RSRQ (Reference Signal Received Quality) is the LTE and 5G measurement of how clean a cell's reference signal is compared with everything else the device's antenna is receiving. It combines RSRP and RSSI into a single figure, so it reflects interference, noise and cell load as well as signal strength.

RSRQ is reported in dB as a negative number, with values closer to zero indicating better quality. -10 dB or higher is excellent, -10 to -15 dB as good, -15 to -20 dB as fair to poor, and -20 dB or lower as poor. Always read RSRQ alongside RSRP: a strong RSRP with a poor RSRQ usually points to interference or a busy cell, not a coverage problem.

RSRQ is calculated as (N × RSRP) / RSSI, where N is the number of resource blocks in the measured bandwidth. Because RSSI includes power from neighbouring cells, other interference and noise, RSRQ falls whenever that unwanted energy rises, even if RSRP stays the same. In 5G NR, the equivalent measurement is SS-RSRQ, which is based on the synchronisation signal rather than the LTE reference signal.

In deployment and troubleshooting, RSRQ is a useful tiebreaker between antenna positions, bands or networks with similar RSRP. An option with slightly weaker RSRP but clearly better RSRQ is likely to deliver more consistent throughput.