science 25.1.2016 12:24

IJS Communication Systems Department addressing radio spectrum scarcity

Ljubljana, 25 January - The Communication Systems Department of the Jožef Stefan Institute (IJS) concluded last October a five-year European project, CREW, as part of which it established an experimental network called Log-a-tec, named after the town of Logatec where it was set up. The network enables the monitoring and detection of the of load of radio spectrum in a specific area and at a specific time. Spectrum has become a very limited resource because of the multitude of wireless devices, says department head Mihael Mohorčič, PhD.

Ljubljana, IJS.
Vodja Odseka za komunikacijske sisteme na IJS Mihael Mohorčič.
Foto: Anže Malovrh/STA

Ljubljana, IJS.
Vodja Odseka za komunikacijske sisteme na IJS Mihael Mohorčič.
Foto: Anže Malovrh/STA

Ljubljana, IJS.
Vodja Odseka za komunikacijske sisteme na IJS Mihael Mohorčič.
Foto: Anže Malovrh/STA

Two clusters of sensor devices were installed in the Log-a-tec sensor network, mostly on street lights and roofs. Researchers can remotely configure and launch a specific experiment and collect data detected by sensors through a web interface. "If we see that someone is already using a certain channel or frequency, we know that we must not emit there because there would be disturbances," Mohorčič explains.

The Log-a-tec experimental network, which joins individual pilot and experimental systems, was also integrated in the European federation of experimental networks FIRE/FIRE+ through the CREW and Fed4FIRE projects. FIRE/FIRE+ is available for experimental work to both domestic and foreign researchers and research groups.

The IJS has also secured the eWINE project, which will upgrade the work on the CREW project until the end of 2017. More than measurements of occupancy and availability of radio spectrum, emphasis will be put on the usage of this information in the optimization of wireless networks. Networks will automatically adjust to changes in the environment, which could significantly improve utilization of radio spectrum, which has become of key importance given the increasing number of wireless devices and the spread of the Internet of Things.

"Cognitive radio networks are networks of devices which are aware of their settings, and through detection of radio spectrum also its radio environment, i.e. the presence and activities of other devices and possible disturbances they can cause. Taking into account the needs for transfer capacity, and limitations by the regulator or operator and user, these devices are configured to prevent interference using methods of machine learning and decision-making from the field of artificial intelligence."

Mohorčič sees the biggest challenge in the field of networked sensor systems in bridging the development of hardware and software, which must be in line with wireless communication standards. When it comes to the Internet of Things and smart cities, one major challenge is the clustering of devices which currently do not operate under same communication standards. "All these devices need to be able to connect to the Internet, which represents a junction through which we will be able to contact and access them".

VESNA as a common thread of the Communication Systems Department

A common thread of the research and development work at the department is VESNA - a modular sensor platform developed in the inter-departmental laboratory SensorLab, where the researchers from the department an the artificial intelligence laboratory at IJS jointly work. A variety of communication and application modules can be added to this underlying platform.

VESNA serves as a basis for the development of sensor solutions, production of prototypes and pilot systems in various fields, from the more efficient use of the radio spectrum (CREW, eWINE projects) and support for communication systems in extraordinary situations (ABSOLUTE project) to participatory detection of air quality in cities (CITI-SENSE project) and monitoring of the state and quality of electricity distribution (SUNSEED project).

Communication Systems Department

The research and development work at the department is carried out in the framework of the Communication Technology Laboratory (CTL), Parallel and Distributed Systems Laboratory (PDSL) and Networked Embedded Systems Laboratory (NESL), in which Mohorčič spends the bulk of his research time.

Work in the latter laboratory originally focused on wireless sensor networks, while in the recent years the emphasis has been on the Internet of Things and wireless communications. The laboratories complement each other, which is primarily reflected in the implementation of applied projects.

Mohorčič already cooperated with the Communication Systems Department when he was working on his thesis, while he has been employed there since 1994. He has headed the department for the last five years.

In the recent years the department produced internationally recognized results with projects such as the study of broadband wireless communications through high-altitude platform stations, development of its own portable sensor device for monitoring of ECG and other vital signs, modeling of complex physical phenomena such as accumulation of ice on overhead power lines, and a concept of a portable sensor device for monitoring air quality.

The department also participates in SUNSEED, a project in which it is developing two sensors and measuring devices for the quality of distribution of electricity, which will be implemented on the network operated by Elektro Primorska. Four of the nine project partners come from Slovenia. In addition to IJS, the partners from Slovenia are Elektro Primorska, engineering company Elektroservisi and telco Telekom Slovenije as the coordinator of the project. The objective of the project, which will conclude in February, is to develop a technical and economic model for achieving optimal efficiency of the use of communication infrastructure in smart electricity networks of the future.

Mihael Mohorčič's diagram of cooperation

Source: Slovenian Science Atlas