29 research outputs found
A proposal on frequency management methodologies for WCDMA systems using cell coupling matrices
International audienceAlthough a single carrier frequency is usually considered in Wideband Code Division Multiple Access (WCDMA) systems, each operator has more than one carrier frequency in practical 3G systems. Moreover, QoS levels and the throughput within a given frequency highly depend on interference patterns, which are mainly related to cell-frequency allocation. Therefore, frequency management plays a key role in WCDMA network planning. However, the frequency management problem has not been in the center of attention for WCDMA systems so far due to the fact that WCDMA has not yet been implemented in wide range with all possible services. Nevertheless, the arrival of multimedia services will emphasize the critical importance of a smart frequency allocation. In this context, the presence of several frequencies for each operator (typically 2 or 3 in Europe) manifests itself as a fertile dimension of flexibility to be exploited. This paper introduces a novel frequency management methodology based on coupling matrices that reflects the interaction between cells for a given interference pattern. The proposed methodology is implemented as an integral task of the planning tool and has lead to better results than the frequency allocation in the classical hierarchical cell structur
Development of a Radio Enabler for Reconfiguration Management within the IEEE P1900.4 Working Group
An important emerging capability is for mobile terminals to be dynamically reconfigured. Through ongoing advances in technology such as software defined radio, reconfiguration of mobile terminals will in the near future be achievable across all layers of the protocol stack. However, along
with the capability for such wide-ranging reconfiguration comes the need to manage reconfiguration procedures. This is necessary to coordinate reconfigurations, to ensure that there are no negative effects (e.g. interference to other RATs) as a result of reconfigurations, and to leverage maximal potential benefits of reconfiguration and ensuing technologies such as those involving dynamic spectrum access. The IEEE P1900.4 working group is therefore defining three building blocks for reconfiguration management: Network Reconfiguration Management (NRM),
Terminal Reconfiguration Management (TRM), and a radio
enabler to provide connectivity between the NRM and TRMs. In
this paper we concentrate on aspects of the radio enabler,
highlighting its relevance in heterogeneous radio access scenarios, its advantages, and some aspects of its technical realization
Opportunistic channel allocation algorithms for WLANs based on IEEE802.11
The deployment of highly dense wireless local area networks (WLAN)
can cause an excessive level of interference in the commonly used 2.4 GHz ISM
band, which leads to network performance degradation. This paper analyses the
possibility to reduce congestion in the crowded ISM band by allowing some access
points (APs) to opportunistically operate in a primary band. Although the problem of
opportunistic channel allocation considering both ISM and primary bands can be
formulated mathematically as a Binary Linear Programming (BLP) problem, existing
algorithms (e.g., branch and bound) capable to provide optimal solutions for BLP
problems are quite inefficient for large deployments. Therefore, we propose three
different heuristic algorithms to solve this opportunistic channel allocation problem
by properly extending graph coloring algorithms: First Fit (FF), Saturation Degree
Ordering (SDO) and Minimum Spanning Tree (MST). A performance analysis of the
three algorithms is carried out under different conditions of primary band availability
and AP densityPostprint (published version
Joint vegetation and mammalian records at the early Pleistocene sequence of Bòvila Ordis (Banyoles-Besalú Basin, NE Spain) and their bearing on early hominin occupation in Europe
International audienc
A Novel Frequency Management Methodology for WCDMA using Statistical Coupling Matrices
International audienceFuture wireless systems are expected to endure significant increase in cell loads as well as non-uniform distribution of the traffic over cells. Hence, interference profiles are subject to high increases that can highly affect interference limited systems. The allocation of several frequencies to each operator in 3G systems presents new dimensions to reduce interference patterns by the use of intelligent frequency management methodologies. However, the frequency management problem has not been sufficiently studied for WCDMA systems due to the fact that WCDMA has not yet been implemented in wide range with all possible services. Nevertheless, the arrival of multimedia services will emphasize the critical importance of a smart frequency allocation. Herein, we introduce a novel frequency management methodology based on statistical coupling matrices that reflect the interaction between cells for a given interference pattern. The proposed methodology is implemented as an integral task of the planning tool and has lead to better results than the frequency allocation in the classical hierarchical cell structure