Video Tester -- A multiple-metric framework for video quality assessment over IP networks

This paper presents an extensible and reusable framework which addresses the problem of video quality assessment over IP networks. The proposed tool (referred to as Video-Tester) supports raw uncompressed video encoding and decoding. It also includes different video over IP transmission methods (i.e.: RTP over UDP unicast and multicast, as well as RTP over TCP). In addition, it is furnished with a rich set of offline analysis capabilities. Video-Tester analysis includes QoS and bitstream parameters estimation (i.e.: bandwidth, packet inter-arrival time, jitter and loss rate, as well as GOP size and I-frame loss rate). Our design facilitates the integration of virtually any existing video quality metric thanks to the adopted Python-based modular approach. Video-Tester currently provides PSNR, SSIM, ITU-T G.1070 video quality metric, DIV and PSNR-based MOS estimations. In order to promote its use and extension, Video-Tester is open and publicly available.Comment: 5 pages, 5 figures. For the Google Code project, see http://video-tester.googlecode.com

Collision Avoidance Resource Allocation for LoRaWAN

Data Availability Statement: The data presented in this study are available on request from the corresponding author.Funding: This research was partially funded by the Andalusian Knowledge Agency (project A-TIC- 241-UGR18), the Spanish Ministry of Economy and Competitiveness (project TEC2016-76795-C6-4-R) and the H2020 research and innovation project 5G-CLARITY (Grant No. 871428).The number of connected IoT devices is significantly increasing and it is expected to reach more than two dozens of billions of IoT connections in the coming years. Low Power Wide Area Networks (LPWAN) have become very relevant for this new paradigm due to features such as large coverage and low power consumption. One of the most appealing technologies among these networks is LoRaWAN. Although it may be considered as one of the most mature LPWAN platforms, there are still open gaps such as its capacity limitations. For this reason, this work proposes a collision avoidance resource allocation algorithm named the Collision Avoidance Resource Allocation (CARA) algorithm with the objective of significantly increase system capacity. CARA leverages the multichannel structure and the orthogonality of spreading factors in LoRaWAN networks to avoid collisions among devices. Simulation results show that, assuming ideal radio link conditions, our proposal outperforms in 95.2% the capacity of a standard LoRaWAN network and increases the capacity by almost 40% assuming a realistic propagation model. In addition, it has been verified that CARA devices can coexist with LoRaWAN traditional devices, thus allowing the simultaneous transmissions of both types of devices. Moreover, a proof-of-concept has been implemented using commercial equipment in order to check the feasibility and the correct operation of our solution.Andalusian Knowledge Agency A-TIC-241-UGR18Spanish Ministry of Economy and Competitiveness TEC2016-76795-C6-4-RH2020 research and innovation project 5G-CLARITY 87142

Testbeds for Future Wireless Networks

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A LoRaWAN Architecture for Communications in Areas without Coverage: Design and Pilot Trials

This research was partially funded by the Andalusian Knowledge Agency (projects A-TIC-241-UGR18 and B-TIC-568-UGR20), the Spanish Ministry of Science and Innovation (project PID2019-108713RB-C53), the Spanish Ministry of Economic Affairs and Digital Transformation (project TSI-063000-2021-28) and the Spanish Ministry of Universities (FPU Grant Number: 20/02621).This article proposes a system based on a long-distance communications system with low economic and energy costs that allows connectivity to be carried out independently from the existing cellular coverage in the area. In addition, it describes the design, development, implementation and analysis of an Internet of Things (IoT) architecture based on Long-RangeWide-Area Network (LoRaWAN). Moreover, the system has been deployed as a prototype, and the behavior and scope of the system have been analyzed in various real environments: urban, rural and natural. The results obtained from the analysis show that the system is suitable for working in areas without coverage such as mountains.Andalusian Knowledge Agency A-TIC-241-UGR18 B-TIC-568-UGR20Spanish Government PID2019-108713RB-C53Spanish Ministry of Economic Affairs and Digital Transformation TSI-063000-2021-28Spanish Ministry of Universities (FPU) 20/0262

MEGsim: A Novel methodology for efficient simulation of graphics workloads in GPUs

