Skip to content
Free planNo credit card requiredStart writing
AI for Research home
AI for Research home
Dashboard
Sign inGet started

Search 250 million research papers

Read the abstract, see who wrote it and who cites it, and get the citation in APA, MLA, Chicago or Harvard.

About 10,000 papers for “C-RAN”

Overview of C-RAN

Tony Q. S. Quek, Mugen Peng, Osvaldo Simeone et al. · Cambridge University Press eBooks · 2016

In 2008, as the specification for long-term evolution (LTE) Release 8 was frozen in the Third Generation Partner Project (3GPP), operators began to shift the network deployment focus to 4G. In 2009, the world's first commercial LTE network was launched by TeliaSonera in Norway and Sweden. As of today, there are several hundred LTE networks in operation, providing unprecedented user experiences to customers. Consequently, we are witnessing the recent mobile traffic explosion in the telecom industry. It is expected that by 2020 consumer Internet traffic will increase by a factor of over one thousand [1].

Cited by 0

Caching in C-RAN

Tony Q. S. Quek, Mugen Peng, Osvaldo Simeone et al. · Cambridge University Press eBooks · 2016

Mobile traffic has shown an exponential growth during the past decade and is expected to increase by five times in the upcoming five years [1]. This growth is mainly driven by the proliferation of smart devices such as smartphones, mobile tablets, and cameras, coupled with the rising popularity of social networks. Most of the generated traffic is for mobile videos; this is envisioned to represent 80% to 90% of the total generated traffic by 2019 [1, 2]. To support this rapidly growing traffic and meet the strict quality of serivce (QoS) requirements of video streaming users, wireless networks have evolved into a distributed heterogeneous architecture [3]. This structure ismet by a dense deployment of low-power and low-coverage small base stations (SBSs), which offload the traffic from the conventional macro base stations [4]. The use of dense small base stations allows boosting of the network capacity by reducing the distance between the SBSs and the end-user. Moreover, it gives the possibility of sharing the spectrum more efficiently by an improved spectrum-reuse ratio across multiple cells, ensuring higher transmission rates for the users. However, as the network becomes denser, inter-cell and intra-cell interference become more important and cause the overall system performance to deteriorate [5]. Different approaches have been proposed to alleviate this mutual interference, especially leveraging the cooperation between base stations (BSs) through coordinated multi-point (CoMP) transmission techniques [6, 7]. In CoMP, the base stations exchange information about channel state and cooperate to form a group that serve a given user. Even though this approach can significantly improve the spectral efficiency and increase the system throughput, its performance depends on the number of base stations in the network as well as the capacity of the backhaul links. In fact, cooperation between the distributed base stations requires an important amount of signaling and exchange of control information between the BSs, which limits the performance of CoMP in capacity-limited backhaul networks [6].

Cited by 0

Ethernet-based C-RAN fronthaul

Pedro M. C. Marques · Portuguese National Funding Agency for Science, Research and Technology (RCAAP Project by FCT) · 2018

For the last decade mobile data traffic has been increasing at impressive rates. The proliferation of mobile devices together with high-bandwidth services like video and music streaming, social media and other cloud services have increased the load on top of the mobile network infrastructure. In order to support this massive increase in both users and bandwidth the next generation of mobile telecommunications network - 5G - explores new approaches, like the utilization of new frequency bands and the densification of base stations. This kind of requirements along with the inefficiency of the co-location of base band processing near the radio units encourages a rethink of traditional radio access networks. In this scenario emerges the C-RAN paradigm that intend to centralize all the base band processing (BBU) and replace current base stations for simpler, more efficient and compact solutions that only incorporate the radio front-end and respective radio processing (RRH). In addition to these benefits, centralized processing facilitates virtualization and resource sharing, interference management and cooperative processing technologies. This split of functions brings however, some challenges in respect to the data rates, bandwidth and latency in the link that connects BBUs and RRHs - the fronthaul. Today’s existing standards like CPRI weren’t originally designed for such applications and present some intrinsic bandwidth and flexibility limitations. It’s considered that another approach, based on packet switching, could mitigate some of these problems in addition to bring some advantages such as statistical multiplexing, flexible routing and compatibility with current widespread packet switching networks. They do however, present a number of challenges regarding latency and synchronization. This dissertation work focuses on the study and development of a fronthaul solution based in 10 Gigabit Ethernet over optical fiber. Development is done on top of two development kits based in Field Programmable Gate Array (FPGA) and implemented in an already operational C-RAN test-bed - currently with CPRI based fronthaul - at the Instituto de Telecomunicações - Aveiro.

