Propagation characteristics in an underground shopping area for 5‐GHz‐band wireless access systems

5-GHz-band wireless access systems, such as the RLAN (Radio Local Area Network) system of IEEE 802.11a, HiperLAN/2, HiSWANa, and AWA, are deployed for indoor use at transmission rates over 20 Mbps. These 5-GHz access systems are expected to extend service areas from the office to the so-called “hot spots” in public areas. Underground shopping malls are one type of service area where the application of such nomadic wireless access service can be expected. In order to design radio zone configurations, it is necessary to know broadband propagation characteristics of an underground mall environment even if results obtained by previous measurements in the narrow band are available. This paper presents results of an experimental study on the propagation characteristics for broadband wireless access systems in an underground mall environment. First, broadband propagation path losses are measured and formulated considering the shadowing by human body. A ray trace simulation is used to clarify the basic propagation mechanism in such a closed environment. Next, it was determined that values of the delay spread at different distances during rush hour periods did not exceed 65 ns, which is lower than the permitted maximum value of the present 5-GHz systems. The final conclusion is that the above propagation characteristics corroborate results of transmission tests carried out by using the AWA equipment. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 152(3): 55–64, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20059