Mastering 5G NR:
Professional Signal Metrics Guide

In the world of 5G New Radio (NR), “bars” are a relic of the past. For RF engineers and network enthusiasts, understanding the raw data behind the connection is the only way to truly optimize performance. This guide breaks down the critical metrics used in the CellInfo app.

1. Understanding Signal Power (RSRP vs. RSSI)

While 4G relied heavily on RSSI (Received Signal Strength Indicator), 5G NR utilizes RSRP (Reference Signal Received Power) as the primary metric for coverage. RSRP measures the average power of the resource elements that carry cell-specific reference signals.

• 🚀 Excellent (-80 dBm or stronger): Maximum throughput; ideal for 4K streaming and low-latency gaming.
• ⚠️ Poor (-110 dBm or weaker): Frequent handovers to LTE; significant speed degradation.

2. The Quality Trio: RSRQ, SINR, and CQI

Strength alone isn’t enough. You can have a “strong” signal that is completely unusable due to noise.

• RSRQ (Reference Signal Received Quality): Indicates the quality of the received reference signal, taking into account interference and thermal noise.
• SINR (Signal-to-Interference-plus-Noise Ratio): The ultimate metric for stability. A higher positive SINR (e.g., 20dB+) allows your device to use higher-order modulation like 256QAM.
• CQI (Channel Quality Indicator): A value from 0-15 that your phone sends back to the tower to say, “I can handle this much speed.”

3. Timing Advance & Distance Mapping

One of the most powerful tools in the CellInfo arsenal is Timing Advance (TA). In 5G NR, TA is used to synchronize the uplink transmissions from the device to the gNodeB (tower). By measuring this delay in microseconds, CellInfo can calculate your approximate physical distance from the cell site, allowing for precision mapping during drive tests.