After a 7-year corporate stint, Tanveer found his love for writing and tech too much to resist. An MBA in Marketing and the owner of a PC building business, he writes on PC hardware, technology, and Windows. When not scouring the web for ideas, he can be found building PCs, watching anime, or playing Smash Karts on his RTX 3080 (sigh).
Most people, when optimizing their Wi-Fi settings, assume that the bigger number is better. To be fair, the 5 GHz and 6 GHz bands are faster than the 2.4 GHz band, and a 160 MHz channel width increases your throughput. However, these speed boosts aren't free of downsides, such as reduced range and more interference. Your router or access point's transmit power operates the same way.
Transmit power, or TX power, represents the strength of the signal broadcast by your router or access point. Increasing the transmit power helps the signal travel farther and penetrate obstacles, but it also makes it difficult for your devices to communicate back. Finding a balance between signal strength and coverage is the key.
Transmit power doesn't work the way you probably think
Less can be more
Whether it's your router or an access point (AP), the default transmit power in the settings is usually "100%." This means your APs are transmitting at maximum power, whether you want them to or not. Most people rarely look at this setting on the admin page, but high transmit power might be behind poor Wi-Fi performance on your smartphone or laptop.
The biggest drawback of blasting your AP's signal at full power is the asymmetrical transmit power trap. While your router is capable of transmitting a 20–30 dBm signal, smartphones and laptops are limited to around 10–18 dBm. These are wireless devices where conserving battery power is important; hence, they don't feature stronger radios.
Your router may be shouting at the top of its voice, reaching every corner of the house, but your smartphone can't shout back at the same intensity. Even though the signal on your phone shows full bars, it's effectively in a dead zone as it fails to transmit to the router. It can get stuck in a loop of packet retransmissions or drop the connection entirely.
The needlessly high transmit power of your router or AP creates an illusion of robust coverage. The phone or laptop keeps trying to talk back despite the AP being too far, introducing high latency.
More access points can compound the problem
The more, the merrier? Not quite
In a house with multiple access points in proximity, overlapping signals can become a problem rather than a solution for coverage. An access point broadcasting at 100% power increases interference in the airwaves. Your device can very well stick to a distant AP whose signal strength overrides every other consideration. Despite a closer AP offering a better signal, your device will refuse to switch.
For a smooth handover between access points, you should use a Wi-Fi analyzer to measure the signal strength at different points of your house. At the midpoint between two access points, the signal strength shown on your phone should be around -67 dBm for seamless switching between the APs. If it's stronger than that, your phone will refuse to switch to the closer AP; if it's weaker, it will result in a dead zone. Adjust the TX power of both APs till you achieve a balance.
Another aspect is band steering. You want clean switching between the 2.4 GHz and 5 GHz bands when the latter offers a faster signal. To do this, set your 2.4 GHz band's TX power to "Low" or "Medium," and choose "Medium" or "High" for the 5 GHz band. If your router allows custom values, set the 2.4 GHz and 5 GHz bands to around 11 dBm and 18 dBm, respectively, achieving an ideal 6–9 dBm separation and creating roughly equal signal "cells."
WiFi Analyzer
Lowering the transmit power made my Wi-Fi snappier
I wish I had done it sooner
When I learned about tweaking the transmit power of my router and access point, I was curious to observe the impact on my home Wi-Fi. I logged into my router's admin page and reduced the transmit power from "100%" to "75%." I then did the same on my access point and measured the difference in Wi-Fi performance. The speed improvement was negligible, but the perceived performance got a nice push.
Buffering in long YouTube videos dropped considerably, uploading videos became faster, and the signal stopped dropping out in the furthest rooms. With the access point not shouting at full strength anymore, it allowed my phone and laptop to seamlessly switch between the router and AP when needed. I tried lowering the TX power to "50%," but it worsened the performance, so I switched back to "75%."
The connection also improved during the night when airtime congestion was at maximum. With nearly everything in the house transmitting at the same time, the balanced transmit power made a noticeable improvement to the network.
Your access points don't need to broadcast at full strength
The default transmit power of your router and APs is typically set to the maximum value, but it doesn't need to be. Lowering it can actually benefit your Wi-Fi performance. Blasting a strong signal to your devices when they can't transmit back at nearly the same strength doesn't help your cause. Balancing signal strength and range allows your wireless devices to transition to the best AP in their vicinity.