User details
BV
BV
Breda Vujasinovic
@breda_vujasinovic_v6k9z70wq
Cellular Telecommunications Engineer
Chicago, IL, United States
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Member since: Dec 18, 2024Experienced RF engineer (18 years+), deployed on several international, direct customer facing projects (Telekom Srbija, Turkcell, Vodafone, Orange, ATT) with hands-on multi-vendor (Ericsson/Nokia), multiple radio access technology (2G,3G,LTE/VOLTE,5G) experience. Highly focused on delivery of targets, quality and deadlines, capable of working both as a member of a team, or a team leader, using, improving and adopting new technologies and systems.
Responsibilities:
• Chicago/Milwaukee Market SON POC:
◦ 6k/64k/26k cells/(2G,4G,5G)-3.7k sites
◦ Daily maintenance of all vital SON modules maintaining market excellent level KPIs
◦ SON market compliance ownership (SON dashboard)
◦ Assuring seamless PCI/frequency 5G or LTE retunes in the market using SON
◦ Providing solutions and troubleshooting for sites with various validation errors
◦ Providing support in troubleshooting SON PCE configuration files during market level feature or field alert implementations to FSC and Central Region teams
◦ Created 2 queries in python to help OBT group track daily new site launches cell status check 0
• RMOCN project Chicago/Milwaukee Market POC:
◦ Ownership and handling of entire Phase 1,2,3 of RMOCN and FMOCN implementation for Chicago/Milwaukee market for Magenta sites
◦ RMOCN Dashboard compliance troubleshooting and maintenance
• Daily BTS HW and SW issues troubleshooting assuring seamless network performance
• Periodic overall area optimization based on drive test analysis
• Providing analysis and solution for customer complaints
• Live events network performance monitoring, optimization, reporting
• Cell cluster parameter optimization and troubleshooting to improve OneScore KPI levels:
◦ 5G (data) DCR SA+NSA: Degradations due
◦ SA:
◦ Xn link availability and corresponding SON module troubleshooting
◦ Xn link duplicate, unavailable, or going to inexistent gnbId; NRADJNRCELL, NRADJENB and Xn link without NRREL defined; Xn link without NRADJGNB; NRREL or NRADJNRCELLpointing to inexistent gnbID with NRADJGNB defined; intergnb NRREL without defined.
◦ Cell to cell SA HO analysis
◦ Carrier bw part(BWP) profile definition audit and troubleshooting
◦ SA LMS discrepancies troubleshooting
◦ NRCA (New Radio Carrier aggregation) functionality discrepancies
◦ NSA:
◦ ENDC (Eutran-New radio_Dual Connectivity) functionality and SON module troubleshooting
◦ Detailed check of parameter objects involved in ENDC that SON module could not change due to potential validation errors:
◦ LNADJGNB-adjgnbId of neighbor 5G site, administrative state of the x2 link, Ip address of neighbor 5G, cPlane IP address control(oam ctrl or gnb control LNRELGNBCELL-5G ENDC related neighbor cellIds, EDNC allowed activation param, NR neigbhbor cell availability and removal allowed or fobidden; LNADJ-ENDC related LTE neighbors; cplane and uplane IP addresses, PLMN and MME groups(TMob and Sprint), neighbor LTE enbIds and x2 link availability;
• Post launch RAN features/parameters audit and optimization to bring KPIs Accessibility, Retainability, Intra/Interfrequency HO/IRAT success and Throughput to levels acceptable to the customer (VSWR, RSSI, power settings, transmission issues, alarms, RF parameter tuning, various features activation/parameter audit, Layer Management, neighbor list optimization, Mobility over Iur(UMTS), dlAttenuation, faulty HW, CPRI blocks etc.)
