[计算机软件及应用]tems基本介绍与使用.ppt

August 11, 2000,Jim Luan, Lin Mubao,Drive Test Log analysis,2019/4/20,2,Drive Test Procedure,Drive Test,Netplan,FICS,Statistics Analysis,Problem Finding,VOT/GEP,Preparation,2019/4/20,3,Preparation (1),Definition File Without it, it is impossible to observe overshooing neighbors GenDef7.exe can convert FP to definition file,Neighbor list with definition file,Neighbor list without definition file,2019/4/20,4,Preparation (2),Frequency Plan & Configuration map Software:TEMS, FICS, GEP, VOT Hardware: TEMS, GPS, Portable PC Test Problem Sheet Route Map,2019/4/20,5,Drive Test,For Benchmark 2 minutes per call 10 15 minutes a log files Force to appropriate band (GSM only, DCS only or Dual) For Special Problem Planning route No limitation,2019/4/20,6,TEMS Introduction,Interface Functions,2019/4/20,7,Log File Process,TEMS Log File,NetPlan,FICS,VOT/GEP,.CSV,.FMT,Route Map,.STA,Excel VB,.NP/.TXT,Much shorter cycle time by VOT and GEP.,2019/4/20,8,TEMS .log file Analysis,Undecoded BCCH BSIC Undecode in Other Site No Handover Delay Handover Ping Pong Handover Negative Handover Overshooting High Overlapping No Dominant Server,Poor Coverage Unreasonable Serving Area Interference Handover Failure Handover Loss UL Drop Drop Call Sudden Power Drop MS Power Rapid Increase,Below lists common problems which can be observed from Drive Test Log.,2019/4/20,9,Undecoded BCCH (1),Description: BSICs cant be decoded in 5s Usually consider 3 strongest neighbors Reason: GCLK shift, only decode same site BSICs Channel interference Non-BCCH carrier, no dedicated spectrum for BCCH,2019/4/20,10,Undecoded BCCH (2),2019/4/20,11,BSIC Undecode in Other Site,Description: BSIC in same site can be decoded but not for other sites Handover can only happen in intra-site basis It is similar to former Undecoded BCCH case Reason: GCLK shift GCLK recalibration is required No one monitors OMC-R alarms,2019/4/20,12,No Handover (1),Description: Neighbor BSIC is decoded and COMMON handover requirement is fulfilled but there is never a handover Reason: Missing neighbor No such neighbor in CM database Incorrect external neighbor Target cells LAC/BCCH/BSIC in add_neighbor is different from those in equip_rtf Engineer modifies external neighbor at MMI, not through GUI Never use OMC-R Proxy Cell to propagate external neighbor information N hreqt. Great HO_MARGIN. Improper algorithm 1-7 setting Missing_rpt =1 Serving cell overshoots/covers too far away Refer to GSM BSS Statistics Analysis Handbook,2019/4/20,13,No Handover (2),2019/4/20,14,Delay Handover (1),Description: Neighbor BSIC is decoded but handover occurs in much later time Reason: All possible neighbors suffer blocking Large hreqt * hreqave qual_power_flag is enabled, full BTS/MS power must be reached before handover Large handover_recognized_period and bssmap_t7 setting Refer to GSM BSS Statistics Analysis Handbook,2019/4/20,15,Delay Handover (2),2019/4/20,16,Ping Pong Handover (1),Description: Lot of handovers between cells “Time between Handover” is around hreqt*hreqave of such HO cause Reason: Improper hardware calibration Hardware fault UL/DL interference Negative handover Different coverage footprint for antennas of a cell,2019/4/20,17,Ping Pong Handover (2),2019/4/20,18,Negative Handover (1),Description: Serving cell hands over to a weaker neighbor Reason: ho_only_max_power is enabled qual_margin_flag is disabled ho_margin_usage_flag is enabled with negative ho_margin_rxqual/rxlev Negative HO_MARGIN Micro-cellular algorithms are enabled, especially type 5,2019/4/20,19,Negative Handover (2),-59dBm before HO,-66dBm after HO,2019/4/20,20,OverShooting (1),Description: Cell shoots at far distance but that location has