Selected papers

Over The Top (OTT) content management

Mugen Peng, Senior Member, IEEE, Shi Yan, Kecheng Zhang, and Chonggang Wang › Fog Computing based Radio Access Networks: Issues and Challenges
A fog computing based radio access network (F-RAN) is presented in this article as a promising paradigm for the fifth generation (5G) wireless communication system to provide high spectral and energy efficiency. The core idea is to take full advantages of local radio signal processing, cooperative radio resource management, and distributed storing capabilities in edge devices, which can decrease the heavy burden on fronthaul and avoid large-scale radio signal processing in the centralized baseband unit pool. This article comprehensively presents the system architecture and key techniques of F-RANs. In particular, key techniques and their corresponding solutions, including transmission mode selection and interference suppression, are discussed. Open issues in terms of edge caching, software-defined networking, and network function virtualization, are also identified. Read More ›

D'Ambrosio, Matteo, et al › MDHT: a hierarchical name resolution service for information-centric networks
Information-centric network architectures are an increasingly important approach for future Internet architectures. Several approaches are based on a non-hierarchical identifier (ID) namespace that requires some kind of global Name Resolution Service (NRS) to translate the object IDs into network addresses. Building a world-wide NRS for such a namespace with 1015 expected IDs is challenging because of requirements such as low latency, efficient network utilization, and anycast routing. In this paper, we present an NRS called Multi-level Distributed Hash Table (MDHT). It provides name-based anycast routing, can support constant hop resolution, and fulfills the afore mentioned requirements. A scalability assessment shows that our system can scale to the Internet level, managing 1015 objects with today's storage technology and 1/10th of today's DNS nodes. The evaluation indicates that a non-hierarchical namespace can be adopted on a global scale, opening up several design alternatives for information-centric network architectures. Read More ›

Saucez, Damien, Chadi Barakat, and Thierry Turletti › Over the top video: the gorilla in cellular networks
Cellular networks have witnessed tremendous traffic growth recently, fueled by smartphones, tablets and new high speed broadband cellular access technologies. A key application driving that growth is video streaming. Yet very little is known about the characteristics of this traffic class. In this paper, we examine video traffic generated by three million users across one of the world's largest 3G cellular networks. This first deep dive into cellular video streaming shows that HLS, an adaptive bitrate streaming protocol, accounts for one third of the streaming video traffic and that it is common to see changes in encoding bitrates within a session. We also observe that most of the content is streamed at less than 255 Kbps and that only 40% of the videos are fully downloaded. Another key finding is that there exists significant potential for caching to deliver this content. Read More ›

Saucez, Damien, Chadi Barakat, and Thierry Turletti › Leveraging Information Centric Networking in Over-The-Top Services
The ubiquity of broadband Internet and the proliferation of connected devices like laptops, tablets or TV result in a high demand of multimedia content such as high definition video on demand (VOD) for which the Internet has been poorly designed with the Internet Protocol (IP). Information-Centric Networking and more precisely Content Centric Networking (CCN) overtake the limitation of IP by considering content as the essential element of the network instead of the topology. CCN and its content caching capabilities is particularly adapted to Over-The-Top (OTT) services like YouTube or Netflix that distribute high-definition multimedia content to millions of consumers, independently of their location. However, bringing content as the most important component of the network implies fundamental changes in the Internet and the transition to a fully CCN Internet might take a long time. Despite this transition period where CCN and IP will co-exist, we show that OTT service providers and consumers have strong incentives for migrating to CCN. We also propose a transition mechanism that leverages caching and enable loosely collaboration. Read More ›

Liu, Xi, et al › A case for a coordinated internet video control plane
Video traffic already represents a significant fraction of today's traffic and is projected to exceed 90% in the next five years. In parallel, user expectations for a high quality viewing experience (e.g., low startup delays, low buffering, and high bitrates) are continuously increasing. Unlike traditional workloads that either require low latency (e.g., short web transfers) or high average throughput (e.g., large file transfers), a high quality video viewing experience requires sustained performance over extended periods of time (e.g., tens of minutes). This imposes fundamentally different demands on content delivery infrastructures than those envisioned for traditional traffic patterns. Our large-scale measurements over 200 million video sessions show that today's delivery infrastructure fails to meet these requirements: more than 20% of sessions have a rebuffering ratio ≥ 10% and more than 14% of sessions have a video startup delay ≥ 10s. Using measurement-driven insights, we make a case for a video control plane that can use a global view of client and network conditions to dynamically optimize the video delivery in order to provide a high quality viewing experience despite an unreliable delivery infrastructure. Our analysis shows that such a control plane can potentially improve the rebuffering ratio by up to 2× in the average case and by more than one order of magnitude under stress. Read More ›

