17 research outputs found
Optimisation de la gestion des interférences inter-cellulaires et de l'attachement des mobiles dans les réseaux cellulaires LTE
Driven by an exponential growth in mobile broadband-enabled devices and a continue dincrease in individual data consumption, mobile data traffic has grown 4000-fold over the past 10 years and almost 400-million-fold over the past 15 years. Homogeneouscellular networks have been facing limitations to handle soaring mobile data traffic and to meet the growing end-user demand for more bandwidth and betterquality of experience. These limitations are mainly related to the available spectrumand the capacity of the network. Telecommunication industry has to address these challenges and meet exploding demand. At the same time, it has to guarantee a healthy economic model to reduce the carbon footprint which is caused by mobile communications.Heterogeneous Networks (HetNets), composed of macro base stations and low powerbase stations of different types, are seen as the key solution to improve spectral efficiency per unit area and to eliminate coverage holes. In such networks, intelligent user association and interference management schemes are needed to achieve gains in performance. Due to the large imbalance in transmission power between macroand small cells, user association based on strongest signal received is not adapted inHetNets as only few users would attach to low power nodes. A technique based onCell Individual Offset (CIO) is therefore required to perform load balancing and to favor some Small Cell (SC) attraction against Macro Cell (MC). This offset is addedto users’ Reference Signal Received Power (RSRP) measurements and hence inducing handover towards different eNodeBs. As Long Term Evolution (LTE) cellular networks use the same frequency sub-bands, mobile users may experience strong inter-cellxv interference, especially at cell edge. Therefore, there is a need to coordinate resource allocation among the cells and minimize inter-cell interference. To mitigate stronginter-cell interference, the resource, in time, frequency and power domain, should be allocated efficiently. A pattern for each dimension is computed to permit especially for cell edge users to benefit of higher throughput and quality of experience. The optimization of all these parameters can also offer gain in energy use. In this thesis,we propose a concrete versatile dynamic solution performing an optimization of user association and resource allocation in LTE cellular networks maximizing a certainnet work utility function that can be adequately chosen. Our solution, based on gametheory, permits to compute Cell Individual Offset and a pattern of power transmission over frequency and time domain for each cell. We present numerical simulations toillustrate the important performance gain brought by this optimization. We obtain significant benefits in the average throughput and also cell edge user through put of40% and 55% gains respectively. Furthermore, we also obtain a meaningful improvement in energy efficiency. This work addresses industrial research challenges and assuch, a prototype acting on emulated HetNets traffic has been implemented.Conduit par une croissance exponentielle dans les appareils mobiles et une augmentation continue de la consommation individuelle des données, le trafic de données mobiles a augmenté de 4000 fois au cours des 10 dernières années et près de 400millions fois au cours des 15 dernières années. Les réseaux cellulaires homogènes rencontrent de plus en plus de difficultés à gérer l’énorme trafic de données mobiles et à assurer un débit plus élevé et une meilleure qualité d’expérience pour les utilisateurs.Ces difficultés sont essentiellement liées au spectre disponible et à la capacité du réseau.L’industrie de télécommunication doit relever ces défis et en même temps doit garantir un modèle économique pour les opérateurs qui leur permettra de continuer à investir pour répondre à la demande croissante et réduire l’empreinte carbone due aux communications mobiles. Les réseaux cellulaires hétérogènes (HetNets), composés de stations de base macro et de différentes stations de base de faible puissance,sont considérés comme la solution clé pour améliorer l’efficacité spectrale par unité de surface et pour éliminer les trous de couverture. Dans de tels réseaux, il est primordial d’attacher intelligemment les utilisateurs aux stations de base et de bien gérer les interférences afin de gagner en performance. Comme la différence de puissance d’émission est importante entre les grandes et petites cellules, l’association habituelle des mobiles aux stations de bases en se basant sur le signal le plus fort, n’est plus adaptée dans les HetNets. Une technique basée sur des offsets individuelles par cellule Offset(CIO) est donc nécessaire afin d’équilibrer la charge entre les cellules et d’augmenter l’attraction des petites cellules (SC) par