This book gives you the basic knowledge about 3g/UMTS/WCDMA call flow/channel discription.Full description
This book gives you the basic knowledge about 3g/UMTS/WCDMA call flow/channel discription.Full description
Huawei Call Setup Time OptimizationFull description
Numerical Optimization - Solutions Manual
Very good & thorough document regarding 3G (UMTS) -DATA (HSPA) Throughput & Coverage enhancement/Optimization
Numerical Optimization - Solutions Manual
UMTS KPI Optimization Analysis and Guide
Drops Jazz
Solutions Manual Design and Optimization
LTE Notes eRAB Drops
Full description
Full description
Patroon & werkbeschrijving
Low throughput due to pooer coverge at output at repeater end
Case Name： Description：
Date： 11/28/2011
Top level Optimization solutions UMTS Access Failure & Call drop Analysis Solutions UMTS
Alarm： Handling
How resolve the access failure & call drop In more than 50%
Process
loaded network •
Investigate the reasons for poor 3G radio performance (access failure, call drop, IRAT failures, low throughput)
•
Describe the potential reasons
•
Propose actions to improve performance (as top 10 optimisation actions) –
•
Both common and service specific (Voice, Video and PS data)
First check could be done with Radio Planning tool or/and Nastar by looking at the CPICH coverage, TP distribution, cell dominance, SHO overhead, service coverage, link imbalance and RTWP interference areas.
•
The main reasons for poor radio performance are related to: –
Non
optimum
cell
design
(location,
antenna
type/height/bearing/tilt) –
Wrong site implementation (antennas, cables, parameters, sector swap)
–
Wrong or bad parameter planning (scrambling code allocations etc, CPICH etc.)
–
2014-6-12
Wrong or missing neighbour relations
Low throughput due to pooer coverge at output at repeater end
Date： 11/28/2011
• Drop Call Rate / SHO Failures and Overhead Missing neighbour •
A good usable neighbour is present within cells coverage area, can cause DL interference if it is not in the active set.
•
Swapped sectors in BTS.
Solutions: Check Nastar data and look for missing neighbours. Check the cabling in antenna line
Too many neighbours •
In SHO area the number of combined neighbouring cells become more than 31. HO list is created using RNC algorithm in the final stage some of the neighbours will randomly be removed.
•
Solutions:
Delete unnecessary neighbours.
High SHO overhead •
No main server in the area, too many cells with weak CPICH level.
•
CPICH EcNo is usually very bad even the RSCP is good e.q. RSCP – 80…-90 dBm but EcNo about –10 dB
Solution: Use buildings and other environmental structures to isolate cell(s) coverage. Down tilt antennas to make cells dominant and limit effects of interfering cell(s). Check antenna bearing and height. Add a site.
Access Failures •
Poor coverage in area
•
If problem is poor coverage, this means poor RSCP (<-95 dBm) thus also the EcNo degrades very rapidly (< -12 dB) when the coverage border is reached.
Solutions:Check Antenna line installation (antenna position and quality, cable length and quality). Check that CPICH powers are balanced between the studied cells. 2014-6-12
Low throughput due to pooer coverge at output at repeater end
Date： 11/28/2011
Check presence of shadowing obstacles. Add a site to the area. •
Poor dominance in area, which usually leads high SHO overhead.
•
No main server in the area, too many cells with weak CPICH level.
•
CPICH EcNo is usually very bad even the RSCP is good e.q. RSCP – 80…-90 dBm but EcNo about –10 dB
Solutions:Use buildings and other environmental structures to isolate cell(s) coverage. Down tilt antennas to make cells dominant and limit effects of interfering cell(s). Check antenna bearing and height. Add a site.
Pilot Pollution •
Bad CPICH Ec/Io (<-12 dB) level although CPICH RSCP level is good. High site in the neighbourhood may cause interference.
Solutions:Find interfering cell from Nastar TP analysis and drive test results. Adjust antenna bearing and down tilt or lower the antenna height (too much tilt will break the dominance). Add interfering cell to the neighbour of the serving cell.
High RTWP due to UL External interference •
The RTWP level is significantly higher than expected in no/low load conditions.
Solutions:Try to figure the possible area/direction of the interference by checking RTWP level on neighbouring cells. Alternatively use spectrum analyser & directive antenna to locate interferer. Inform operator/regulator about the found conditions. Check if auto tuning range is large enough (20 dB). Suggestion：
attachment：
2014-6-12
Above mentioned is the best analysis solution for Access failures & call drop.
