Page 241 - Integrated Wireless Propagation Models
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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    219

                   -20.00
                          �
                   --40.00
                                                                        Measured
                E'          �'t�                                       v
                co   -60.00   "'\'
                2.              -H-'  +  +  + ++            $ +   +   �   +  + /   0
                                                        \ _:
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                                           i
                (/)  -80.00                              +   +       +   + �
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                                                        +
                                                                               +p
                  -100.00                        f  +t     �  /     OOo  ,f:  ���
                                                 +           I
                                                         �redicted    f l    h   "\¥
                  -120.00
                        0.00  500.00  1 0 00.00 1 5 00.00 2000.00 2500.00 3000.00 3500.00 4000.00 4500.00
                                                  Distance (feet)
                                                      (a)
                    1 . 00
                                                            �
                    0.80                                _r-
                                                c____s
                    0.60                 �
                  u..
                  0                 w
                  ()              ,----
                    0.40
                             ,J
                    0.20
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                    0.00
                       0.0         5.00       1 0 .00     1 5 .00    20.00       25.00
                                                  Delta (dB)
                                                     (b)
               FIGURE 4.2.7.7  Zigzag-run case: measured versus predicted on Drum-Sacramento Street at
               1937 M H z. (a) RSSI of measured versus predicted. (b) CDF of the deviation between measured
               and predicted.




                                                i
               4.2.8  Integrating Other Attributes  n to the  Model
               The Lee microcell model has successfully integrated building and terrain attributes to
               provide an accurate propagation model. There are many other important attributes in
                                                                                     8
               the dense urban area, such as, water, trees, parks, and open areas shown in Fig. 4.2. . 1 .
                                                           t
               The model needs to  e   able to integrate capabilities  o   handle all these different attri­
                                b
               butes. The Lee macrocell model has developed the ability to integrate these attributes,
               such as water, and other morphologies into the model.
                  The grid along the radio radial in the map can be divided into a smaller unit, a
               "bin." Each bin has its own unique attributes associated with it. During the calculation
               of the prediction, the associated "attributes" in each bin can be considered and the
               adjusted to the final prediction value. This capability enables the Lee microcell model
               to handle many different environments as well as many unique challenges in the com­
               plex urban area.
                  The attribute file can be overlaid on the terrain and building information to enable
               the model to be more flexible in handling different characteristics of the environment.
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