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To efficiently plan future personal communications services (PCS's), we need to solve various mobility/traffic problems in one-dimensional (1-D), two-dimensional (2-D), and three-dimensional (3-D) micro or picocell environments. However, mobility/traffic problems have thus far primarily been studied in 1-D and 2-D cell structures. In this paper, we extend the previous mobility modeling from 1-D or 2-D space to 3-D indoor building environments by considering the proper boundary conditions on each floor and analytically modeling mobility in multistory buildings to estimate the number of handoffs. We then propose a blocking probability model with mobility as a traffic model in 3-D indoor environments. Utilizing this model, we can obtain the required number of channels per cell under the given blocking probability constraint. These results can be utilized in planning the networks of future PCS's. Index Terms - Bounded, handoff, indoor, mobility, PCS, 3-D environments, unbounded.

The reduction of radio wave attenuation in rectangular tunnels is discussed. The attenuation of the dominant mode due to its field penetration into a lossy dielectric wall is reduced by means of the attachment of wire netting (mesh). First, a reflection coefficient from a mesh screen over a lossy surface is analytically evaluated. Then, based on a geometrical optical approach to the propagation model in tunnels, the attenuation of the dominant mode in a rectangular tunnel is derived using the reflection coefficient. The calculated attenuation constants are in good agreement with experimental ones obtained in a laboratory. Finally, the efficiency of attenuation reduction rate by the mesh shielding method is summarized as a function of spatial ratio of the mesh wire interval divided by the wavelength. It is shown that the efficiency of reduction rate by mesh is significant. Index Terms - Tunnel, waveguide, attenuation constant, propagation loss, mesh.

This paper presents the principle of synthetic aperture frequency modulated continuous wave (FM-CW) radar and demonstrates the detection results of several objects buried in natural snowpack using the radar system. First, the synthetic aperture technique is explained with emphasis placed on showing that the Fourier transformed beat signal obtained by the FM-CW radar is equivalent to one kind of Fresnel hologram, which leads us to use SAR technique. Then a radar system operative in the microwave L-band is explored to detect objects buried in natural snowpack. Several detection results are presented demonstrating the potential capability of high resolution imaging in the azimuth direction, comparing with real aperture images.

Modeling cellular telephone systems presents a formidable challenge. A major difficulty lies in the relation between communication and vehicular traffic. So far, studies concentrate on the communication traffic while assuming a homogeneous vehicular traffic. A method of analysis is introduced which incorporates vehicular traffic theory into the model. By obtaining position and time-dependent vehicle density data, we may investigate the behavior of communication traffic under any type of road traffic. Simulation and analysis results are presented.