Evaluation and improvement of the field prediction method in recommendation ITU-R P.1546-3

In this paper, the method of recommendation ITU-R P.1546-3 for point-to-area predictions is evaluated. This evaluation is done by comparing the predicted field strengths with those obtained by utilizing the IS-95 pilot signal in a commercial CDMA network in rural Australia. The obtained results show that definition of terrain clearance angle in this recommendation introduces a huge error in the predicted field strengths. On the other hand, for those field points where the transmitting/base antenna height, h₁, is less than 10 m, the method of recommendation may lead to some results which do not have any agreement with the field measurements. To overcome these difficulties, definition of the terrain clearance angle and the method of field prediction for h₁ < 10 m should be modified. It is shown that by using these modifications, the predicted results will be improved.