When a router broadcasts both 2.4GHz and 5GHz signals under the same name, it's simply transmitting two networks simultaneously—one on each frequency. Devices that support both bands recognize this and typically opt for the faster 5GHz connection if the signal is strong enough. Older devices that display both networks can confuse users, leading to misconceptions like "someone has hacked my WiFi." Meanwhile, devices that only support 2.4GHz are completely unaware of the 5GHz signal and connect to 2.4GHz as if the other network doesn’t exist.
The idea that naming both bands the same could break connections for devices that don’t support 5GHz is flawed. A device incapable of detecting 5GHz is unaffected by its presence; it functions as if only a 2.4GHz network exists. Industry best practices recommend using a single SSID name, allowing devices to switch between bands seamlessly for optimal performance. SKY, for instance, benefits from this approach when streaming high-bandwidth content like 4K video. If SSIDs are split, devices using WPS push-button pairing may mistakenly connect to the 2.4GHz network, missing out on the superior speed of 5GHz.
The 2.4GHz band is congested—not just with WiFi but also Bluetooth (used by TV remotes, headphones, printers, smart bulbs, and more), baby monitors, microwave ovens, and neighboring networks. This is why manually selecting a 2.4GHz channel is often a bad idea. A channel that appears "free" may be packed with non-WiFi devices using the spectrum constantly, leading to interference. For example, if AirPods are streaming music on the same channel as WiFi, both signals must retransmit data multiple times due to conflicts. This wastes bandwidth, drains battery life, generates heat, and degrades device performance.
If a device refuses to connect to a 2.4GHz network, the issue lies in its compatibility with that 2.4GHz network, not in the presence of 5GHz. Many older or poorly designed devices fail to support WPA3, despite it being a year -old security standard. If a security camera requires WPA2 (introduced in 2004) to function, that raises serious concerns about the manufacturer’s commitment to security updates.
Misconceptions such as this bother me. It's the same people that buy into these notions that also buy into concepts such as a nearby phone mast is higher radiation than one far away, when, in reality, the phone in their hand is the bigger concern. When a mast is far away, phones must transmit their data multiple times (as interference increases with distance meaning the original transmission doesn't reach the mast). This happens at maximum power to try and enaure it reaches the mast, increasing radiation exposure, battery drain, and heat. A nearby mast allows phones to operate at lower power with fewer transmissions, making radiation exposure lower, not higher. When data is slow, this is because it's being retransmitted over and over and over to get through just once.
Applying this to a school setting, if a mast is distant and signal is weak, every student's phone in a classroom is working overtime, all transmitting at max power, with data being resent multiple times. The radiation from 30 phones in close proximity, reflecting off insulated walls, far exceeds what would occur if a mast were nearby. A strong signal means phones transmit once, at lower power, and then remain idle except for occasional check-ins.
For dual-band devices a single SSID means, the choice between 2.4GHz and 5GHz depends on signal strength. If 5GHz is above -68dBm (around two bars on iOS), the device will prefer it. Below -75dBm (around where the bars flip flop between 1 and 2 on iOS), it switches to 2.4GHz. Below -75 interference means there will be retransmissions, this increases wastage and now every device with good signal has to wait for the bad device to finish up sending the same thing say 7x over and over. Hence whilst the device with bad signal may itself show a better speed on 5GHz with low signal, it's not worth the knock on impact it has on slowing down every other device on that band. Rather, moving it to 2.4GHz means it may be slower but there's not all of these retransmissions (as 2.4 has stronger signal), and other devices remain able to benefit from 5GHz speeds. Allowing the network to manage this flow is much more likely to ensure overall good performance than manually doing it, where one bad apple stuck on the 5GHz band will make everything slow.
ultinatwly - Devices on 2.4GHz only see one network, even if a 5GHz one exists with the same name.
applogies on my long post but these invalid notions need to be explained so that we can do away with these repeated posts that only misinform and further perpetuate disinformation that leads to users having bad experiences down the line.
a classic sign of retransmissions are zoom / teams / FaceTime calls breaking up. The breaking up is because a live call cannot retransmit 50 times and still be live. It would mean when you speak, it takes several seconds to get to the other person in the call. Hence it goes silent when retransmissions exceed around 120ms (1024ms in a second).
