(Source Wi-Fi Signal Strength Basics | MetaGeek )
Ideal Signal Strength
So what signal strength should you shoot for? For simple, low-throughput tasks like sending emails, browsing the web, or scanning barcodes, -70 dBm is a good signal strength. For higher-throughput applications like voice over IP or streaming video, -67 dBm is better, and some engineers recommend -65 dBm if you plan to support mobile devices like iPhones and Android tablets.
Note: The numbers in this chart are suggestions only. The desired signal strengths will vary, based on the requirements for the network.
| Signal Strength | TL;DR | Required for | |
|---|---|---|---|
| -30 dBm | Amazing | Max achievable signal strength. The client can only be a few feet from the AP to achieve this. Not typical or desirable in the real world. | N/A |
| -67 dBm | Very Good | Minimum signal strength for applications that require very reliable, timely delivery of data packets. | VoIP/VoWi-Fi, streaming video |
| -70 dBm | Okay | Minimum signal strength for reliable packet delivery. | Email, web |
| -80 dBm | Not Good | Minimum signal strength for basic connectivity. Packet delivery may be unreliable. | N/A |
| -90 dBm | Unusable | Approaching or drowning in the noise floor. Any functionality is highly unlikely. | N/A |
