What can we try to improve when access failure is high?

When access failure is high we can try the following to improve RACH performance:

• Increase maximum UE transmit power allowed: Max_allowed_UL_TX_Power.
• Increase power quickly: power_Offset_P0.
• Increase number of preambles sent in a given preamble cycle: preamble_Retrans_Max.
• Increase the number of preamble cycles: max_Preamble_Cycle.
• Increase number of RRC Connection Request retries: N300.

Know What are the Possible Reasons for Access Failure in UMTS?

What is Hard Handover in UMTS? When will it happen?

· Hard Handover in UMTS is a break before make type Handover
· It can happen in the inter RNC boundaries where there is no Iur link.

This may Helpful to You

IRAT Handover Guide
Inter System Cell Reselection Optimization Guide
TEMS UMTS Dropped and Block Call Specification 

What are the possible causes for a Drop Call on a UMTS network?

There are several reasons for RAB Drop in WCDMA network.

·         Poor Coverage (DL / UL)

·         Pilot Pollution / Pilot Spillover

·         Missing Neighbor

·         SC Collisions

·         Delayed Handovers

·         No resource availability (Congestion) for Hand in

·         Loss of Synchronization

·         Fast Fading

·         Delayed IRAT Triggers

·         Hardware Issues

·         External Interference

You may like this
WCDMA Optimization Tech for Drive Test
WCDMA Neighbor Cell, Scrambling Code and LAC Planning
TEMS UMTS Dropped & Blocked Call Specifications

What are the possible causes for a lower PSR?

There are several different reason for low Paging Success Ratio

- Non-continuous RF Coverage – UE going in and out of coverage area frequently
- Very High ‘Periodic Location Update Timer’ – Keeping UEs in VLR long time after it moved out of coverage
- Lower Paging Channel Power
- Access Channel Parameter Issues
- Delayed Location Update when crossing the LA / CN Boundaries

Also Check

E Book on GPRS and EDGE Performance

What is G-RAKE Receiver?

How WCDMA OSS Works?

Doc For This with Below Containing :

• Cell & Channel Management
• Adjacent Cell Configuration Management
• Radio Network Optimization
• WCDMA Neighboring Cell Support (WNCS)
• WCDMA Measurement Result Recording (WMRR)
• Alarms Status Matrix
• Alarm Log Browser
• Alarm List Viewer
• Element Manager
• RNC Element Manager
• RBS Element Manager
• Bulk Configuration C

Doc Link : WCDMA OSS DOC

What is Paging Success Ratio? What is the typical PSR that you have seen in a WCDMA UMTS network?

Paging Success Ratio:

Its Paging Responces to the Paging Attempts in WCDMA UMTS network.

Typical Value for Good WCDMA Cellular Network is greater than 90%. 

What are the possible causes for an IRAT Failure?

There are several reasons for IRAT failure in cellular network optimization.
Major 4 reasons which played good role in WCDMA Optimization.

·         Missing 2G relations

·         Non availability of 2G Resources

·         Poor 2G Coverage

·         Missing 3G Relations