• Reporting daily and weekly on the course of post launch process in the markets to the group of managers in charge (current status and actions taken to resolve various issues on newly launched sites)-based on Business Object reports
• Delivering closing reports for launched SSVs/Clusters (Close Out Packages) after all checkups performed, existing issues resolved and desired KPI levels achieved
• Providing detailed reports to the customer on applied parameter changes, optimization steps, drive test results of poor coverage areas in case of site close outs with KPIs below expected target levels
• Correcting wrong definitions and optimizing BCCH/BSIC/LAC values for co-sited GSM sites to UMTS sites with low Retainability due to bad IRAT Succ rate
• Performance monitoring and optimization of sites after cutover, sector split or correction of feeder connections
• Traffic balancing applying Hi Cap parameter settings in high populated city areas
• Resolving cell downtime due to SIB11 congestion on overshooting sites with SON tool activated
• Resolving sudden and heavy degradation of Retainability and Accessibility due to SCR collision coming from new site launches in neighboring markets, other operator networks or off-air cells after cutover
• Resolving PCI collision/confusion coming from overshooting new launched LTE sites or off air cells after cutover
• Improving values of KPI Time not on LTE by properly defining SIB 19 set of parameters, optimizing selection/reselection parameters from LTE to UMTS
• Resolving congestion on LTE carriers correctly activating/defining Load Balancing feature, Layer Management and Hi Cap parameters and disabled termpoints, optimizing selection/reselection or increasing rate of Active RwR to UMTS co-sited cells to Ericsson swap), Acceptance team
Leading the complete post launch process for 2nd, 3rd and 4th carrier (159 Single Sites and 8 Clusters with 72 sites)
• Post launch RAN parameters audit using Moshell (VSWR, RSSI, transport network issues, active alarms, RF parameter tuning, Layer Management, CPICH, power settings, dlAttenuation etc.)
• Reporting daily and weekly on the course of post launch process in the markets to the group of managers in charge (current status and actions taken to resolve HW issues on newly launched sites)-based on Retainability and Accessibility Business Object reports
• Delivering closing reports for launched SSVs/Clusters (Close Out Packages) after all checkups performed and existing issues solved
• Competence transfer while leading the team of engineers
• Maintaining Accessibility levels on 98% success rate through fine parameter tuning, optimizing cell selection reselection , hi-cap parameter implementation, neighbor list optimization, layer management audit power distribution among carriers analysis (traffic balancing between carriers by changing selection/reselection parameters, IFHO Load Balancing, Load Sharing margins and thresholds) reducing interference overshooters' coverage control troubleshooting: crash of boards, transport network congestion, faulty TMAs installed; analyzing counter values for RAB or RRC failure, SCR code collision
• Maintaining Retainability levels on 98% success rate through: Optimizing neighbor lists and LM (Intra/Inter Frequency, GSM) Fine parameter tuning (power settings, hoType, compressed mode parameters, selection/reselection parameters) Troubleshooting: faulty neighboring cells, Exception Codes using Moshell, diversity branch swap, sector swap, SCR code collision
Composing and presenting TGV(High Speed Railway) Mobile Network 2G/3G parameter optimization solutions document based on field tests done in China, Germany,Spain:
• Solutions for cell parameters/timers/filters controlling 2G/3G Cell Selection,Reselection, Locating and HO/SOHO/IRATHO
• Solutions to improve HO Success Rate by reducing number of neighbors and keeping overlapping cell areas longer
◦ Solutions to improve poor Retainability due to high speed impacted radio conditions (RSCP degraded)
Performance monitoring of live events during London Olympics and Paralympics 2012, Wimbledon, Battersea Park and Isle of Wight Music Festival (Ericsson):
• RAN parameters audit using Moshell (VSWR, RSSI, T1 Error seconds, active alarms, RF parameter settings, Layer Management, CPICH, dlAttenuation)
• Point of Contact for Ericsson GNOC Romania, reporting detected HW failures using Mycom statistics and Moshell commands
• Point of Contact for the team of field engineers assigned to repair detected HW issues
• Reporting on daily performance and traffic volume in Olympic venues to high management
