http://www.adv-radio-sci.net/Advances in Radio Science Latest Articlesenhttp://www.adv-radio-sci.net/9/401/2011/<b>3-D transponder antennas for future SHF RFID applications</b><br /><br />Advances in Radio Science, 9, 401-405, 2011<br /><br />Author(s): R. Zichner and R. R. Baumann<br /><br />The radio frequency identification (RFID) technology is omnipresent since a few years. Some of the most popular fields of application are the use for security tasks, for logistics and for the consumer segment. For example, chip card or key ring sized RFID transponders can allow wireless access to secured rooms. The number of applications for wireless data transmission for the identification and tracking of objects increases every year. There is a large development need for highly functional and inexpensive RFID transponders due to the ever-increasing demand on improved reliability, higher data rates and read and write ranges of the RFID systems. Therefore, research was performed on new 3-D transponder antennas for the Super High Frequency Band around 5.8 GHz. Additionally, wave propagation effects and the influence of different dielectric environments were considered. Parallel to the design of the novel antenna structures, the printing process for inexpensive manufacturing was investigated. The gained results are the basis for prospective RFID applications.Thu, 08 Dec 2011 00:00:00 +0100http://www.adv-radio-sci.net/9/397/2011/<b>Equitable access to spectrum in further development of the Geneva 2006 frequency plan</b><br /><br />Advances in Radio Science, 9, 397-400, 2011<br /><br />Author(s): J. Philipp<br /><br />Since the frequency plan of the Regional Radiocommunication Conference Geneva 2006 has come into force, many attempts have been made towards its enhancement. The preliminary results, however, seem not to be compliant with elementary principles of distribution justice. Therefore, the planning principles which lead to the observed imbalance will be scrutinized. Furthermore it will be shown that the utilization of spectrum can be advanced in a balanced way when the same (necessary) condition for "equitable access", which has been used by a group of middle European countries for the construction of the original frequency plan, is applied to plan refinements as well. The necessary condition mentioned consists simply in the parity of the number of coverages (constituted of disjoint allotments) configured in the plan for each country. In order to be able to plan enhancements, the concept of coverage number has to be generalized to the case of incomplete coverages of potentially overlapping allotments. The computation of coverage numbers is straightforward and renders the concept of coverage number parity a useful tool to be applied as a necessary condition in testing a frequency plan variant for equitable access.Thu, 08 Dec 2011 00:00:00 +0100http://www.adv-radio-sci.net/9/391/2011/<b>Traditional protection ratios in FM sound broadcasting – still appropriate for interference management?</b><br /><br />Advances in Radio Science, 9, 391-396, 2011<br /><br />Author(s): J. Philipp<br /><br />A detailed analysis of the measurement procedures recommended by the International Telecommunication Union (ITU) shows that – with proper definition of audio quality – the FM broadcasting system can provide an audio signal-to-noise ratio of no better than 40 dB, when the interference in the neighboring channels exhausts the limits established by the internationally agreed protection ratios. Thus any attempt to relax the protection, be it motivated by the desire to implement additional FM or new digital services in the FM band, would inevitably degrade reception quality of existing services to levels hardly acceptable by broadcast listeners.Thu, 08 Dec 2011 00:00:00 +0100http://www.adv-radio-sci.net/9/383/2011/<b>Advanced parametrical modelling of 24 GHz radar sensor IC packaging components</b><br /><br />Advances in Radio Science, 9, 383-389, 2011<br /><br />Author(s): R. Kazemzadeh, W. John, J. Wellmann, U. B. Bala, and A. Thiede<br /><br />This paper deals with the development of an advanced parametrical modelling concept for packaging components of a 24 GHz radar sensor IC used in automotive driver assistance systems. For fast and efficient design of packages for system-in-package modules (SiP), a simplified model for the description of parasitic electromagnetic effects within the package is desirable, as 3-D field computation becomes inefficient