All you can stream: Investigating the role of user behavior for greenhouse gas intensity of video streaming

The information and communication technology sector reportedly has a relevant impact on the environment. Within this sector, video streaming has been identified as a major driver of CO2-emissions. To make streaming more sustainable, environmentally relevant factors must be identified on both the user and the provider side. Hence, environmental assessments, like life cycle assessments (LCA), need to broaden their perspective from a mere technological to one that includes user decisions and behavior. However, quantitative data on user behavior (e.g. streaming duration, choice of end device and resolution) are often lacking or difficult to integrate in LCA. Additionally, identifying relevant determinants of user behavior, such as the design of streaming platforms or user motivations, may help to design streaming services that keep environmental impact at a passable level. In order to carry out assessments in such a way, interdisciplinary collaboration is necessary. Therefore, this exploratory study combined LCA with an online survey (N= 91, 7 consecutive days of assessment). Based on this dataset the use phase of online video streaming was modeled. Additionally, factors such as sociodemographic, motivational and contextual determinants were measured. Results show that CO2-intensity of video streaming depends on several factors. It is shown that for climate intensity there is a factor 10 between choosing a smart TV and smartphone for video streaming. Furthermore, results show that some factors can be tackled from provider side to reduce overall energy demand at the user side; one of which is setting a low resolution as default.Comment: 7th International Conference on ICT for Sustainability (ICT4S

Energy-efficient management and control in video distribution networks: "legacy" hardware based solutions and perspectives of virtualized networking environments

The chapter focuses in particular on energy-efficiency issues in the context of video distribution networks (VDNs), where additional paradigms, as content delivery and caching operations, play a relevant role. We first provide a short review on the current state and on energy-related aspects in VDNs; then, we focus on Local Control Policies / Network Control Policies in this context, and the possible role of the Green Abstraction Layer (GAL), a recent ETSI standard, to provide an abstract interface to convey energy efficiency related parameters to the management and control entities. In doing this, we consider both \u2018traditional\u2019 networking architectures based on specialized hardware, and the evolution towards virtualized infrastructures, where the GAL can still play a significant role, if suitably adapted to the specific environment

Decentralized self-adaptive computing at the edge

Nowadays, computing infrastructures are usually deployed in fully controlled environments and managed in a centralized fashion. Leveraging on centralized infrastructures prevent the system to deal with scalability and performance issues, which are inherent to modern large-scale data-intensive applications. On the other hand, we envision fully decentralized computing infrastructures deployed at the edge of the network providing the required support for operating data-intensive systems. However, engineering such systems raises many challenges, as decentralization introduces uncertainty, which in turn may harm the dependability of the system. To this end, self-adaptation is a key approach to manage uncertainties at runtime and satisfy the requirements of decentralized data-intensive systems. This paper shows the research directions and current contributions towards this vision by (i) evaluating the impact of the distribution of computational entities, (ii) engineering decentralized computing through self-adaptation and, (iii) evaluating decentralized and self-adaptive applications.</p