Ibrahim, Ghida, et al › Toward a new Telco role in future content distribution services
In the recent years the following two trends have been accelerated: on the one hand, as Content Services became at the center of Internet usages, OTTs strengthen their position. On the other hand, in several cases, Telcos are seeing their role shrinking to “dumb pipes” providers. This paper introduces advanced Telcos' positioning in future content distribution services. In particular, it focuses on the “value” that Telcos can bring to CDN providers and Content providers and analyses the required evolutions of the involved systems' architectures (network and content delivery). Value is assessed with respect to both users' trends and content ecosystem evolution. We show that existing Telcos' assets could indeed be leveraged to make the proposed move, bringing to Telcos a major differentiator in this arena. For that, an open and efficient control infrastructure is necessary, the paper presents the core required functionalities and architectural framework, as well as related challenges. Read More ›

Bouten, Niels, et al › A multicast-enabled delivery framework for QoE assurance of over-the-top services in multimedia access networks
Over-The-Top (OTT) video services are becoming more and more important in today’s broadband access networks. While original OTT services only offered short duration medium quality videos, more recently, premium content such as high definition full feature movies and live video are offered as well. For operators, who see the potential in providing Quality of Experience (QoE) assurance for an increased revenue, this introduces important new network management challenges. Traditional network management paradigms are often not suited for ensuring QoE guarantees as the provider does not have any control on the content’s origin. In this article, we focus on the management of an OTT-based video service. We present a loosely coupled architecture that can be seamlessly integrated into an existing OTT-based video delivery architecture. The framework has the goal of resolving the network bottleneck that might occur from high peaks in the requests for OTT video services. The proposed approach groups the existing Hypertext Transfer Protocol (HTTP) based video connections to be multicasted over an access network’s bottleneck and then splits them again to reconstruct the original HTTP connections. A prototype of this architecture is presented, which includes the caching of videos and incorporates retransmission schemes to ensure robust transmission. Furthermore, an autonomic algorithm is presented that allows to intelligently select which OTT videos need to be multicasted by making a remote assessment of the cache state to predict the future availability of content. The approach was evaluated through both simulation and large scale emulation and shows a significant gain in scalability of the prototype compared to a traditional video delivery architecture. Read More ›

Seppanen, J., and Martín Varela › QoE-driven network management for real-time over-the-top multimedia services
This paper introduces a network access point (AP) control solution in the context of over-the-top (OTT) multimedia services. The solution is designed to provide network-level management mechanisms for packet traffic while using Quality of Experience (QoE) as a performance indicator. The results showed that with customer subscription scheme, traffic differentiation and QoE-driven management it is possible to both improve the perceived quality of multimedia traffic and increase the average revenue per user. Read More ›

Nam, Hyunwoo, et al › Towards A Dynamic QoS-aware Over-The-Top Video Streaming in LTE
We present a study of traffic behavior of two popular over-the-top (OTT) video streaming services (YouTube and Netflix). Our analysis is conducted on different mobile devices (iOS and Android) over various wireless networks (Wi-Fi, 3G and LTE) under dynamic network conditions. Our measurements show that the video players frequently discard a large amount of video content although it is successfully delivered to a client. We first investigate the root cause of this unwanted behavior. Then, we propose a Quality-of-Service (QoS)-aware video streaming architecture in Long Term Evolution (LTE) networks to reduce the waste of network resource and improve user experience. The architecture includes a selective packet discarding mechanism, which can be placed in packet data network gateways (P-GW). In addition, our QoS-aware rules assist video players in selecting an appropriate resolution under a fluctuating channel condition. We monitor network condition and configure QoS parameters to control availability of the maximum bandwidth in real time. In our experimental setup, the proposed platform shows up to 20.58% improvement in saving downlink bandwidth and improves user experience by reducing buffer underflow period to an average of 32 seconds. Read More ›