ECE 5221 Personal Communication Systems. Prepared by: Dr . Ivica Kostanic Lecture 4: Estimation of coverage reliability. Spring 2011. Outline . Macroscopic propagation modeling Edge reliability Area reliability Reudnik curves and fade margin calculations Examples.
Dr. Ivica Kostanic
Lecture 4: Estimation of coverage reliability
Important note: Slides present summary of the results. Detailed derivations are given in notes.
Log distance path loss model
More general models
Comparison of measurements and predictions
Distribution of prediction error
Goal: determine RSLP contour that meets edge reliability requirements
Assume that one needs to perform design for RSLT = -90dBm. The area is characterized with standard deviation of s=8dB. What contour RSLP provides 70% edge reliability.
Answer: RSLP = -85.2dBm, D=4.8dB
Following the same approach one obtains the table
Where Rais the area reliability.
Typical values for area reliability are 90-95%
Note: there is tradeoff between coverage reliability and cell count
Illustration of cell coverage area
Based on log-distance path model
Area reliability calculations – complicated
Edge reliability calculations – easy
Reudnik curves relate area and edge reliabilities
Properties of environments
Example 1: Consider environment with s/n = 3. Determine reliability over the area bounded with a contour having edge reliability of 70%
Example 2: Consider the following design task
Design threshold: -95dBm
Area reliability: 90%
Path loss exponent: 3.84
Standard deviation of the modeling accuracy: 8dB
s/n = 2.29
FM = 1.10 x 8 = 8.8 dB