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LTE-Advanced radio access enhancements: A survey
Long Term Evolution Advanced (LTE-Advanced) is the next step in LTE evolution and allows operators to improve network performance and service capabilities through smooth deployment of new techniques and technologies. LTE-Advanced uses some new features on top of the existing LTE standards to provide better user experience and higher throughputs. Some of the most significant features introduced in LTE-Advanced are carrier aggregation, enhancements in heterogeneous networks, coordinated multipoint transmission and reception, enhanced multiple input multiple output usage and deployment of relay nodes in the radio network. Mentioned features are mainly aimed to enhance the radio access part of the cellular networks. This survey article presents an overview of the key radio access features and functionalities of the LTE-Advanced radio access network, supported by the simulation results. We also provide a detailed review of the literature together with a very rich list of the references for each of the features. An LTE-Advanced roadmap and the latest updates and trends in LTE markets are also presented
Reputation-based network selection solution in heterogeneous wireless network environments
The significant developments in terms of both mobile computing device (e.g., smartphones, tablets, laptops, etc.) and the wireless communication technologies (e.g., LTE, LTE-Advanced, WiMAX, etc.), lead towards a converged heterogeneous wireless environment. In this context, the user will be facing the problem of selecting from a number of Radio Access Networks that differ in technology, coverage, pricing scheme, bandwidth, latency, etc. In order to provide high quality of service (QoS) to the user in this heterogeneous wireless environment, a network selection solution is required that will efficiently facilitate the vertical handover between different wireless access networks in a seamless manner. In this paper, we propose a reputation-based network selection solution which aims to select the best value network for the user. We propose a network profiling algorithm that used to compute the reputation of each of the available networks based on the joint collaboration of the users within the network. The network with the best reputation value is recommended for selection and handover
Neural-Encoded Fuzzy Models for Load Balancing in 3GPP LTE
Post third generation (3G) broadband mobile networks such as HSPA+, LTE and LTE-Advanced offer improved spectral efficiency and higher data rates using innovative technologies such as relay nodes and femto cells. In addition, these networks are normally deployed for parallel operation with existing heterogeneous networks. This increases the complexity of network management and operations, which reflects in higher operational and capital cost. In order to address these challenges, self-organizing network operations were envisioned for these next generation networks. For LTE in particular, Self-organizing networks operations were built into the specifications for the radio access network. Load balancing is a key self-organizing operation aimed at ensuring an equitable distribution of users in the network. Several iterative techniques have been adopted for load balancing. However, these iterative techniques require precision, rigor and certainty, which carry a computational cost. Retrospect, these techniques use load indicators to achieve load balancing. This paper proposes two neural encoded fuzzy models, developed from network simulation for load balancing. The two models use both load indicators and key performance indicators for a more informed and intuitive load balancing. The result of the model checking and testing satisfactorily validates the model
Designing energy-efficient wireless access networks: LTE and LTE-advanced
As large energy consumers, base stations need energy-efficient wireless access networks. This article compares the design of Long-Term Evolution (LTE) networks to energy-efficient LTE-Advanced networks. LIE-Advanced introduces three new functionalities - carrier aggregation, heterogeneous networks, and extended multiple-input, multiple-output (MIMO) support. The authors develop a power consumption model for LIE and LIE-Advanced macrocell and femtocell base stations, along with an energy efficiency measure. They show that LIE-Advanced's carrier aggregation and MIMO improve networks' energy efficiency up to 400 and 450 percent, respectively
Energy efficiency in heterogeneous wireless access networks
In this article, we bring forward the important aspect of energy savings in wireless access networks. We specifically focus on the energy saving opportunities in the recently evolving heterogeneous networks (HetNets), both Single- RAT and Multi-RAT. Issues such as sleep/wakeup cycles and interference management are discussed for co-channel Single-RAT HetNets. In addition to that, a simulation based study for LTE macro-femto HetNets is presented, indicating the need for dynamic energy efficient resource management schemes. Multi-RAT HetNets also come with challenges such as network integration, combined resource management and network selection. Along with a discussion on these challenges, we also investigate the performance of the conventional WLAN-first network selection mechanism in terms of energy efficiency (EE) and suggest that EE can be improved by the application of intelligent call admission control policies
Coordinated Multipoint Communications In Heterogeneous Networks
As users' demands on cellular service escalate rapidly, operators are required to deploy technologies with wider and more sophisticated techniques. In order to meet the future service needs, the standardization body 3rd Generation Partnership Project (3GPP) has standardized Long Term Evolution (LTE) and it has been working on enhancement of LTE and LTE-Advanced. The two key enabling technologies of LTE-Advanced are Heterogeneous Networks (HetNets) and Coordinated Multipoint (CoMP) communications. The former is aimed to improve inconsistent user experience and its basic feature is standardized in 3GPP release 11. The latter one where small cells are deployed within macro-cellular networks has been considered to enhance coverage and capacity.