due to the high density of conductive elements of the various signal paths in the package. By using lumped element models for the characterization of the conductive components, a fast indication of the design's signal-quality can be gained, but so far does not offer enough flexibility to cover the whole range of geometric arrangements of signal paths in a contemporary package. This work pursues to meet the challenge of developing a flexible and fast package modelling concept by defining <i>parametric</i> lumped-element models for all basic signal path components, e.g. bond wires, vias, strip lines, bumps and balls.Mon, 01 Aug 2011 00:00:00 +0200http://www.adv-radio-sci.net/9/377/2011/<b>Challenges for Wireless Mesh Networks to provide reliable carrier-grade services</b><br /><br />Advances in Radio Science, 9, 377-382, 2011<br /><br />Author(s): D. von Hugo and N. Bayer<br /><br />Provision of mobile and wireless services today within a competitive environment and driven by a huge amount of steadily emerging new services and applications is both challenge and chance for radio network operators. Deployment and operation of an infrastructure for mobile and wireless broadband connectivity generally requires planning effort and large investments. A promising approach to reduce expenses for radio access networking is offered by Wireless Mesh Networks (WMNs). Here traditional dedicated backhaul connections to each access point are replaced by wireless multi-hop links between neighbouring access nodes and few gateways to the backbone employing standard radio technology. Such a solution provides at the same time high flexibility in both deployment and the amount of offered capacity and shall reduce overall expenses. <br><br> On the other hand currently available mesh solutions do not provide carrier grade service quality and reliability and often fail to cope with high traffic load. EU project CARMEN (CARrier grade MEsh Networks) was initiated to incorporate different heterogeneous technologies and new protocols to allow for reliable transmission over "best effort" radio channels, to support a reliable mobility and network management, self-configuration and dynamic resource usage, and thus to offer a permanent or temporary broadband access at high cost efficiency. <br><br> The contribution provides an overview on preliminary project results with focus on main technical challenges from a research and implementation point of view. Especially impact of mesh topology on the overall system performance in terms of throughput and connection reliability and aspects of a dedicated hybrid mobility management solution will be discussed.Mon, 01 Aug 2011 00:00:00 +0200http://www.adv-radio-sci.net/9/373/2011/<b>Classifying user states in next generation networks</b><br /><br />Advances in Radio Science, 9, 373-376, 2011<br /><br />Author(s): Y. He and A. Bilgic<br /><br />In this paper we apply a classification method to learn geographic regions using Location Based Services (LBS) in IP Multimedia Subsystem (IMS). We assume that the information in Local Network (cellular network) can be freely exchanged with Global IP Network (IMS) and the information can be gathered in a data base. LBS in the IMS also provide location information for the data sets. Statistic classification methods are applied to the data sets in the data base. Depending on the information provided by the users, they are divided into different user groups (event classes) using Type Filters (TF). Then discriminant analysis is applied to the position information offered by LBS in IMS to determine the geographic regions of the different classes. The learned geographic regions can be used to inform the users in this region or other regions over IMS. This kind of service can be used for any location-based events.Mon, 01 Aug 2011 00:00:00 +0200http://www.adv-radio-sci.net/9/359/2011/<b>Betrachtungen zur Frequenzplanung für terrestrisches Fernsehen in den 50er Jahren in Mitteleuropa</b><br /><br />Advances in Radio Science, 9, 359-371, 2011<br /><br />Author(s): U. Kühn<br /><br />Der Bericht beleuchtet die Entwicklung der Fernseh- und Rundfunknetze im Osten Deutschlands ab Anfang der 50er Jahre. Neben einer ausführlichen Darstellung der technischen Aspekte liegt ein weiterer Schwerpunkt auf der Darstellung der nötigen Zusammenarbeit mit den Arbeitsgruppen der angrenzenden Länder. Diese war, bedingt durch die politische Lage, gerade mit den Experten aus Westdeutschland oft