Traditional Macro-tower to Heterogeneous Cellular Networks: A Survey (original) (raw)

Uplink spectrum resource allocation in heterogeneous networks (small cell/macrocell)

annals of telecommunications - annales des télécommunications, 2014

Small cells are expected to increase network capacity, extend the macrocell coverage and to add edgebased intelligence. These advantages are achieved by overlaying macrocell networks with the small cells, resulting in a two-tier network. However, the average capacity of the network is reduced due to interference generated by the two-tier configuration. Conventional small cells are configured to have either an open or closed access scheme. Small cells with a hybrid access scheme or partially open access scheme are known for their flexibility and improved performance achieved through their interference-mitigating ability and adaptive resource allocation capabilities. In a hybrid access scheme, resource allocation is a vital issue in the design of small cells networks. In this paper, we propose an uplink resource allocation technique to enhance

Small Cells in Cellular Networks: Challenges of Future HetNets

Due to their low cost and easy deployment, small cells provide a viable and costeffective way of improving the cellular coverage and capacity both for homes and enterprises, both in metropolitan and rural areas. Stimulated by their attractive features and advantages, the ongoing development and deployment of small cells by manufacturers and mobile network operators have seen a surge in recent years. Together with macro-cells, they form, what are called Heterogeneous Networks or HetNets. However, the successful rollout and operation of small cells are still facing significan issues. In this paper the need for, challenges and solutions of small cell deployments are analyzed. This analysis is conducted with respect to self-organizing features, interference coordination, energy efficiency and spectrum efficiency. The analysis is complemented with numerical results based on system simulations in Macroonly and HetNet scenarios and also on real measurements performed on an mobile operator network. Results show the clear improvement that a HetNet brings in term of user throughput and also the amunt of spectrum waste that is present in nowadays' operator networks.

Are Heterogeneous Cellular Networks Superior to Homogeneous Ones?

Lecture Notes in Computer Science, 2012

In this paper, the performance of homogeneous cellular networks (HMCNs) and heterogeneous cellular networks (HTCNs) is evaluated and compared. The HTCN discussed in this paper consists of three kinds of cells: macrocells, microcells and femtocells. The macrocells are evenly deployed. The microcells are densely deployed in the offices and public areas and sparsely deployed in the universities areas. The femtocells are deployed in the residential areas. And, a user mobility pattern is defined to model real communication environment. Our simulation results show that the HTCN requires less power (in Watt/km 2 /Mbps) and achieves higher throughput compared to the HMCN.

Analysis of small cell partitioning in urban two-tier heterogeneous cellular networks

2014 11th International Symposium on Wireless Communications Systems (ISWCS), 2014

This paper presents a system model that enables the analysis of indoor downlink performance in urban two-tier heterogeneous cellular networks. The urban building topology is modeled as a process of randomly distributed circles. Each building is deployed with an indoor small cell with a certain occupation probability. Macro base stations are sited outdoors. Their signals experience distance-dependent shadowing due to the blockage of the buildings. Given a typical building at the origin, expressions for the coverage probability with-and without small cell occupation are derived. The analysis of the asymmetric interference field as observed by a typical indoor user is simplified by approximations. Their accuracy is verified by Monte Carlo simulations. Our results show that isolation by wall partitioning can enhance indoor rate, and that the improvement is more sensitive to building density, rather than penetration loss per building.

K-tier heterogeneous small-cell networks: Towards balancing the spectrum usage and power consumption with aggressive frequency reuse

With the cell coverage area of current and future mobile networks becoming smaller, heterogeneous small-cell networks (HetSNets), where multiple low-power, low-cost base stations (BSs) complement the existing macrocell infrastructure, are considered constitutive elements of future mobile networks. In this paper, we propose a K tier HetSNet, where multiple tiers of small-cells are padded between macrocells which in turn expand the network coverage and significantly increase in capacity without compromising the frequency reuse factor. In this context, we derive analytical capacity bounds of the K tier HetSNets based on the distance of the desired user from its serving BS and all other interfering BSs. It was observed that the upper bound of the capacity becomes tighter as the number of small-cell tiers increases due to the increase in the number of small-cells. Simulation results show the performance of the proposed K tier HetSNets against the macro-only network in terms of frequency reuse factor, capacity and area spectral efficiency.