Cited by 0Open access

A Review Of Futuristic Technology: Cloud Ran (C- Ran) Technologies

Upadhyay, Vimal, Gupta, Manoj · Zenodo (CERN European Organization for Nuclear Research) · 2017

According to the report of CISCO study, traffic on the net due to mobile data increased rapidly and it will be nearly 11 times between 2013 and 2018. This rapidly increased traffic demands a high bandwidth carrier to increase the network capacity. The demand of <br> increased network capacity rises when the world moves to 4G and onward generations. Limited amount of spectrum efficiency improved by using Wi-Fi offloads, 4G and so on. Frequency reuse play important role to improve the network capacity. The frequency reuse with the help of small cells improves capacity up to 1600x. The use of small cells makes important benefits to macro network. Suppose if we place four small cells within one macro, it delivers data 50 percentage of offload and also improves macro network performance by 315 percentages. Now to keep in mind C-RAN play important role to increases the network capacity, I write this article that will beneficiary for those who want to make research area in this field, to spread awareness among youth related to futuristic technologies.

Cited by 0Open access

Remote radio head for C-RAN

Beltran Obiol, Salvador · RECERCAT (Consorci de Serveis Universitaris de Catalunya) · 2018

The project's main objective is to develop a Remote Radio Head (RRH) to be used under the cloud radio access networks (C-RAN) concept. Actually, the wireless market tendency related with infrastructure implementation consist in separating the computing part of base station (BS) from the radiofrequency part. Therefore, digital signal processing is assumed in a datacenter and under the cloud computing concept. Signal samples are processed there and data streams are send to the RRH. The project consist in developing the appropriate software layer in the RRH to interface with the virtual machine (VM) allocated in the data center. Two different hardware has been considered to implement the RRH. In both, we followed a similar methodology, splitting the software layer in different functional modules and defining well defined implementation steps. During project development, we addressed several test in order to verify the proper management of the involved board and check the quality and performance of the signal generated or received.

Cited by 0Open access

A Feasibility Study On C-RAN

Thrishna S, Dr. Anto Sahaya Dhas · Zenodo (CERN European Organization for Nuclear Research) · 2018

<em>Now a days the number of users of mobile phone are increasing exponentially, so it will cause jamming in the network and require large bandwidth So among promising technology candidates to overcome this problem, cloud radio access network (C-RAN) used. C-RAN, having one baseband unit (BBU) communicates with users through distributed Remote Radio Heads (RRHs) .RRH are connected to the BBU via high capability, low latency fronthaul links and performs soft relaying. The architecture of C-RAN imposes a shortage of fronthaul bandwidth because raw I/Q samples are exchanged between the RRHs and the BBU. In BBU different algorithms are used to improve the capacity, joint decompression and decoding (JDD) and wyner ziv coding.</em>

Cited by 0Open access

Blend encapsulation by random copolymers: C/B/A-ran-B and C/D/A-ran-B systems

M. S. Lee, Timothy P. Lodge, C. W. Macosko · Macromolecular Chemistry and Physics · 1998

Random copolymers with the same monomeric units as blended homopolymers A and B have a strong tendency to encapsulate the minor phase in A/B/A-ran-B ternary systems. In this study we investigate encapsulation when one or both monomeric units in the random copolymer are chemically distinct from, but completely or partially miscible with, the other blend components, i.e., a C/D/A-ran-B blend. As model polymers, a styrene/methyl methacrylate random copolymer (70% styrene by weight) (SMMA), and polystyrene (PS), poly(methyl methacrylate) (PMMA), polycarbonate (PC), and poly(phenylene oxide) (PPO) homopolymers are chosen; PPO is completely miscible with PS and PC is partially miscible with PMMA. Three blend systems were prepared by melt mixing: PS/PC/SMMA, PPO/PMMA/SMMA, and PPO/PC/SMMA. Transmission electron microscopy demonstrated that for all cases SMMA moves to the interface between the matrix and dispersed phases during melt mixing, and forms an encapsulating layer. However, the resulting average size of a dispersed phase droplet is not significantly decreased by the addition of SMMA. Moreover, this size increased significantly upon further annealing, except for the blend with a PPO matrix which has a very high melt viscosity, demonstrating that encapsulation by SMMA does not provide stability against static coalescence.

