Experimental Evaluation of Interactive Edge/Cloud Virtual Reality Gaming over Wi-Fi using Unity Render Streaming

Virtual Reality (VR) streaming enables end-users to seamlessly immerse themselves in interactive virtual environments using even low-end devices. However, the quality of the VR experience heavily relies on Wireless Fidelity (Wi-Fi) performance, since it serves as the last hop in the network chain. Our study delves into the intricate interplay between Wi-Fi and VR traffic, drawing upon empirical data and leveraging a Wi-Fi simulator. In this work, we further evaluate Wi-Fi's suitability for VR streaming in terms of the Quality of Service (QoS) it provides. In particular, we employ Unity Render Streaming to remotely stream real-time VR gaming content over Wi-Fi 6 using Web Real-Time Communication (WebRTC), considering a server physically located at the network's edge, near the end user. Our findings demonstrate the system's sustained network performance, showcasing minimal round-trip time (RTT) and jitter at 60 and 90 frames per second (fps). In addition, we uncover the characteristics and patterns of the generated traffic streams, unveiling a distinctive video transmission approach inherent to WebRTC-based services: the systematic packetization of video frames (VFs) and their transmission in discrete batches at regular intervals, regardless of the targeted frame rate. This interval-based transmission strategy maintains consistent video packet delays across video frame rates but leads to increased Wi-Fi airtime consumption. Our results demonstrate that shortening the interval between batches is advantageous, as it enhances Wi-Fi efficiency and reduces delays in delivering complete frames.Comment: 17 pages, 26 figure

Performance Evaluation of MLO for XR Streaming: Can Wi-Fi 7 Meet the Expectations?

Extended Reality (XR) has stringent throughput and delay requirements that are hard to meet with current wireless technologies. Missing these requirements can lead to worsened picture quality, perceived lag between user input and corresponding output, and even dizziness for the end user. In this paper, we study the capability of upcoming Wi-Fi 7, and its novel support for Multi-Link Operation (MLO), to cope with these tight requirements. Our study is based on simulation results extracted from an MLO-compliant simulator that realistically reproduces VR traffic. Results show that MLO can sustain VR applications. By jointly using multiple links with independent channel access procedures, MLO can reduce the overall delay, which is especially useful in the uplink, as it has more stringent requirements than the downlink, and is instrumental in delivering the expected performance. We show that using MLO can allow more users per network than an equivalent number of links using SLO. We also show that while maintaining the same overall bandwidth, a higher number of MLO links with narrow channels leads to lower delays than a lower number of links with wider channels

Extraordinaria Función de Gala con motivo del IX Cincuentenario del regreso del glorioso Almirante Descubridor, Cristobal Colón

Director : F. Obradors i E. ToldràEmpresa J. Mestres CalvetPrograma : La siega de Zamacois, Tres danzas fantásticas de Turina, Goyescas de Granados, Asturias de Albéniz, Canción incierta i Anacreontica de Toldrá, Serranilla, Cántico a la esposa i Esta niña se lleva la flor de Rodrigo, La revoltosa de Chapí, El amor brujo de Fall

Multi-link operation for low-latency

Next generation applications will have strict network requirement, such as higher throughput and low latency. As Wi-Fi continues to grow, it needs to adapt to these new requirements. This thesis focuses on latency reduction over Wi-Fi networks and one of the main features of the upcoming Wi-Fi 7: Multi-Link Operation (MLO). With MLO, devices can associate to an Access Point over multiple links at the same time and transmit over multiple channels simultaneously, multiplying their bandwidth. This feature can also be used to improve network delay, as using independent backoffs in different links allows the device to adapt and choose the least congested link opportunistically. We focus on this aspect of MLO, showing that this can lead to an order of magnitude delay reduction over the worst-case delay in Single-Link Wi-Fi. We also analyze the use of MLO to deliver the traffic of Cloud gaming and Virtual Reality applications.Les aplicacions de nova generació tindran estrictes requisits per operar, com ara major throughput i baixa latència. A mesura que Wi-Fi continua creixent, necessita adaptar-se a aquests nous requisits. Aquesta tesi es centra en la reducció de latència per a xarxes Wi-Fi, utilitzant una de les característiques principals de Wi-Fi 7: Multi-Link Operation (MLO). Amb MLO, un node es pot associar a un Punt d'Accés amb multiples links al mateix temps i transmetre simultàneament per múltiples canals, multiplicant la seva amplada de banda. MLO pot també ajudar a millorar el retard de la xarxa, ja que utilitzar backoffs independents permet escollir el link menys congestionat de manera oportunista. Mostrem que MLO pot obtenir una reducció del retard d'una ordre de magnitud respecte el pitjor cas del Wi-Fi amb un sol link. També analitzem l’ús de MLO per l'enviament del tràfic cloud gaming i realitat virtual de manera ràpida i efectiva.Programa de Doctorat en Tecnologies de la Informació i les Comunicacion