Publications

First demonstration of service-differentiated converged optical sub-wavelength and LTE/WiFi networks over GEANT

Authors: Bijan Rahimzadeh Rofoee, Kostas Katsalis, Anna Tzanakaki, Yan Yan, Georgios Zervas, Yi Shu, Thanasis Korakis, Dimitra Simeonidou, Leandros Tassiulas

Download paper: LTE/WiFi-networks-over-GEANT

Bits and Coins: Supporting Collaborative Consumption of Mobile Internet

Authors: Dimitris Syrivelis, George Iosifidis, Dimosthenis Delimbasis, Kostas Chounos, Thanasis Korakis and Leandros Tassiulas

Conference:  IEEE Infocom 2015, Hong Kong, 26 April - 01 May 2015

Abstract: The recent mobile data explosion has increased the interest for mobile user-provided networks (MUPNs), where users share their Internet access by exploiting the diversity in their needs and resource availability. Although promising, MUPNs raise unique challenges. Namely, the success of such services relies on user participation which in turn can be achieved on the basis of a fair and efficient resource (i.e., Internet access and battery energy) exchange policy. The latter should be devised and imposed in a very fast time scale, based on near real-time feedback from mobile users regarding their needs, resources, and network conditions that are rapidly changing. To address these challenges we design and implement a novel cloud-controlled MUPN system, that employs software defined networking support on mobile terminals, to dynamically apply data forwarding policies with adaptive flow-control. We devise these policies by solving a coalitional game that is played among the users. We prove that the game has a non-empty core and hence the solution, which determines the servicing policy, incentivizes the users to participate. Finally, we evaluate the performance of the service in a prototype, where we investigate its performance limits, quantify the implementation overheads, and justify our architecture design choices.

Download paper: Bits and coins: Supporting collaborative consumption of mobile internet

Enabling SDN Experimentation with Wired and Wireless Resources: The SmartFIRE facility

Authors: Kostas Choumas, Thanasis Korakis, Hyunwoo Lee, Donghyun Kim, Junho Suh, Ted “Taekyoung” Kwon, Pedro Martinez-Julia, Antonio Skarmeta, Taewan You, Loic Baron, Serge Fdida and JongWon Kim

Conference: EAI CloudComp 2015, Daejeon, South Korea, 28-29 October 2015

Abstract: Over the last few years, several experimentation platforms have been deployed around the world, providing to the computer science research community a way to remotely perform and control networking experiments. Most of the platforms, called testbeds, offer experimentation as a service. However, each testbed is specialized in a specific technology: wired, wireless or cloud. The challenge for experimenters is thus to combine different technologies in order to tackle the research questions they address. Therefore a federation framework has been developed thanks to several projects, including SmartFIRE. SmartFIRE is an intercontinental federation of SDN, wireless and cloud testbeds, aiming at providing experimentation services with resources from these various networking fields. This federation framework enables easy experimentation with the heterogeneous resources that the individual testbeds provide. In this article, we present our contributions towards the extension of the state-of-the-art control and management framework, in order to orchestrate the federated SmartFIRE facility. As a proof of concept, we demonstrate several use cases that take advantage of our contributions, providing the availability of experimentation on novel architectures.

Download paper: Enabling SDN Experimentation with Wired and Wireless Resources: The SmartFIRE facility

Distributed Load Shedding with Minimum Energy

Authors: Kostas Choumas, Giorgos S. Paschos, Thanasis Korakis and Leandros Tassiulas

Conference: IEEE INFOCOM 2016, San Francisco, CA, USA, 10 - 15 April 2016

Abstract: This paper proposes distributed load shedding policies for regulating excessive network load. Data packets are inserted into the network to be delivered to intended destinations. The intermediate network nodes may decide to forward or shed some packets depending on temporally available resources. It is possible for some packets to traverse several nodes in the network until they are finally dropped before reaching the destination, which exacerbates energy consumption. We define a multi-objective optimization problem where we aim to minimize the used energy subject to providing maximum sum throughput. For the case of single-path unicast sessions, we show that Energyefficient Distributed Load Shedding (E-DLS), a simple shedding mechanism combined with pushback routing, solves this load shedding optimization. We implement E-DLS in a testbed and use the experiments to select policy parameter values that strike a good balance between energy and delay performance. We then propose a heuristic extension of E-DLS for multirate multicast routing, and showcase via testbed experiments its optimal performance.

Download paper: kohoumas_infocom_2016_edls.pdf