Cited by 12

Utveckling av en C-RAN Fronthaul Simulator

Noel Tesfalidet, Sam Khosravi · Diva portal (Dalarna University Library) · 2023

Cellular networks have significantly transformed the way we communicate and access data and the data rates have only been increasing for the last 30 years. 5G is the current generation of cellular networks and enables faster data rates and lower latency. One of the cellular network architectures used to enable 5g is centralized radio access networks (C-RAN). C-RAN centralizes all the baseband units (BBU) into one or a few locations in contrast to traditional architectures where BBUs are separated. This centralization causes more demand on the fronthaul to transfer larger amounts of data. To mitigate this demand on the fronthaul, functional splits were developed to distribute the baseband functions dependent on the need. This thesis focuses on simulating several functional splits in C-RAN with packetized fronthaul. The objective is to study the impact the functional split options have on the network by investigating key metrics such as fronthaul link throughput, utilization, and, buffer usage. The thesis includes the development of a digital twin (DT) of C-RAN deployments. This digital twin is implemented in Python using the SimPy library to enable discrete event simulation. The DT was then used to simulate each split option over low, medium, and high traffic loads. The network that was simulated includes one BBU, fronthual link, one switch, and three remote radio units with 64 antennas. The fronthaul link is 1 km long and has a transfer rate of 100 Gbps. The results show that various functional split options have a significant impact on the network’s overall performance. This impact is mostly dependent on the split option choice and not on the load for this configuration. Overall, this thesis contributes to the understanding of functional splits in centralized radio access networks with packetized fronthaul.

Cited by 0Open access

Soft-Stacked PON for Soft C-RAN

Weisheng Hu, Lilin Yi, Hao He et al. · Journal of Optical Communications and Networking · 2016

Cloud radio access networks (C-RANs) feature central pooling baseband processing units (BBUs) and low-cost remote radio headends (RRHs) with fiber-connected fronthauls between them, and they are promising for 4G. Researchers are redesigning the C-RAN with different split approaches to relax the fronthaul capacity for 5G with massive antennas, which is termed soft C-RAN. In this paper, we propose a soft-stacked passive optical network (PON) to support the soft C-RAN as an integrated solution. Two approaches are investigated in this paper. The first one is realized by employing an arrayed waveguide grating router (AWGR) and directly modulated tunable lasers, and it is promising for digital fronthaul and midhaul transmission and switching. The second is realized by employing wavelength-selective switches (WSSs) to allocate one-to-one and many-to-many connections, and it is promising for analog fronthaul transmission and switching. Their performances are analyzed and measured with directly modulated lasers (DMLs) that are either fixed or tunable. A delay interferometer is used for the DMLs&#x2019; chirp and fiber dispersion management. The result is significant for future soft C-RANs and stacked PON.

Cited by 17

C-RAN CoMP Methods for MPR Receivers

Raposo, Tiago Miguel de Góis · Portuguese National Funding Agency for Science, Research and Technology (RCAAP Project by FCT) · 2018

The growth in mobile network traffic due to the increase in MTC (Machine Type Communication) applications, brings along a series of new challenges in traffic routing and management. The goals are to have effective resolution times (less delay), low energy consuption (given that wide sensor networks which are included in the MTC category, are built to last years with respect to their battery consuption) and extremely reliable communication (low Packet Error Rates), following the fifth generation (5G) mobile network demands. In order to deal with this type of dense traffic, several uplink strategies can be devised, where diversity variables like space (several Base Stations deployed), time (number of retransmissions of a given packet per user) and power spreading (power value diversity at the receiver, introducing the concept of SIC and Power-NOMA) have to be handled carefully to fulfill the requirements demanded in Ultra-Reliable Low-Latency Communication (URLLC). This thesis, besides being restricted in terms of transmission power and processing of a User Equipment (UE), works on top of an Iterative Block Decision Feedback Equalization Reciever that allows Multi Packet Reception to deal with the diversity types mentioned earlier. The results of this thesis explore the possibility of fragmenting the processing capabilities in an integrated cloud network (C-RAN) environment through an SINR estimation at the receiver to better understand how and where we can break and distribute our processing needs in order to handle near Base Station users and cell-edge users, the latters being the hardest to deal with in dense networks like the ones deployed in a MTC environment.

