RSRP stands for Reference Signal Received Power, and it measures how strong the signal is between your device and the nearest cell tower. It’s the single most important number for understanding your LTE or 5G connection strength, expressed in dBm on a scale from -140 dBm to -44 dBm. The closer your reading is to -44, the stronger your signal.
How RSRP Works
Cell towers constantly broadcast small “reference signals” that your phone listens for. RSRP is the average power your device picks up from those specific reference signals, measured at the antenna. Think of it like a lighthouse beacon: RSRP tells you how bright that beacon appears from where you’re standing, ignoring everything else in the sky.
This is more useful than measuring total signal power (which includes noise, interference, and signals from other towers) because it isolates the one signal your phone actually needs to maintain a connection. Your phone reports RSRP back to the network, and the network uses that information to decide things like when to hand you off to a closer tower or how much data it can push to your device.
What Good and Bad RSRP Values Look Like
RSRP is measured in dBm, which is a logarithmic scale. That means a difference of just 10 dBm represents a tenfold change in power. Here’s how to interpret your reading:
- -65 to -80 dBm (Excellent): Strong signal, ideal for high-speed data and reliable connections.
- -80 to -85 dBm (Good): Reliable for most activities including video streaming.
- -85 to -90 dBm (Fair): Weaker signal. You may notice slower speeds or occasional drops.
- Below -90 dBm (Poor): Very weak signal with frequent drops and slow speeds.
If you’re seeing values below -100 dBm, your connection is likely struggling. Calls may cut out, pages load slowly, and video streaming becomes unreliable. At -120 dBm or worse, you’re at the edge of usable coverage.
RSRP vs. RSSI vs. RSRQ
Your phone tracks several signal metrics, and they each tell you something different. RSSI (Received Signal Strength Indicator) measures the total power coming into your antenna from all sources, including noise, interference, and signals from neighboring towers. It ranges from -100 dBm to 0 dBm. RSSI is a blunt tool: it tells you there’s energy in the air, but not whether any of it is useful.
RSRP is more precise because it filters out everything except the reference signal from your serving cell. This makes it the better metric for understanding whether your connection to a specific tower is strong enough.
RSRQ (Reference Signal Received Quality) goes a step further. It’s calculated by dividing RSRP by RSSI, producing a ratio that reflects signal quality relative to noise and interference. RSRQ ranges from -19.5 dB to -3 dB, with higher values indicating cleaner signals. You can have decent RSRP but poor RSRQ if there’s heavy interference from nearby towers or equipment. In practice, your network uses RSRP and RSRQ together to decide when to hand your connection to a different tower.
RSRP in 5G Networks
5G New Radio (NR) uses the same concept but splits it into two types. SS-RSRP measures power from synchronization signal blocks, which are the 5G equivalent of LTE’s reference signals. CSI-RSRP measures power from a different set of reference signals used for channel quality feedback. Both serve the same basic purpose: telling the network how well your device can hear the tower.
The reporting range in 5G is wider than in LTE. For layer 3 measurements (the ones used for handover decisions), 5G RSRP spans from -156 dBm to -31 dBm with 1 dB resolution. This extended range accounts for the fact that 5G signals, particularly in higher frequency bands, can be weaker at the same distance compared to LTE.
What Causes Low RSRP
Distance from the tower is the most obvious factor, but it’s rarely the only one. Building materials make a huge difference: concrete walls, metal roofing, and energy-efficient windows with metallic coatings can cut signal strength dramatically. Terrain matters too. Hills, dense trees, and nearby buildings all block or scatter the signal before it reaches your device.
Weather has a smaller but real effect, particularly for higher-frequency 5G bands where rain can absorb signal energy. Indoor locations are almost always worse than outdoor ones, sometimes by 20 dB or more, which on a logarithmic scale means your indoor signal can be 100 times weaker than the signal just outside your window.
Interestingly, antenna orientation can shift your readings in unexpected ways. Pointing a directional antenna toward a distant tower might lower your total received power (RSSI) because it filters out nearby interference, while actually improving your RSRP and signal-to-noise ratio. This is why RSRP is more useful than RSSI for diagnosing connection problems.
How to Check Your RSRP
On an iPhone, open the Phone app and dial *3001#12345#*, then tap the green call button. This opens Field Test Mode, where you’ll find RSRP and RSRQ values listed under both the “LTE” and “5G” headings on the dashboard. You’ll need iOS 18 or later for the current version of this interface.
On Android, the easiest approach is a free app called SignalStream or Network Cell Info Lite from the Play Store. Turn off Wi-Fi first so the app measures your cellular connection accurately. SignalStream lets you save readings from different spots around your home or office, which is useful if you’re trying to figure out where signal is strongest or whether a signal booster would help.
Take readings in several locations. RSRP can change significantly just by moving a few feet, especially indoors. A reading near a window facing the tower might show -75 dBm while a basement room in the same building reads -105 dBm.
How RSRP Affects Your Data Speeds
Your network uses RSRP to make real-time decisions about your connection. When RSRP is strong, the tower can use more efficient data encoding, pushing more bits per second to your device. As RSRP drops, the network switches to more resilient but slower encoding to prevent errors. This is why your download speed can plummet even before you lose signal entirely.
RSRP also drives handover decisions. When the RSRP from a neighboring cell tower exceeds the RSRP from your current tower by a set margin, and that difference holds for a brief period, your phone switches to the stronger tower. A failed handover means a dropped call or a momentary loss of data, so the network takes these measurements seriously. In 5G networks for high-speed rail, optimized handover algorithms based on RSRP have achieved measurable improvements in both success rates and handover delay, even at speeds above 350 km/h.
If you’re troubleshooting slow mobile data, RSRP is the first number to check. A value above -80 dBm that still delivers poor speeds points to congestion or interference rather than weak signal. A value below -100 dBm tells you the signal itself is the bottleneck, and moving closer to a window or higher in a building is the quickest fix.