and Receive Quality Rank 6)(times) Number of MRs on Downlink TCHF (Receive Level Rank 6 and Receive Quality Rank 7)(times) Number of MRs on Downlink TCHF (Receive Level Rank 7 and Receive Quality Rank 0)(times) Number of MRs on Downlink TCHF (Receive Level Rank 7 and Receive Quality Rank 1)(times) Number of MRs on Downlink TCHF (Receive Level Rank 7 and Receive Quality Rank 2)(times) Number of MRs on Downlink TCHF (Receive Level Rank 7 and Receive Quality Rank 3)(times) Number of MRs on Downlink TCHF (Receive Level Rank 7 and Receive Quality Rank 4)(times) Number of MRs on Downlink TCHF (Receive Level Rank 7 and Receive Quality Rank 5)(times) Number of MRs on Downlink TCHF (Receive Level Rank 7 and Receive Quality Rank 6)(times) Number of MRs on Downlink TCHF (Receive Level Rank 7 and Receive Quality Rank 7)(times) elo .Fro Radio Li k Failure Measure e t ased o TA per TRX ou ters. ou ould ha e a idea of here ells drop generally occurs. RxQuality between 0-7. If it is gathered to one TA. TCHF Re ei e Le el Measure e t per TRX ou ters are sho 7 (-110 dBm—47 dBm). As seen above. TCHH Re ei e Le el Measure e t per TRX easure e t sets should e used. coverage gap related call drop may occur. Interference Band Measurement per Cell .3. mechanic and electric tilt degree may be changed or cell addition may be done. ala ed upli k a d do li k R Le els. it ea s ell is For solutions of coverage gaps and overshoot problems. For HW problems. If ell’s TCH Re ei e Le el easure e ts sho s ells ha e u a dragon cells with overshoot service areas or have HW problem. coverage gap related call drop may occur. I terfere e Ba d Measure e t per Cell ou ters are sho elo . Neighbor Cell Level Measurement per Cell . TCHF Re ei e Le el Measure e t per TRX . If ell’s TA distribution shows cell covers a big area with overshoots. As a result. in that TRX there is some Uplink signal level problem. . Cross connection. ell o er a ig area a d drop gathers i o e TA (or so e of TA). HW check should be done detailed. VSWR may be problem. cells antenna direction. 3. If ell’s RLT o er TA a d TA distri utio sho s together. RLT over TA distribution and TCH Receive Level measurements. height. according to TA distribution.4 QUALITY and INTERFERENCE PROBLEMS For finding quality and interference problems. If there is interference. it means that Band5 counters should be incremented. it means cell have uplink interference and frequency change should be considered. (Keep in mind that BB Hopping will affect this result. for test hopping should be closed) . BTS measure uplink interference according to below signal level table.COUNTER NUMBER AS4200A AS4200B AS4200C AS4200D AS4200E AS4207A AS4207B AS4207C AS4207D AS4207E AS4208A AS4208B AS4208C AS4208D AS4208E COUNTER NAME Mean Number of SDCCHs in Interference Band 1(number) Mean Number of SDCCHs in Interference Band 2(number) Mean Number of SDCCHs in Interference Band 3(number) Mean Number of SDCCHs in Interference Band 4(number) Mean Number of SDCCHs in Interference Band 5(number) Mean Number of TCHFs in Interference Band 1(number) Mean Number of TCHFs in Interference Band 2(number) Mean Number of TCHFs in Interference Band 3(number) Mean Number of TCHFs in Interference Band 4(number) Mean Number of TCHFs in Interference Band 5(number) Mean Number of TCHHs in Interference Band 1(number) Mean Number of TCHHs in Interference Band 2(number) Mean Number of TCHHs in Interference Band 3(number) Mean Number of TCHHs in Interference Band 4(number) Mean Number of TCHHs in Interference Band 5(number) With these counters. generally this TRX has less interference If Band5 numbers is high. Interference Band Interference band 1 Interference band 2 Interference band 3 Interference band 4 Interference band 5 Level Threshold of the Interference Band -105 dBm to -98 dBm -98 dBm to -90 dBm -90 dBm to -87 dBm -87 dBm to -85 dBm -85 dBm to -47 dBm As seen above. COUNTER NUMBER COUNTER NAME S363 Number of MRs in Which the Signal Strength Difference Between the Serving Cell and the Neighbor Cell is Smaller Than the Neighbor Cell Interference Level Threshold 1(number) S364 Number of MRs in Which the Signal Strength Difference Between the Serving Cell and the Neighbor Cell is Greater Than the Neighbor