Summary
Objectives: In medical institutions, unauthorized access points and terminals obstruct the stable
operation of a large-scale wireless local area network (LAN) system. By establishing
a real-time monitoring method to detect such unauthorized wireless devices, we can
improve the efficiency of security management.
Methods: We detected unauthorized wireless devices by using a centralized wireless LAN system
and a location detection system at 370 access points at the University of Tokyo Hospital.
By storing the detected radio signal strength and location information in a database,
we evaluated the risk level from the detection history. We also evaluated the location
detection performance in our hospital ward using Wi-Fi tags.
Results: The presence of electric waves outside the hospital and those emitted from portable
game machines with wireless communication capability was confirmed from the detection
result. The location detection performance showed an error margin of approximately
4 m in detection accuracy and approximately 5% in false detection. Therefore, it was
effective to consider the radio signal strength as both an index of likelihood at
the detection location and an index for the level of risk.
Conclusions: We determined the location of wireless devices with high accuracy by filtering the
detection results on the basis of radio signal strength and detection history. Results
of this study showed that it would be effective to use the developed location database
containing radio signal strength and detection history for security management of
wireless LAN systems and more general-purpose location detection applications.
Keywords
Wireless LAN - security management - location detection
