Gwendal Simon

Huawei Technologies · Department of R&D

The emerging technologies of Virtual Reality (VR) and 360 $^\circ $ video introduce new challenges for state-of-the-art video communication systems. Enormous data volume and spatial user navigation are unique characteristics of 360 $^\circ$ videos that necessitate a space-time effective allocation of the available network streaming bandwidth over...

The softwarization and virtualization based Network Slicing (NS) technology provides the momentum for integrating the Information-Centric Networking (ICN) systems into the 5G infrastructure, such that ICN can be virtualized as a NS to co-exist with other IP-based vertical services slices. The implementation of the ICN network slice (ICN-NS) is esse...

Heterogeneous spatial quality in 360-degree videos is characterized by regions of high and low quality appearing in the same video chunk. Encoding quality-varying omnidirectional videos enables bandwidth waste optimization without compromising the quality inside the client’s viewport. Heterogeneous spatial quality has been implemented using either...

Mobile Edge Computing (MEC) architecture is composed of geographically distributed edge servers, in which computing capabilities are provisioned at the boundary of the network, which is in close proximity to the end users to provide network services with low latency. The planning of MEC edge servers at appropriate locations is the fundamental first...

Today’s network operators strive to create self-healing cellular networks that have a fully automated troubleshooting management process. To this end, the network monitoring system should be capable of detecting issues, diagnosing them, and triggering the adequate recovery action. In this paper, we propose an unsupervised solution to diagnose the r...

This artifact includes source code, scripts and datasets required to reproduce the experimental figures in the evaluation of the MM'18 paper, which is entitled "MiniView Layout for Bandwidth-Efficient 360-Degree Video". The artifact reports the comparison results among the standard cube layout (CUBE), the equi-angular layout (EAC), and the MiniView...

In this article, we propose video delivery schemes insuring around 1s delivery latency with Dynamic Adaptive Streaming over HTTP (DASH), which is a standard version of HTTP Live Streaming (HLS), so as to benefit from the video representation switching between successive video segments. We also propose HTTP/2-based algorithms to apply video frame di...

Congestion is one of the most critical issues im- pacting the performance of Internet networks, hence the need of Congestion Control Algorithms (CCAs) to either prevent or remove it. Nevertheless, CCAs may affect the network fairness given that the transport behavior can drastically change in func- tion of the CCA (e.g., Performance-oriented Conges...

While I was attending the MMSys conference (last June in Amsterdam), I tweeted about my personal highlights of the conference, in the hope to share with those who did not have the opportunity to attend the conference. Fortunately, I have been chosen as "Best Social Media Reporter" of the conference, a new award given by ACM SIGMM chapter to promote...

Downlink data rates can vary significantly in cellular networks, with a potentially non-negligible effect on the user experience. Content providers address this problem by using different representations (e.g., picture resolution, video resolution and rate) of the same content and switch among these based on measurements collected during the connec...

This column discusses the efforts of ACM SIGMM towards sharing and reproducibility. Apart from the specific sessions dedicated to open source and datasets, ACM Multimedia Systems started to provide official ACM badges for articles that make artifacts available since last year. This year, it has marked a record with 45% of the articles acquiring suc...

While cloud servers provide a tremendous amount of resources for networked video applications, most successful stories of cloud-assisted video applications are presentational video services, such as YouTube and NetFlix. This article surveys the recent advances on delay-sensitive video computations in the cloud, which are crucial to cloud-assisted c...

In order to track the users who illegally re-stream live video streams, one solution is to embed identified watermark sequences in the video segments to distinguish the users. However, since all types of watermarked segments should be prepared, the existing solutions require an extra cost of bandwidth for delivery (at least multiplying by two the r...

Full immersion inside a Virtual Reality (VR) scene requires six Degrees of Freedom (6DoF) applications where the user is allowed to perform translational and rotational movements within the virtual space. The implementation of 6DoF applications is however still an open question. In this paper we study a multi-viewpoint (MVP) 360-degree video stream...

The growing popularity of virtual and augmented reality communications and 360{\deg} video streaming is moving video communication systems into much more dynamic and resource-limited operating settings. The enormous data volume of 360{\deg} videos requires an efficient use of network bandwidth to maintain the desired quality of experience for the e...

With the development of network function virtualization and software-defined network standards, the mobile network operators are interested in integrating content delivery network (CDN) functionalities into the mobile network to enhance their capability for supporting content oriented services. We consider a mobile CDN system, where Base Stations (...

We present a multi-level multi-overlay hybrid peer-to-peer live video system that enables players of Massively Multiplayer Online Games to simultaneously stream the video of their game and watch the game videos of other players. Each live video bitstream is encoded with rateless codes and multiple trees are used to transmit the encoded symbols. Tre...

With the decreasing price of Head-Mounted Displays (HMDs), 360-degree videos are becoming popular. The streaming of such videos through the Internet with state of the art streaming architectures requires, to provide high immersion feeling, much more bandwidth than the median user's access bandwidth. To decrease the need for bandwidth consumption wh...

