If you've ever been told your building has a mobile signal problem but struggled to quantify it, RSRP is the metric that gives you a clear answer. It's the most widely used measurement of cellular signal strength in 4G LTE and 5G networks, and it's particularly relevant when you're trying to understand why connectivity drops out inside a building.
This article explains what RSRP is, how it's measured, what values are considered good (especially for indoor environments), and how it relates to the other signal metrics you'll see referenced alongside it: RSRQ, RSSI, and SINR.
RSRP stands for Reference Signal Received Power. It measures the average power of the reference signals transmitted by a cell tower, as received by your device. In simple terms, it tells you how strong the signal from the tower is at the point where your phone, modem, or EFTPOS terminal is sitting.
RSRP is expressed in dBm (decibels relative to one milliwatt), and values are always negative. The closer the value is to zero, the stronger the signal. A reading of –80 dBm is significantly stronger than –110 dBm.
Because RSRP isolates the reference signal from background noise and interference, it gives a more accurate picture of signal strength than older metrics like RSSI. That's why it's the primary measurement used in LTE and 5G networks for cell selection, handover decisions, and coverage assessment.
RSRP values typically fall between –44 dBm (exceptionally strong) and –140 dBm (no usable signal). In practice, most real-world readings sit between –80 dBm and –110 dBm.
Here's a general reference for interpreting RSRP signal strength values:
|
RSRP Range (dBm) |
Signal Strength |
What It Means Indoors |
|
–44 to –80 |
Excellent to Good |
Reliable for all applications including high-speed data, VoLTE calls, and payment terminals. |
|
–80 to –90 |
Good to Fair |
Generally sufficient for most use cases. Minor slowdowns possible under heavy load. |
|
–90 to –100 |
Fair to Poor |
Connectivity may be intermittent. EFTPOS terminals and IoT devices may experience dropouts. |
|
–100 to –110 |
Poor |
Unreliable for real-time applications. Calls may drop and transactions may fail. |
|
Below –110 |
Very Poor / No Signal |
Effectively unusable for most business operations. |
For indoor environments, an RSRP above –85 dBm is generally what you need for consistent, reliable connectivity. Once readings drop below –95 dBm, you're likely to see the kind of issues that affect payment processing, voice calls, and real-time communication.
RSRP is especially important in the context of in-building connectivity because it degrades as the signal passes through building materials. Reinforced concrete, steel framing, Low-E glass, and internal walls all attenuate the signal between the external cell tower and your device.
A location that shows good outdoor coverage on a carrier map may still have poor RSRP indoors. This is one of the most common reasons businesses experience unreliable mobile connectivity, failed EFTPOS transactions, and dropped calls inside their premises, even when external coverage appears adequate.
When a professional site audit is conducted, RSRP is one of the first measurements taken. It gives an objective baseline for where coverage is strong, where it's marginal, and where it fails entirely.
While RSRP is the primary indicator of signal strength, it doesn't tell the whole story. Three other metrics are commonly used alongside RSRP to assess the full picture of cellular signal quality.
RSRQ measures signal quality rather than raw power. It factors in the number of resource blocks being used and the level of interference on the channel. RSRQ is expressed in dB, with typical values ranging from –3 dB (excellent) to –20 dB (very poor). Where RSRP tells you how strong the signal is, RSRQ tells you how clean that signal is relative to the noise around it.
RSSI is a broader measurement of total received power across the entire channel bandwidth. Unlike RSRP, it includes not just the reference signal but also interference, noise, and signals from neighbouring cells. RSSI was the standard metric in 3G networks, but in 4G LTE and 5G, RSRP is preferred because it's more specific and accurate. RSSI is still reported by most devices and can be useful as a supplementary data point.
SINR measures the ratio of signal power to the combined interference and noise on the channel. It's expressed in dB, with higher values indicating better conditions. A SINR above 20 dB is excellent, while anything below 0 dB typically means the signal is being overwhelmed by interference. SINR directly affects achievable data speeds and is a critical factor in environments where multiple cells or frequency bands overlap.
No single measurement gives you the full picture. A strong RSRP reading paired with a poor SINR value might mean the signal is reaching the building but is being degraded by interference. A fair RSRP with a good RSRQ can still support basic connectivity. Understanding how these parameters relate to each other is what separates a useful signal assessment from a simple bar count on a phone screen.
For in-building coverage design, all four metrics matter. A properly engineered solution needs to account not just for raw signal power but for the quality and usability of that signal throughout the indoor environment.
If you're seeing weak RSRP values inside your building, the underlying cause is usually the building itself. Dense construction materials, underground areas, and shielded zones reduce signal strength to the point where devices can't maintain a reliable connection.
In-building coverage (IBC) systems are designed to solve this. A signal booster captures an existing outdoor signal, amplifies it, and redistributes it indoors through internal antennas. For larger or more complex sites, a Distributed Antenna System (DAS) provides engineered coverage across the full premises using a network of antennas connected to a central system.
The right approach depends on the size and layout of the building, the signal environment outside, and how mobile connectivity is used on site. A professional site audit is the best starting point. It maps the actual RSRP values across the building, identifies where and why coverage is failing, and determines which solution will deliver reliable results.
MobileCorp is an Australian in-building mobile coverage specialist. We conduct professional site audits that measure RSRP and related signal metrics across your premises, then design and deliver the right IBC or DAS solution to restore reliable indoor connectivity. If your business is experiencing dropped connections, failed payments, or poor mobile signal inside your building, we can help you identify the cause and fix it.
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For reliable indoor connectivity, an RSRP above –85 dBm is generally considered good. Values between –85 and –95 dBm are workable for most applications, but below –95 dBm you're likely to experience intermittent connectivity, slower data speeds, and issues with payment terminals and voice calls.
RSRP measures the power of the specific reference signal from a cell tower, while RSSI measures total received power across the entire channel, including noise and interference. RSRP gives a more accurate and specific reading of signal strength, which is why it's the preferred metric in LTE and 5G networks.
Yes. In-building coverage solutions such as signal boosters and Distributed Antenna Systems (DAS) are specifically designed to improve mobile signal strength in areas where the external network can't reach effectively. A site audit will confirm whether poor RSRP is the issue and what solution is appropriate.
Signal bars are a simplified representation and don't reflect the full picture. You might have a marginal RSRP reading that's enough to show a bar or two, but poor RSRQ or SINR values mean the signal quality isn't sufficient for reliable data, calls, or payments. Measuring the actual signal parameters gives a much more accurate understanding.
While you can check RSRP on individual devices using diagnostic apps, a professional site audit provides a comprehensive, location-mapped assessment across the entire building. It measures RSRP along with RSRQ, RSSI, and SINR at multiple points, giving you a clear picture of where coverage is strong, where it's failing, and what's causing it.