On the Reliability of LTE Random Access: Performance Bounds for Machine-to-Machine Burst Resolution Time

Random Access Channel (RACH) has been identified as one of the major bottlenecks for accommodating massive number of machine-to-machine (M2M) users in LTE networks, especially for the case of burst arrival of connection requests. As a consequence, the burst resolution problem has sparked a large number of works in the area, analyzing and optimizing the average performance of RACH. However, the understanding of what are the probabilistic performance limits of RACH is still missing. To address this limitation, in the paper, we investigate the reliability of RACH with access class barring (ACB). We model RACH as a queuing system, and apply stochastic network calculus to derive probabilistic performance bounds for burst resolution time, i.e., the worst case time it takes to connect a burst of M2M devices to the base station. We illustrate the accuracy of the proposed methodology and its potential applications in performance assessment and system dimensioning.Comment: Presented at IEEE International Conference on Communications (ICC), 201

Adaptive access class barring for efficient mMTC

[EN] In massive machine-type communications (mMTC), an immense number of wireless devices communicate autonomously to provide users with ubiquitous access to information and services. The current 4G LTE-A cellular system and its Internet of Things (IoT) implementation, the narrowband IoT (NB-IoT), present appealing options for the interconnection of these wireless devices. However, severe congestion may arise whenever a massive number of highly-synchronized access requests occur. Consequently, access control schemes, such as the access class barring (ACB), have become a major research topic. In the latter, the precise selection of the barring parameters in a real-time fashion is needed to maximize performance, but is hindered by numerous characteristics and limitations of the current cellular systems. In this paper, we present a novel ACB configuration (ACBC) scheme that can be directly implemented at the cellular base stations. In our ACBC scheme, we calculate the ratio of idle to total available resources, which then serves as the input to an adaptive filtering algorithm. The main objective of the latter is to enhance the selection of the barring parameters by reducing the effect of the inherent randomness of the system. Results show that our ACBC scheme greatly enhances the performance of the system during periods of high congestion. In addition, the increase in the access delay during periods of light traffic load is minimal.This research has been supported in part by the Ministry of Economy and Competitiveness of Spain under Grant TIN2013-47272-C2-1-R and Grant TEC2015-71932-REDT. The research of I. Leyva-Mayorga was partially funded by grant 383936 CONACYT-GEM 2014.Leyva-Mayorga, I.; Rodríguez-Hernández, MA.; Pla, V.; Martínez Bauset, J.; Tello-Oquendo, L. (2019). Adaptive access class barring for efficient mMTC. Computer Networks. 149:252-264. https://doi.org/10.1016/j.comnet.2018.12.003S25226414

Gestion des accès massifs des équipements dans les réseaux NB-IoT : une stratégie basée sur l'apprentissage par renforcement

International audienc

Modelling of a Hybrid MAC Protocol for M2M Communications

Machine-to-machine (M2M) communications is one of the enabling technologies for connecting massive number of devices to the Internet of Things (IoT). M2M communications have different characteristics than human-to-human (H2H) communications. In this work, we propose a scalable, hybrid MAC protocol that will satisfy user quality-of-service (QoS) requirements. We model both periodic and nonperiodic traffic. The proposed MAC protocol organizes transmissions into superframes consisting of a number of frames. A machine is assumed to generate a one or zero packet per its period. The machines have been divided into several types according to their packet generation probabilities. The generated packets are classified into different traffic classes according to their tolerance to packet losses and served by a subframe. Further, each subframe is divided into two sub-periods one serving contention and the other reserved traffic of that traffic class. We formulated an optimization problem that minimizes frame length subject to QoS user requirements. Then, we derived packet loss probability for each class as well as total packet loss probability for the optimization. Formulation resulted in a nonlinear optimization problem, but numerical results show that an LP approximation provides a nearly optimal solution. The work also considered the proposed protocol under user mobility. The packet arrival process under user mobility has been derived. Then the performance of the protocol has been evaluated with the contention service under this arrival process. The contention service with and without packet losses have been considered. A priority queueing mechanism also has been studied for M2M communication. The results of this thesis may be useful in the design of M2M communication system

Security in Computer and Information Sciences

This open access book constitutes the thoroughly refereed proceedings of the Second International Symposium on Computer and Information Sciences, EuroCybersec 2021, held in Nice, France, in October 2021. The 9 papers presented together with 1 invited paper were carefully reviewed and selected from 21 submissions. The papers focus on topics of security of distributed interconnected systems, software systems, Internet of Things, health informatics systems, energy systems, digital cities, digital economy, mobile networks, and the underlying physical and network infrastructures. This is an open access book

Contrôle de charge des réseaux IoT : D'une étude théorique à une implantation réelle

Prenons en exemple une salle de classe composée d’un professeur et de nombreux élèves, lorsque trop d’élèves s’adressent en même temps au professeur ce dernier n’est plus en mesure de comprendre les paroles transmisses par les élèves. Cette illustration s’étend évidemment aux systèmes de communications sans fil (la 4G par exemple). Dans ces systèmes, les terminaux (les élèves par analogie) transmettent sur un canal, nommé canal en accès aléatoire, des messages qui sont potentiellement réceptionnés par la station de base (le professeur par analogie). Ces canaux ne sont habituellement pas surchargés car leur capacité (nombre de messages reçus par seconde) est tellement importante qu’il est très complexe de surcharger le canal. L’émergence de l’Internet des objets où des milliards de petits objets devraient être déployés partout dans le monde a changé la donne. Étant donné leur nombre et leur type de trafic, ces derniers peuvent surcharger les canaux en accès aléatoire. Ainsi, le sujet : « contrôle de charge des canaux en accès aléatoire » a connu un gain d’intérêts ces dernières années. Dans cette thèse nous avons développé des algorithmes de contrôle de charge permettant d’éviter qu’une station de base soit surchargée. Cela est très utile pour les opérateurs Télécoms, ils sont désormais certains qu’il y n’y aura pas de perte de service à cause de ces surcharges. Tous les principes développés dans cette thèse seront intégrés dans un futur proche aux produits IoT d’Airbus