Telecommunication--Equipment and supplies

We explored the possible effects of various interferences on Bluetooth devices in the ISM band. We developed a model of Bluetooth and interference from sources such as WLAN devices and Microwave oven, and evaluate the functionality of Bluetooth in the presence of these interferences. As a first step we created Bluetooth, WLAN and Microwave oven models using SPW (Signal Processing Workstation). In our exploration, we undertake three cases: (1) When the Bluetooth is in the presence of only noises in the channel; (2) When the Bluetooth is in the presence of Microwave oven interference; (3) When the Bluetooth is in the presence of WLAN interference. We show that these models can be used to analyze the interferences on the Bluetooth in the ISM band. Future efforts of our group will be to analyze this Bluetooth model with combined interference from all the sources, to come up with possible solutions to reduce the effect of these interferences.

Wireless personal area networks (WPAN) are becoming more and more popular for use by mobile professionals in areas like airports, hotels, or convention centers. The demand for wireless networks is expected to undergo an explosive growth as Bluetooth(TM) capable devices become more and more popular. In such a scenario, it is imperative that designer are aware of the performance characteristics of several Bluetooth(TM) networks operating within the same area. There are several issues that need consideration like security, self-interference and adjacent network interference. The objective of this research is to evaluate the performance of a Bluetooth(TM) network in the presence of self-interference which included adjacent and co-channel interference from neighboring Bluetooth(TM) networks. Specific to the above topics of interest, the following research tasks are performed: (1) The magnitude of self-interference problem in Bluetooth(TM) networks. (2) The system throughput is evaluated by varying duty cycles of the various networks. (3) The pathloss difference is measured between the desired and the interfering device.

Body-proximate telecommunications devices are examined in both direct and multipath propagation. The study begins with a characterization of standard field strength sensitivity measurement methods for body-proximate telecommunications devices. Original measurements on a group of anthropometrically diverse people reveal that human adults, in a standard pose, are remarkably similar with respect to belt worn sensitivity performance, which motivates and justifies the use of an existing and a newly introduced light weight simulated human body device for testing, analysis and optimization of body worn telecommunications devices. Standard measurement methods using standard open air test ranges are established and validated by international transfers of measurements. The study extends to optimization of telecommunications devices in multipath, and particularly to the diversity reception of signals. A novel signal simulation model is introduced which includes multipath and shadowing, and is validated against both theoretical statistics and measurements. The signal simulation model is extended to characterize polarization randomization and cross-coupling based on an urban generalization of building height to street width ratio. The model is used to analyze measurements of polarization randomization of signals originating from an airborne transmitter flying a path whose geometry is consistent with low earth orbiting communications satellites.