444 research outputs found
Downlink and Uplink Cell Association with Traditional Macrocells and Millimeter Wave Small Cells
Millimeter wave (mmWave) links will offer high capacity but are poor at
penetrating into or diffracting around solid objects. Thus, we consider a
hybrid cellular network with traditional sub 6 GHz macrocells coexisting with
denser mmWave small cells, where a mobile user can connect to either
opportunistically. We develop a general analytical model to characterize and
derive the uplink and downlink cell association in view of the SINR and rate
coverage probabilities in such a mixed deployment. We offer extensive
validation of these analytical results (which rely on several simplifying
assumptions) with simulation results. Using the analytical results, different
decoupled uplink and downlink cell association strategies are investigated and
their superiority is shown compared to the traditional coupled approach.
Finally, small cell biasing in mmWave is studied, and we show that
unprecedented biasing values are desirable due to the wide bandwidth.Comment: 30 pages, 9 figures. Submitted to IEEE Transactions on Wireless
Communication
Downlink and Uplink Decoupling: a Disruptive Architectural Design for 5G Networks
Cell association in cellular networks has traditionally been based on the
downlink received signal power only, despite the fact that up and downlink
transmission powers and interference levels differed significantly. This
approach was adequate in homogeneous networks with macro base stations all
having similar transmission power levels. However, with the growth of
heterogeneous networks where there is a big disparity in the transmit power of
the different base station types, this approach is highly inefficient. In this
paper, we study the notion of Downlink and Uplink Decoupling (DUDe) where the
downlink cell association is based on the downlink received power while the
uplink is based on the pathloss. We present the motivation and assess the gains
of this 5G design approach with simulations that are based on Vodafone's LTE
field trial network in a dense urban area, employing a high resolution
ray-tracing pathloss prediction and realistic traffic maps based on live
network measurements.Comment: 6 pages, 7 figures, conference paper, submitted to IEEE GLOBECOM 201
MM-Wave HetNet in 5G and beyond Cellular Networks Reinforcement Learning Method to improve QoS and Exploiting Path Loss Model
This paper presents High density heterogeneous networks (HetNet) which are the most promising technology for the fifth generation (5G) cellular network. Since 5G will be available for a long time, previous generation networking systems will need customization and updates. We examine the merits and drawbacks of legacy and Q-Learning (QL)-based adaptive resource allocation systems. Furthermore, various comparisons between methods and schemes are made for the purpose of evaluating the solutions for future generation. Microwave macro cells are used to enable extra high capacity such as Long-Term Evolution (LTE), eNodeB (eNB), and Multimedia Communications Wireless technology (MC), in which they are most likely to be deployed. This paper also presents four scenarios for 5G mm-Wave implementation, including proposed system architectures. The WL algorithm allocates optimal power to the small cell base station (SBS) to satisfy the minimum necessary capacity of macro cell user equipment (MUEs) and small cell user equipment (SCUEs) in order to provide quality of service (QoS) (SUEs). The challenges with dense HetNet and the massive backhaul traffic they generate are discussed in this study. Finally, a core HetNet design based on clusters is aimed at reducing backhaul traffic. According to our findings, MM-wave HetNet and MEC can be useful in a wide range of applications, including ultra-high data rate and low latency communications in 5G and beyond. We also used the channel model simulator to examine the directional power delay profile with received signal power, path loss, and path loss exponent (PLE) for both LOS and NLOS using uniform linear array (ULA) 2X2 and 64x16 antenna configurations at 38 GHz and 73 GHz mmWave bands for both LOS and NLOS (NYUSIM). The simulation results show the performance of several path loss models in the mmWave and sub-6 GHz bands. The path loss in the close-in (CI) model at mmWave bands is higher than that of open space and two ray path loss models because it considers all shadowing and reflection effects between transmitter and receiver. We also compared the suggested method to existing models like Amiri, Su, Alsobhi, Iqbal, and greedy (non adaptive), and found that it not only enhanced MUE and SUE minimum capacities and reduced BT complexity, but it also established a new minimum QoS threshold. We also talked about 6G researches in the future. When compared to utilizing the dual slope route loss model alone in a hybrid heterogeneous network, our simulation findings show that decoupling is more visible when employing the dual slope path loss model, which enhances system performance in terms of coverage and data rate
Tractable Resource Management with Uplink Decoupled Millimeter-Wave Overlay in Ultra-Dense Cellular Networks
The forthcoming 5G cellular network is expected to overlay millimeter-wave
(mmW) transmissions with the incumbent micro-wave ({\mu}W) architecture. The
overall mm-{\mu}W resource management should therefore harmonize with each
other. This paper aims at maximizing the overall downlink (DL) rate with a
minimum uplink (UL) rate constraint, and concludes: mmW tends to focus more on
DL transmissions while {\mu}W has high priority for complementing UL, under
time-division duplex (TDD) mmW operations. Such UL dedication of {\mu}W results
from the limited use of mmW UL bandwidth due to excessive power consumption
and/or high peak-to-average power ratio (PAPR) at mobile users. To further
relieve this UL bottleneck, we propose mmW UL decoupling that allows each
legacy {\mu}W base station (BS) to receive mmW signals. Its impact on mm-{\mu}W
resource management is provided in a tractable way by virtue of a novel
closed-form mm-{\mu}W spectral efficiency (SE) derivation. In an ultra-dense
cellular network (UDN), our derivation verifies mmW (or {\mu}W) SE is a
logarithmic function of BS-to-user density ratio. This strikingly simple yet
practically valid analysis is enabled by exploiting stochastic geometry in
conjunction with real three dimensional (3D) building blockage statistics in
Seoul, Korea.Comment: to appear in IEEE Transactions on Wireless Communications (17 pages,
11 figures, 1 table
Evolution Toward 5G Mobile Networks - A Survey on Enabling Technologies
In this paper, an extensive review has been carried out on the trends of existing as well as proposed potential enabling technologies that are expected to shape the fifth generation (5G) mobile wireless networks. Based on the classification of the trends, we develop a 5G network architectural evolution framework that comprises three evolutionary directions, namely, (1) radio access network node and performance enabler, (2) network control programming platform, and (3) backhaul network platform and synchronization. In (1), we discuss node classification including low power nodes in emerging machine-type communications, and network capacity enablers, e.g., millimeter wave communications and massive multiple-input multiple-output. In (2), both logically distributed cell/device-centric platforms, and logically centralized conventional/wireless software defined networking control programming approaches are discussed. In (3), backhaul networks and network synchronization are discussed. A comparative analysis for each direction as well as future evolutionary directions and challenges toward 5G networks are discussed. This survey will be helpful for further research exploitations and network operators for a smooth evolution of their existing networks toward 5G networks
Load & Backhaul Aware Decoupled Downlink/Uplink Access in 5G Systems
Until the 4th Generation (4G) cellular 3GPP systems, a user equipment's (UE)
cell association has been based on the downlink received power from the
strongest base station. Recent work has shown that - with an increasing degree
of heterogeneity in emerging 5G systems - such an approach is dramatically
suboptimal, advocating for an independent association of the downlink and
uplink where the downlink is served by the macro cell and the uplink by the
nearest small cell. In this paper, we advance prior art by explicitly
considering the cell-load as well as the available backhaul capacity during the
association process. We introduce a novel association algorithm and prove its
superiority w.r.t. prior art by means of simulations that are based on
Vodafone's small cell trial network and employing a high resolution pathloss
prediction and realistic user distributions. We also study the effect that
different power control settings have on the performance of our algorithm.Comment: 6 pages, 6 figures. Submitted to the IEEE International Conference on
Communications (ICC 2015
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