rapport aux cellules macro (MC). Cette offset est ajoutée à la valeur moyenne de la puissance reçue du signal de référence(RSRP) mesurée par le mobile et peut donc induire à un changement d’attachement vers différents eNodeB. Comme les stations de bases dans les réseaux cellulaires LTE utilisent les mêmes sous-bandes de fréquences, les mobiles peuvent connaître une forte interférence intercellulaire, en particulier en bordure de cellules. Par conséquent, il est primordial de coordonner l’allocation des ressources entre les cellules et de minimiser l’interférence entre les cellules. Pour atténuer la forte interférence intercellulaire, les ressources, en termes de temps, fréquence et puissance d’émission, devraient être alloués efficacement. Un modèle pour chaque dimension est calculé pour permettre en particulier aux utilisateurs en bordure de cellule de bénéficier d’un débit plus élevé et d’une meilleure qualité de l’expérience. L’optimisation de tous ces paramètres peut également offrir un gain en consommation d’énergie. Dans cette thèse, nous proposons une solution dynamique polyvalente effectuant une optimisation de l’attachement des mobiles aux stations de base et de l’allocation des ressources dans les réseaux cellulaires LTE maximisant une fonction d’utilité du réseau qui peut être choisie de manière adéquate.Notre solution, basée sur la théorie des jeux, permet de calculer les meilleures valeurs pour l’offset individuelle par cellule (CIO) et pour les niveaux de puissance à appliquer au niveau temporel et fréquentiel pour chaque cellule. Nous présentons des résultats des simulations effectuées pour illustrer le gain de performance important apporté par cette optimisation. Nous obtenons une significative hausse dans le débit moyen et le débit des utilisateurs en bordure de cellule avec 40 % et 55 % de gains respectivement. En outre, on obtient un gain important en énergie. Ce travail aborde des défis pour l’industrie des télécoms et en tant que tel, un prototype de l’optimiseur a été implémenté en se basant sur un trafic HetNets émulé
Resource and Mobility Management in the Network Layer of 5G Cellular Ultra-Dense Networks
© 2017 IEEE. Personal use of this material is permitted. Permissíon from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertisíng or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.[EN] The provision of very high capacity is one of the big challenges of the 5G cellular technology. This challenge will not be met using traditional approaches like increasing spectral efficiency and bandwidth, as witnessed in previous technology generations. Cell densification will play a major role thanks to its ability to increase the spatial reuse of the available resources. However, this solution is accompanied by some additional management challenges. In this article, we analyze and present the most promising solutions identified in the METIS project for the most relevant network layer challenges of cell densification: resource, interference and mobility management.This work was performed in the framework of the FP7 project ICT-317669 METIS, which is partly funded by the European Union. The authors would like to acknowledge the contributions of their colleagues in METIS, although the views expressed are those of the authors and do not necessarily represent the project.Calabuig Soler, D.; Barmpounakis, S.; Giménez Colás, S.; Kousaridas, A.; Lakshmana, TR.; Lorca, J.; Lunden, P.... (2017). Resource and Mobility Management in the Network Layer of 5G Cellular Ultra-Dense Networks. IEEE Communications Magazine. 55(6):162-169. https://doi.org/10.1109/MCOM.2017.1600293S16216955
Joint Optimization on Inter-cell Interference Management and User Attachment in LTE-A HetNets
International audienceTo optimize the network utility in 3GPP Long Term Evolution-Advanced (LTE-A) heterogeneous networks (HetNets), it is necessary to jointly consider inter-cell interference mitigation and user attachment. Based on potential game formulation, we optimize almost blank subframe (ABS) and/or cell selection bias (CSB) settings for both macrocells and picocells in a distributed manner. We demonstrate the need of joint ABS and CSB optimization via simulation case studies. Extensive simulations confirm that joint ABS and CSB optimizations can lead to a 20% improvement in spectral efficiency and a 46% improvement in energy efficiency while increasing the fairness of the achieved rates of users
A Game Theoretic Distributed Algorithm for FeICIC Optimization in LTE-A HetNets
