GSM - TRX Planning

ZTE Magic RRU consists of 6 ports to which 3 PA (power amplifiers) can be connected. Each PA supports 80 Watt linked with a sector/cell and the power is distributed uniformly among the TRXs connected to a PA. This means that with a minimum recommended power of 20 W per TRX, no more than 4 TRXs should be configured on one PA or sector. Thus, for a site having 3 sectors, 444 configuration is suitable.

Transmission requirement for TRX depends on multiple factors such as:

• TRX configuration
• Coding Scheme - Higher coding scheme (MCS-9) requires more transmission bandwidth
• Number of static and dynamic PDCH configuration
• Half Rate utilization

In general, a site with a 444 configuration, 2 static and 4 dynamic PDCHs per cell, 100% Half Rate utilization, and an average of MCS6 can be supported by 1 E1 (2.048 Mbps).

GSM - Paging Success Rate (PSR) Analysis

Paging success rate can be degraded due to increase in MOC/MTC attempts, low TCH availability of source and neighboring cells, high LAC/BSC utilization. Following steps should be taken to analyze the root cause:

• Check for MOC/MTC trend - increase may cause high PPS (Paging Per Second) causing paging discards, indicating paging capacity limitation. LAC splitting could be done to resolve the issue
• Examine TCH Availbility of sites in the affected BSC
• Inspect cell level paging stats from the core network to zero in on the problematic LACs
• Parameter discrepancy between BSC and MSC can cause degradation - check parameters such as Location Update Timer, paging retransmissions by MSC, paging times etc.
• Interference, low coverage due to large distance or dense areas, path balance issues contribute to PSR degradation