UMTS Drive Test Basic Analysis

A basic overview of UMTS drive test analysis comprises of two key KPIs which are RSCP and EcIo corresponding to coverage and quality. The common cases and their remedies are presented below:

1. Bad RSCP and bad EcIo (Coverage): This means weak coverage of the serving cell which should be improved to better the EcIo
2. Good RSCP and bad EcIo (Pilot Pollution/High Cell Load): If the issue is due to multiple servers (pilot pollution) having RSCP within 3dB, dominance of one cell should be formed. For high cell load problem, carrier expansion or traffic balancing are some ways of improving the EcIo.
3. Bad RSCP and good EcIo: Low cell load or no handover in the area represents this condition. 

An example of pilot pollution issue is shown below:

BS PA MFRMS - PSR Alcatel-Lucent

Improvement in PSR (Paging Success Rate) can be achieved by tuning of BS_PA_MFRMS and reducing Paging discards. Paging discards are mostly due to congestion in the BSC, on the Abis link and/or on the PCH (Paging Channel) ie Air interface.

Parameter:

• BS_PA_MFRMS

Target Cells: Cells with higher number of paging discards

Theory: 

• This parameter defines the the number of 51 multiframes between two consecutive occurrences of Paging group (a number of pagings)
• Higher value means less number of pagings will be transmitted in a given interval thereby conserving lesser power of the MS
• Reducing this parameter increases number of pagings per paging group (for a given value of MSC paging timer T3113) and therefore probability of no paging response decreases