The Implications of Cognitive Femtocell Based Spectrum Allocation Over Macrocell Networks

Wireless Personal Communications, 2016

We propose an analytical framework of significant influence of deployment of femto base stations (FBSs) in a dual-tier network constituted of macro base stations (MBSs). As because of uncoordinated deployment, FBSs results in destructive interference to MBSs and vice versa. But, throughput efficiency of indoor (femtocell) and outdoor (macrocell) environment substantially increases due to an optimum reutilization of available spectrum. The quality of service is further getting optimized in terms of throughput and network coverage because of incorporation of steerable beamforming. Finally, the effectiveness of the scheme is verified by extensive matlab simulation.

Deployment of Femto / Pico / Microcell in Urban Indoor and Outdoor Environments with High Layout of Subscribers

2016

In this work, we analyze the ways of optimization of each user's channel capacity and spectral efficiency in a modern hierarchy of incorporated microcell, picocell and femtocell networks. We consider the co-existence of microcell Base Stations (MBSs), Picocell (PAPs) and Femtocell Access Points (FAPs) with shared and dedicated carrier frequency allocations. The simulation framework, based on the multi-parametric stochastic model of radio propagation for various scenarios, occurring in the urban environment, is introduced for analysis of channel capacity and spectral efficiency improvements in complex urban environment taking, as a real example, the description of one of the urban tested area, consisting integrated micro/picocell and femtocell configurations. The analysis of the network consisting of dedicated and shared femtocells for home coverage in a presence of traditional microcell pattern is presented. The advantages and drawbacks for different deployment strategies are in...

Design of a cell selection mechanism to mitigate interference for cell-edge macro users in femto-macro heterogeneous network

Bulletin of Electrical Engineering and Informatics, 2019

The Femto-Macro heterogeneous network is a promising solution to improve the network capacity and coverage in mobile network. However interference may rise due to femtocell deployment nearby to macro user equipment (MUE) within macrocell network coverage. Femtocell offers main priority in resource allocation to its subscribed femto user equipment (FUE) rather than unsubscribed MUE. MUEs will suffer severe interference when they are placed near or within the femtocell area range especially at the cell edge. This phenomenon occurs due to the distance is far from its serving macro base station (MBS) to receive good signal strength. This paper presents a design of cell selection scheme for cell-edge MUE to select an optimal femto base station (FBS) as its primary serving cell in physical resource block allocation. In this study, the proposed cell selection consists of four main elements: measuring the closest FBS distance, Signal to Interference-plus- Noise-Ratio (SINR), physical resour...

Cell Association and Interference Coordination in Heterogeneous LTE-A Cellular Networks

IEEE Journal on Selected Areas in Communications, 2010

Embedding pico/femto base-stations and relay nodes in a macro-cellular network is a promising method for achieving substantial gains in coverage and capacity compared to macro-only networks. These new types of base-stations can operate on the same wireless channel as the macro-cellular network, providing higher spatial reuse via cell splitting. However, these base-stations are deployed in an unplanned manner, can have very different transmit powers, and may not have traffic aggregation among many users. This could potentially result in much higher interference magnitude and variability. Hence, such deployments require the use of innovative cell association and inter-cell interference coordination techniques in order to realize the promised capacity and coverage gains. In this paper, we describe new paradigms for design and operation of such heterogeneous cellular networks. Specifically, we focus on cell splitting, range expansion, semi-static resource negotiation on third-party backhaul connections, and fast dynamic interference management for QoS via over-the-air signaling. Notably, our methodologies and algorithms are simple, lightweight, and incur extremely low overhead. Numerical studies show that they provide large gains over currently used methods for cellular networks.