Investigating Inclusiveness and Backward Compatibility of IEEE 802.11be Multi-link Operation

Nowadays is not possible to avoid considering the coexistence and the fusion of different wireless technologies as completely separated entities. The ever-growing number of devices employing multi-RATs (Radio Access Technologies) that require continuous wireless connectivity is posing great challenges. Furthermore, the requirements in terms of both throughput and latency originated by the use cases, are pushing the current technologies to their limits, especially for indoor dense deployments that are usually covered by Wi-Fi. The IEEE 802.11 Working Group is currently tackling such challenges by working on a new amendment of the standard (namely 802.11be), which introduces, among other novelties, the multi-link operation (MLO). Through MLO, the target is to achieve simultaneous transmission over multiple bands to obtain massive bitrate up to 40 Gbps. The introduction of MLO poses challenges on the coexistence with older legacy devices in mixed networks. This contribution explores how the coexistence of legacy IEEE 802.11 devices and new IEEE 802.11be devices realizing the proposed multi-link feature can be improved by using an appropriate static band assignment policy. Another issue is how the overall network behaves when varying the number of devices and the legacy/new nodes ratio. Simulations for three different band allocation cases close to reality are developed. Performance results in terms of aggregated, average throughput and fairness are derived for different conditions.info:eu-repo/semantics/acceptedVersio

Survey on 5G Second Phase RAN Architectures and Functional Splits

The Radio Access Network (RAN) architecture evolves with different generations of mobile communication technologies and forms an indispensable component of the mobile network architecture. The main component of the RAN infrastructure is the base station, which includes a Radio Frequency unit and a baseband unit. The RAN is a collection of base stations connected to the core network to provide coverage through one or more radio access technologies. The advancement towards cloud native networks has led to centralizing the baseband processing of radio signals. There is a trade-off between the advantages of RAN centralization (energy efficiency, power cost reduction, and the cost of the fronthaul) and the complexity of carrying traffic between the data processing unit and distributed antennas. 5G networks hold high potential for adopting the centralized architecture to reduce maintenance costs while reducing deployment costs and improving resilience, reliability, and coordination. Incorporating the concept of virtualization and centralized RAN architecture enables to meet the overall requirements for both the customer and Mobile Network Operator. Functional splitting is one of the key enablers for 5G networks. It supports Centralized RAN, virtualized Radio Access Network, and the recent Open Radio Access Networks. This survey provides a comprehensive tutorial on the paradigms of the RAN architecture evolution, its key features, and implementation challenges. It provides a thorough review of the 3rd Generation Partnership Project functional splitting complemented by associated challenges and potential solutions. The survey also presents an overview of the fronthaul and its requirements and possible solutions for implementation, algorithms, and required tools whilst providing a vision of the evaluation beyond 5G second phase.info:eu-repo/semantics/submittedVersio

Wave Propagation in Urban Microcells: a Massively Parallel Approach Using the TLM Method

. We consider a new approach to modeling wave propagation in urban environments, based on the Transmission Line Matrix (TLM) method. Two-dimensional simulations are performed using a map of a city A renormalization technique is proposed to convert the results to the three-dimensional space. Our approach provides good predictions for the intensity of a wave when compared with in-situ measurements and is appropriate to very fast massively parallel computations. In order to provide a performance analysis, the algorithm has been used as a benchmark on different parallel architecture (CM200, CM5, IBM SP2 and Cray T3D). 1 Introduction The fast development and the growing importance of mobile, personal communication systems such as cellular phones require a detailed knowledge of wave propagation in heterogeneous media. Urban environments constitute a difficult problem which is studied by various authors[1, 2, 3]. Radio waves are absorbed, reflected, diffracted and scattered in a complicated ..

TAKE ::Tactical ad-hox network emulation

The Swiss Army uses tactical radios to communicate between troops on the field. Due to the operating environment, these radios experience specific characteristics such as limited bandwidth, in addition to high delay and packet losses. This paper presents the work achieved to develop, evaluate and test a novel application-layer routing algorithm specifically designed for tactical MANET networks. In order to evaluate the proposed algorithm in real conditions, two platforms and specific Quality of Experience metrics have been developed

Reproducing measured MANET radio performances using the EMANE framework

Simulation or emulation of mobile ad hoc networks (MANET) is used to predict or analyze the performance of MANETs under various scenarios. One challenge is to emulate realistically the MANET's radio performance. Running the Extendable Mobile Ad Hoc Network Emulator (EMANE) framework, we show how to reproduce measured characteristics, namely throughput and round-trip time, of real tactical radios using wideband or narrowband TDMA-based waveforms. Additionally, a solution to simulate rate adaptation is proposed. An introduction to EMANE and the EMANE radio model plugins is also provided

Multi objective resource scheduling in LTE networks using reinforcement learning

The use of the intelligent packet scheduling process is absolutely necessary in order to make the radio resources usage more efficient in recent high-bit-rate demanding radio access technologies such as Long Term Evolution (LTE). Packet scheduling procedure works with various dispatching rules with different behaviors. In the literature, the scheduling disciplines are applied for the entire transmission sessions and the scheduler performance strongly depends on the exploited discipline. The method proposed in this paper aims to discuss how a straightforward schedule can be provided within the transmission time interval (TTI) sub-frame using a mixture of dispatching disciplines per TTI instead of a single rule adopted across the whole transmission. This is to maximize the system throughput while assuring the best user fairness. This requires adopting a policy of how to mix the rules and a refinement procedure to call the best rule each time. Two scheduling policies are proposed for how to mix the rules including use of Q learning algorithm for refining the policies. Simulation results indicate that the proposed methods outperform the existing scheduling techniques by maximizing the system throughput without harming the user fairness performance. © 2012, IGI Global

A novel dynamic Q-learning-based scheduler technique for LTE-advanced technologies using neural networks

The tradeoff concept between system capacity and user fairness attracts a big interest in LTE-Advanced resource allocation strategies. By using static threshold values for throughput or fairness, regardless the network conditions, makes the scheduler to be inflexible when different tradeoff levels are required by the system. This paper proposes a novel dynamic neural Q-learning-based scheduling technique that achieves a flexible throughput-fairness tradeoff by offering optimal solutions according to the Channel Quality Indicator (CQI) for different classes of users. The Q-learning algorithm is used to adopt different policies of scheduling rules, at each Transmission Time Interval (TTI). The novel scheduling technique makes use of neural networks in order to estimate proper scheduling rules for different states which have not been explored yet. Simulation results indicate that the novel proposed method outperforms the existing scheduling techniques by maximizing the system throughput when different levels of fairness are required. Moreover, the system achieves a desired throughput-fairness tradeoff and an overall satisfaction for different classes of users

SECTION D’INFORMATIQUE ÉCOLE POLYTECHNIQUE FÉDÉRALE DE LAUSANNE POUR L’OBTENTION DU GRADE DE DOCTEUR ÈS SCIENCES PAR

Ingénieur physicien diplômé de l’Université d’État d’Erevan, Arménie et de nationalité arménienne acceptée sur proposition du jury: Prof. Boi Faltings, président du jury Prof. Roger D. Hersch, directeur de thès