• Maintaining Accessibility levels above 98%: Detecting and resolving congestion due to lack of resources CE, codes, power Traffic balancing between carriers by fine parameter tuning, coverage control, hicap parameter implementation Troubleshooting: transport network congestion due to HW faults/misconfiguration, intermodulation (PIM) issues, faulty defined dlAttenuation etc
• Maintaining Call Drop Rate levels below 2%: Layer management settings audits (intra/inter Frequency,GSM neighbors), neighbor list optimization, troubleshooting faulty neighboring sites, sector swap, transmission issues Olympic venues optimization
• test analysis (coverage control, control based on neighboring analysis, analysis, and planning)
• by and
reduction
• Final pre-event parameter settings implementation and parameter/features, Layer Management audit
Ownership
• Delivering 2G/3G network performance daily reports and troubleshooting issues affecting Availability, Accessibility and Retainability (investigating KPIs and counters for BTS, BTS HW, ICSU, RNC, Accessibility Control, Transmission, E-DCH fails, and drive trial logs for SCR collision and overshooting or sites with bad coverage)
• Analysis of initial NSN network parameter design (such as Cell Selection- Reselection or Mobility parameters) and further optimization to improve performance in Reading (UMTS2100 and 900)
• Proposing Capacity Management solutions (analyzing statistics for power,CE, code, IuB utilization, UL interference and traffic)
• Troubleshooting poor UL throughput caused by SW faults or misconfiguration of NSN equipment (analyzing statistics for RTWP and Rise of Thermal Noise Load)
• Ownership of Izmir-Mugla region (Turkey) for performance and optimization
• Reporting on performance of Turkcell UMTS network in Izmir-Mugla region
• Maintaining network Retainability on levels higher than 98% by fine parameter tuning, network signal quality improvement and neighbor lists optimization
• Operating Ericsson OSS tool for alarms and electrical tilt monitoring
• Solving issues caused by out of range RSSI values
• Solving issues of unsuccessful UMTS to GSM cell change and handover by fine parameter tuning, network capacity and signal quality improvement
WCDMA2100: . Network Performance Analysis and troubleshooting of poor CS/PS Interactive/HSInteractive Accessibility (RRC or RAB phase issues), CS/PS/R99/HS Call Drop Rate, poor user throughput HSDPA/R99 DL, Intra and Inter neighbor list optimization, fine parameter tuning
• Analyzing and improving KPIs to improve poor signal coverage area by parameter tuning and control of coverage of worst offenders
• planning initial number of Channel Elements for sites to be deployed and monitoring CE utilization, adding new CE to RBS's
• Prelaunch preparation of new WCDMA sites (SCR codes plan, CCR files, neighbor lists and Cell Priority planning, preparing and implementing xml activation files during site launch process
• Planning lub link budget (initial number of El links on sites to be deployed), and adding new El links
• Preparation of drive test routes and optimization clusters
• Post launch drive test analysis to verify status of the network (call set-up, best service cell, HO verification, coverage analysis)
• Single site verification to insure site functionality such as soft handover for each sector, no swapped sector and reliability of site identifier (LAC, RAC, SCR code)
• Preparing and importing MML commands for rehoming RBSs from one RNC to another, or uploading new cell data for RNC or MSC
• Consistency checkup, benchmarking and post processing to ensure service continuity after and before cluster swap and rehoming Ericsson to NSN equipment, and comparing the overall cluster performances within a short timeframe and from the perspective of end-users
GSM900/1800:
• Analyzing the quality of network coverage, troubleshooting network problems and customers' complaints; Radio Network Planning prediction, frequency planning, data link budget for new RBS equipment specifications and antenna selection; azimuth, tilt, power, neighbor relations planning)
• Optimization of coverage and interference problems, changing azimuths, tilts, and BCCH/BSIC and neighbor
• Preparation of Cell Design Data for new sites implementation, xml files, MML commands, importing cell data for BSC and MSC
• Optimizing HO performance, TCH & SDCCH drop rate, TCH & SDCCH congestion (adding new SDCCH or offloading traffic from the worst
• Radio network parameters and features design (frequency hopping, HSN planning, MAIO, HCS (OL/UL, Layer Management); TCH and SDCCH dimensioning, frequency retuning
• Micro and repeater sites implementation (site equipment propagation frequency planning)