We have already looked at the First generation of telecommunication system. I think it is necessary to understand the basic principles of Mobile radio Propagation. Without the basic understanding of the principles of mobile radio propagation it is impossible to understand the practical problems related any communication system. Trust me, even with complete understanding of these principles solving the problems in network is difficult!! Lets say for safer side that with understanding of these principles, life will be easier!!
Wireless propagation can be split into three parts
1. Mechanisms of Propagation
2. Large scale Path Loss
3. Small scale Fading
There are numerous great books describing these phenomena. I am just going to present a brief idea so that one is not overwhelmed with the amount of information presented by enormous resources.
Diffraction : When the path between Transmitter and Receiver is obstructed by a surface with sharp irregularities.
Scattering : When the medium has objects smaller compared to the wavelength.
Now lets get to Propagation.If you go the wiki page of Radio Propagation, it says, " Radio propagation is the behavior of radio waves when they are transmitted, or propagated from one point on the Earth to another, or into various parts of the atmosphere."
Large scale propagation models deal with predicting mean signal strength for an arbitrary Transmitter-Receiver separation distance, they are called large scale as they characterize signal strength over a large distances. One most important formula one needs to know is the Friis equation. This describes the signal strength over the distance.
Wireless propagation can be split into three parts
1. Mechanisms of Propagation
2. Large scale Path Loss
3. Small scale Fading
There are numerous great books describing these phenomena. I am just going to present a brief idea so that one is not overwhelmed with the amount of information presented by enormous resources.
Reflection : When the electromagnetic wave impinges upon an object with very large dimensions as compared to its wavelength.(like buildings, walls)
Diffraction : When the path between Transmitter and Receiver is obstructed by a surface with sharp irregularities.
Scattering : When the medium has objects smaller compared to the wavelength.
Now lets get to Propagation.If you go the wiki page of Radio Propagation, it says, " Radio propagation is the behavior of radio waves when they are transmitted, or propagated from one point on the Earth to another, or into various parts of the atmosphere."
Large scale propagation models deal with predicting mean signal strength for an arbitrary Transmitter-Receiver separation distance, they are called large scale as they characterize signal strength over a large distances. One most important formula one needs to know is the Friis equation. This describes the signal strength over the distance.
Small scale propagation models characterize the rapid fluctuations of received signal strength over very short distances or short duration of time.
Small scale fading can be further classified into Flat and frequency selective fading. Another way pf classification is fast and slow fading.
Small scale fading can be further classified into Flat and frequency selective fading. Another way pf classification is fast and slow fading.
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