This thesis presents a concise literature survey of cooperative communications and CoMP technologies. Furthermore, a detailed Matlab-based simulation study on CoMP between macro and small cells in HetNets is presented. Comparative analyses and evaluations are also made for different CoMP schemes under different deployed scenarios. At the same time, a new CoMP UE selection criterion is proposed to fit the modified round robin scheduling deployed in simulation and optimize the resource allocation among CoMP and non-CoMP UEs
Next Generation M2M Cellular Networks: Challenges and Practical Considerations
In this article, we present the major challenges of future machine-to-machine
(M2M) cellular networks such as spectrum scarcity problem, support for
low-power, low-cost, and numerous number of devices. As being an integral part
of the future Internet-of-Things (IoT), the true vision of M2M communications
cannot be reached with conventional solutions that are typically cost
inefficient. Cognitive radio concept has emerged to significantly tackle the
spectrum under-utilization or scarcity problem. Heterogeneous network model is
another alternative to relax the number of covered users. To this extent, we
present a complete fundamental understanding and engineering knowledge of
cognitive radios, heterogeneous network model, and power and cost challenges in
the context of future M2M cellular networks
5GNOW: Challenging the LTE Design Paradigms of Orthogonality and Synchronicity
LTE and LTE-Advanced have been optimized to deliver high bandwidth pipes to
wireless users. The transport mechanisms have been tailored to maximize single
cell performance by enforcing strict synchronism and orthogonality within a
single cell and within a single contiguous frequency band. Various emerging
trends reveal major shortcomings of those design criteria: 1) The fraction of
machine-type-communications (MTC) is growing fast. Transmissions of this kind
are suffering from the bulky procedures necessary to ensure strict synchronism.
2) Collaborative schemes have been introduced to boost capacity and coverage
(CoMP), and wireless networks are becoming more and more heterogeneous
following the non-uniform distribution of users. Tremendous efforts must be
spent to collect the gains and to manage such systems under the premise of
strict synchronism and orthogonality. 3) The advent of the Digital Agenda and
the introduction of carrier aggregation are forcing the transmission systems to
deal with fragmented spectrum. 5GNOW is an European research project supported
by the European Commission within FP7 ICT Call 8. It will question the design
targets of LTE and LTE-Advanced having these shortcomings in mind and the
obedience to strict synchronism and orthogonality will be challenged. It will
develop new PHY and MAC layer concepts being better suited to meet the upcoming
needs with respect to service variety and heterogeneous transmission setups.
Wireless transmission networks following the outcomes of 5GNOW will be better
suited to meet the manifoldness of services, device classes and transmission
setups present in envisioned future scenarios like smart cities. The
integration of systems relying heavily on MTC into the communication network
will be eased. The per-user experience will be more uniform and satisfying. To
ensure this 5GNOW will contribute to upcoming 5G standardization.Comment: Submitted to Workshop on Mobile and Wireless Communication Systems
for 2020 and beyond (at IEEE VTC 2013, Spring
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