Search results for: Zwi Altman
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IEEE Transactions on Vehicular Technology > 2016 > 65 > 9 > 7184 - 7194
The increasing densification of telecommunications mobile networks raises the compelling problem of exposure to electromagnetic fields (EMF). In this paper, we address the particular concept of heterogeneous networks, where small cells (SCs) are deployed to build up a second layer to the existing macrocell network. SC deployment is shown to be particularly effective in reducing EMF exposure, in addition...
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In future networks, Radio Resource Management (RRM) could benefit from Geo-Localized Measurements (GLM) thanks to the Minimization of Drive Testing (MDT) feature introduced in Long Term Evolution (LTE). Such measurements can be processed by the network and be used to optimize its performance. The purpose of this papera is to use GLM to significantly improve scheduling. We introduce the concept of...
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Cellular networks are witnessing an exponential traffic growth leading to an increase in Energy Consumption (EC), and having both environmental and economic impact. Recently, different approaches have been studied to build Green cellular networks focusing mainly on the Base Stations (BSs) as the access network represents 80% of the total wireless network consumption [1] [2]. One of the promising solutions...
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The aim of this papera is to study new antenna array technologies in order to manage efficiently heterogeneous, fixed and mobile traffic. Traffic light close to the cell edge is introduced to generate non stationary mobility pattern in the cell. A car following model is used to model the mobility behavior of the vehicles. A heterogeneous antenna system with different large antenna array technologies...
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IEEE Wireless Communications Letters > 2015 > 4 > 6 > 645 - 648
Self-organizing network (SON) technology aims at autonomously deploying, optimizing and repairing radio access networks (RANs). SON algorithms typically use key performance indicators (KPIs) from the RAN. It is shown that in certain cases, it is essential to take into account the impact of the backhaul state in the design of the SON algorithm. We revisit the base station (BS) load definition taking...
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IEEE Communications Magazine > 2015 > 53 > 7 > 154 - 161
SON technologies have been a promising approach for simplified and automated RAN management. Currently, SON functions can be D-SON among the network elements or C-SON as part of the OSS/NMS. D-SON technology is typically provided by equipment vendors, while C-SON is provided by both third parties and equipment vendors. D-SON has high reactivity but is usually provided as black boxes with poor or no...
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Vertical Sectorisation (VS) is a feature that exploits the capabilities of Active Antenna Systems (AAS) to improve service performance and network capacity, by splitting a single cell into an inner and outer sector. The attained gains primarily depend on the suitable and timely (de)activation of VS in response to the observed/estimated traffic distribution within the cell, while further gains can...
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Virtual Sectorization (ViSn) aims at covering a confined area such as a traffic hot-spot using a narrow beam. The beam is generated by a remote antenna array located at- or close to the Base Station (BS). This paper develops the ViSn model and provides the guidelines for designing the Virtual Sector (ViS) antenna. In order to mitigate interference between the ViS and the traditional macro sector covering...
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The aim of this paper is to study resource allocation and control in a LTE-Advanced heterogeneous network with vehicular traffic in the presence of traffic light. A car following model is used to model the cars' speed and their interactions. A small cell is deployed near the traffic light to relieve periodic congestion and QoS degradation. Three resource allocation and control schemes are investigated:...
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Vertical Sectorization (VS) consists in creating vertically separated sectors in the original cell using an Active Antenna Systems (AAS) supporting two distinct beams with different downtilts. The total transmit power is split between the two sectors, while the frequency bandwidth can be reused by each sector, creating additional interference between the two sectors. For low traffic demand, VS may...
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With an increasing number of SON functions deployed in cellular radio networks, conflicts between the actions proposed by independently-designed and distributed SON functions may arise. The process of minimizing the occurrence, and the consequences, of such conflicts is referred to as SON coordination. SON coordination can be achieved either by a separate entity, a SON coordinator, controlling the...
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The advent of Active Antenna Systems has provided new ways and features for increasing the capacity of mobile networks in order to cope with the ever increasing traffic demand. One such feature is the vertical sectorisation (VS) technique where a cell is divided into an inner and an outer sector by using a second downtilted beam from one antenna. The two sectors use the same spectrum resources but...
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This paper focuses on the exposure to Radio Frequency (RF) Electromagnetic Fields (EMF) and on optimization methods to reduce it. Within the FP7 LEXNET project, an Exposure Index (EI) has been defined that aggregates the essential components that impact exposure to EMF. The EI includes, among other, downlink (DL) exposure induced by the base stations (BSs) and access points, the uplink (UL) exposure...
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Small cells have been identified as an effective solution for coping with the important traffic increase that is expected in the coming years. But this solution is accompanied by additional interference that needs to be mitigated. The enhanced Inter Cell Interference Coordination (eICIC) feature has been introduced to address the interference problem. eICIC involves two parameters which need to be...
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Developments in autonomic network management offer many promises, but its economic benefits are hard to assess. This paper proposes a method to calculate the OPEX gains of a typical network on the basis of a scenario, for which a management framework and autonomous mechanisms have been developed. It makes use of a novel approach, a Toy model, taking into account expert opinions as well as simulation...
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This paper presents a self-optimizing solution for Mobility Load Balancing (MLB). The MLB-SON is performed in two phases. In the first, a MLB controller is designed using Multi-Objective Particle Swarm Optimization (MO-PSO) which incorporates a priori expert knowledge to considerably reduce the search space and optimization time. The dynamicity of the optimization phase is addressed. In the second...
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IEEE Journal on Selected Areas in Communications > 2014 > 32 > 6 > 1219 - 1229
Three dimensional (3D) beamforming (also elevation beamforming) is now gaining interest among researchers in wireless communication. The reason can be attributed to its potential for enabling a variety of strategies such as sector or user specific elevation beamforming and cell-splitting. Since these techniques cannot be directly supported by current LTE releases, the 3GPP is now working on defining...
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IEEE Transactions on Control of Network Systems > 2014 > 1 > 4 > 328 - 337
The fast development of the self-organizing networks (SON) technology in mobile networks renders critical the problem of coordinating SON functionalities operating simultaneously. SON functionalities can be viewed as control loops that may need to be coordinated to guarantee conflict-free operation, to enforce stability of the network, and to achieve performance gain. This paper proposes a distributed...
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International Journal of Network Management > 23 > 4 > 259 - 271
Femtocell technology is expected to be fully self‐managed, empowered by self‐organizing network functionalities. This paper proposes a solution for self‐optimized offloading of macrocell traffic towards open/hybrid‐access femtocells. A heterogeneous network comprising macro‐ and femtocells is modeled as parallel queues. The coverage area of the femtocells is self‐optimized by dynamically adapting...
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The adoption of autonomic features in network management becomes a necessity to cope with the increasing complexity of the telecommunications ecosystem. The purpose of this paper is to present the concept of Unified Management Framework (UMF) developed in the FP7 UniverSelf project. The core of UMF comprises three functional blocks, namely Governance, Coordination and Knowledge which allow to efficiently...