International audienceIn order to obtain good network performance in Long Term Evolution-Advanced (LTE-A) heterogeneous networks (HetNets), enhanced inter-cell interference coordination (eICIC) and further enhanced inter-cell interference coordination (FeICIC) have been proposed by LTE standardization bodies to address the entangled inter-cell interference and the user association problems. We propose distributed algorithms based on the exact potential game framework for both eICIC and FeICIC optimizations. We demonstrate via simulations a 64% gain on energy efficiency (EE) achieved by eICIC and another 17% gain on EE achieved by FeICIC. We also show that FeICIC can bring other significant gains in terms of cell-edge throughput, spectral efficiency (SE) and fairness among user throughputs. Moreover, we propose a downlink scheduler based on a cake-cutting algorithm that can further improve the performance of the optimization algorithms compared to conventional schedulers
A multi-traffic inter-cell interference coordination scheme in dense cellular networks
This paper proposes a novel semi-distributed and practical ICIC scheme based on the Almost Blank Sub-Frame (ABSF) approach specified by 3GPP. We define two mathematical programming problems for the cases of guaranteed and best-effort traffic, and use game theory to study the properties of the derived ICIC distributed schemes, which are compared in detail against unaffordable centralized schemes. Based on the analysis of the proposed models, we define Distributed Multi-traffic Scheduling (DMS), a unified distributed framework for adaptive interference-aware scheduling of base stations in future cellular networks, which accounts for both guaranteed and best-effort traffic. DMS follows a two-tier approach, consisting of local ABSF schedulers, which perform the resource distribution between the guaranteed and best effort traffic, and a light-weight local supervisor, which coordinates ABSF local decisions. As a result of such a two-tier design, DMS requires very light signaling to drive the local schedulers to globally efficient operating points. As shown by means of numerical results, DMS allows to: (i) maximize radio resources resue; (ii) provide requested quality for guaranteed traffic; (iii) minimize the time dedicated to guaranteed traffic to leave room for best-effort traffic; and (iv) maximize resource utilization efficiency for the best-effort traffic.The work of A. Banchs was supported by the H2020 5GMoNArch project (Grant Agreement No. 761445) and the 5GCity project of the Spanish Ministry of Economy and
Competitiveness (TEC2016-76795-C6-3-R). The work of V. Mancuso has been supported by a Ramon y Cajal grant (ref: RYC-2014-16285) in part by the Spanish Ministry of Science, Innovation and Universities under grant TIN2017-88749-R and by the Madrid Regional Government through the TIGRE5-CM program (S2013/ICE-2919)
D4.3 Final Report on Network-Level Solutions
Research activities in METIS reported in this document focus on proposing solutions
to the network-level challenges of future wireless communication networks. Thereby, a large variety of scenarios is considered and a set of technical concepts is proposed to serve the needs envisioned for the 2020 and beyond.
This document provides the final findings on several network-level aspects and groups of
solutions that are considered essential for designing future 5G solutions. Specifically, it
elaborates on:
-Interference management and resource allocation schemes
-Mobility management and robustness enhancements
-Context aware approaches
-D2D and V2X mechanisms
-Technology components focused on clustering
-Dynamic reconfiguration enablers
These novel network-level technology concepts are evaluated against requirements defined
by METIS for future 5G systems. Moreover, functional enablers which can support the
solutions mentioned aboveare proposed.
We find that the network level solutions and technology components developed during the course of METIS complement the lower layer technology components and thereby effectively contribute to meeting 5G requirements and targets.Aydin, O.; Valentin, S.; Ren, Z.; Botsov, M.; Lakshmana, TR.; Sui, Y.; Sun, W.... (2015). D4.3 Final Report on Network-Level Solutions. http://hdl.handle.net/10251/7675
Definition and specification of connectivity and QoE/QoS management mechanisms – final report
This document summarizes the WP5 work throughout the project, describing its functional architecture and the solutions that implement the WP5 concepts on network control and orchestration. For this purpose, we defined 3 innovative controllers that embody the network slicing and multi tenancy: SDM-C, SDM-X and SDM-O. The functionalities of each block are detailed with the interfaces connecting them and validated through exemplary network processes, highlighting thus 5G NORMA innovations. All the proposed modules are designed to implement the functionality needed to provide the challenging KPIs required by future 5G networks while keeping the largest possible compatibility with the state of the art
Dense wireless network design and evaluation – an aircraft cabin use case
One of the key requirements of fifth generation (5G) systems is having a connection to mobile
networks without interruption at anytime and anywhere, which is also known as seamless connectivity.
