Filip Jelenkovic

TaaSOR – Testbed-as-a-Service Ontology Repository

This demonstration is introducing Testbed-as-a-Service (TaaS) infrastructure that illustrates use of community based approach to building experimental ontologies and generation of supporting testbed resources applied to OMF based testbed. While this TaaS demo is initially primarily targeting virtualization and community collaboration, the final objective is to support domain specific experimental description languages and resource management in federated testbeds.

The CoordSS experimentation framework ontologies

The CoordSS experimentation framework aims to provide a solid practical evidence that testbeds and other experimentation infrastructure provided by EU FP7 FLEX project is capable of supporting advanced experimentation with proposed use of LTE Advanced in unlicensed 5 GHz spectrum (LTE-U). By integrating technologies such as spectrum sensing, various coexistence mechanisms between legacy unlicensed technologies (primarily WiFi) and LTE, and a range of coordination protocols, the frameworks primary objective is to enable experimentation with SDR based LTE in unlicensed spectrum. The flexibility of such experimental environment is addressed by adoption of domain and system ontologies for formal representation of semantics of the problem. This paper deals with ontologies that are needed for the CoordSS experimentation framework implementation.

Semantic driven code generation for networking testbed experimentation

ABSTRACT This paper investigates how semantic technologies can be used for automatic code generation with a goal to provide easier to use and more efficient working environment to users of large complex infrastructures such as networking testbeds. A new Semantic Driven Code Generation (SecGENE) approach is proposed in the light of a testbed-driven experimentation. The target use-case scenario focuses on heterogeneous telecommunication systems and optimal spectrum usage. The SecGENE approach is examined on the example of semantic coordination process in an environment containing coordinated as well as uncoordinated WiFi networks. Abbreviations: CLOnt – Command Line ontology; ExFOnt – Experiment Flow Ontology; MSAO – Meta System Architecture ontology; NVF – Network Virtualization Function; OEDL – OMF Experiment Description Language; OMN- Open-Multinet ontology; RDFO – A standard W3C Resource Description Framework ontology; SOEDL– Semantic OEDL

Wireless Networks Coexistence in Unlicensed Bands

Mobile communication networks are constantly evolving and each new generation provides considerably higher data transmission capabilities. Having in mind predictions of high cellular data traffic growth over the next few years, it is clear that the licensed band communications would have problems to support such a high bandwidth demand. One of the possible solutions to this problem is to adaptively use some additional spectrum out of the dedicated licensed band, such as the unlicensed bands. LTE-A standard introduced a new mechanism, named Carrier Aggregation, which provides the possibility to simultaneously use multiple frequency bands, such as the licensed and unlicensed bands. In order to work in an unlicensed band, LTE has to employ some new procedures that provide shared access with other systems using the same frequency band, such as WiFi. These procedures include spectrum sensing, dynamic frequency selection, as well as the coordination of the shared access. Performance measurements and the analysis of the procedures in 5 GHz frequency band will be shown in this paper. Since there is no available LTE hardware operating in 5 GHz band, it has to be made in a laboratory using the software radio approach. The description of such an experiment may be complex, and therefore we describe and propose the concept of the automatic experiment code generation. The automatic code generation is based on the semantic descriptions of experiments, and it is flexible due to the adoption of the domain and system ontologies for formal representation of the semantics of the problem.

A semantic approach to wireless networking testbed infrastructure

High market demand for wireless networking services and devices has resulted in increased complexity of an infrastructure of networking testbeds because of the scale, diversity and exploitation levels of the involved resources. In this paper, we address the problem of managing the infrastructure of large wireless networking testbed by adopting a semantics-based approach to knowledge-driven system management. A novel data transformation language, fully based on the semantic web standards, is introduced. Using the introduced language, an XML description of testbed services can be transformed to semantically enriched data. Workflow of the transformation is explained on the example of semantic lifting of the ORBIT testbed infrastructure. The example provides experimental evidence for successful application of the proposed approach.

Semantic coordination protocol for LTE and Wi-Fi coexistence

In this paper, we address the challenges in facilitating the intra-band coexistence of WiFi and LTE technologies in multi-RAT networks and propose a semantic coordination protocol that improves the communication performance among inter-network devices. Effective communication in LTE networks is a critical task to achieve as the heterogeneity of the devices and coexisting technologies arises. This paper introduces an internetwork spectrum coordination across Wi-Fi and LTE systems based on an ontological framework as a possible solution for improved coexistence. We develop and evaluate our approach under real-world settings. The results we obtained using the proposed semantic coordination protocol have shown significant gains for both the under-study Wi-Fi and LTE networks.

Spectrum sensing for the unlicensed band cognitive radio

If several different systems operate in the same frequency band, in order to effectively use the available spectrum there has to be some coordination between them. The coordination is especially important if the systems are not designed to operate in such an environment. The initial and a very important part of the coordination process is the acquiring of the spectrum usage map or spectrum sensing. The paper describes the spectrum sensing experimentation in the unlicensed 2.4 GHz band during the WiFi transmission. It shows the experiment flow and the obtained results. The experiments were performed at NITOS testbed at the University of Thessaly, Greece.

Semantic Web technologies for pay-as-you-go networking services integration

In this paper we present challenges for full integration of services in todays networking testbeds, and show how they can be addressed by applications based on the Semantic Web. We demonstrate particular implementation of such a web application, and discuss benefits of using this application in creation of tests that can be run in networking testbeds environment.