Tags: 4g LTE

Recent cluster architectures include dozens of cores per node, with all cores sharing the network resources. To program such architectures, hybrid models mixing MPI+threads, and in particular MPI+OpenMP are gaining popularity. This imposes new requirements on communication libraries, such as the need for MPI_THREAD_MULTIPLE level of multi-threading support. Moreover, the high number of cores brings new opportunities…

Major problems in diffusion based molecular communication are Inter Symbol Interference (ISI), low data rates and limited range of communication. Keeping symbol duration as long as possible leads to avoid ISI may be a solution, but this leads to even further reduced data rates. In order to cope with limited range of communication, using relays is one of the…

Cooperation among cognitive radio users improves the spectrum sensing performance by combining local decisions measured over independent sensing channels, allowing reduction of miss-detection and false alarm probabilities. While most of the works in cooperative spectrum sensing techniques assume perfect channels between the cooperating users, this paper studies the effect of imperfect channels when local users report their sensed…

The decentralized Cognitive Radio Medium Access Control (CR MAC) protocols proposed so far are usually evaluated considering homogeneous sensing conditions where all Secondary Users (SUs) share the same view of the channel. By doing so, realistic heterogeneous channel sensing conditions are neglected, which happens due to different spectrum sensing errors and/or different patterns of channel occupation by the…

Internet of Things (IoT) enables various applications (crop growth monitoring and selection, irrigation decision support, etc) in Digital Agriculture domain. Semantic enhancements to IoT platforms address challenges of interoperability, data fusion, integration of heterogeneous IoT silos, annotation of data streams, just to name a few. This paper discusses the recently developed OpenIoT platform which demonstrated its applicability and efficiency…

Management of bulk sensor data is one of the challenging problems in the development of Internet of Things (IoT) applications. High volume of sensor data induces for optimal implementation of appropriate sensor data compression technique to deal with the problem of energy-efficient transmission, storage space optimization for tiny sensor devices, and cost-effective sensor analytics. The…

In this paper, an energy efficient cognitive radio system is proposed. The proposed design optimizes the secondary user transmission power and the sensing duration combined with soft-sensing information to minimize the energy per goodbit. Due to the non-convex nature of the problem we prove its pseudo-convexity to guarantee the optimal solution. Furthermore, a quantization scheme, that discretize the…

This article describes one of many possible paradigms for future wireless applications. The spectrum in which Wi-Fi operates these days is overcrowded and currently applied rules for Wi-Fi operation are not up-to-date. By adopting a new set of rules for Wi-Fi, it is possible to eliminate some of the currently defined constraints such as Equivalent…

This paper proposes a virtual resource (VR) allocation scheme for OFDMA based wireless virtualization networks (WVNs). The scheme considers the time-variant wireless channel quality from the technical perspective, as well as the network benefits for WVN elements, e.g., subscriber user equipments (SUEs), mobile network operators (MNOs) and wireless service providers (WSPs), from the economic perspective. Regarding the available VR for a…