The Cognitive Radio part of the LOG-a-TEC testbed consists of several clusters of permanently mounted VESNA sensor nodes that are dedicated to experimentation with spectrum sensing and radio communications within wireless sensor networks. Each sensor node in these clusters is equipped with multiple reconfigurable radio interfaces that can be used in various modes. A license from the local regulator allows for experimentation in TV whitespaces as well as frequency bands for unlicensed devices.
Testbed is remotely accessible over the Internet and uses a dedicated, wireless management network to control individual sensor nodes in a cluster. Different approaches can be used to perform experiments, depending on the latency requirements and complexity of experimental scenarios: from high-level control using Python or graphical network stack composition to reprogramming the nodes with native applications. Radio propagation modeling tools can be used as well to plan the experiments.
In addition to permanently mounted nodes, several kinds of mobile nodes or instruments can be added to the testbed in special cases and after previous agreement.
VESNA sensor node core (SNC) provides processing and storage at each sensor node. It contains an ARM Cortex M3 CPU at 64 MHz, 512 kB FlashROM, 64 kB RAM and an 2 GB SD card for code and data storage.
Different sensor node clusters contain different combinations of the following embedded radio hardware:
Additionally, a small number of software-defined radio nodes using the Ettus Reseach USRP N200 can be used in the test bed as needed. A Rohde & Schwarz SMBV100A vector signal generator and a FSV signal analyzer are available for on-site measurements.
See hardware page for more details on testbed hardware.
Cognitive Radio part of LOG-a-TEC testbed consists of the following permanently mounted clusters:
Logatec is a small city with approximately 10.000 inhabitants in the south-west of Slovenia. Three sensor node clusters cover approximately 350.000 m2 of out-door public space in the city center and an industrial zone using a total of 52 sensor nodes on street lights and other public infrastructure:
These clusters are currently used for spectrum sensing experiments and radio environment mapping. Three distinct hardware node configurations are deployed:
Nodes in the cluster are running the vesna-drivers firmware and use a dedicated, low-speed IEEE 802.15.4 management network (independent of the experimental radio hardware) for control and reprogramming. Each node is accessible from the Internet using a REST API and an application protocol similar to HTTP (ALH).
20 sensor nodes are mounted at the campus of the Jožef Stefan Institute in Ljubljana, Slovenia. They cover approximately 3000 m2 of in-door and out-door space.
This cluster is currently used for experiments with packet-based transmissions and dynamic network stack composition in wireless sensor networks. All nodes in the cluster contain one CC1101 and one AT86RF231 radio.
Nodes at JSI campus are running Contiki operating system with a dual, composable networking stack. A 6LoWPAN network using the AT86RF231 radio is used to control and reprogram the nodes. Each node is directly accessible from the Internet using IPv6.
The following is a list of the major software components of the LOG-a-TEC testbed.
See software page for more details on testbed software.
See experiments page for more details on past experiments performed on the testbed.
The LOG-a-TEC testbed is a member of the Fed4FIRE federation of testbeds.
The following material is available for LOG-a-TEC.
A MSc thesis describing the cogitive radio experimentation facilities in LOG-a-TEC: Zoltan Padrah: Distributed Spectrum Sensing in Unlicensed Bands Using the VESNA Platform, MSc thesis, MPS, Ljubljana, Slovenia.
A getting started tutorial that includes (1) an overview of the LOG-a-TEC testbed with its hardware and software components and (2) demos using the available Python tools is Tomaž Šolc: Performing cognitive radio experiments on the LOG-a-TEC sensor network testbed, CREW Training days, Brussels, Belgium., February 2013, while the code can be downloaded from our GitHub page.
A paper describing the adaptation and experimentation with the game theoretic based PAPU algorithm on LOG-a-TEC Ciprian Anton, Andrei Toma, Ligia Cremene, Mihael Mohorčič and Carolina Fortuna: Power Allocation Game for Interference Mitigation in a Real-world Experimental Testbed, IEEE ICC 2014 - Cognitive Radio and Networks Symposium..
A general paper describing LOG-a-TEC Mihael Mohorčič, Miha Smolnikar, Tomaž Javornik: Wireless Sensor Network Based Infrastructure for Experimentally Driven Research, The Tenth International Symposium on Wireless Communication Systems, Ilmenau, Germany, August 2013.
A paper benchmarking different sensing devices Peter Van Wesemael, Wei Liu, Mikolaj Chwalisz, Justin Tallon, Danny Finn, Zoltan Padrah, Sophie Pollin, Stefan Bouckaert, Ingrid Moerman, and D. Willkomm: Robust distributed sensing with heterogeneous devices, Future Network & Mobile Summit 2012..
A demonstration of SNE-ISMTV hardware capabilities Tomaž Šolc: SNE-ISMTV: VESNA wireless sensor node expansion for cognitive radio experiments, The Tenth International Symposium on Wireless Communication Systems, Ilmenau, Germany, August 2013.
Various experiments can be performed using the LOG-a-TEC infrastructure, for example:
In order to access LOG-a-TEC you first need to get a user account. Please contact Matevz Vucnik, Tomaz Solc or Carolina Fortuna for this (firstname.lastname(at)ijs.si).
Once you have a user account, log in here.