Interference, Why you do not have the signal strength you think you should have

This is where all your cell phone signal gets lost. You walk out the house and see perfectly good signal strength on your phone but only not the case when you walk indoors. Their are 2 kinds of interference one can run into when dealing with interference:

a) Physical Interference
b)Electromagnetic Interference

Physical Interference

As the name suggests, it is the physical structure like the walls, curtains, and other barriers that prevent the signal from reaching the farthest places inside your building. Now lets talk about the source of signal! Signal are nothing but electromagnetic waves that is typically generated by a transducer (one that converts electrical signal into electromagnetic wavers) . These electromagnetic waves gets transmitted and received by antennas. The bigger the antenna the longer the distance these electromagnetic waves can travel. Since the antennas play such a major role in signal strength, lets investigate a little on antenna placement.

Antenna Placement

Antenna placement is very important in how the signal gets transmitted. The radiation pattern of a typical antenna is 360 degrees, but really depends on what type of antenna. The best practice for antenna placement is to keep the 3D space around an antenna clear of any objects, walls, floor, door or any other obstructions. Because the signal travels in all dimensions, any obstruction in one direction may result in blocking signal in that direction and loosing the signal strength. It is a good idea to find the tallest place like the roof or attic to place an antenna. Think of your home or office as a holistic body that the whole area inside the building needs to get covered with signal. Now a strong cell phone signal can travel through walls provided they are wooden and not painted with lead additives or walls that have metal mesh inside. The interior walls of a typical building is not metal studded or wire messed, but the exterior walls are or thick brick walls that act like a shield.

Electromagnetic Interference

This unlike the physical interference is not visible to human eyes, cause they are invisible electromagnetic wavers like the cell phone signals. These interferences come from the cell phone signals interfering with their counter cousin like signals from other sources. Every device that operates on electricity generate electromagnetic waves. Electromagnetic waves are the by product when electricity is conducted from one point to another in this case it happens with in the several electrical appliances and devices we operate. Electricity and electromagnetic waves are the two faces of the same coin. Now you see the problem! The good news is that not all electromagnetic waves are the same, they come in different colors , ie in different frequencies . The radio waves are classified as AM (amplitude modulated) and FM (frequency modulated) signals , we will not dwell into the details of these two on this article.
One major contributor that interferes with cell phone signal in particular are the Wi-Fi signal broadcasters inside our homes. From my own personal experience I have seen that my text message will have trouble being sent when I have the wifi turned ON while I am at home. Once the wi-fi signal is turned OFF, the text message be sent immediately. This is a perfect example to illustrate that the cell phone is having trouble deciding what signal to use to transmit the date packet. As a good rule of thumb, separate the cell phone broadcast antenna and the wi-fi router by a good distance .

Use the table below:

Protocol Frequency Distance of Seperation
802.11b
2.4 G hz
100 ft
802.11g
2.4 G hz
80 ft
802.11a
5.8 G hz
60 ft