This is a common question about home internet
networks. We're always happy to know if there is, in fact, any relationship
between distance from a router and our internet speeds. Sometimes the Wi-Fi
speed becomes so slow that uploads are nowhere near as fast as promised in your
subscription package. And as soon as you move from your bedroom to the living
room, where the router is placed, in the hope of improving your download speed,
you will notice an increase in download speed as soon as you enter the room
where the router is located... Which naturally makes you wonder how distance
from the router affects your internet speed!
In fact, yes, the distance between the router and
receiver can affect your internet speed. Download speeds depend on the strength
of the received signal, which decreases as an inverse square of the distance in
free space. On the other hand, a general rule of thumb is that if you double
the distance between the router and the client (or receiver), the throughput
drops by a third of its original strength. Things like metal or water also act
as a signal block. So, to get a strong signal, remove any objects that might
block the radio waves. But to be more precise in answering this question, it is
important to understand how Wi-Fi works, and the real factors that affect the
quality of the received signal.
Basics of Wi-Fi Signals
Wi-Fi networks are a set of wireless networking
protocols (a set of rules that enable electronic devices to communicate with
each other wirelessly without wired media) that connect devices in a local area
via radio waves to the Internet. Radio waves are electromagnetic waves that lie
in the frequency range from 3 kHz to 300 GHz. In contrast, Wi-Fi only uses the
2.4GHz and 5GHz bands.
This means that Wi-Fi radio waves oscillate (change
the direction of polarization) 2.4 x 109 - 5 x 109 times per second while
traveling at the speed of light, which is 3 x 106 km/s. In fact, there are many
equations that will link the distance and the speed of the Internet, but we
will not go into its complexities and we will lead you to the real reason
behind your poor download the further you are from the router in your home.
Thus, radio waves, like all electromagnetic waves,
experience a loss in signal strength with the distance traveled. This is called
attenuation, the loss of signal strength. It is the most important factor in
determining the range of a Wi-Fi router. Both indoor and outdoor environments
cause signal attenuation due to a combination of factors such as scattering,
reflection, interference, and path loss.
1- Dispersion of signals
The wavelength of 2.4 GHz is 12.5 cm, while the
wavelength of 5 GHz is 6 cm. Thus, similar-sized objects with irregular
surfaces, such as doors, cabinets, walls, etc., will scatter Wi-Fi signals,
resulting in a weaker signal reaching the receiver. It also results in a wave
energy drop, whereby some of the energy is lost to the obstructed particles
during the collision, then converted into heat and eventually dissipated.
2- Reflection of signals
Reflection of radio waves by metallic surfaces causes
a change in the direction of propagation, as well as a phase shift
("phase" roughly describes the time it takes for a wave to travel one
wavelength). When two waves of different phases overlap, a redistribution of
energy occurs, such that there are regions of very low energy density and
regions of very high energy density. This is called interference; Which changes
the original signal, which means the receiving antenna can't pick it up. This
is another reason that explains the weakness of the Internet that we notice!
3- Loss of track for the signal
Path loss refers to the attenuation of a radio signal
due to the distance between the source and receiver. There are many path loss
models that simulate the general environment of Wi-Fi operation. The simplest
model is one in which there is one transmitter and one receiver spaced apart in
free space (generally air). There are no physical obstructions causing any
reflection or scattering.
Depending on some factor, the power at the receiver
decreases as an inverse square of the distance, i.e. doubling the distance
times the power loss four times. Can you imagine! This goes to show that being
away from a Wi-Fi router is not very conducive to downloading files, as the
signal strength (measured in power) drops a lot. But if we are in an ideal
environment free of physical obstacles, what if we return to reality and study
the environment of our homes? We will notice that there are two types of path
loss,they:
First, the internal path loss of the signal: the
indoor model simulates environments such as a bedroom, where the path loss
depends only on the distance between the source and the receiver, and general
obstructions such as doors, corners, windows, etc.
Second, signal path loss: wave path loss in outdoor
environments is approximated by the same formula as used in indoor environments
by including the attenuation due to walls. This simulates environments such as
public Wi-Fi sites in parks, plazas, etc.
Thus, it is evident that the Wi-Fi signal strength
decreases exponentially compared to the distance traveled. Where distance
affects download speeds and upload speeds to a degree that we could not imagine
before! So get really close to your router, if you can't stand any Internet
lag! In fact, WiFi networks can defy the laws of physics themselves, so be
prepared for any slowdowns in your network.