Nowadays, fourth generation (4G) systems, Long Term Evolution (LTE) and Long
Term Evolution Advanced (LTE-A), are mature enough to provide connectivity to most terrestrial
mobile users. However, for airborne mobile users, there is no connection that exists
without interruption. According to the regulations, mobile connectivity for aircraft passengers
can only be established when the altitude of the aircraft is above 3000 m. Along with demands
to have mobile connectivity during a flight and the seamless connectivity requirement of 5G
systems, there is a notable interest in providing in-flight wireless services during all phases of
a flight. In this thesis, many issues related to the deployment and operation of the onboard
systems have been investigated.
A measurement and modelling procedure to investigate radio frequency (RF) propagation inside
an aircraft is proposed in this thesis. Unlike in existing studies for in-cabin channel characterization,
the proposed procedure takes into account the deployment of a multi-cell onboard
system. The proposed model is verified through another set of measurements where reference
signal received power (RSRP) levels inside the aircraft are measured. The results show that
the proposed model closely matches the in-cabin RSRP measurements. Moreover, in order to
enforce the distance between a user and an interfering resource, cell sectorization is employed
in the multi-cell onboard system deployment. The proposed propagation model is used to find
an optimum antenna orientation that minimizes the interference level among the neighbouring
evolved nodeBs (eNBs).
Once the optimum antenna deployment is obtained, comprehensive downlink performance evaluations
of the multi-cell, multi-user onboard LTE-A system is carried out. Techniques that are
proposed for LTE-A systems, namely enhanced inter-cell interference coordination (eICIC) and
carrier aggregation (CA), are employed in the system analysis. Different numbers of eNBs, antenna
mounting positions and scheduling policies are examined. A scheduling algorithm that
provides a good tradeoff between fairness and system throughput is proposed. The results show
that the downlink performance of the proposed onboard LTE-A system achieves not only 75%
of the theoretical limits of the overall system throughput but also fair user data rate performance,
irrespective of a passenger’s seat location.
In order to provide the seamless connectivity requirement of 5G systems, compatibility between
the proposed onboard system deployment and the already deployed terrestrial networks
is investigated. Simulation based analyses are carried out to investigate power leakage from
the onboard systems while the aircraft is in the parked position on the apron. According to
the regulations, the onboard system should not increase the noise level of the already deployed
terrestrial system by 1 dB. Results show that the proposed onboard communication system can
be operated while the aircraft is in the parked position on the apron without exceeding the 1 dB
increase in the noise level of the already deployed terrestrial 4G network. Furthermore, handover
parameters are obtained for different transmission power levels of both the terrestrial and
onboard systems to make the transition from one system to another without interruption while
a passenger boards or leaves the aircraft. Simulation and measurement based analyses show
that when the RSRP level of the terrestrial system is below -65 dBm around the aircraft, a
boarding passenger can be smoothly handed over to the onboard system and vice versa. Moreover,
in order to trigger the handover process without interfering with the data transmission, a
broadcast control channel (BCCH) power boosting feature is proposed for the in-cabin eNBs.
Results show that employing the BCCH power boosting feature helps to trigger the handover
process as soon as the passengers step on board the aircraft
On Improving Data Rates of Users in LTE HetNets
The proliferation of smartphones and tablets has led to huge demand for data
services over cellular networks. Cisco VNI mobile forecast (2014-2019) tells that although only 3.9% of mobile connections were Long Term Evolution (LTE) based they
accounted for 40% of the mobile traffic and this will rise to 51% by 2019, by which
the mobile data usage will grow 11 fold to over 15 Exabytes per month. Reports by
Cisco and Huawei tell that 70% of the traffic is generated in indoor environments
such as homes, enterprise buildings and hotspots. Hence, it is very important for
mobile operators to improve coverage and capacity of indoor environments. Indoor
data demand is partly met by intensifying the deployment of Macro Base Stations
(MBSs/eNodeBs) in LTE cellular networks. Owing to many obstacles in the communication path between MBS and users inside the building, radio signals attenuate at a
faster rate as the distance increases. Thus, Indoor User Equipments (IUEs) receive
still low signal strength ( i.e., Signal-to-Noise Ratio, SNR) compared to Outdoor
User Equipments (OUEs). To address this problem, one can deploy a large number
of Low Power Nodes (LPNs) a.k.a. small cells (e.g., Picos and Femtos) under an
umbrella MBS coverage and thereby form an LTE Heterogeneous Network (HetNet).
Small cells are mainly being deployed in homes, enterprise buildings and hotspots
like shopping malls and airports to improve indoor coverage and data rates. This is
a win-win situation as telecom operators also benefit by reduction in their CAPEX
and OPEX.
