In a noteworthy presence at the 16th IEEE/ACM International Conference on Utility and Cloud Computing (UCC 2023), Dragi Kimovski and Narges Mehran presented three workshop papers:

  1. Marcus Reitzl and Dragi Kimovski, “Multi-Objective Optimisation of Container Orchestration Systems”,
  2. Narges Mehran, Dragi Kimovski, Hermann Hellwagner, Dumitru Roman, Ahmet Soylu, and Radu Prodan, “Scheduling on the Computing Continuum: A Survey “,
  3. Narges Mehran, Arman Haghighi, Pedram Aminharati, Nikolay Nikolov, Ahmet Soylu, Dimitru Roman and Radu Prodan, “Comparison of Microservice Call Rate Prediction for Replication in the Cloud”. 

 Additionally, Dragi Kimovski took on the role of a session chair, leading discussions on the intricacies of scheduling in the computing continuum. 

Ran from December 15 to 17, 2023

With 165 registered participants and 35 games submitted, this was the largest game jam hosted in Klagenfurt to date!
A warm thank you to everyone who participated and/or helped – this event was a big success.

Same as every semester, students, teachers, alumni, and externals all worked together, formed teams, and made various games within 48 hours. We also had many international online participants joining us, e.g. from the Netherlands or even from Brazil.
This time, the topic was “Caution Fragile”, which was interpreted in different ways – from detective stories, board games and, pen-and-paper games, VR games, to classical arcade video games, the results were more varied than ever!

Please feel free to check out all the games here:

A final shoutout to Dynatrace, Plincs, Sensolligent, Fire Totem Games, Dirty Paws Studio, the FTF and the University for making this possible!

Our paper has been accepted at ICASSP 2024:

Mohammad Ghasempour (AAU, Austria), Hadi Amirpour (AAU, Austria), Mohammad Ghanbari (University of Essex, UK), and Christian Timmerer (AAU, Austria)

Abstract: With the ubiquity of video streaming, optimizing the delivery of video content while reducing energy consumption has become increasingly critical. Traditional adaptive streaming relies on a fixed set of bitrate-resolution pairs, known as bitrate ladders, for encoding. However, this one-size-fits-all approach is suboptimal for diverse video content. As a result, per-title encoding approaches dynamically select the bitrate ladder for each content. In this paper, we address the pressing issue of increasing energy consumption in video streaming by introducing GreenRes, a novel approach that goes beyond traditional quality-centric resolution selection. Instead, GreenRes considers both video quality and energy consumption to construct an optimal bitrate ladder tailored to the unique characteristics of each video content.
To achieve this, GreenRes, similar to per-title encoding, encodes each video content at various resolutions, each with a set of bitrates. It then establishes a maximum acceptable quality drop threshold and selects resolutions that not only maintain video quality above this threshold, but also minimize energy consumption. Our experimental results demonstrate a 30.82% reduction in energy consumption on average, while ensuring a maximum quality drop of 0.53 Video Multimethod Assessment Fusion (VMAF) points.

Funded by the EU, HiPEAC (High-Performance Edge And Cloud computing) is the premier focal point for networking, dissemination, training, and collaboration activities in Europe for researchers, industry, and policy related to computing systems.

The HiPEAC webinar series allows you to keep up to date on the latest advances in computer architecture and compilation research via online sessions, which can be accessed anywhere.

The Graph-Massivizer Project webinar took place on November 29, 2023. After an introduction by Nuria De LamaRadu Prodan presented the background of GraphProcessing, from Euler‘s five-node graphs to the massive graphs of today, and the motivations for the project.

 Project details have been presented by Reza Farahani and Matteo Angelinelli.

WEBINAR is online now:



At Christian Doppler Laboratory ATHENA, we offer an internship*)**) for 2024 for Master Students, and we kindly request your applications by the 19th of January 2024 with the following data (in German or English):

  • CV
  • Record of study/transcript (“Studienerfolgsnachweis”)

*) A 3 months period in 2024 (with an exact time slot to be discussed) with the possibility to spend up to 1-month at the industrial partner; 20h per week “Universitäts-KV, Verwendungsgruppe C1, studentische Hilfskraft”
**) Depending on whether the funding gets approval from the CDG.

Please send your application by email to

About ATHENA: The Christian Doppler laboratory ATHENA (AdapTive Streaming over HTTP and Emerging Networked MultimediA Services) is jointly proposed by the Institute of Information Technology (ITEC; at Alpen-Adria-Universität Klagenfurt (AAU) and Bitmovin GmbH ( to address current and future research and deployment challenges of HAS and emerging streaming methods. AAU (ITEC) has been working on adaptive video streaming for more than a decade, has a proven record of successful research projects and publications in the field, and has been actively contributing to MPEG standardization for many years, including MPEG-DASH; Bitmovin is a video streaming software company founded by ITEC researchers in 2013 and has developed highly successful, global R&D and sales activities and a world-wide customer base since then.

