A Cyber Physical Test-Bed for Virtualization of RF Access Environment for Body Sensor Network

Performance evaluation of wireless access and localization is important for body sensor networks, as any defects in the design not only cause wastage of resources, but also threaten an individual's health and safety. The typical cyber methods, however, such as software simulation, often fail to accurately simulate the influence of hardware implementation. The traditional physical methods, however, such as field testing, are not capable of creating repeatable and controllable channel conditions. To combine cyber and physical factors as well as to address the issue, we present a cyber physical test-bed for environment virtualization to facilitate the performance evaluation of wireless access and localization in body sensor networks. This test-bed creates a virtualized environment by emulating the wireless channel in a cybernetic way using a real time channel emulator. The original devices or systems under testing can be physically connected to a channel emulator to evaluate the performance in the virtualization environment. Furthermore, the cyber physical test-bed supports various scenarios from in-body data transmission to time of arrival based indoor localization. To validate the cyber physical approach, emulated outputs are compared with the empirical data obtained from actual measurements. To overcome the bandwidth limitation of traditional digital channel emulators, we have designed an analog channel emulator for UWB technologies. The preliminary verification of this analog emulator is introduced at the end of this paper.