Cited by 0Open access

Development of a C-RAN Fronthaul Simulator

Tesfalidet, Noel, Khosravi, Sam · KTH Publication Database DiVA (KTH Royal Institute of Technology) · 2023

Cellular networks have significantly transformed the way we communicate and access data and the data rates have only been increasing for the last 30 years. 5G is the current generation of cellular networks and enables faster data rates and lower latency. One of the cellular network architectures used to enable 5g is centralized radio access networks (C-RAN). C-RAN centralizes all the baseband units (BBU) into one or a few locations in contrast to traditional architectures where BBUs are separated. This centralization causes more demand on the fronthaul to transfer larger amounts of data. To mitigate this demand on the fronthaul, functional splits were developed to distribute the baseband functions dependent on the need. This thesis focuses on simulating several functional splits in C-RAN with packetized fronthaul. The objective is to study the impact the functional split options have on the network by investigating key metrics such as fronthaul link throughput, utilization, and, buffer usage. The thesis includes the development of a digital twin (DT) of C-RAN deployments. This digital twin is implemented in Python using the SimPy library to enable discrete event simulation. The DT was then used to simulate each split option over low, medium, and high traffic loads. The network that was simulated includes one BBU, fronthual link, one switch, and three remote radio units with 64 antennas. The fronthaul link is 1 km long and has a transfer rate of 100 Gbps. The results show that various functional split options have a significant impact on the network’s overall performance. This impact is mostly dependent on the split option choice and not on the load for this configuration. Overall, this thesis contributes to the understanding of functional splits in centralized radio access networks with packetized fronthaul.

Cited by 1Open access

División de funciones en arquitecturas C-RAN

Sarasúa Zubimendi, Paula · UCrea (University of Cantabria) · 2017

Las previsiones para los próximos años respecto a la evolución de las redes de comunicación actuales, pasan por un importante aumento de demanda de tráfico en las redes móviles, causando situaciones de congestión y de retardo en las mismas. Dicho incremento en la demanda de tráfico, se produciría por el aumento notable de nodos y por la consolidación de servicios de gran capacidad, tales como el vídeo streaming o los juegos online, que conviven con otros más básicos como la navegación web. En respuesta a estos problemas, el Third Generation Partnership Project (3GPP) propone, entre otras soluciones, el Cloud Radio Access Network (C-RAN) como posible arquitectura de red de acceso de los futuros sistemas 5G. El principio básico de funcionamiento de esta nueva arquitectura consiste en llevar la inteligencia de los elementos de acceso de las redes de comunicación a la nube, basándose en tres grandes pilares: coordinación, centralización y virtualización de red. Además, surge como solución que satisface las nuevas necesidades de hoy en día por parte de los usuarios finales y de los operadores, reduciendo los costes en el despliegue de nuevos nodos en las redes de comunicación. Esta nueva filosofía no supondría ningún perjuicio para el usuario final, ya que el acceso se acercaría a la aplicación, y disminuiría la congestión y el retardo en el enlace de acceso. En este trabajo se plantea un análisis de viabilidad de estas técnicas mediante la creación de una herramienta de simulación de acceso de redes 4G. Haciendo uso de las posibilidades que ofrece la herramienta desarrollada y utilizando optimización basada en programación con restricciones, se han implementado los algoritmos correspondientes para calcular las posiciones óptimas de los controladores que gestionarán los nodos de la red y el nivel de división de funciones óptimo para cada elemento de acceso.

Cited by 0Open access

Cooperation Strategies for Partly Wireless C-RAN

Donggu Kim, Yanpeng Yang, Ki Won Sung et al. · IEEE Communications Letters · 2018

This letter presents a variant of cloud radio access network (C-RAN) architecture, which we term partly wireless C-RAN (PW-CRAN). It is characterized by extra radio nodes connected through the existing remote radio heads. Because of the newly connected nodes and the consequent additional delay, the operation of PW-CRAN requires different approaches compared with that of the typical C-RAN. Specifically, the effect of delayed channel state information on the suitability of network cooperation should be identified. To tackle this problem, we introduce two representative cooperation strategies and evaluate the performance with regard to the delay via simulations. Numerical results suggest that it is better to exclude the extra nodes from cooperation if they incur excess delay. Furthermore, whether the delay is deemed excessive depends on the interference environment. Hence, we provide quantified guidelines on the cooperation strategy of PW-CRAN.

