Radio propagation at microwave frequencies for line-of-sight microcellular mobile and personal communications

Improving Propagation Modeling in Urban Environments for Vehicular Ad Hoc Networks

“…A number of available measurement studies [22] were carried out in the cellular band at 900 MHz and were used as a point of comparison by others [10] [14], whereas Dedicated Short Range Communications (DSRC) devices [23] at the data-link and physical layers under IEEE 802.11p [24] operate at 5.9 GHz. Therefore, before proceeding one should consider how relevant are these measurement studies to the new band?…”

“…Though the two-ray ground propagation model may be appropriate in rural areas, it has long been known [22] that a six-ray model in urban areas (ones with high-rise buildings acting as reflectors) for LOS is more appropriate, as it takes account of the effect of road width.…”

Unified approach to predicting cellular characteristics in urban environments with rectangular grid‐plan streets

“…In our calculations we used the same conditions of measurement presented by Rustako et al [1989Rustako et al [ , 1991 To show this fact, let us now compare the theoretically obtained formulas, both for LOS and NLOS conditions, with Tadiran's experimentally measured received signal power spatial distribution in the urban area investigated. For LOS conditions in our first estimations of path loss we used (7); for clutter conditions for the moving radio port at the street level, including intersections between streets, we used both ( depending on the geometry of the street and the dielectric properties of the building's walls lining the street, using the ray model one can take into account only main reflected "wall-to-wall" waves to obtain the total field intensity at the street level.…”

“…Tests described by Rustako et al [1989,1991] carried out in New York City indicate that subscribers at street level, moving radially from the base station, or on streets parallel to these, may receive a signal 10-20 dB higher than that received when moving on the perpendicular streets. This effect is more significant in the microcell area (up to 1-2 km away from the base station), becoming negligible at distances above 10 km, that is, in the macrocell area [Rustako et al, 1989[Rustako et al, , 1991. Certain research investigators have used approximate geometric-optic or ray-tracing models [Harley, 1989 Tan and Tan, 1993, 1995, which have some simplifications and do not give a satisfactory physical explanation of experimentally observed wave channeling effects in an urban area with rectangular grid-plan streets.…”

“…First we will compare the results of theoretical prediction in LOS conditions estimated from the evaluated equations (2) and (7) with experimental data presented by Rustako et al [1989,1991] building walls (presented by a thin continuous curve in Figure 7) and the approximate model (equation (2)) (presented by a dotted curve in Figure 7), which accounts for the real properties of walls, were compared with published experimental data [Rustako et al, 1989[Rustako et al, , 1991 along Lexington Avenue in Manhattan (presented by a thick continuous curve in Figure 7). In our calculations we used the same conditions of measurement presented by Rustako et al [1989Rustako et al [ , 1991 To show this fact, let us now compare the theoretically obtained formulas, both for LOS and NLOS conditions, with Tadiran's experimentally measured received signal power spatial distribution in the urban area investigated.…”