The Experts below are selected from a list of 28119 Experts worldwide ranked by ideXlab platform
Sayandev Mukherjee - One of the best experts on this subject based on the ideXlab platform.
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Distribution of downlink SINR in heterogeneous cellular Networks
IEEE Journal on Selected Areas in Communications, 2012Co-Authors: Sayandev MukherjeeAbstract:The Signal to Interference Plus Noise Ratio (SINR) on a wireless link is an important basis for consideration of outage, capacity, and throughput in a cellular Network. It is therefore important to understand the SINR distribution within such Networks, and in particular heterogeneous cellular Networks, since these are expected to dominate future Network deployments . Until recently the distribution of SINR in heterogeneous Networks was studied almost exclusively via simulation, for selected scenarios representing pre-defined arrangements of users and the elements of the heterogeneous Network such as Macro-cells, femto-cells, etc. However, the dynamic nature of heterogeneous Networks makes it difficult to design a few representative simulation scenarios from which general inferences can be drawn that apply to all deployments. In this paper, we examine the downlink of a heterogeneous cellular Network made up of multiple tiers of transmitters (e.g., Macro-, micro-, pico-, and femto-cells) and provide a general theoretical analysis of the distribution of the SINR at an arbitrarily-located user. Using physically realistic stochastic models for the locations of the base stations (BSs) in the tiers, we can compute the general SINR distribution in closed form. We illustrate a use of this approach for a three-tier Network by calculating the probability of the user being able to camp on a Macro-cell or an open-access (OA) femto-cell in the presence of Closed Subscriber Group (CSG) femto-cells. We show that this probability depends only on the relative densities and transmit powers of the Macro- and femto-cells, the fraction of femto-cells operating in OA vs. Closed Subscriber Group (CSG) mode, and on the parameters of the wireless channel model. For an operator considering a femto overlay on a Macro Network, the parameters of the femto deployment can be selected from a set of universal curves.
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ue coverage in lte Macro Network with mixed csg and open access femto overlay
International Conference on Communications, 2011Co-Authors: Sayandev MukherjeeAbstract:Downlink coverage issues for users (UEs) in a Macrocellular Network with femtocellular overlay have so far been investigated almost exclusively via simulation~\cite{key-2}. In this paper, we employ general models for Macro Node B and femto access point (AP) locations to get closed-form expressions for the probability that an arbitrary UE can camp on a Macro Node B or an open access (OA) femto AP. These expressions depend only on the relative densities and transmit powers of the Macro Node Bs and femto APs, the fraction of femto APs operating in OA vs.~Closed Subscriber Group (CSG) mode, and on the parameters of the wireless channel model. For a Macrocellular operator considering a femtocellular overlay on a Macrocellular Network, we show how a set of universal curves could be used to choose the parameters of the femtocellular deployment.
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analysis of ue outage probability and Macrocellular traffic offloading for wcdma Macro Network with femto overlay under closed and open access
International Conference on Communications, 2011Co-Authors: Sayandev MukherjeeAbstract:Downlink coverage issues for Macrocellular users (UEs) in a Macrocellular Network with Closed Subscriber Group (CSG) femtocellular overlay have so far been investigated almost exclusively via simulation. However, consideration of specific scenarios via simulation may not provide general insights applicable to long-term planning for femto-Macro deployments. In this paper, we employ general models for Macro Node B and femto access point (AP) locations to derive analytical expressions for the probability that an arbitrary UE cannot be served a Macro Node B because of interference on the downlink from a nearby femto AP under CSG, and for the probability that the UE is served by the femto AP instead, if the femto AP operates with Open Access (OA). These expressions depend only on the ranges and densities of the Macro Node Bs and femto APs, and on the parameters of the wireless channel model. We then show how to apply these results to compute measures of the fraction of overall Macrocellular traffic that could be offloaded to an OA femtocellular Network, thereby reducing the load on the Macrocellular backhaul and increasing overall system capacity. These results are of interest to operators weighing the capacity vs. coverage tradeoff of a femtocellular overlay on a Macrocellular Network.
Kimmo Hiltunen - One of the best experts on this subject based on the ideXlab platform.
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the gain of a targeted introduction of osg femtocells into a lte Macro Network
Vehicular Technology Conference, 2012Co-Authors: Kimmo HiltunenAbstract:Previous studies have indicated that the drawback of a heterogeneous Network deployment is that the required number of new sites to fulfill a desired coverage and capacity requirement becomes considerably larger compared to a densified Macro deployment. Therefore, the scope of this study is to investigate if a more targeted introduction of femtocells, under the assumption of a non-uniform user traffic, could help to reduce the required number of new femto sites. The enhanced femto deployments evaluated in this paper are aiming to offload initially the users with the worst Macro coverage and/or the users generating most of the traffic. The obtained results show that an approach, which deploys femto eNodeBs initially within the traffic-heavy apartments provides considerable gains compared to a random deployment, or a deployment looking only at the Macro cell coverage. The best results are achieved, when the approach based on the user traffic is combined with the coverage-based approach.
