Abstract: A computing system (36) provides a network designer with a mechanism for adaptively predicting the propagation of a radio wave (22) along radials (24) emanating from a base station (26) in a wireless communication environment (20). The computing system (36) includes executable code in the form of a propagation prediction process (58, 130). The propagation prediction process (58, 130) selects segments (78) of a selected one of the radials (24) on a per segment basis and ascertains a propagation environment (28, 30, 32, 34) through which the selected segment (78) traverses. The process (58, 130) chooses, in response to a switching parameter (88, 90, 92), a propagation model (62, 64, 66, 68) from a collection of propagation models (60) that is best suited for predicting the propagation of the radio wave (22) at the selected segment (78).

Abstract: In a cellular communication network (20) employing a network planning tool (38), a method (42) and system (48) associate servers (22) with pixels (74) that correspond to locations in an actual cellular environment. When the server (22) resides in a proximity region (88) surrounding a pixel (74) at which a radiofrequency signal (90, 102) is detected, that server (22) is associated with the pixel (74). When no servers (22) reside in the proximity region (88), a server (22) is selected in response to power levels (124, 128) of the detected radiofrequency signals (90, 102) at the pixel (74). When a computed power difference between the power levels is below a power difference threshold, the server (22) is selected for association with the pixel (74) in response to a random selection procedure.

Abstract: A method, executed on a simulation system (20), characterizes propagation of a radiofrequency signal (56) in a three-dimensional environment (52). The method includes forming a database (42) of propagation paths (54) of the radiofrequency signal (56) transmitted from a transmitter (58) at a fixed location (66) in the three-dimensional environment (52). The propagation paths (54) are represented by a plurality of line segments (120, 122) in the database (42). Local line segments (188) are selected from the plurality of line segments (120, 122) to establish a subset (47) of the propagation paths (54). The subset (47) includes those propagation paths (54) each having one of the local line segments (188) proximate a location (182) of a receiver (72) in the environment (52). Distinct multipath components (246) representing distinct wavefronts of the radiofrequency signal (56) are subsequently identified from the subset (47) of the propagation paths (54).

Abstract: In a radio communications network (20) having a plurality of cells (34) employing a plurality of cell site configurations (22, 24, 26, 28, 30, and 32), a computing system (116) and a computer-based method (178) create a hierarchical data structure (136) modeling the radio communications network (20). The hierarchical data structure (136) is created using object oriented programming methodology to create objects, representing the various physical components of a cell site. In addition, objects are created to represent the auxiliary information, such as available channels, channel assignment constraints, carrier-to-interference ratios, and neighbors lists under which a particular radio communications network configuration is devised.

Abstract: A system and method for wireless network planning utilizing raster data, stored and manipulated in raster data planes (204-212) and vector data (522) stored and manipulated in vector data planes (528-532). The invention increases the accuracy of network planning by simultaneously utilizing vector data planes (528-532) and raster data planes (204-212) to perform computations using vector features contained within map pixels (604). The disclosed method makes it possible to perform accurate computations such as propagation loss to vector points (602) contained within map pixels (604). Accuracy is further increased because other characteristics such as received power, elevation, and best server can be computed to the vector features rather than processing them with traditional raster resolutions.

Abstract: A method and computerized apparatus for assigning frequencies to a plurality of cells in a cellular network. Each cell requires a predetermined number of frequencies. The method includes generating a difficulty factor for each cell, wherein each cell's difficulty factor is based on an adjustment factor for that cell, and wherein, following a first unsuccessful assignment attempt, each cell's adjustment factor is indicative of a relative level of difficulty in selecting frequencies for that cell during the first unsuccessful assignment attempt.

Abstract: A reflector for coupling light from a light source into an optical waveguide includes input and output ends, a central axis and a reflecting surface disposed around the central axis. A light source, such as an arc lamp, is positioned on the central axis at the input end of the reflector. An input end of an optical waveguide is positioned on the central axis at the output end of the reflector. The reflecting surface has a first section adjacent to the input end with a first curvature that is concave toward the central axis, a second section adjacent to the output end with a second curvature that is concave away from the central axis, and an inflection section between the first and second sections. The first and second curvatures are selected to reflect light through the output end of the reflector within a prescribed range of angles that corresponds to the acceptance angle of the optical waveguide.