As well as demonstrating the neXt Generation XG nodes, Shared Spectrum Company set up their spectrum monitoring station on top of ComReg’s HQ in Dublin with superb help from ComReg’s team during the IEEE DySPAN conference in April. Shared Spectrum Company has carried out a similar set of measurements in New York City and Washington DC and it was the first time they had ventured to Europe to carry out a similar set of measurements.
For approximately 40 hours, the wireless activity in Dublin city, from 30MHz up to 3000MHz was measured using their state of the art monitoring equipment
The measurements show how spectrum usage varies between day and night. In some frequency bands, no spectrum usage was detected (at this location anyway). In others, especially in the case of the mobile phone, analogue and digital terrestrial TV (DTT), and digital audio broadcasting (DAB), frequency spectrum is in continuous use. The intermittent use of frequency spectrum is especially apparent in the UHF personal mobile radio (PMR) bands. The frequency-sweeping characteristics of radar signals can be observed in the 2686 to 2900MHz range. On some channels, the RF power from the antenna was almost -10dBm, probably due to high power transmissions from Three Rock mountain, which is visible from this location. The 88-108MHz frequency range was blocked to avoid desensitising the monitoring equipment due to the extremely high power in this band.
A brief report and plots of Shared Spectrum Company’s measurements in Dublin can be downloaded as a zip file here
Alternatively, Shared Spectrum Company’s spectrum measurement plots can be viewed here:
We have just posted a video on our YouTube channel showing our reconfigurable OFDM system in action. In this example, we are transmitting at 2.35GHz using a bandwidth of 1MHz. We have a test licence from ComReg under their innovative Wireless Test and Trial scheme for cognitive radio & dynamic spectrum access testing within a 25MHz band centred at this frequency in addition to another 25MHz centered at 2.08GHz.
In this case, the FFT size is 256 and the number of subcarriers is varied from 255 (full-bandwidth), right down to zero, in both contiguous and non-contiguous configurations. We are using one of the Universal Software Radio Peripherals (USRPs) by Ettus Research LLC
The Emerging Networks (EN) strand is one of the five research strands in the CTVR, the Centre for Telecommunications Value-Chain Research. CTVR was established in July 2004 and is funded by the Science Foundation of Ireland. The CTVR brings together a multi-disciplinary group of researchers, drawn from eight Irish Universities to work on industry-guided engineering and scientific challenges that will redefine key elements of telecommunications systems, architectures and networks and the value chains used to design, build, market, and service them.
Emerging Networks (EN) is based in Trinity College, University of Dublin, Ireland. Dr. Linda Doyle from Trinity College is the leader of the EN strand.
In the Emerging Networks focus on fixed and wireless networks. We concentrate on networks that are distributed and disaggregated and look to design unified architectures that support fixed and mobile communications. We work from the physical to the application layer as well as looking at the wider economic context of the research advances.
To achieve our research goals we work hand in hand with the other CTVR strands (RF, Photonics, Test & Reliability and Optimisation & Management) and with our industrial partners. The combining of the various areas of expertise leads to a rich and multi-faceted approach to our research.
QinetiQ, Shared Spectrum Company, Motorola, SRI International, Virginia Tech and Kansas University were among those taking part in a collaborative attempt to see the latest dynamic spectrum access technology in action using both licenced and licence-exempt spectrum.
It was a valuable and enjoyable experience for all as it was the first time all of these groups were in the same place and delegates could see the latest technologies up close rather than just reading about them in a publication.
On the Saturday before the conference, Shared Spectrum Company conducted a trial of two XG nodes operating in the same DySPAN trial channels as QiniteQ’s HAVE QUICK radios.
On Monday and Tuesday, the conference venue became a ‘hack-fest’ where just about all of the demonstrators spent their time tweaking, debugging and developing their systems even further.