Huseyin Uzunalioglu - One of the best experts on this subject based on the ideXlab platform.
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On femto deployment architectures and Macrocell offloading benefits in joint Macro-femto deployments
IEEE Communications Magazine, 2010Co-Authors: Doru Calin, Holger Claussen, Huseyin UzunaliogluAbstract:This article provides an overview of opportunities and challenges related to joint deployments of Macro and femtocells. It provides insights on possible deployment architectures for femtocells along with an analysis framework for quantifying Macro offloading benefits in realistic Network deployment scenarios by means of advanced performance analysis techniques. Such benefits include potential enhancement in quality of radio signals for users served by the Macro Network in joint Macro-femto deployments. This in turn translates into potentially better data rates (throughput) for Macrocell users and may offer the possibility of adding more users to the Macro Network while preserving the Network configuration -- resulting in direct capital expenditure savings. The approach taken in this article consists of creating a framework for quantifying Macro offloading benefits in joint Macro-femto deployments. A baseline configuration where all users (indoor and outdoor) are served by a traditional Macro Network (state-of-the-art Macro only Network) is considered first. The analysis is followed through joint Macro-femto deployments, where femtocells serve indoor users. Through comparison of the baseline configuration and the joint Macro-femto analysis, we quantify the benefits of the joint Macro-femto deployment.
Stefano Battiston - One of the best experts on this subject based on the ideXlab platform.
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a financial Macro Network approach to climate policy evaluation
Social Science Research Network, 2017Co-Authors: Veronika Stolbova, Irene Monasterolo, Stefano BattistonAbstract:Existing approaches to assess the economic impact of climate policies tend to overlook the financial sector and to focus only on direct effects of policies on the specific institutional sector they target, neglecting possible feedbacks between sectors, thus, underestimating the overall policy effect. To fill in this gap, we develop a methodology based on financial Networks, which allows for analyzing the transmission throughout the economy of positive or negative shocks induced by the introduction of specific climate policies. We apply the methodology to empirical data of the Euro Area to identify the feedback loops between the financial sector and the real economy both through direct and indirect chains of financial exposures across multiple financial instruments. By focusing on climate policy-induced shocks that affect directly either the banking sector or non-financial firms, we analyze the reinforcing feedback loops that could amplify the effects of shocks on the financial sector and then cascade on the real economy. Our analysis helps to understand the conditions for virtuous or vicious cycles to arise in the climate-finance nexus and to provide a comprehensive assessment of the economic impact of climate policies.
Alan Barbieri - One of the best experts on this subject based on the ideXlab platform.
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coordinated downlink multi point communications in heterogeneous cellular Networks
Information Theory and Applications, 2012Co-Authors: Alan Barbieri, Durga Prasad Malladi, Peter Gaal, Stefan Geirhofer, Y Wei, Feng XueAbstract:In this paper we assess how coordination among base stations can be exploited to improve downlink capacity in fourth generation (4G) cellular Networks. We focus on heterogeneous Networks where low-power pico cells are deployed within the coverage area of an existing Macro Network with the aim of offloading traffic from the (potentially congested) Macro cells to low-power cells. Firstly, we describe an enhanced inter-cell interference coordination scheme which is shown to achieve a significant capacity gain in such deployments by leveraging a loose coordination among neighbor base stations. Secondly, we explore how a tighter coordination among base stations can be exploited to further improve the Network capacity. Even though the schemes described in this paper apply to long term evolution (LTE) wireless Networks, we point out that most of the findings and conclusions we draw apply to any cellular Network.
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LTE Femtocells: System Design and Performance Analysis
2011 IEEE 73rd Vehicular Technology Conference (VTC Spring), 2011Co-Authors: Alan Barbieri, Aleksandar Damnjanovic, Tingfang Ji, Juan Montojo, Durga MalladiAbstract:In this paper we consider a heterogeneous LTE Network where femto cells are randomly deployed in a Macro Network according to the two models described in [1], namely dual-strip and NxN. Femto cells are modeled as closed cells, namely only group member UEs can be associated with the femto cells. Therefore, dominant interference may be experienced by non-member UEs that are in proximity of a closed cell and leave these UEs in outage. We show geometry performance in a practical deployment, and discuss an autonomous power control method, which allows to dramatically reduce the outage probability, and we evaluate a resource partitioning method between Macro and femto cells that further improves the performance of Macro users.