Though the deployment of Femtocells improves indoor data rates, the resulting
LTE HetNet may face a host of problems like co-tier and cross-tier interference (due
to frequency reuse one in LTE) and frequent handovers (due to short coverage areas of
Femtocells). Deployment of Femtos inside a building can lead to signal leakage at the
edges/corners of the buildings. This causes cross-tier interference and degrades the
performance of OUEs in High Interference Zone (HIZone) around the building area,
which are connected to one of the MBSs in the LTE HetNet. Arbitrary placement of
Femtos can lead to high co-channel cross-tier interference among Femtos and Macro
BSs and coverage holes inside buildings. If Femtos are placed without power control,
this leads to high power consumption and high inter-cell interference in large scale deployments. Our goal is to address these problems by developing efficient architecture,
Femto placement and power control schemes in LTE HetNets.
Random or unplanned placement of the Femtos leads to poor SNR and hence
affects achievable data rates of IUEs. Hence, placement of Femtos is important for
the cellular operators to perform planned deployment of minimum number of Femtos
with no coverage holes and guarantee a good signal quality with no co-tier interference. Once the placement of Femtos is done optimally in enterprise environments,
operators need to ensure that traffic load is evenly distributed among neighboring
Femtos for improving Quality of Service (QoS) of IUEs by efficiently utilizing the
network resources. In traditional cellular networks, the uplink access and downlink
access of UEs are coupled to the same (Femto) cell. Suppose a Femto is fully loaded
when compared to its neighboring Femtos, the traditional offloading or load balancing algorithms will try offloading some of the UEs for both their uplink and downlink
access from the loaded cell to one of less loaded neighboring cells (i.e., target cell)
provided that these UEs could get connected to the chosen target cell. This type of
offloading is a forced handover to reduce traffic imbalance and trigger for handover is
not based on better signal strength from the target cell. But, the offloaded UEs are
connected for both their uplink and downlink access to the same target cell. Since
UEs are most likely separated by walls and floors from their connected cells in enterprise environments, these offloaded UEs now have to transmit with higher transmit
power in the uplink and thereby affects their battery lives. In order to reduce the
battery drain for the offloaded UEs while maintaining their QoS, we employ the Decoupled Uplink and Downlink (DUD) access method in such a way that, the uplink
of UE is connected to the closest Femto while the downlink is connected to a less
loaded neighboring Femto.
To maximize the utilization of the limited operating spectrum and provide higher
data rate for IUEs, operators can configure Femtos in open access mode with frequency reuse one (i.e., all Femtos and MBSs operates on a same frequency) in LTE
HetNets. However, this leads to high co-tier interference and cross-tier interference.
Another problem in enterprise buildings having Femtos is frequent handovers, that
happens when IUEs move from one room/floor to another room/floor inside the
building. This leads to degradation of network performance in terms of increased
signaling overhead and low throughputs. In order to reduce this kind of unnecessary
handovers in enterprise buildings, Femtos should be placed optimally with handover
constraints. Hence, we obtain the optimal coordinates from the OptHO model by
adding handover constraints to the Minimize Number of Femtos (MinNF) model
which guarantees threshold Signal-to-Interference plus Noise Ratio (SINR) of -2 dB
for all IUEs inside the building. Such optimized deployment of Femtos reduces the
number of handovers while guaranteeing good SINR to all IUEs.
In LTE HetNets, even though planned deployment of Femtos in open access mode
boosts the IUEs performance, the power leakage from indoor Femtos create interferix
ence to the OUEs in the HIZone in the buildings surrounding areas. We propose
an efficient placement and power control SON (Self organizing Network) algorithm
which optimally places Femtos and dynamically adjusts the transmit power of Femtos
based on the occupancy of Macro connected OUEs in the HIZone. To do this, we
use the same MinNF model to place the Femtos optimally and solve Optimal Femto
Power (OptFP) allocation problem (Mixed Integer Linear Programming (MILP))
which guarantees threshold SINR of -4 dB for IUEs with the Macro users SINR
degradation as lesser than 2 dB. In the OptFP model, Femto’s transmit power is
tuned dynamically according to the occupancy of OUEs in the HIZone. But the
presence of even a single OUE in the HIZone decreases SINR of numerous IUEs,
which is not fair to IUEs. In order to address this issue, we propose two solutions
a) On improving SINR in LTE HetNets with D2D relays and b) A novel resource
allocation and power control mechanism for Hybrid Access Femtos in LTE HetNets,
which we describe in the following two paragraphs.