The aim of ATHENA is to research and develop novel paradigms, approaches, (prototype) tools, and evaluation results for the phases

  1. multimedia content provisioning,
  2. content delivery, and
  3. content consumption in the media delivery chain as well as for
  4. end-to-end aspects, with a focus on, but not being limited to, HTTP Adaptive Streaming (HAS).

The new approaches and insights are to enable Bitmovin to build innovative applications and services to account for the steadily increasing and changing multimedia traffic on the Internet.


Radu Prodan/ITEC will organise the CERCIRAS Training School (on behalf of COST Action CA19135) from August 26 – 30, 2024 at the University of Klagenfurt. Details and programs will be available soon.

With the current popularity of ECO in the Asia–Pacific (APAC), the Bitmovin team in APAC, led by Adrian Britton, expressed an interest in the energy-aware research initiatives conducted within the GAIA project in Austria. Following an introductory meeting between the APAC team and AAU on October 17, 2023, both teams decided to meet in person on November 21, 2023, to explore the topics further.

The meeting proved to be highly productive, centering around two recent research topics:

– VE-Match: Video Encoding Matching-Based Model in the Cloud and Edge (presented by Samira Afzal & Narges Mehran)

– Energy-aware Spatial and Temporal Resolution Selection for Per-Title (presented by Mohammad Ghasempour & Hadi Amirpour)

Many interesting Q&As appeared during each presentation due to customer and provider requirements and the future insight of climate-friendly video streaming in the Cloud and Edge. The fruitful discussions opened up avenues for future exploration in this dynamic field.

On the 18th of November, 2023, Sebastian held a talk about his game development story, Fire Totem Games, A Webbing Journey, and the Austrian game development scene at the first Austrian Game Dev Night in Warsaw.

Benjamin Hanussek, a Game Studies and Engineering alumni, initialized the idea for the event. Frederic Schulte organized it from the Austrian Cultural Forum Warsaw and the PJAIT Game Lab, which Benjamin leads.

The event took place in the Austrian Cultural Forum in Warsaw, and visitors were able to play A Webbing Journey and Primal Fray, a game developed by Tymoteusz Pietruszka, a Polish game developer, during the day. In the evening, Sebastian held his talk, followed by a Q&A session and ended with many valuable new connections to the Polish game development scene. The event was a big success and laid the foundation for future Austrian Game Dev Nights.



We’re excited to share that the ACM Special Interest Group in Multimedia (SIGMM) presents to

Stefan Lederer, Christopher Müller, and Christian Timmerer

The SIGMM Test of Time Paper Honorable Mention in the category of “MM Systems & Networking”

for their paper “Dynamic Adaptive Streaming over HTTP Dataset”. In Proceedings of the 3rd Multimedia Systems Conference, MMSys ’12, page 89–94, New York, NY, USA, 2012. ACM. doi:10.1145/2155555.2155570

IEEE Transactions on Network and Service Management

Authors: Reza Farahani, Ekrem Cetinkaya, Christian Timmerer, Mohammad Shojafar, Mohammad Ghanbari, and Hermann Hellwagner

Abstract: Recent years have witnessed video streaming demands evolve into one of the most popular Internet applications. With the ever-increasing personalized demands for high-definition and low-latency video streaming services, network-assisted video streaming schemes employing modern networking paradigms have become a promising complementary solution in the HTTP Adaptive Streaming (HAS) context. The emergence of such techniques addresses long-standing challenges of enhancing users’ Quality of Experience (QoE), end-to-end (E2E) latency, as well as network utilization. However, designing a cost-effective, scalable, and flexible network-assisted video streaming architecture that supports the aforementioned requirements for live streaming services is still an open challenge. This article leverage novel networking paradigms, i.e., edge computing and Network Function Virtualization (NFV), and promising video solutions, i.e., HAS, Video Super-Resolution (SR), and Distributed Video Transcoding (TR), to introduce A Latency- and cost-aware hybrId P2P-CDN framework for liVe video strEaming (ALIVE). We first introduce the ALIVE multi-layer architecture and design an action tree that considers all feasible resources (i.e., storage, computation, and bandwidth) provided by peers, edge, and CDN servers for serving peer requests with acceptable latency and quality. We then formulate the problem as a Mixed Integer Linear Programming (MILP) optimization model executed at the edge of the network. To alleviate the optimization model’s high time complexity, we propose a lightweight heuristic, namely, Greedy-Based Algorithm (GBA). Finally, we (i) design and instantiate a large-scale cloud-based testbed including 350 HAS players, (ii) deploy ALIVE on it, and (iii) conduct a series of experiments to evaluate the performance of ALIVE in various scenarios. Experimental results indicate that ALIVE (i) improves the users’ QoE by at least 22%, (ii) decreases incurred cost of the streaming service provider by at least 34%, (iii) shortens clients’ serving latency by at least 40%, (iv) enhances edge server energy consumption by at least 31%, and (v) reduces backhaul bandwidth usage by at least 24% compared to baseline approaches.

Keywords: HTTP Adaptive Streaming (HAS); Edge Com- puting; Network Function Virtualization (NFV); Content Deliv- ery Network (CDN); Peer-to-Peer (P2P); Quality of Experience (QoE); Video Transcoding; Video Super-Resolution.