A Monitoring Network for Spectrum Governance

Dynamic Spectrum Access (DSA) is an exciting new technology, which has introduced a paradigm shift in spectrum access. As a result it also changes the role of the regulator. On one hand the scarce radio spectrum should be used in an optimal way, so that society is best served. On the other hand interference between users and between networks should be avoided. For that reason rules have to be defined for spectrum use. This topic is called spectrum governance. For evaluation and to check whether devices obey the rules, a monitoring system is needed. In this paper, we propose to use a fleet of mobile monitoring vehicles for this purpose.\u

A T-DAB field trial using a low-mast infrastructure

Between October 2004 and July 2006, the University of Twente carried out a technical T-DAB field trial in Amsterdam which was commissioned by the Dutch Ministry of Economic Affairs. For this trial, a low-power low-mast T-DAB pilot network was constructed both for band III (channel 12B) and the L-band (channel LH).\ud This field trial provided evidence that a low-power low-mast network topology can coexist with a high-mast high-power network in an adjacent channel. Using gap fillers, the holes in the service area of the high-mast high-power network can be neutralized effectively. Other possible\ud solutions such as a smaller vertical opening angle of the antenna system were not investigated. The minimum power level of the gap fillers should be 24 dB below the output power of the low-mast infrastructure.\ud If no gap fillers or other solution is used, there exists an interference area with a radius of 1 km on average, where there is no reception of the high-mast high-power network. The interference area around a high-power mast was not investigated, but it is expected that this\ud interference area will be significantly larger. The T-DAB pilot network was mounted on masts of the C2000 TETRA network. The interference of the T-DAB signal on the TETRA system was investigated by the C2000 organization.\ud For indoor coverage in 95% of the buildings, the indoor penetration loss measurements revealed that the loss for band III is 21.9 dB and for L-band 25.8 dB. For indoor coverage, the outdoor field strength has to be 67.9 dBμV/m for band III and 81.9 dBμV/m for L-band for 50% of the\ud locations and 50% of the time at an antenna height of 1.5 m. This value can be used in coverage planning software.\ud Both the existing T-DAB network of the Publieke Omroep and the pilot network (band III and L-band) do not provide good indoor coverage in Amsterdam. If output power is increased by 10 dB at every transmission site, both band III networks will provide good indoor coverage. Of course,\ud an alternative is to use more transmitter locations. For the L-band more transmitters as well as more output power are required for good indoor reception in Amsterdam.\ud However, current internati-onal regulations are based on outdoor coverage and it was decided at the RRC06 conference that the interference level at the Dutch border may increase by 3 dB and it in particular cases\ud by 6 dB to achieve indoor coverage. So, both the high-mast and low-mast topologies require more transmitter locations to obtain indoor coverage and to be in line with the RRC06 agreement.\ud In addition, the performance of T-DAB consumer receivers was evaluated according to the EN 50248 norm. For a kitchen radio, assuming an urban channel model and a passive whipe antenna, the typically achievable sensitivity will be 39 dBμV/m for band III (which is 4 dB higher than the minimum sensitivity specified in the Wiesbaden agreement); for the L-band this is 51 dBμV/m (5 dB higher). The median T-DAB consumer receiver achieves the typically achievable band III sensitivity. However,\ud for the L-band, the sensitivity of the median T-DAB consumer receiver is 6.5 dB less than the typically achievable L-band sensitivity

Spectral Weighting Functions for Single-symbol Phase-noise Specifications in OFDM Systems

For the specification of phase-noise requirements for the front-end of a HiperLAN/2 system we investigated available literature on the subject. Literature differed in several aspects. One aspect is in the type of phase-noise used (Wiener phase-noise or small-angle phase noise). A Wiener phase-noise based analysis leads to contradictions with the type of analysis normally used in the solid state oscillator literature. However, a phase-noise spectrum with a Wiener phase-noise shape can be used provided that the small-angle approximation is satisfied. An other aspect is whether a Fourier Series or DFT based approach is used. The approaches use weighting functions to relate phase-noise power spectral densities to phase-noise power. The two types of analysis are presented in a unified fashion that allows easy comparison of the weighting functions involved. It can be shown that for practical purposes results are identical. Finally phase-noise specifications for the Hiper-LAN/2 case are presented

Channel selection requirements for Bluetooth receivers using a simple demodulation algorithm

In our Software Defined Radio (SDR) project we combine two different types of standards, Bluetooth and HiperLAN/2, on one common hardware platform. SDR system research aims at the design, implementation and deployment of flexible radio systems that are reprogrammable and re-configurable by software. Goal of our project is to generate knowledge about designing the front end of an SDR system (from the antenna signal to the channel bit stream) where especially an approach from both analog and digital perspective is essential. This paper discusses the channel selection requirements for the Bluetooth standard. The standard specifications specify only the power level of the interferers, the power level of the wanted signal and the maximum allowed Bit Error Rate (BER). In order to build a radio front-end, one has to know the required (channel) suppression of these interferers. From [1] it is known that the required SNR for a Bluetooth demodulator is 21 dB, but by which value should interferers be suppressed? This paper will validate if the SNR value needs to be used for the suppression of adjacent channels. In order to answer this question a simulation model of a Bluetooth radio front-end is built

Public safety and cognitive radio

This book gives comprehensive and balanced coverage of the principles of cognitive radio communications, cognitive networks, and details of their implementation, including the latest developments in the standards and spectrum policy. Case studies, end-of-chapter questions, and descriptions of various platforms and test beds, together with sample code, give hands-on knowledge of how cognitive radio systems can be implemented in practice. Extensive treatment is given to several standards, including IEEE 802.22 for TV White Spaces and IEEE SCC41

Opportunistic Error Correction for WLAN Applications

The current error correction layer of IEEE 802.11a WLAN is designed\ud for worst case scenarios, which often do not apply. In this paper,\ud we propose a new opportunistic error correction layer based on\ud Fountain codes and a resolution adaptive ADC. The key part in the\ud new proposed system is that only packets are processed by the\ud receiver chain which have encountered ``good'' channel conditions.\ud Others are discarded. With this new approach, around $\frac{2}{3}$\ud of the energy consumption can be saved compared with the\ud conventional IEEE 802.11a WLAN system under the same channel\ud conditions and throughput