schwierig. Die maßgeblich beteiligten Personen und ihre Arbeiten werden vorgestellt. Der Autor war in leitender Position an der Entwicklung in Ostdeutschland beteiligt und liefert mit diesem Bericht einen aus technischer und historischer Sicht wertvollen Beitrag zur Entwicklung des Rundfunks.Mon, 01 Aug 2011 00:00:00 +0200http://www.adv-radio-sci.net/9/349/2011/<b>Multi beam observations of cosmic radio noise using a VHF radar with beam forming by a Butler matrix</b><br /><br />Advances in Radio Science, 9, 349-357, 2011<br /><br />Author(s): T. Renkwitz, W. Singer, R. Latteck, and M. Rapp<br /><br />The Leibniz-Institute of Atmospheric Physics (IAP) in Kühlungsborn started to install a new MST radar on the North-Norwegian island Andøya (69.30° N, 16.04° E) in 2009. The new Middle Atmosphere Alomar Radar System (MAARSY) replaces the previous ALWIN radar which has been successfully operated for more than 10 years. The MAARSY radar provides increased temporal and spatial resolution combined with a flexible sequential point-to-point steering of the radar beam. To increase the spatiotemporal resolution of the observations a 16-port Butler matrix has been built and implemented to the radar. In conjunction with 64 Yagi antennas of the former ALWIN antenna array the Butler matrix simultaneously provides 16 individual beams. The beam forming capability of the Butler matrix arrangement has been verified observing the galactic cosmic radio noise of the supernova remnant Cassiopeia A. Furthermore, this multi beam configuration has been used in passive experiments to estimate the cosmic noise absorption at 53.5 MHz during events of enhanced solar and geomagnetic activity as indicators for enhanced ionization at altitudes below 90 km. These observations are well correlated with simultaneous observations of corresponding beams of the co-located imaging riometer AIRIS (69.14° N, 16.02° E) at 38.2 MHz. In addition, enhanced cosmic noise absorption goes along with enhanced electron densities at altitudes below about 90 km as observed with the co-located Saura MF radar using differential absorption and differential phase measurements.Mon, 01 Aug 2011 00:00:00 +0200http://www.adv-radio-sci.net/9/343/2011/<b>Some anomalies of mesosphere/lower thermosphere parameters during the recent solar minimum</b><br /><br />Advances in Radio Science, 9, 343-348, 2011<br /><br />Author(s): Ch. Jacobi, P. Hoffmann, M. Placke, and G. Stober<br /><br />The recent solar minimum has been characterized by an anomalous strong decrease of thermospheric density since 2005. Here we analyze anomalies of mesosphere/lower thermosphere parameters possibly connected with this effect. In particular, nighttime mean LF reflection heights measured at Collm, Germany, show a very strong decrease after 2005, indicating a density decrease. This decrease is also visible in mean meteor heights measured with VHF meteor radar at Collm. This density decrease is accompanied by an increase of gravity wave (GW) amplitudes in the upper mesosphere and a decrease in the lower thermosphere. On the decadal scale, GWs are negatively correlated with the background zonal wind, but this correlation is modulated in the course of the solar cycle, indicating the combined effect of GW filtering and density decrease.Mon, 01 Aug 2011 00:00:00 +0200http://www.adv-radio-sci.net/9/335/2011/<b>Meteor radar measurements of mean winds and tides over Collm (51.3° N, 13° E) and comparison with LF drift measurements 2005–2007</b><br /><br />Advances in Radio Science, 9, 335-341, 2011<br /><br />Author(s): C. Jacobi<br /><br />An all-sky VHF meteor radar (MR) has been continuously operated at Collm (51.3° N, 13° E) since summer 2004. The radar measures meteor parameters, diffusion coefficients, and horizontal winds in the mesopause region. There exists a temporal overlap of the MR wind measurements with co-located low-frequency (LF) ionospheric drift measurements until 2007. Comparison of MR and LF semidiurnal tidal phases allows to empirically determine the virtual height overestimation of LF reflection heights due to the group retardation of LF waves. LF reference heights have to be reduced by up to 20 km to match real heights. Correction of LF heights for group retardation allows to determine the wind underestimation by the LF method compared with meteor radar measurements and opens the possibility to continue long-term trend analysis using mesosphere/lower thermosphere winds.Mon, 01 Aug 2011 00:00:00 +0200