WiFi is one of many technologies we use on a daily basis. Whether it be checking email, posting to Instagram, or streaming Netflix, WiFi is a technology we rely on to stay connected. Rarely do we give it a thought until something isn’t working. Sometimes our connection is just frustratingly slow. This raises the question, is Wi-Fi speed affected by distance?
WiFi is very much affected by distance. The further a Wi-Fi signal travels through the air the weaker it signal becomes. The chance of interference affecting the signal also increased. Distance is one factor that impacts Wi-Fi speed. Other factors include walls and other obstructions that attenuate your Wi-Fi signal. Some materials such as concrete will almost entirely block a Wi-Fi signal, even at very short distances. Other materials such as wood and drywall will also reduce your Wi-Fi speed, but not as much as a denser material such as brick or concrete.
Factors That Impact Wi-Fi Speed
There are many factors involved that will effect the range of your WiFi coverage. WiFi rarely performs as expected, even professional RF engineers struggle to predict coverage areas. Here is a list of the top 5 factors that impact how far your WiFi will reach.
- Distance between your device and the wireless access point.
- Obstructions between your device and the wireless access point.
- The type and quality of the antennas both on your device and the access point.
- The frequency band being used, 2.4 GHz is much slower than 5 GHz.
- Interference from other wireless devices.
- The Wi-Fi standard used by your Wi-Fi hardware.
The distance between your client device and the wireless access point is a factor that will affect your Wi-Fi speed greatly. Although Wi-Fi is often advertised as have a range of several hundred feet or more, you will not get the fastest speeds past about 100 feet even under ideal conditions. In most real world situations with walls and other obstructions, even 50 feet can greatly impact your Wi-Fi speed. It is better to have more access points broadcasting at a lower power level than a single access point cranked up to the max. Getting the access point closer to the client device will almost always improve your Wi-Fi speed.
The amount of obstructions between your device and the wireless access point is one of the most important factors in determining your Wi-Fi speed. WiFi signal loss is referred to as attenuation. WiFi attenuation is primarily a function of distance and obstruction. Different materials have different amounts of attenuation.
Generally dense materials such as brick, concrete, and stone have the greatest effect on your signal. In many cases a single concrete wall can completely block a WiFi signal just a few feet away. If you need WiFi coverage in these situations you will likely need an access point on both sides of the wall. Brick is also particularly hard on WiFi signals, as is most other hard dense materials.
Other materials such as wood and drywall play more friendly with WiFi. That said ,they still attenuate the signal to a certain extent. If you have more than 2 walls between your device and the wireless access point your signal may be negatively impacted. Floors tend to be a little toucher for WiFi to pass through than walls. Ideally you never want to connect between more than one floor, as this can have a significant impact on your Wi-Fi speed.
Obstructions such as trees and tree branches can have a major effect on Wi-Fi speed. If your Wi-Fi speeds are poor outdoors, the first thing you will want to do is to position your device to have as much of a line of sight to the access point as possible. This will increase your speed greatly, possibly even double it in many cases.
The type of antenna on both the client device and the access point is an important factor. Most access points and WiFI devices come with omnidirectional antennas. This allows for easier placement since the signal is transmitted equally in all directions. This is great in most cases but does not offer the greatest speed if you are not at close range.
In some environments especially outdoors, a directional antenna can be a better choice because it helps to focus the signal in the direction it is needed rather than spraying signal every which way. Some wireless access points offer the option of using an external antenna. This can be useful in some situations where the placement of the access point is such that all client devices are facing in one direction.
It is also possible to use a high gain directional antenna on the client side. If you are using a laptop, one option is a high gain directional USB WiFi adapter. This will allow you to point the antenna at the wireless access point, greatly increasing the effective signal strength, therefore increase your Wi-Fi speed. If you often need to connect to WiFi at longer distances, investing in a directional antenna for your laptop could make sense. This works especially well outdoors in areas such as parks and campgrounds that offer WiFi.
Most modern WiFi devices are capable of operating in both the 2.4 GHz and 5 GHz frequency bands. As with most things in life, there are pros and cons to both frequency bands. Fortunately most devices are able to select the optimal choice automatically.
The 5 GHz band is generally at least 3 times faster than the 2.4 GHz band. Given a choice, use the 5 GHz band for maximum speed. The 5 GHz band is almost always better if you can use it. The amount of frequency spectrum available in the 5 GHz spectrum is so much greater, and therefore allows for much faster speeds. If you have a choice using 5 GHz is generally better. There are some situations where the 2.4 GHz band can be beneficial.
The 2.4 GHz band offers longer range than the 5 GHz band. This is due to the way RF signals behave. Generally 2.4 GHz offers about 40% more range outdoors, without obstructions. Indoors with walls and other obstacles the difference is even more pronounced. The lower frequency band of the 2.4 GHz band has an easier time penetrating through objects including walls, floors, and ceilings.
There are some situations where you will not be able to use 5 GHz. This will include situations where you are far from the access point or have multiple obstructions in the way. In these cases 2.4 GHz is useful for keeping you connected, albeit at reduced speeds.
Fortunately most modern WiFi devices make the selection automatically. However, if you are having trouble connecting, you may want to try manually setting the frequency band on your device.
The wireless spectrum is a very busy place. Devices are assigned operating frequencies which are regulated by a government authority in most countries. In the United States we have the Federal Communications Commission (FCC). They regulate the use of the RF spectrum by frequency band and by transmit power. Many frequency bands are licensed to particular companies for specific uses. For example T-Mobile uses part of the 600 MHz band to deliver LTE and 5G data services.
Other frequency bands are licensed for a certain application such as 72 MHz for RC model aircraft operations. This regulation generally means less interference on these frequency bands.
Other frequency bands are less regulated. For example, frequency bands such as 27 MHz and 49 MHz are unlicensed bands. This allows for general use with fewer restrictions. This also means that interference is much more likely.
WiFi operates in two unlicensed frequency bands. The unlicensed nature of these frequency bands make interference all too common of an issue. Interference can come from a variety of sources, including Bluetooth devices, cordless telephones, alarm systems, baby monitors, and microwave ovens.
Interference can also come from other WiFi networks that are operating on the same channel or overlapping channels. In the 2.4 GHz band there are only 3 non overlapping channels. This makes frequency congestion a real issue, especially in dense environments such as apartment complexes and stadiums.
The 5 GHz band is more forgiving for a few reasons. The primary reason 5 GHz has less interference is because there are more non-overlapping WiFi channels available in 5 GHz band. Other reasons include less devices using the 5 GHz band, and the shorter range of the signal. That is right, the shorter range can actually be an advantage in dense environments. Interference is a common culprit of slow Wi-Fi speeds but less common of an issue when using the 5 GHz band.
Wi-Fi Standard Used
The Wi-Fi standard used by your devices and your wireless access point has a huge effect on your Wi-Fi speed. Many of the older Wi-Fi standards only supported speeds of 54 Mbps or less. This was under ideal conditions and real world speeds were usually half of that or less. The latest Wi-Fi 6 standard allows for theoretical speeds of 1 Gbps or higher. Real world tests show that speeds of 600+ Mbps is possible in many cases using Wi-Fi 6. If you are using a wireless router or access point that doesn’t support Wi-Fi 6 you may want to consider upgrading. Also make sure your client devices support Wi-Fi 6. Most newer smartphones and laptops come standard with Wi-Fi 6 technology.