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Within this special session paper we present a selection of our designed and prototyped silicon integrated circuits realized in SiGe BiCMOS technology at 10 GHz and 35 GHz. The circuits have been prototyped within European Space Agency contracts that SIRC implements as well as in an NCBiR project. The ICs, prototyped in IHP SG25V and SG13S technologies, have been mounted as chip on board and measured...
Energy is a critical resource in the design of wireless networks since wireless devices are usually powered by batteries. Without any new approaches for energy saving, 4G mobile users will relentlessly be searching for power outlets rather than network access, and becoming once again bound to a single location. To avoid the so called 4G “energy trap” and to help wireless devices become more environment...
Physical resource sharing between wireless operators and service providers is necessary in order to support efficient, competitive, and innovative wireless communication markets. By sharing resources, such as spectrum or infrastructure, which are usually exclusively allocated interference is created on the physical layer. Therefore, the economic gains, regulatory overhead, and engineering efforts...
Cognitive Radio (CR) is currently regarded as the most promising solution to the problem of coexistence of different radio technologies by allowing smart spectrum management and cooperation in future wireless communication systems. The paper presents CR as a radio system that can adapt its transmission or reception parameters based on cognitive interaction with the wireless environment in which it...
Cognitive networks are becoming extremely popular in the network domain. This paper proposes a novel concept in cognitive network management and protocol configuration, where any protocol of the TCP/IP protocol reference model can be extended to dynamically tune its configuration parameters based on "immediate past" performance. The approach is focused on inter-node cognitive adaptation...
Standard GMPLS protocols used for dynamic establishment of lightpaths in transparent optical networks suffer from lack of physical layer impairments (PLIs) information, which makes it difficult to evaluate optical feasibility. In this paper, we compare two impairment aware (IA)-GMPLS architectures: signalling based-in which RSVP-TE is extended to carry PLIs and hybrid architecture-in which RSVP-TE...
We propose a hybrid control plane architecture, in which both RSVP-TE and OSPF-TE are extended to carry PLIs information and disseminate wavelength availability information, respectively, for impairment-aware routing in transparent optical networks. The results suggest that, hybrid approach provides good trade-off between control overhead and network performance.
In this paper we present the spectrum sensing performance for detecting the IEEE 802.11n Wi-Fi terminals for ultrawideband (UWB) based cognitive radio (CR) systems. The 802.11 n WiFi system lies in the 5 GHz un-licensed frequency band and is subjected to interferences from the UWB transmissions. The UWB based CR terminals perform secondary communications by opportunistically utilizing the available...
Most critical component of the cognitive radio paradigm is spectrum sensing and accordingly, detection of primary users. Recently proposed cooperative spectrum sensing methods do not consider errors occurring during the transmission of local cognitive radio decisions to the cognitive base station. However, perfect communication is clearly not the case in realistic cooperative spectrum sensing scenarios...
In this paper we present a time divisional and a time-frequency divisional cooperative spectrum sensing technique suitable for cognitive radio (CR) networks. The two methods are well suited for very high bandwidth CR networks, such as UWB networks, where the individual nodes need to scan a wide range of spectrum which is a time consuming process. With the time divisional and the time-frequency divisional...
In transparent optical networks, physical layer impairments (PLIs) incurred by non-ideal optical transmission media accumulate along an optical path, and the overall effect determines the feasibility of the lightpaths. If the received signal quality is not within the receiver sensitivity threshold, the receiver may not be able to correctly detect the optical signal. Hence it is important to understand...
This paper presents an extension of the Cognitive Pilot Channel (CPC) concept to the case of a distributed version thereof (namely, DCPC), and demonstrates a potential instantiation of this concept in the design of Smart Femto-Cell Controllers (SFC-C) for handling the management of co-existing homogeneous or heterogeneous networks. Instead of covering the various networks by a single CPC, the novel...
Cooperative spectrum sensing for cognitive radio networks is recently being studied to simultaneously minimize uncertainty in primary user detection and solve hidden terminal problem. Sensing wideband spectrum is another challenging task for a single cognitive radio due to large sensing time required. In this paper, we introduce a technique to tackle both wideband and cooperative spectrum sensing...
With an increasing number of collocated personal, local and cellular wireless communication systems, the question of optimum coexistence and inter-networking are raised. Although some mitigation techniques, like DAA, LDC, Frequency band notching etc. are being widely studied by industries, regulation bodies and standardization authorities, none of them show good performance in terms of detection and...
The interference produced by WiMAX mobile wireless transmissions operating in the 3.5 GHz band on a WiMedia-defined ultra-wideband (UWB) wireless link is experimentally analyzed in this paper. The investigation includes standard IEEE 802.16e WiMAX, and ECMA-368 UWB equipment as defined by the WiMedia alliance. A conventional meeting room scenario has been considered for the measurements. The experimental...
In this paper we consider cooperative localization and tracking of primary users (PU) in a cognitive radio network using Bayesian techniques. We use particle filtering methods to track the location of a PU in the network using cooperative localization techniques and present some results for noisy measurements. The cognitive radio (CR) nodes estimate the information related to the geographical position...
Cognitive radio has emerged as an innovative approach able to cope with the spectral limitations. Cognitive radio networks rely on detecting whether a particular segment of the radio spectrum is currently in use and to exploit the temporarily unused spectrum rapidly without interfering with the transmissions of other users. Thus, one of the most important and critical components of the cognitive radio...
This paper deals with the problem of routing and wavelength assignment (RWA) of fault-tolerant sliding scheduled lightpath demands (FSSLDs) in WDM optical mesh networks. Sliding scheduled traffic model allows the service provider and end-users to negotiate the starting time and ending time of the demands. We have developed a time conflict resolving algorithm that exploits the time disjointness that...
A 300 GHz channel measurement and transmission system designed for the characterization of THz communication channels has been set up. It consists of autarkic transmitter and detector units based on Schottky diode mixers. The system performance is shown including signal levels and noise. For demonstration of THz communications, analogue video signals have been transmitted over distances of up to 22...
This paper reports on the aircraft cabin UWB channel modeling based on a measurement campaign conducted on board an Airbus A319 cabin in the frequency range from 3 - 8 GHz. Besides path loss (L) and time dispersion parameters (maximum excess delay (taumax), RMS delay spread (sigmatau)), a modified Saleh-Velenuela (SV) model is derived for this new environment.
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