Transcript
PT.Telkomsel Proposal for GSM Network Optimization
September 2009
HS
Overview
Optimization is all actions intended to tune all aspects of the GSM network performance, covering access network, core network, and transmission network. Access network optimization procedure consists of two phases: cluster testing and system integration optimization. In other words, the initial pass of the RF optimization will be performed as a part of cluster tests: the second, more detailed, tuning phase will occur after completion of all cluster tests, which occur after activation of all cell sites in the GSM network. The primary reason for breaking the optimization work into two phases is to reduce the time and resources required to complete the cluster test cycles.
Objective
• To ensure the achievement of acceptable coverage
• To maximize the quality of service
• To maximize the network efficiency (including load balancing)
Consideration
• System stability and performance : To easy and simplify optimization
process, instability and bad performance of system should be clarified.
• Coverage : Can be adjusted by power settings (total, overhead), antenna tilting and orientation, hand-off area and so on.
• Capacity : Trunk lines, Number of traffic channel and elements should be equipped with sufficient quantity
• Parameters : Can be adjusted for f or the better coverage and capacity adjustment
Project Organization
AGTINDO PT.Telkomsel
PM Network Optimizations
PM & Local Engineer
Optimization
Audit
Support
Management
Co-work
Vendor PM & Local Engineer
ptimization Process (1)
START(Preparation)
Preparation: BTS info. & Parameter Review o BTS position, type, output power, antenna info. o Frequency Status
Survey & Simulation
Network Evaluation
o Neighbor list • Site Survey & Simulation
Optimization Target & Method Decision
o Drive test & walk test o Rx Quality, Rx Level, Coverage plot o Handoff performance
Optimization Execution
• Network Evaluation: Field measurement & analysis o Field measurement with Tems Investigations o Call event analysis
Optimization Evaluation
- fail and dropped call - signal distribution (Rxqual, RxLev, SQI, etc)
NO
• Reduce bad quality area & Find Optimization method
Performance Objectives ?
o Weak signal and Freq Interference o Parameter error / Missing Neighbor, etc YES
END
o Hardware trouble, etc • Execution, Evaluation and feedback
Optimization Process (2)
Field measurement & analysis - Coverage (bad area) analysis - Coverage overlay overlay ratio ratio - Call quality(drop and fail rate) NMS data analysis - System type / performance - System statistics analysis analysis (C/D rate, Call fail, etc)
Coverage Improvement (Shadow & Bad area) Traffic Balancing (site / sector based) System performance improvement Trouble shooting
Optimization Target - Coverage - Call quality
Decision for Optimization method
Accomplishment & Evaluation - Issue based optimization - Evaluation for for target target goal goal
Optimization result Feedback for engineering • System facilities check • System type change • Parameter error correction • Recommendation
Work Plan Ⅰ)
Basic Data Analysis & CQT
1st week
Ⅱ)
Optimization (System, Parameter, etc)
2nd ~ 3rd week
4th week ~ 11th week
Ⅲ
CQT & Report
12th week
Setup 1st CQT • Project setup • Kick off meeting • MS registration • Data analysis - BTS info. - Parameter - etc.
2nd CQT Access Network Optimization
• Field measurement • BTS Opt. - Site survey • CQT analysis - Fisical Tunning • CQT report • Action plan for opt. - Simulation - Cluster opt. - etc.
CQT Report & Opt. Action Plan Note 1) CQT: Call Quality Test 2) Opt.: Optimization
• Parameter Opt. - System parameter - Access parameter - Handoff - Neighbor list adjust - etc
• 2nd CQT • Report & Presentation
Report & Presentation
etail Items of Optimization S Basic Test(1): Basic Parameter Review • Basic items to be checked o BTS information and Hardware characteristics - Site Name and Type - Antenna type, height, directions and tilting degree, ( VSWR ) o Target service area of the base station and design capacity • Parameter settings to be checked o Neighbor list of each sector o Handoff parameter o Access parameter o Traffic channel parameter (Capacity) o Frequency / Channel Number o Power control parameter, etc • Basic call test o Mobile to mobile, mobile to fix lines, fix lines to mobile call test: origination & termination o Handoff test: in idle and dedicated mode
etail Items of Optimization
BTS Basic Test(2): Considerations
• Database & fisical cheking o Operator input error, Database Parameter loading error for BTS. o Cable connection error between BTS and antenna (VSWR). • RF environment /Condition check o Using real call ( drive test & walk test with measurement test ). - This is used in most cell optimizations optimizations and field trials. trials. Check for Interference, Speech quality, Signal level and Handover (and data com transfer / GPRS check).
etail Items of Optimization
Cluster Test
Center Cell • Goal o To verify the required basic function, performance and network stability through field test (classify the cluster)
Neighbor Cell
Cluster
Considerations o Set the service area o Find the coverage shadowing area / Indicate the shadowing area on the map o Run field drive test / walk test o Set the BTS transmit power and system parameters o Optimize coverage o Define the handoff area and optimize the handoff region: BTS power and antenna direction o BSC parameter and ensure forward and reverse link balance o Optimize FER/AMR
etail Items of Optimization
Network Integration(1) • Optimization Target Area o Weak signal areas o Call drop areas o Access failure areas (call fail) Problem 1) Weak Signal Area
Solution o Check Transmit power o Change antenna tilt o Antenna replacement
etail Items of Optimization
Network Integration(2) • Optimization Target Area o Weak signal areas
o Call drop areas o Access failure areas (call fail) Problem 2) Call droop areas
Solution o Check the frequency - Adjust interferences - changes frequency or ant fisical tunning o Check the neighbor list - Missing neighbor list and - erroneous neighbor list order
etail Items of Optimization
Network Integration(3) • Optimization Target Area o Weak signal areas o Call drop areas
o Access failure areas (call fail) Problem 3) Access failure areas (call fail)
Solution o Check the access parameter - capacity, frequency, signal power o Excessive IDLE handoff: coverage adjust o MSC, zone border: check registration
etail Items of Optimization
Network Integration(4) • Hardware and Parameter Trouble shooting
o Hardware trouble o Handoff and access parameter
Solution
Problem 1) Hardware trouble Type
Phenomenon
Antenna VSWR
Coverage reduction High Tx_adj (above + 10dB)
Optimization scheme Antenna replacement
etail Items of Optimization
Network Integration(5) • Hardware and Parameter Trouble shooting o Hardware trouble
o Handoff and access parameter trouble
Solution
Problem 1) Handoff parameter trouble Type
Phenomenon
Optimization scheme
Poor ID IDLE ha handoff
Temporary NO NO SE SERVICE du during H/ H/O
Neighbor lilist ch check
Poor H/O
Call drop, etc
Neighbor list and signal check
2) Access parameter trouble - Traffic channel parameters - Multi-path delay compensation
