How Far can a Wi-Fi Signal Travel?
You’ve most likely noticed that Wi-Fi signals do not travel an infinite distance. The farther a Wi-Fi signal goes, the weaker it gets. This is known as attenuation. The same thing happens to your voice. When you speak or yell, your voice will be nice and loud nearby, but your voice will get weaker (softer) the farther it travels.
Exactly how far a Wi-Fi signal can travel depends on several factors:
1. The type of wireless router used: More powerful wireless routers (with more powerful antennas) are capable of transmitting a signal farther.
2. The type of 802.11 protocol used. Here are the transmission ranges (indoors):
- 802.11b: 115 ft.
- 802.11a: 115 ft.
- 802.11g: 125 ft.
- 802.11n: 230 ft.
- 802.11ac: 230 ft.
However, keep in mind that calculating attenuation and wireless ranges indoors can be very tricky. That’s because inside your house, the Wi-Fi signal bounces off obstacles and has to penetrate a variety of materials (like walls) that weaken the signal.
What Kinds of Things Can Obstruct a Wireless Signal?
Solid items can greatly attenuate (weaken) communication signals. Let’s compare this to your voice again. If you’re speaking to someone in another room, they’ll be able to hear you more clearly if the door between the two rooms is open rather than closed. Likewise, obstructions like walls and doors can dampen a wireless signal, decreasing its range.
- A solid wood door will attenuate a wireless signal by 6 dB.
- A concrete wall will attenuate a wireless signal by 18 dB.
And each 3 dB of attenuation represents a power loss of ½!
What Else Can Impact a Wireless Signal?
In addition to physical obstructions like walls and doors, radio interference can also impact Wi-Fi signals. For example, various home appliances like microwave ovens, cordless phones, and wireless baby monitors can all interfere with your Wi-Fi network (you can read more about wireless interference here). In addition, if there are too many Wi-Fi networks all using the same wireless channel in the same area, the “noise” can impact your signal.
Let’s return to the voice comparison. What happens when you’re trying to speak and someone else starts speaking, turns on the TV, or turns up the radio volume at the same time? It’s much harder for others to hear what you’re saying.
How Can Wired/Wireless Extenders Help?
If you have a big house, and you’d like to be able to communicate with someone upstairs or in a far room, you might install a home intercom system. This is similar to a wired Wi-Fi extender. These devices use the home’s existing wiring (coax for MoCA-based solutions and electrical wiring for Powerline-based solutions) to extend the wireless network into a far corner of the home. In essence, they carry the wireless signals through a wired connection (where there’s less attenuation and interference) and then send out a strong wireless signal in the new location.