Cell Interference Level Threshold 1(number) S365 Number of MRs in Which the Signal Strength Difference Between the Serving Cell and the Neighbor Cell is Greater Than the Neighbor Cell Interference Level Threshold 2(number) S366 Number of MRs in Which the Signal Strength Difference Between the Serving Cell and the Neighbor Cell is Greater Than the Neighbor Cell Interference Level Threshold 3(number) S367 Number of MRs in Which the Signal Strength Difference Between the Serving Cell and the Neighbor Cell is Greater Than the Neighbor Cell Interference Level Threshold 4(number) S368 Number of MRs in Which the Signal Strength Difference Between the Serving Cell and the Neighbor Cell is Greater Than the Neighbor Cell Interference Level Threshold 5(number) S369 Number of MRs in Which the Signal Strength Difference Between the Serving Cell and the Neighbor Cell is Greater Than the Neighbor Cell Interference Level Threshold 6(number) S370 Number of MRs in Which the Signal Strength Difference Between the Serving Cell and the Neighbor Cell is Greater Than the Neighbor Cell Interference Level Threshold 7(number) INNER PARAMETER Name Neighbour Cell Interference Level Neighbour Cell Interference Level Neighbour Cell Interference Level Neighbour Cell Interference Level Neighbour Cell Interference Level Neighbour Cell Interference Level Neighbour Cell Interference Level Neighbour Cell Interference Level Value Threshold 0 Threshold 1 Threshold 2 Threshold 3 Threshold 4 Threshold 5 Threshold 6 Threshold 7 0 49 55 61 64 67 73 79 According to inner BSC parameter settings. As seen below. These thresholds are shown on the left. . but BCCH frequency should be in active Ba List). According to thresholds.Neigh or Cell Le el Measure e t per Cell ou ters are sho elo . serving cell measures all BCCH in its active Ba List and decodes BSIC (not needed to be neighbor. co-channel and adjacent channel interferer of serving cells could be found. these counters incremented when measured Neighbor Cell signal level and serving cell signal level difference greater than related threshold. quality in good and bad signal levels for uplink and downlink could be detected. As seen upper graph shows uplink RxLevel-RxQual distribution.TCHF Re ei e Le el Measure e t per TRX ou ter a e used for dete ti g i terfere e pro le also. if quality problems exist in a cell. with help of neighbor cell level measurement we could find the best frequency for cell. Qualit pro le s like high Rxquality may be caused by low signal level. lower graph shows downlink RxLevel-RxQual distribution. As seen below with these counters. there is an uplink signal level problem but no interference problem. with help of above stats we should define is there an adjacent or cochannel frequency or is it related with signal level. From the graphs. . it could be said that. If it is frequency. But interference means quality is bad in good signal level also. As a result. If it is a signal level problem we should analysis for coverage gap and HW problems. . you could find which BCCH-BSICs are measured above a certain threshold.3. Best way to find missing neighbor is analysis with help of Neigh or Cell Le el Measure e t per Cell counters.5 MISSING NEIGHBOR PROBLEMS Another cause of high drop rate is missing neighbor. you could find. Than in these measured BCCH-BSICs. By thresholds in BSC Parameters. e should olle t Neigh or Cell Le el Measure e t per Cell for a period (keep i i d that active ba list of serving cell should be modified as contain all BCCHs). These counters collects all BCCH-BSIC reported by MS in MRs for serving cell.3. For example from analysis this cell should be defined as neighbor with serving cell. related counter is incremented according to signal level difference between serving cell and measured BCCH-BSIC. For finding missing eigh or. So try to give same BCCH-BSIC to cells that distance between them are as far as you can). Missing neighbor may be a real closer cell to serving cell or because of serving cell overshoot there is a far away cell that should be neighbor. which ones are defined as neighbor which ones are not. Than with help of MRs on TCHs counter. (Keep in mind that same BCCH-BSIC in an area may affect reliability of result.