IMDEA Networks Institute Digital Repository
Not a member yet
1915 research outputs found
Sort by
On the Outage Probability of Millimeter Wave Links with Quasi-deterministic Propagation
Get PDFMillimeter waves are emerging as a key technology for future wireless communication systems and networks. The
low transmission power allowed by regulation requires high gain steerable antenna arrays to generate directional links that can support high data rates. However, link directionality implies high sensitivity to obstructions, that can cause link outage. This paper presents a new simple analytical model based on stochastic geometry for the estimation of the outage probability of millimeter wave indoor and outdoor connections, accounting for the presence of obstructions.
The accuracy of the model is proved by comparison against
simulation results in a number of cases.TRUEpu
A 5G Mobile Network Architecture to Support Vertical Industries
Get PDFThe telecom industry is moving from a “horizontal” service delivery model, where services are defined independently from their consumers, towards a “vertical” delivery model, where the provided services are tailored to specific industry sectors and verticals. In order to enable this transition, an end-to-end comprehensive 5G architecture is needed, with capabilities to support the use cases of the different vertical industries. A key feature of this architecture is the implementation of network slicing over a single infrastructure to provision highly heterogeneous vertical services, as well as a network slicing management system capable of handling simultaneous slices. On top of the network slicing technology, functionality needs to be devised to deploy the slices required by the different vertical players and provide them with a suitable interface to manage their slice. In this paper, we design a 5G mobile network architecture to support vertical industries. The proposed architecture builds on ongoing standardization efforts at 3GPP and ETSI and incorporates additional modules to provide enhanced MANO and control functionality as well as artificial intelligence-based data analytics; on top of these modules, a service layer is provided to offer vertical players an easy-to-use interface to manage their services.pu
An Implementation Proposal for IEEE 802.11ay SU/MU-MIMO Communication in ns-3
Get PDFWireless communications in the millimeter-wave band bring unprecedented capabilities to achieve wireline performance in wireless networks and alleviate the congestion problem of current wireless technologies. However, efficient wireless networking in this band is extremely challenging compared to wireless technologies operating in the microwave band. IEEE 802.11ay is the next generation multigigabit standard to support wireless networking at 60 GHz. It is envisioned to support extremely high data-rates of up to 300 Gbps, achieved through new complex physical layer techniques including MIMO communication, channel bonding and aggregation, and high order-modulation schemes. Simulating the IEEE 802.11ay standard in a network-level simulator requires accurate abstraction models to incorporate the effects of those techniques. At the time of writing, ns-3, a system-level simulator widely used by the scientific community, still lacks support for MU-MIMO communication. Additionally, it requires generating environment dependent SNR-to-BER look-up tables to accurately simulate SU-MIMO communication. In this paper, we propose a hybrid implementation that includes minimum signal processing blocks to accurately simulate IEEE 802.11ay SU/MU-MIMO communication in ns-3 with high accuracy and reduced computational complexity.TRUEpu
Analytical Models of Floating Content in a Vehicular Urban Environment
Get PDFAmong the proposed opportunistic content sharing services, Floating Content (FC) is of special interest for the vehicular environment, not only for cellular traffic offloading, but also as a natural communication paradigm for location-based context-aware vehicular applications. Previously published results on the performance of vehicular FC have focused on content persistence, without addressing other important aspects of vehicular FC performance, such as the effectiveness with which content is replicated and made available, and the system conditions that enable good FC performance. This work presents a first analytical model of FC performance in vehicular networks in urban settings. It is based on a variation of the random waypoint (RWP) mobility model, and it does not require a model of the road grid geometry for its parametrization. We validate our model extensively, through numerical simulations on real-world traces, showing its accuracy on a variety of mobility patterns and traffic conditions. Through analysis and simulations, we show the feasibility of the FC paradigm in realistic urban settings over a wide range of traffic conditions.pu
Network slicing games: enabling customization in multi-tenant mobile networks
No full textNetwork slicing to enable resource sharing among multiple tenants-network operators and/or services-is considered as a key functionality for next generation mobile networks. This paper provides an analysis of a well-known model for resource sharing, the share-constrained proportional allocation mechanism, to realize network slicing. This mechanism enables tenants to reap the performance benefits of sharing, while retaining the ability to customize their own users' allocation. This results in a network slicing game in which each tenant reacts to the user allocations of the other tenants so as to maximize its own utility. We show that, for elastic traffic, the game associated with such strategic behavior converges to a Nash equilibrium. At the Nash equilibrium, a tenant always achieves the same or better performance than that of a static partitioning of resources, thus providing the same level of protection as static partitioning. We further analyze the efficiency and fairness of the resulting allocations, providing tight bounds for the price of anarchy and envy-freeness. Our analysis and extensive simulation results confirm that the mechanism provides a comprehensive practical solution to realize network slicing. Our theoretical results also fills a gap in the analysis of this resource allocation model under strategic players.pu
A Novel Hyperparameter-Free Approach to Decision Tree Construction That Avoids Overfitting by Design
Get PDFDecision trees are an extremely popular machine learning technique. Unfortunately, overfitting in decision trees still remains an open issue that sometimes prevents achieving good performance. In this paper, we present a novel approach for the construction of decision trees that avoids the overfitting by design, without losing accuracy. A distinctive feature of our algorithm is that it requires neither the optimization of any hyperparameters, nor the use of regularization techniques, thus significantly reducing the decision tree training time. Moreover, our algorithm produces much smaller and shallower trees than traditional algorithms, facilitating the interpretability of the resulting models. For reproducibility, we provide an open source version of the algorithm.pu
MuSher: An Agile Multipath-TCP Scheduler for Dual-Band 802.11ad/ac Wireless LANs
Get PDF802.11ac interfaces. The former provides multi-Gbps rates but is susceptible to blockage, whereas the latter is slower but offers reliable connectivity. A fundamental challenge is thus how to combine those complementary technologies, to make the most of the advantages they offer. In this work, we explore leveraging Multipath TCP (MPTCP) to use both interfaces simultaneously in order to achieve a higher overall throughput as well as seamlessly switching to a single interface when the other one fails. We find that standard MPTCP often performs sub-optimally and may even yield a throughput much lower than that of single path TCP over the faster of the two interfaces. We analyze the cause of these performance issues in detail and then design MuSher, an agile MPTCP scheduler that allows MPTCP to fully utilize the channel resources available to both interfaces. Our evaluation in realistic scenarios shows that MuSher provides a throughput improvement of up to 1.5x/2.3x and speeds up the recovery of a traffic stream, after disruption, by a factor of up to 8x/75x, under WLAN/Internet settings respectively, compared to the default MPTCP scheduler.TRUEpu
Scheduling Dynamic Parallel Workload of Mobile Devices with Access Guarantees
Get PDFWe study a dynamic resource-allocation problem that arises in various parallel computing scenarios such as mobile cloud computing, cloud computing systems, Internet of Things systems and others. Generically, we model the architecture as client mobile devices and static base stations. Each client “arrives” to the system to upload data to base stations by radio transmissions, and then “leaves”. The problem, called Station Assignment, is to assign clients to stations so that every client uploads its data under some restrictions, including a target subset of stations, a maximum delay between transmissions, a volume of data to upload, and a maximum bandwidth for each station. We study the solvability of Station Assignment under an ad-
versary that controls the arrival and departure of clients, limited to maximum rate and burstiness of such arrivals. We show upper and lower bounds on the rate and burstiness for various client arrival schedules and protocol classes. To the best of our knowledge, this is the first time that Station Assignment is studied under adversarial arrivals and departures.pu