closer cells around Reason: Overshooting cell has small downtilt, 0 degree! Overshooting cell has too high altitude Closer cells have overshooting as well BSIC of closer cells cant be decoded,2019/4/20,21,OverShooting (2),2019/4/20,22,High Overlapping (1),Description: Cells have major rxlevel difference within 5dB Reason: Overshooting Too many cells in that area Poor antenna downtilt,2019/4/20,23,High Overlapping (2),Over Lapping Area,-65dBm,-65dBm,-65dBm,-65dBm,2019/4/20,24,No Dominant Server (1),Description: Rxlevel of best neighbors are close to that of serving cell Reason: Poor antenna downtilt Lack of near-by site,2019/4/20,25,No Dominant Server (2),2019/4/20,26,Poor Coverage (1),Description: Low rxlevel with rxquality In rural area, rxlevel is less than 15 (-95dBm) In city center, rxlevel is less than 35 (-75dBm) Different location has different threshold, noise level is the key point Reason: Lack of cell site BSIC of dominant server cant be decoded Dominant server has blocking or cell-bar Handover problem. E.g. missing & incorrect neighbor, negative handover, no & delay handover,2019/4/20,27,Poor Coverage (2),2019/4/20,28,Unreasonable Serving Area (1),Description: Coverage area of the cell is incoherent to the antenna direction Reason: Wrong cable connection to antennas Incorrect record of antenna orientation Incorrect ANTENNA_SELECT,2019/4/20,29,Unreasonable Serving Area (2),Cell ID:101 BCCH: 35,Cell ID:102 BCCH: 40,Cell ID:103 BCCH: 45,2019/4/20,30,Interference (1),Description: High rxlevel with rxquality Reason: Channel interference Not using dominant server No handover Turn the corner with delay handover,2019/4/20,31,Interference (2),2019/4/20,32,Handover Failure (1),Description: MS fails to reach target cell, so return to source cell MS sends HO FAILURE and UL-SABM to source cell and there is response Reason: Channel interference Poor coverage External interference at UL, like wideband repeator Refer to GSM BSS Statistics Analysis Handbook,2019/4/20,33,Handover Failure (2),2019/4/20,34,Handover Loss (1),Description: MS fails to reach target cell, but cant return to source cell MS sends HO FAILURE and UL-SABM to source cell but no response Reason: Channel interference Poor coverage External interference at UL, like wideband repeator Refer to GSM BSS Statistics Analysis Handbook,2019/4/20,35,Handover Loss (2),2019/4/20,36,Description: BSS doesnt receive UL SACCH for link_fail times BSS stops transmitting DL power Reason: External interference Channel interference Faulty ancillary. UL path loss DL path loss Refer to GSM BSS Statistics Analysis Handbook,UL Drop (1),2019/4/20,37,UL Drop (2),2019/4/20,38,Drop Call (1),Description: DL case: Radio_link_timeout counter decreases to 0 UL case: link_fail counter decreases to 0 Layer 2: BSS/MS send SABM/DISC in every T200 for N200+1 times, and no response from recipient Reason: All cases in this presentation Refer to GSM BSS Statistics Analysis Handbook,2019/4/20,39,Drop Call (2),2019/4/20,40,Sudden Power Drop (1),Description: Dedicated ARFCN has significant non-power control rxlevel difference from rxlevel of BCCH Reason: No/improper TX power calibration Faulty ancillary. E.g. combiner, filter Different cable lengths from BTS to antennas Due to air combing, so antennas have different coverage footprints,2019/4/20,41,Sudden Power Drop (2),2019/4/20,42,Description: MS rapidly increases its TX power due to Optimised Power Control or UL SACCH multiframes arent received for link_fail - link_about_to_fail times Reason: Sudden UL interference, e.g. wideband repeator, channel interference Too much rapid power down l_rxlev_ul_p is too small,MS Power Rapid Increase (1),2019/4/20,43,MS Power Rapid Increase (2),