An important drawback of cycle-accurate microarchitectural simulators is that they are several orders of magnitude slower than the system they model. This becomes an important issue when simulations have to be repeated multiple times sweeping over the desired design space. In the specific context of graphics workloads, performing cycle-accurate simulations are even more demanding due to the high number of triangles that have to be shaded, lighted and textured to compose a single frame. As a result, simulating a few minutes of a video game sequence is extremely time-consuming.In this paper, we make the observation that collecting information about the vertices and primitives that are processed, along with the times that shader programs are invoked, allows us to characterize the activity performed on a given frame. Based on that, we propose a novel methodology for the efficient simulation of graphics workloads called MEGsim, an approach that is capable of accurately characterizing entire video sequences by using a small subset of selected frames which substantially drops the simulation time. For a set of popular Android games, we show that MEGsim achieves an average simulation speedup of 126×, achieving remarkably accurate results for the estimated final statistics, e.g., with average relative errors of just 0.84% for the total number of cycles, 0.99% for the number of DRAM accesses, 1.2% for the number of L2 cache accesses, and 0.86% for the number of L1 (tile cache) accesses.This work has been supported by the CoCoUnit ERC Advanced Grant of the EU’s Horizon 2020 program (grant No 833057), the Spanish State Research Agency (MCIN/AEI) under grant PID2020-113172RB-I00, and the ICREA Academia program.Peer ReviewedPostprint (author's final draft

A LoRaWAN testbed design for supporting critical situations: prototype and evaluation

The Internet of Things is one of the hottest topics in communications today, with current revenues of $151B, around 7 billion connected devices, and an unprecedented growth expected for next years. A massive number of sensors and actuators are expected to emerge, requiring new wireless technologies that can extend their battery life and can cover large areas. LoRaWAN is one of the most outstanding technologies which fulfill these demands, attracting the attention of both academia and industry. In this paper, the design of a LoRaWAN testbed to support critical situations, such as emergency scenarios or natural disasters, is proposed. This self-healing LoRaWAN network architecture will provide resilience when part of the equipment in the core network may become faulty. This resilience is achieved by virtualizing and properly orchestrating the different network entities. Different options have been designed and implemented as real prototypes. Based on our performance evaluation, we claim that the usage of microservice orchestration with several replicas of the LoRaWAN network entities and a load balancer produces an almost seamless recovery which makes it a proper solution to recover after a system crash caused by any catastrophic event.Postprint (published version

NarrowBand IoT Data Transmission Procedures for Massive Machine Type Communications

Large-scale deployments of massive Machine Type Communications (mMTC) involve several challenges on cellular networks. To address the challenges of mMTC, or more generally, Internet of Things (IoT), the 3rd Generation Partnership Project has developed NarrowBand IoT (NB-IoT) as part of Release 13. NB-IoT is designed to provide better indoor coverage, support of a massive number of low-throughput devices, with relaxed delay requirements, and lower-energy consumption. NB-IoT reuses Long Term Evolution functionality with simplifications and optimizations. Particularly for small data transmissions, NB-IoT specifies two procedures to reduce the required signaling: one of them based on the Control Plane (CP), and the other on the User Plane (UP). In this work, we provide an overview of these procedures as well as an evaluation of their performance. The results of the energy consumption show both optimizations achieve a battery lifetime extension of more than 2 years for a large range in the considered cases, and up to 8 years for CP with good coverage. In terms of cell capacity relative to SR, CP achieves gains from 26% to 224%, and UP ranges from 36% to 165%. The comparison of CP and UP optimizations yields similar results, except for some specific configurations.This work is partially supported by the Spanish Ministry of Economy and Competitiveness and the European Regional Development Fund (Projects TIN2013-46223-P, and TEC2016-76795- C6-4-R), and the Spanish Ministry of Education, Culture and Sport (FPU Grant 13/04833)

Backhaul-Aware Dimensioning and Planning of Millimeter-Wave Small Cell Networks

The massive deployment of Small Cells (SCs) is increasingly being adopted by mobile operators to face the exponentially growing traffic demand. Using the millimeter-wave (mmWave) band in the access and backhaul networks will be key to provide the capacity that meets such demand. However, dimensioning and planning have become complex tasks, because the capacity requirements for mmWave links can significantly vary with the SC location. In this work, we address the problem of SC planning considering the backhaul constraints, assuming that a line-of-sight (LOS) between the nodes is required to reliably support the traffic demand. Such a LOS condition reduces the set of potential site locations. Simulation results show that, under certain conditions, the proposed algorithm is effective in finding solutions and strongly efficient in computational cost when compared to exhaustive search approaches.H2020 research and innovation project 5G-CLARITY 871428Spanish Ministry of Science, Innovation and Universities PID2019-108713RB-C5

Analítica avanzada para COVID-19 para el Estado de Jalisco

ITESO, A.C