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In this paper, we investigate the concept of database supported Vehicular Dynamic Spectrum Access (VDSA) for platooning. As various researchers show that the 5.9 GHz band, devoted for Intelligent Transportation Systems, may suffer from congestion of the channel, we propose to offload part of this traffic to white-spaces with the guidance of the active database system. In our work, we describe our measurement campaign which delivered data for population of the dedicated radio environment map. Once the map is created, it was used in three proposed algorithms for VDSA: an optimal and two pragmatic approaches.1

In this letter, we propose a computationally efficient method for joint selection of cancellation carriers (CCs) and calculation of their values minimizing the out-of-band (OOB) power in non-contiguous (NC-) OFDM transmission. The proposed new CCs selection method achieves higher OOB power attenuation than algorithms known from literature as well as noticable reception performance improvement.

One of the primary objectives of deploying cognitive radio (CR) within a dynamic spectrum access (DSA) network is to ensure that the legacy rights of incumbent licensed (primary) transmissions are protected with respect to interference mitigation when unlicensed (secondary) communications are simultaneously operating within the same spectral vicinity. In this article, we present non-contiguous orthogonal frequency division multiplexing (NC-OFDM) as a promising and practical approach for achieving spectrally agile wireless data transmission that is suitable for secondary users (SUs) to access fragmented spectral opportunities more efficiently. Furthermore, a review of the current state-of-the-art is conducted with respect to methods specifically designed to protect the transmissions of the primary users (PUs) from possible interference caused by nearby SU transceivers employing NC-OFDM. These methods focus on the suppression of out-of-band (OOB) emissions resulting from the use of NC-OFDM transmission. To achieve the required OOB suppression, we present two practical approaches that can be employed in NC-OFDM, namely, the insertion of cancellation carriers and windowing. In addition to the theoretical development and proposed improvements of these approaches the computer simulation results of their performance are presented. Several real-world scenarios regarding the coexistence of both PU and SU signals are also studied using actual wireless experiments based on software-defined radio. These simulation and experimental results indicate that OOB suppression can be achieved under real-world conditions, making NC-OFDM transmission a viable option for CR usage in DSA networks.

The era of 5G networks is approaching fast and its commercialization is planned for 2020. However, there are still numerous aspects that need to be solved and standardized before an average end-user can benefit from them on a daily basis. The 5G technology is supposed to be faster, provide services of higher quality, and better address the evolving needs of customers. As a consequence, 5th generation network needs to be implemented with efficiency and flexibility in mind, and thus, it fits well with the concepts of virtualization which enable sharing of physical resources among different operators, services, and applications. In this paper, we present an overview of these concepts, resulting from our discussions, i.e. between academic researchers and active network architects, and we describe the operation of a model that is most likely to emerge in such a complex network environment.

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