Mobile gaming is an emerging concept wherein gamers are using mobile devices, like smartphones and tablets, to play best-seller games. Compared to dedicated gaming boxes or PCs, these devices still fall short of executing newly complex 3D video games with a rich immersion. Three novel solutions, relying on cloud computing infrastructure, namely, co...

Software Defined Networking (SDN) and Network Function Virtualization (NFV) have emerged as a promising solution for elastic, dynamic and scalable network management. A collection of works have investigated how virtualization and cloud technology can ameliorate the infrastructure management for the 5G mobile network. However, employing these techni...

While Virtual Reality applications are increasingly attracting the attention of developers and business analysts, the behaviour of users watching 360-degree (i.e. omnidirectional) videos has not been thoroughly studied yet. This paper introduces a dataset of head movements of users watching 360-degree videos on a Head-Mounted Display (HMD). The dat...

To address the problem of illegal re-streaming of video streams, existing solutions are based on watermarking the legal video to track the leak users who re-stream the stream on illegal platform. However, these solutions do not aim at tracking leaks as fast as possible, nor are adaptive to the number of users. We present a CDN-based adaptive delive...

The delivery and display of 360-degree videos on Head-Mounted Displays (HMDs) presents many technical challenges. 360-degree videos are ultra high resolution spherical videos, which contain an omnidirectional view of the scene. However only a portion of this scene is displayed on the HMD. Moreover, HMD need to respond in 10 ms to head movements, wh...

HTTP Adaptive Streaming is a successful and largely adopted content delivery technology. Yet poor bandwidth prediction, notably in mobile networks, may cause bit-rate oscillations, increased segment delivery delays, video freezes, and may thus negatively impact the end user quality of experience. To address this issue, we propose to exploit the str...

Content delivery networks (CDNs) have become key telecommunication actors. They contribute to improve significantly the quality of services delivering content to end users. However, their impact on the ecosystem raises concerns about their “fairness,” and therefore the question of their inclusion in the neutrality debates, becomes relevant. This pa...

The delivery and display of ultra high resolution 360-degree videos on Head-Mounted Displays (HMDs) presents a number of technical challenges. 360-degree videos are high resolution spherical videos that contain an omnidirectional view of the scene, however only a portion of this scene is displayed at any time on the user's HMD. The delivery of such...

Transport protocols that can exploit multiple paths, especially MPTCP, do not match the requirements of video streaming: high average transmission delay, too strict reliability, and frequent head-of-line phenomenons resulting in abrupt throughput drops. In this paper, we address this mismatch by introducing a cross-layer scheduler, which leverages...

Recent trends on how video games are played have pushed for the need to revise the game engine architecture. Indeed, game players are more mobile, using smartphones and tablets that lack CPU resources compared to PC and dedicated box. Two emerging solutions, cloud gaming and computing offload, would represent the next steps toward improving game pl...

In this letter, we describe research activities on the global management of a live video streaming service running in the cloud. We focus on the coordination of these technologies and we show that a management policy that takes into account all the inter-dependencies among technologies can bring significant advantages. In particular, we address the...

Si la question de développer des MOOC a beaucoup intéressé la communauté ces derniers mois, l'intégration de MOOC dans un programme de formation est également importante et porteuse d'évolutions. Nous présentons ici différentes modalités mises en place pour proposer des cours intégrant des MOOC dans un cursus de formation. Mots-clés Innovation péda...

Rate-adaptive streaming technologies, such as the Dynamic Adaptive Streaming over HTTP (DASH) standard, provides an efficient and easy solution to stream multimedia in a heterogenous context. However, it reinforces the streaming capacity problem in the core Content Delivery Network (CDN) infrastructure since delivering one video means delivering an...

In less than 10 years, services over Internet have switched from static Web pages to interactive multimedia applications. To deal with the demand for more interactivity and more multimedia content, service providers have been forced to upgrade their infrastructure to offer their service. This chapter focuses on the service providers that offer mass...

User-Generated live video streaming systems are services that allow anybody to broadcast a video stream over the Internet. These Over-The-Top services have recently gained popularity, in particular with e-sport, and can now be seen as competitors of the traditional cable TV. In this paper, we present a dataset for further works on these systems. Th...

More and more users are watching online videos produced by non-professional sources (e.g., gamers, teachers of online courses, witnesses of public events) by using an increasingly diverse set of devices to access the videos (e.g., smartphones, tablets, HDTV). Live streaming service providers can combine adaptive streaming technologies and cloud com...

This paper identifies and analyzes the key design approaches that have been proposed over the last decade to construct a peer-to-peer (P2P) networked virtual environment (NVE) systems. We discuss each approach, their advantages and drawbacks, and examine several representative P2P-based NVE systems based on the presented approaches, thus providing...

Network neutrality has been topic of discussion for the past 25 years, with current legislation/ regulation in the United States and Europe targeting the ISPs or “common carriers.” But the reality of the Internet in the 2010s is that various actors contribute to the delivery of data, with sometimes contradictory objectives. In this article, we high...

