Characterization of the 5-GHz Elevator Shaft Channel

Abstract

Abstract-In this paper we provide channel characterization results for the elevator shaft channel in the 5-GHz band, based upon measurements conducted in four buildings. This channel is of interest for several applications, including WiFi and public safety. Although several authors have provided elevator shaft channel characteristics for lower-frequency bands (255-MHz, 900-MHz, 1.9-GHz), to our knowledge this is the first work that addresses the 5-GHz band. Moreover, prior work has not thoroughly addressed channel characteristics when the elevator car is in motion, whereas here we provide measurement and modeling results for this dynamic condition. Our measurements were of power delay profiles, from which we estimated propagation path loss and root-mean square delay spread (RMS-DS). Path loss exponents were approximately 2.5 in one building and 5.5 in the other three buildings, with standard deviations about the log-distance linear fits equal to approximately 3 dB and 5.5 dB, respectively. Mean RMS-DS values range from approximately 14-60 ns when the elevator car is motionless. Maximum RMS-DS values were 144 ns and 152 ns in the two different types of buildings when the elevator car is moving. The significant differences in these channel characteristics among the four buildings are likely attributable to the distinct physical features of the buildings.Index Terms-Path loss, RMS delay spread, tapped delay line.

Path loss and delay spread for the stairwell channel at 5 GHz

“…The authors concluded that if reflected signals from surrounding obstacles are present, the received power can increase by up to 10 dB. In this paper, both exterior and interior stairwells were studied, and the conclusions are basically consistent with those in [14] and [15]. In this paper, we report our results for stairwell channel measurements in the 5 GHz band for six different stairwells in four different buildings.…”

“…No path loss model or RMS-DS results were provided. The authors in [14] and [15] put the Tx in the waiting area outside an elevator shaft on the top floor, with the Rx in the same location on other floors. Again, the orientations of quarter-wave monopoles did not affect the path loss and RMS-DS.…”

“…In [14] and [15], exterior and interior elevator shafts were classified, and the exterior shafts can allow external-to-building or 'external' signals from Tx to Rx. These external signals are those that travel from the Tx (inside the building), through an opening (e.g.…”

Measurement and Analysis of Channel Characteristics in Reflective Environments at 3.6 GHz and 14.6 GHz

“…In order to achieve spatial averaging, five spatially separated positions were measured at each receiver location as suggested in [15]. One received position is at the center of one specific location, surrounded by the remaining four positions as shown in Figure 4 (top view); these positions are separated by about 0.17 m, which is about two wavelengths for 3.6 GHz and eight wavelengths for 14.6 GHz.…”

“…One received position is at the center of one specific location, surrounded by the remaining four positions as shown in Figure 4 (top view); these positions are separated by about 0.17 m, which is about two wavelengths for 3.6 GHz and eight wavelengths for 14.6 GHz. Assuming that the phase of received signal is uniformly distributed, it is reasonable to average out the small-scale fading effect via these five positions [15] in the Ricean channel. …”