CWINS: An Integrated Multi-Layer Wireless LAN Testbed (NSF)

An Integrated Multi-Layer Wireless LAN Testbed
PIs: Kaveh Pahlavan, Emanuel Agu, Rick Brown, Sergey Makarov, Mark Claypool, Robert Kineck, John Orr
Personnel:
Sponsored by NSF

The testbed for performance evaluation of indoor positioning systems. The center of this picture is the PROPSIM simulator, on the left is pile of three access points used for reference, on top is laptop running EKAHAU engine. The rest are Network Analyzer, spectrum analyzer, signal generator, and a monitor used for control and performance assessments.

Project Description and Outcomes

Ideas:

Using the IEEE 802.11 WLAN access points, PCMCIA WLAN cards, EKAHAU positioning software, and laptops acquired from the CNS support and our PROPSIM real-time channel simulator acquired from a DoD grant we have completed a novel laboratory testbed for performance evaluation of the indoor positioning systems operating based on RSS. This is the first laboratory testbed that is developed for performance monitoring of indoor positioning systems. The novel methodology adopted in this experiment uses our existing Ray-tracing software to identify location of the training points and measure the performance of the positioning software (in this case EKAHAU engine). The WLAN access points and a laptop with PCMCIA cards as well as the Ray-tracing software are connected to the real-time channel simulator that simulates the channel behavior between location of the access points and the mobile, specified in the Ray-tracing GUI. This innovative setup allows low cost repeatable performance analysis of indoor positioning systems. Our first publication in this field describes the architecture of the testbed and the preliminary results of performance evaluation that relates the density of the training points to the accuracy of the measurements. (see the picture)

Tools:

Using UWB network analyzer, digital scope and antennas purchased with CNS support, we have developed a measurement system for radio channel modeling for indoor positioning systems using TOA and UWB technology. Our exiting network analyzer and digital scope, acquired from previous NSF and industrial grants, were not capable of measuring UWB channel characteristics. An MS and a PhD student, working on measurement and modeling of the indoor radio channel for TOA based positioning system, will use the new system to extend their models, developed for bandwidths up to a few 100MHz, to UWB environment with bandwidths on the order of several GHz. We also use this measurement system in an SBIR project with an industrial partner, supported by DARPA, to develop a framework for design and performance evaluation of positioning algorithms for indoor geolocation systems using UWB technology.

People:

So far we had five ECE and two CS undergraduate students using equipment acquired for this research proposal to perform their Major Qualifying Projects (MQP) at WPI. These students formed three groups, one working on performance monitoring of the IEEE 802.11b and 802.11g WLANs, one on application development and performance monitoring of the EKAHAU indoor positioning software, and one on the design of indoor positioning software. Three MS, one PhD, and one Post-Doctoral students have used the equipment for their research work. A group of minority student visited our laboratory and we arrange demonstrations to stimulate their interest to pursue their education in electrical engineering.

The 50GHz network analyzer, a pair of connected bow-tie antennas, a pair of cone antennas, and a large triangular base antenna all used for UWB channel measurement and modeling program.