The delivery of live video channels for services such as twitch.tv leverages the so-called Telco-CDN -Content Delivery Network (CDN) deployed within the Internet Service Provider (ISP) domain. A Telco-CDN can be regarded as an intra-domain overlay network with tight resources and critical deployment constraints. This paper addresses two problems in...

Adaptive streaming addresses the increasing and heterogeneous demand of multimedia content over the Internet by offering several encoded versions for each video sequence. Each version (or representation) is characterized by a resolution and a bit rate, and it is aimed at a specific set of users, like TV or mobile phone clients. While most existing...

Live game streaming platforms such as Twitch allow gamers to broadcast their gameplay over the Internet. The popularity of these platforms boosts the market of eSport but poses new delivery problems. In this paper, we focus on the implementation of adaptive bitrate streaming in massive live game streaming platforms. Based on three months of real da...

The growing importance of Content Delivery Network (CDN) in the value chain of content delivery raises concerns about the 'neutrality' of these players. We propose in this paper a model to analyze the impact of revenue-oriented CDN management policies on the fairness of the competition among two content providers that use CDN services to deliver co...

The cloud was originally designed to provide general-purpose computing using commodity hardware and its focus was on increasing resource consolidation as a means to lower cost. Hence, it was not particularly adapted to the requirements of multimedia applications that are highly latency sensitive and require specialized hardware, such as graphical p...

Adaptive streaming addresses the increasing and heterogenous demand of multimedia content over the Internet by offering several encoded versions for each video sequence. Each version (or representation) has a different resolution and bit rate, aimed at a specific set of users, like TV or mobile phone clients. While most existing works on adaptive s...

The growth of Internet video traffic imposes a severe capacity problem in today's Content Delivery Network (CDN). Rate-adaptive streaming technologies, such as the Dynamic Adaptive Streaming over HTTP (DASH) standard, reinforces this problem in the core CDN infrastructure since delivering one video means delivering multiple representations for an a...

The growth of Internet video traffic imposes a severe capacity problem in today's Content Delivery Network (CDN). Rate-adaptive streaming technologies, such as the Dynamic Adaptive Streaming over HTTP (DASH) standard, reinforces this problem in the core CDN infrastructure since delivering one video means delivering multiple representations for an a...

To deal with the explosion of mobile traffic, network operators deploy heterogeneous networks (HetNet), a combination of macro and pico eNodeBs. In this paper, we propose an optimization framework for the study of the optimal performances of HetNet on the uplink. We focus on video traffic because technologies like WebRTC allow mobile users to uploa...

Adaptive streaming addresses the increasing and heterogenous demand of multimedia content over the Internet by offering several streams for each video. Each stream has a different resolution and bit rate, aimed at a specific set of users, e.g., TV, mobile phone. While most existing works on adaptive streaming deal with optimal playout-control strat...

Recent work on Information Centric Networking enables the exploitation of the caching resources of the new generation of routers [Content Routers (CR)]. So far, only a basic Least Recently Used strategy implemented on every CR has been proposed. In this paper, we introduce a cooperative caching strategy in the context of a Content-Centric-Network (...

The on-demand connectivity service is one of the main requirements of the cellular data network. It consists in moving sessions transparently and temporarily from one network equipment to another without causing user session interruption. This service enables networks to cope with the ever-changing network condition such as sudden congestion or arb...

Edit paper A Peer-to-Peer (P2P) network is decentralised and relies on end-users capacities for a good delivery of service. The more end-users are sharing the content, the more powerful the system is. P2P applications are now widely used for many services. But P2P systems are still based on a end-to-end connectivity on the current IP-based Internet...

The Internet architecture, based on end-to-end connections, had difficulties to efficiently deliver the always increasing number of contents. Content Delivery Networks (CDN) have been deployed to improve the delivery. Recent research works propose a new networking architecture, much more adapted to the current Internet usage (end-users just care ab...

A Telco-CDN can be regarded as an intra-domain overlay network with tight resources and critical deployment constraints. This paper addresses two problems in this context: (1) the construction of the overlays used to deliver the video channels from the entrypoints of the Telco-CDN to the appropriate edge servers; and (2) the allocation of the requi...

The exploding HD video streaming traffic calls for deploying content servers deeper inside network operators' infrastructures. Telco-CDN are new content distribution services that are managed by Internet Service Providers (ISP). Since the network operator controls both the infrastructure and the content delivery overlay, it is in a position to engi...

Virtualizing data center networks has been considered a feasible alternative to satisfy the requirements of advanced cloud services. Proper mapping of virtual data center (VDC) resources to their physical counterparts, also known as virtual data center embedding, can impact the revenue of cloud providers. Similar to virtual networks, the problem of...

Cloud computing promises to provide computing resources to a large number of service applications in an on demand manner. Traditionally, cloud providers such as Amazon only provide guaranteed allocation for compute and storage resources, and fail to support bandwidth requirements and performance isolation among these applications. To address this l...

Content Delivery Networks (CDNs) are confronted with a sharp increase in traffic related to live video (channel) streaming. Previous theoretical models that deal with streaming capacity problems do not capture the emerging reality faced by today's CDNs. In particular, a modern CDN has to deliver a large set of independent non-divisible data streams...