Experimental Investigation of Co-channel and Adjacent Channel Operations of Microwave Power and IEEE 802.11g Data Transmissions

Norikatsu IMOTO  Shota YAMASHITA  Takuya ICHIHARA  Koji YAMAMOTO  Takayuki NISHIO  Masahiro MORIKURA  Naoki SHINOHARA  

Publication
IEICE TRANSACTIONS on Communications   Vol.E97-B    No.9    pp.1835-1842
Publication Date: 2014/09/01
Online ISSN: 1745-1345
DOI: 10.1587/transcom.E97.B.1835
Type of Manuscript: Special Section PAPER (Special Section on Ambient Intelligence and Sensor Networks)
Category: 
Keyword: 
microwave power transmission,  IEEE 802.11,  CSMA/CA,  WLAN,  adjacent channel interference,  

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Summary: 
We discuss the division of radio resources in the time and frequency domains for wireless local area network (WLAN) devices powered with microwave energy. In general, there are two ways to avoid microwave power transmission (MPT) from influencing data communications: adjacent channel operation of continuous MPT and WLAN data transmission and co-channel operation of intermittent MPT and WLAN data transmission. Experimental results reveal that, even when we implement these methods, several problems arise because WLAN devices have been developed without supposing the existence of MPT. One problem clarified in our experiment is that adjacent channel operation at 2.4GHz does not necessarily perform well owing to the interference from MPT. This interference occurs regardless of the frequency separation at 2.4GHz. The other problem is that intermittent MPT could result in throughput degradation owing to the data rate control algorithm and the association scheme of the WLAN. In addition, the experimental results imply that a microwave energy source and a WLAN device should share information on the timings of intermittent MPT and data transmission to avoid buffer overflow.