Energy efficiency benefits of RAN-as-a-service concept for a cloud-based 5G mobile network infrastructure

This paper focuses on energy efficiency aspects and related benefits of radio-access-network-as-a-service (RANaaS) implementation (using commodity hardware) as architectural evolution of LTE-advanced networks toward 5G infrastructure. RANaaS is a novel concept introduced recently, which enables the partial centralization of RAN functionalities depending on the actual needs as well as on network characteristics. In the view of future definition of 5G systems, this cloud-based design is an important solution in terms of efficient usage of network resources. The aim of this paper is to give a vision of the advantages of the RANaaS, to present its benefits in terms of energy efficiency and to propose a consistent system-level power model as a reference for assessing innovative functionalities toward 5G systems. The incremental benefits through the years are also discussed in perspective, by considering technological evolution of IT platforms and the increasing matching between their capabilities and the need for progressive virtualization of RAN functionalities. The description is complemented by an exemplary evaluation in terms of energy efficiency, analyzing the achievable gains associated with the RANaaS paradigm

Cloud technologies for flexible 5G radio access networks

The evolution toward 5G mobile networks will be characterized by an increasing number of wireless devices, increasing device and service complexity, and the requirement to access mobile services ubiquitously. Two key enablers will allow the realization of the vision of 5G: very dense deployments and centralized processing. This article discusses the challenges and requirements in the design of 5G mobile networks based on these two key enablers. It discusses how cloud technologies and flexible functionality assignment in radio access networks enable network densification and centralized operation of the radio access network over heterogeneous backhaul networks. The article describes the fundamental concepts, shows how to evolve the 3GPP LTE architecture, and outlines the expected benefits.The research leading to these results has received funding from the European Community's Seventh Framework Programme FP7/2007-2013 under grant agreement no. 317941-project iJOIN, http://www.ict-ijoin.eu.Publicad

Optimisation de la concaténation de codes spatio-temporels et de codes correcteurs d'erreurs dans une transmission MIMO

Cette thèse traite du codage correcteur d'erreurs, du codage spatio-temporel ainsi que de l'utilisation conjointe de ces deux techniques dans un contexte à plusieurs antennes d'émission/réception ou contexte MIMO. L'objectif est de pouvoir améliorer le débit utile tout en conservant une bonne qualité de transmission. Dans un premier temps, les codes correcteurs d'erreurs algébriques binaires BCH et q-aires RS sont abordés. Le nouvel algorithme de la fenêtre d encodage glissante est présenté et ses performances sont illustrées sur canal gaussien. Son impact sur le décodage et la vitesse de convergence des turbo codes en bloc est également mis en avant, de même que ses limites. Dans un second temps, les principales structures de codage MIMO sont décrites : les codes spatio-temporels en bloc orthogonaux (STBO) et les architectures en couche. Le modèle de canal retenu est celui du canal de Rayleigh sans mémoire invariant par bloc. L'utilisation des codes de RS en tant que codes spatio-temporels est également proposée et leurs performances par rapport à celles des codes STBO classiques sont exposées. Enfin dans un troisième temps, les codes spatio-temporels correcteurs d'erreurs sont introduits pour deux antennes d'émission. Ces codes utilisent les propriétés de linéarité des codes correcteurs d'erreurs afin de créer une corrélation spatio-temporelle exploitable en réception. Leurs performances sont comparées à celles de structures classiques combinant codage correcteur d'erreurs et codage STBO, laissant entrevoir le potentiel de la solution proposée. Exploitant la redondance, la notion de poinçonnage est également introduite afin d'augmenter l efficacité spectrale.RENNES1-BU Sciences Philo (352382102) / SudocBREST-Télécom Bretagne (290192306) / SudocSudocFranceF

Space-time error correcting codes

International audienceA new space-time block code family for two transmitters, called the space-time error correcting codes (STECCs), is presented. As it is built from any linear forward error correcting code (FEC), a STECC is able to correct errors while achieving high spectral efficiencies. The key principle is the FEC linearity which is exploited to transmit linear combinations of FEC codewords to create a space-time redundancy. The proposed code exhibits interesting performance on an ISI-free block fading channel. This result is all the more true as the number of FEC codewords considered in the combination is high

Sliding encoding window for Reed-Solomon code decoding

International audienceTwo major types of decoding schemes are used for the soft decoding of block codes: encoding-based and algebraic decoding-based algorithms. Both techniques generate a list of codewords used by the decoder to choose inside the most probable. If these techniques are optimal for binary block codes, their strict adaptation to q-ary block codes leads to a prohibitive complexity. Therefore, we often use sub-optimal versions of these schemes for the decoding of Reed-Solomon q-ary codes. In this paper, we present a simple but efficient soft-input soft-output encoding-based algorithm, which uses a sliding window. The proposed sliding encoding-window (SEW) algorithm exploits the cyclic and systematic properties of systematic RS codes in order to generate a list of candidates in the neighborhood of the received sequence. As the SEW algorithm naturally creates codeword diversity, it is also efficient in the generation of reliable soft outputs necessary in iterative processes. Moreover, this algorithm can be combined with decoding-based algorithms, such as Berlekamp-Massey or Chase algorithms, to increase the codeword diversity. In this case, the performance improvement is significant, while the added cost due to encoding is minor as it is a low-cost process compared to that of algebraic decoding

Iterative decoding of space-time error correcting codes

International audienceMost of multiple-input multiple-output (MIMO) coding schemes can be sorted into two families. The first one includes the space-time block codes (STBCs) and in particular, the orthogonal STBCs (OSTBCs) as they can be optimally decoded with a low complexity. They improve the transmission quality, the communication range or the receiver robustness. The second family is based on the layered space-time (LST) architecture and aims at increasing the data rate without bandwidth nor power extra cost. To guarantee a given transmission quality, the use of a forward error correcting code (FEC) is mandatory like in the space-time bit interleaved coded modulation (ST-BICM) case. The space-time error correcting codes (STECCs) we introduced, which are based on any linear FEC, appear to be a good compromise between both families. They achieve better performance than the usual Alamouti code associated with the same FEC and propose higher data-rate with space-time puncturing techniques. However, the bottleneck of these codes is the detection stage which complexity grows exponentially with the number of FEC codewords involved in the creation of one STECC codeword. By applying the turbo equalization principle, we can significantly reduce this complexity, while achieving equivalent level of performance

Kalman filter-based localization for Internet of Things LoRaWAN™ end points

International audienceThis paper addresses the problem of estimating the location of Internet of Things (IoT) Long Range Wide Area Networks (LoRaWAN) devices from time of arrival differences measured at gateways. An Extended Kalman Filter (EKF) based approach is considered to aggregate the measurements obtained at different time instants. Particular attention is paid to the processing of outliers. Based on experimental data obtained from field measurements conducted on a real LoRaWAN™ network an insight into the realistic localization accuracy of the considered localization approach is provided

D4.2: Performance Evaluation of Low Exposure Index Solutions for Components and Transmission Techniques

<p>Based on a common evaluation 5-step methodology, initial performance assessments of the innovative solutions considered within WP4 are carried out. A dozen of radio components and transmission techniques solutions are developed and evaluated through ratio of the Exposure Index.The proposed intermediate performances assessments show a large range of exposure reduction from non-significant to ninety percent reduction, while keeping QoS constant.Despite a large diversity of solutions, the adopted methodology makes possible the comparison of their effectiveness but also allows to highlight some compatibility or at the opposite some conflicts between these solutions.This last point is a mandatory step to prepare solution prioritization and global exposure reduction assessment.</p