Cited by 5

Review of 5G C-RAN Resource Allocation

Louis Obi Chenke, Charles Nche, Éric Michel Deussom Djomadji et al. · Greater South Information System · 2023

The Fifth Generation (5G) Network will bring different types of services, namely: EMBB, mMTC and URLLC and as more devices connect to the network, each user device request for data capacity will continue to grow. The increase in the number of devices and capacity request for each device will require an increase in network capacity, which will also need an increase in the number of Base Stations in the network. More Base Stations will increase the the Mobile Network Operator's capital investment and operation costs. However, this increase in CAPEX and OPEX will not provide a corresponding increase in ARPU as users tend to be less willing to pay more as their capacity request increases. Mobile vendors and Mobile Network Operators will face the challenge of providing higher capacity for the same or less ARPU for their customers to maintain their customer base and maintain the business profitability. C-RAN was identified as a new and promising paradigm to help Mobile Network Operators reduce their CAPEX and OPEX while delivering higher capacity to their customers and maintaining business profitability. How C-RAN resources are allocated and managed within the 5G network will determine how efficient and profitable this optimisation process will be. In this article, we provide a high-level review of the crucial enabling 5G Technologies and an exhaustive review of C-RAN resource allocation algorithms for 5G networks with emphasis on resource allocation metrics/parameters. The main resource allocation metrics considered in this work include BBU computational/processing resource, capacity, Power/ energy consumption, wavelength, UE-RRH mapping and RRH-BBU mapping. Furthermore, Energy Harvesting in 5G C-RAN is discussed, including its architecture, categorised taxonomy and requirements. Lastly, future research directions and open research issues for efficient C-RAN resource allocation are highlighted.

Cited by 0Open access

Flexible C-RAN: Radio technology for 5G

Liljana Gavrilovska, Valentin Rakovic, Aleksandar Ichkov et al. · 2017

Conventional radio access networks are designed to utilize static configuration and are statically deployed. As results they are inefficient in handling any spatio-temporal fluctuations of the underlying traffic demand. Cloud-RAN represents a novel centralized technology based on softwareization and virtualization technology that can efficiently address the problems of legacy networks. Cloud-RAN facilitates high data rates as well as high network and radio adaptability across the software defined wireless networks. This paper elaborates the CRAN concept providing overview of current status, relevant features and research challenges related to it. Moreover, the paper presents a developed demo platform capable of efficient virtualization of different types of wireless technologies that belong to a heterogeneous wireless environment. It utilizes commercial and open-source solutions, such as OpenStack and SDR software. The performance analysis highlights the behavior of GSM and LTE technologies, with respect to cloud resource allocation. The paper also discusses some aspects and technical requirements for a C-RAN based dynamical resource allocation.

Cited by 19

Review of 5G C-RAN Resource Allocation

Louis Obi Chenke, Charles Nche, Éric Michel Deussom Djomadji et al. · ICST Transactions on Mobile Communications and Applications · 2023

The Fifth Generation (5G) Network will bring different types of services, namely: EMBB, mMTC and URLLC and as more devices connect to the network, each user device request for data capacity will continue to grow. The increase in the number of devices and capacity request for each device will require an increase in network capacity, which will also need an increase in the number of Base Stations in the network. More Base Stations will increase the the Mobile Network Operator’s capital investment and operation costs. However, this increase in CAPEX and OPEX will not provide a corresponding increase in ARPU as users tend to be less willing to pay more as their capacity request increases. Mobile vendors and Mobile Network Operators will face the challenge of providing higher capacity for the same or less ARPU for their customers to maintain their customer base and maintain the business profitability. C-RAN was identified as a new and promising paradigm to help Mobile Network Operators reduce their CAPEX and OPEX while delivering higher capacity to their customers and maintaining business profitability. How C-RAN resources are allocated and managed within the 5G network will determine how efficient and profitable this optimisation process will be. In this article, we provide a high-level review of the crucial enabling 5G Technologies and an exhaustive review of C-RAN resource allocation algorithms for 5G networks with emphasis on resource allocation metrics/parameters. The main resource allocation metrics considered in this work include BBU computational/processing resource, capacity, Power/ energy consumption, wavelength, UE-RRH mapping and RRH-BBU mapping. Furthermore, Energy Harvesting in 5G C-RAN is discussed, including its architecture, categorised taxonomy and requirements. Lastly, future research directions and open research issues for efficient C-RAN resource allocation are highlighted.

Cited by 2Open access