Page 253 - Integrated Wireless Propagation Models
P. 253

M i c r o c e l l   P r e d i c t i o n   M  o d e l s    231

                               -20.00         ·  -  --
                                     I'
                               -30.00
                               -40.00   �
                            E'         � �
                            co  -50.00    ..                  o  Meas (dBm)
                            :s   -60.00   ...... g  ;oa _
                                               •
                            if.)            '"'�  ....   •   l'"..   o  Pred (dBm)
                            (/)  -70.00                 '0   "'
                            a:                   . ,"  �    �.·
                               -80.00
                                                         ;'"'
                               -90.00
                              -100.00
                                    0.00  0.20  0.40  0.60  0.80  1 . 00
                                           Distance (mile)
                                               (a)
                                   1 0 0
                                                          /
                                    80
                                                  /
                                 �  60
                                 u..          ;��"
                                 8  40
                                          /
                                    20
                                       J
                                    00
                                      0.00     5.00     1 0 .00   1 5 .00
                                                 Deviation (dB)
                                                     (b)
               FIGURE 4.3.3.2  Route s_1900_02. (a) Measured and predicted versus distance. (b) CDF of
               difference between measured and predicted.




               are 3, 6, 3.5, and 4.5, respectively. Thus, the predicted values follow the measured signal
               data fairly accurately, and the standard deviation is approximately 3 to 6 dB on average.
                  This prediction in the four figures utilizes a statistical approach and a multiple­
               breakpoint model to calculate the path  loss.  The method is simple and easy to
               implement and does not require building data. Validation was done in several dif­
               ferent countries/ cities, and the prediction results are very encouraging. One area
               that can still be enhanced is the specification of the average building height for each
               radial so that the multiple-breakpoint model can more accurately predict the near­
               in distance.
                  It is imperative that the two prediction models, macrocell and microcell, can work
               seamlessly to ensure a smooth transition of coverage. Understanding the characteristics
               of micro- and macrocells as well as the ability to model them provides a huge advantage
               to network deployment and engineering. This integrated micro- and macrocell model
               demonstrates another unique advantage of the Lee models. The integrated model has
               been used in many different cities, countries, and continents for the success of planning
               network deployment.
   248   249   250   251   252   253   254   255   256   257   258