Guest

tunnel radio propagation disadvantages

tunnel radio propagation disadvantages


 

Grade:

1 Answers

Saurabh Kumar
askIITians Faculty 2400 Points
9 years ago
1, Frequency distortion... EM waves gets distorted as there is in visible 3-d propagation

RF propagation models generally characterize two aspect
s of RF
propagation: large scale and small scale fading

Large Scale propagation models predict the mean signal
strength
for a given transmitter and receiver separation distance
and are
used to predict RF coverage

Friis Free Space Path Loss Model

Two Ray Ground Reflection Model

Log Distance Path Loss Model with Shadowing

2. Node Coverage:
Test under the coal mine shows that when the RF
transmitting power is 100mW (maximal transmitting power of 2.4GHz set by the state), it can cover 100–150 m by using omni-directional antenna. But if using
directional antenna, the cover range’s radius can reach 300m in the straight main
tunnel. IEEE 802.15.4 specifies that each device shall be capable of transmitting
at least 1 mW . Typical devices (1mW) are expected to cover a 10–20 m range. As radio propagation along the coalmine tunnel has a strong waveguide
effect, we can confirm that the cover range is at least 10 – 100 m in the coalmine tunnel.

Think You Can Provide A Better Answer ?

ASK QUESTION

Get your questions answered by the expert for free