Knowledge Base
What’s the difference between cell signal strength and cell signal quality?
Cell signal strength: RSRP
4G LTE and 5G cell signal strength are measured by RSRP (Reference Signal Received Power) in decibel-milliwatts (dBm). The greater the RSRP value, the stronger the cellular signal. RSRP is usually a negative number, so −90 dBm RSRP is stronger than −100 dBm RSRP. (Learn more about cell signal strength and how to measure it here.)
Signal strength is important, but it’s only as good as the quality of the signal itself. Increasing the strength of a poor-quality signal is like turning up the volume on a television that’s only producing static—all you get is louder static.
Cell signal quality: RSRQ
4G LTE and 5G cell signal quality are measured by RSRQ (Reference Signal Received Quality) in decibels (dB). The greater the RSRQ value, the less interference the signal is getting from other cells operating at or near the same channel. Like RSRP, RSRQ is a negative number; therefore, −8 dB RSRQ is higher-quality signal than −12 dB RSRQ.
Cell signal boosters amplify the strength (RSRP) of the ambient cell signal available at the outside antenna. A cell signal booster can’t improve the quality (RSRQ) of the signal, but an outside directional antenna (an LPDA or a Yagi) can isolate a specific cell tower and help reduce interference from other nearby towers. Even a small increase in RSRQ can result in a significant improvement in cellular data rates.
Cell signal quality: SINR
Although SINR (Signal to Interference-plus Noise Ratio) is not included in the 3GPP mobile broadband specifications
, some equipment manufacturers use this traditional way of measuring the ratio of signal to noise:
- Signal (S) refers to the desired signal coming from the cellular tower. It carries the data and information that the device is trying to receive.
- Interference (I) consists of unwanted signals from sources other than the serving cell tower, including neighboring cell towers, adjacent bands of frequency, or other electronic devices operating in the vicinity. Interference can degrade the quality of the desired signal and cause data errors or dropped connections.
- Noise (N) refers to random electrical signals that can come from electronic components, atmospheric conditions, thermal effects, and other sources. Noise adds an additional layer of unwanted information that can negatively affect the quality of the received signal.
- Ratio (R) is the mathematical relationship between the signal (S) and the combined strength of interference (I) and noise (N):
R = S / (I + N)
SINR is a positive number; the greater the value, the better quality the signal.