To guarantee certain minimum SINR and fairness to both IUEs and OUEs in
HIZone, we consider a system model by applying the concept of Device-to-Device
(D2D) communication wherein free/idle IUEs connected to Femto act like UE-relays
(i.e., UE-like BS, forwarding downlink data plane traffic for some of the HIZone
users connected to MBS). We formulate a Mixed-Integer Linear Programming (MILP)
optimization model which efficiently establishes D2D pairs between free/idle celledge IUEs and HIZone users by guaranteeing certain SINRT h for both IUEs and
HIZone users. As D2D MILP model takes more computation time, it is not usable
in real-world scenarios for establishing D2D pairs on the fly. Hence, we propose a
two-step D2D heuristic algorithm for establishing D2D pairs.
In above works, we assume that Femtos are configured in open access mode. But
Hybrid Access Femtocells (HAFs) are favored by the operators because they ensure
the paid Subscribed Group (SG) users certain QoS and then try to maximize the system capacity by serving near-by Non Subscribed Group (NSG) users in a best-effort
manner. To reap in the benefits of HAFs, the operators need to employ effective
resource sharing and scheduling mechanisms to contain co-tier and cross-tier interference arising out of reuse one in the HetNet system. Towards this, we address various
challenges in terms of deployment and operation of HAFs in indoor environments. We
propose an Optimal Placement of hybrid access Femtos (OPF) model which ensures
a certain SINRT h inside the building and a certain SINRT h in the HIZone of the
building. Unlike in previous optimization models, in this model, users in HIZone are
connected to HAF s deployed inside the building. Also we propose a decentralized
Dynamic Bandwidth Allocation (BWA) mechanism which divides the available HAF
bandwidth between the two sets of user groups: SG and NSG. In order to mitigate
co-tier and cross-tier interference, we then propose a dynamic Optimal Power Control
(OPC) mechanism which adjusts the transmit powers of HAFs whenever the users in
the HIZone cannot be served by the HAFs. In such a case, HIZone users connect
to an MBS instead. Since the OPC problem is hard to solve in polynomial time,
we also present a Sub-Optimal Power Control (SOPC) mechanism. To maintain fair
resource allocation between SG and NSG users, we propose an Enhanced Priority
(EP) scheduling mechanism which employs two schedulers which are based on the
Proportional Fair (PF) and the Priority Set (PS) scheduling mechanisms.
In above works, placement of Femtos is optimized to reduce co-channel co-tier
interference among neighboring Femtos and transmit power of Femtos is optimized
to reduce cross-tier interference between MBSs and Femtos. But, for arbitrary deployed Femtos, Inter Cell Interference Coordination (ICIC) techniques could be employed to address co-tier interference problem among Femtos which are connected with
each other over X2 interface. Hence, in this work, we propose an ICIC technique,
Variable Radius (VR) algorithm which dynamically increases or decreases the cell
edge/non-cell edge regions of Femtos and efficiently allocates radio resources among
cell edge/non-cell edge regions of Femtos so that the interference between neighboring Femtos can be avoided. We implement the proposed VR algorithm on top of PF
scheduler in NS-3 simulator and find that it significantly improves average network
throughput when compared to existing techniques in the literature
D2.2 Draft Overall 5G RAN Design
This deliverable provides the consolidated preliminary view of the METIS-II partners on the 5 th generation (5G) radio access network (RAN) design at a mid-point of the project. The overall 5G RAN is envisaged to operate over a wide range of spectrum bands comprising of heterogeneous spectrum usage scenarios. More precisely, the 5G air interface (AI) is expected to be composed of multiple so-called AI variants (AIVs), which include evolved legacy technology such as Long Term Evolution Advanced (LTE-A) as well as novel AIVs, which may be tailored to particular services or frequency bands.Arnold, P.; Bayer, N.; Belschner, J.; Rosowski, T.; Zimmermann, G.; Ericson, M.; Da Silva, IL.... (2016). D2.2 Draft Overall 5G RAN Design. https://doi.org/10.13140/RG.2.2.17831.1424