Publications

Demonstration of a Video-aware Multicast Opportunistic Routing protocol over 802.11 two-hop mesh networks

Authors: Ilias Syrigos, Kostas Choumas, Thanasis Korakis and Leandros Tassiulas

Conference:  IEEE SECON 2014, Singapore, Singapore, July 2014

Abstract: In this demo paper, we demonstrate and evaluate a novel Opportunistic Routing (OR) protocol for video multicast, namely Video-aware Multicast Opportunistic Routing (ViMOR), over 802.11 two-hop mesh networks. OR exploits the broadcast nature of the wireless medium and offers spatial diversity among the receivers. ViMOR extends MORE, a state of the art OR algorithm, by orchestrating packet transmissions and prioritizing video traffic, in order to conform with video streaming requirements. For the demonstration and evaluation of the proposed scheme, we proceeded with the development of the implementation on NITOS wireless testbed. Results showed a significant increase in average video-perception quality, compared to MORE protocol.

Download paper: Syrigos_SECON_2014

Enabling AGILE Spectrum Adaptation in Commercial 802.11 WLAN Deployments

Authors: Stratos Keranidis, Kostas Chounos, Thanasis Korakis, Iordanis Koutsopoulos, Leandros Tassiulas

Conference:  ACM Mobicom 2014, Maui, Hawaii, USA, September 7, 2014

Abstract: In this work, we present the AGILE Spectrum Adaptation system that is able to dynamically tune the channel central frequency and bandwidth of wireless links in an adaptive to the interference and traffic conditions way. The developed system is able to detect under-utilised spectrum fragments and optimally adjust the occupied spectrum. Through the online execution of 3 specifically designed experimental scenarios, we demonstrate the ability to implement distributed spectrum adaptation in commercial WLAN deployments, along with the obtained performance benefits.

Download paper: Keranidis_AGILE_Mobicom_2014

Online Assessment of Sensing Performance in Experimental Spectrum Sensing Platforms

Authors: Stratos Keranidis, Virgilios Passas, Kostas Chounos, Wei Liu, Thanasis Korakis, Iordanis Koutsopoulos, Ingrid Moerman, Leandros Tassiulas

Conference:  ACM WiNTECH, Maui, Hawaii, USA, September 7, 2014

Abstract: Dynamic Spectrum Access aims at exploiting underutilized frequency bands towards improving wireless network performance. In this context, spectrum sensing is employed, in order to monitor spectrum occupancy and drive appropriate adaptation decisions. Researchers in the field primarily evaluate proposed sensing approaches in terms of detection accuracy and efficiency of free spectrum utilization. In this work, we focus on online assessment of spectrum occupancy with respect to sensing delay and energy efficiency. Evaluation of spectrum sensing methods with respect to these two metrics is rather lagging in recent experimental developments. The first is related to the latency induced by the spectrum sensing process and its impact on sensing eefficiency, which is tightly connected to the resulting performance of the cognitive solution. On the other hand, energy consumption is considered as a crucial issue in all types of wireless communications. Therefore, it is important to extend existing testbed experimentation tools and develop new ones, in order to equip cognitive testbeds with such advanced monitoring capabilities. To this aim, we integrated the proposed monitoring procedure with the experimentation tools of the CREW testbed federation. In order to demonstrate the applicability of our framework, we experimentally validate the performance of four different sensing platforms, as well as a real-time spectrum sensing engine that implements parallel processing on software-defined radios, in terms of the aforementioned metrics.

Download paper: Keranidis_CREW_WiNTECH_2014.pdf

NITOS BikesNet: Enabling Mobile Sensing Experiments through the OMF Framework in a city-wide environment

Authors:  Giannis Kazdaridis, Donatos Stavropoulos, Vasilis Maglogiannis, Thanasis Korakis, Spyros Lalis and Leandros Tassiulas

Conference:  IEEE MDM 2014, Brisbane, Australia, July 15-18 2014

Abstract: In this paper we present the NITOS BikesNet platform, a city-scale mobile sensing infrastructure that relies on bicycles of volunteer users. NITOS BikesNet employs a custom-built embedded node that can be equipped with different types of sensors, and which can be easily mounted on a bicycle in order to opportunistically collect environmental and WiFi measurements in different parts of the city. Experimenters can remotely reserve and control the sensor nodes on bicycles as well as collect/visualize their measurements via the OMF/OML framework, which was extended in order to handle the intermittent connectivity and disconnected operation of the mobile nodes. We also provide a performance analysis of our node prototype in terms of sensing latency, end-to-end data transmission capability and power consumption, and report on a first experiment that was performed using NITOS BikesNet in the city of Volos, Greece.

Download paper: NITOS Bikes Net

More Articles ...

  1. Towards the efficient performance of LTE-A systems: Implementing a Cell Planning framework based on Cognitive Sensing
  2. Building an infrastructure for experimentation between Brazil and Europe to enhance research collaboration in future Internet
  3. NITOS Mobile Monitoring Solution: Realistic Energy Consumption Profiling of Mobile Devices
  4. Video-aware Multicast Opportunistic Routing over 802.11 mesh networks