Global Spectrum Observatory Network Setup and Initial Findings

Abstract

This paper describes the current efforts underway to set up matched long-term continuously running spectrum observatories in the US (in Chicago and Blacksburg) and in Turku, Finland. The measurement equipment setup is described, along with the architecture for the networked database used to aggregate, archive and share the spectrum measurement data collected across the multiple international locations. High performance computer infrastructure to permit analysis and as appropriate fusion specific elements of the terabytes of data is described. The measurement parameters and spectrum measurement band plans are listed. Preliminary analysis results are also provided-particularly, simple occupancy statistics in Chicago and in Turku. To demonstrate the utility of the global spectrum observatory network, an interesting example is provided that compares and contrasts the very different signals that occupy the same spectral band, but in different geographic regions.

A High-performance Tiered Storage System for a Global Spectrum Observatory Network

“…The measurements are conducted with (a) the band plan introduced in [16] and (b) the band plan introduced in Table I of this paper. The occupancy results with the old band plan were obtained from the 100-6000 MHz band measurement in [16] with a frequency resolution of 312.5 kHz, while the new band plan results are obtained with the parameters listed in Table I. To determine occupancy, we need to calculate the noise floor for each of the frequency points and add a threshold so as to determine if the measured power exceeds a minimal power level and thus is a valid signal [14].…”

“…Spectrum Observatories in both the US and Finland use the CRFS RFeye spectrum measurement receiver [13] as described in [16]. The initial measurement band plan has evolved over time as the project participants have become more familiar with the RF response of the measurement device, and gathered knowledge on what kind of data would be most useful for both regulators and researchers.…”

“…Otherwise the strong signals cause the RF front end to use a high attenuation setting, which raises the overall noise floor while lowering the sensitivity to weak signals. This was a problem in the previous setup [16], where only one RF port was used and there was no bandpass or band-reject filtering. The use of different filters feeding into the 4 different ports of the RFeye eliminates this problem.…”

“…At an international level, IIT in partnership with Virginia Tech, VTT Technical Institute of Finland, Turku University of Applied Sciences, and University of Oulu, has deployed a network of Spectrum Observatories in Chicago and Blacksburg, VA in the USA, and at Turku in Finland. This ongoing WirelessFinland-US (WiFiUS) Global Spectrum Observatory Network project [16] is funded by the government funding agencies -NSF in the US and Tekes in Finland. This geographically dispersed spectrum observatory network, with three (3) sensor locations in the US, and two (2) in Finland gathers data of use to policy makers and researchers.…”

“…The rest of the paper is organized as follows: Section II describes the WiFiUS measurement setup that has been updated and modified since [16]. The tiered database architecture is described in Section III.…”