Virtual Resource Allocation for Wireless Virtualized Heterogeneous Network with Hybrid Energy Supply

In this work, two novel virtual user association and resource allocation algorithms are introduced for a wireless virtualized heterogeneous network with hybrid energy supply. In the considered system, macro base stations (MBSs) are supplied by the grid power and small base stations (SBSs) have the energy harvesting capability in addition to the grid power supplement. Multiple infrastructure providers (InPs) own the physical resources, i.e., BSs and radio resources. The Mobile Virtual Network Operators (MVNOs) are able to recent these resources from the InPs and operate the virtualized resources for providing services to different users. In particular, aiming to maximize the overall utility …

Device-to-device communication for LTE-advanced network system

Device-to-device (D2D) communication has been proposed as a mean for local connections in future ellular networks in order to provide improved throughput, spectrum savings, and longer battery lives. Here we widen the investigations of D2D communication to a 3GPP Long Term Evolution (LTE) system simulated in the interference limited macro-cellular environment, in which D2D communication is applied with D2D specific power control and resource allocation schemes and with a wide range of deployment ratios. Furthermore, we introduce channel model parameters applicable for a fair performance comparison between conventional cellular and D2D enhanced systems. The simulation results demonstrate that…

Isomer effects in fragmentation of Polycyclic Aromatic Hydrocarbons

We have observed significant differences in the fragmentation patterns of isomeric Polycyclic Aromatic Hydrocarbon (PAH) cations following collisions with helium atoms at center-of-mass energies around 100 eV. This is in contrast to the situation at other collision energies or in photo-absorption experiments where isomeric effects are very weak and where the lowest-energy dissociation channels (H- and C2H2-loss) domihate in statistical fragmentation processes. In the 100 eV range, non-statistical fragmentation also competes and is uniquely linked to losses of single carbon atoms (CHx-losses). We find that such CHx-losses are correlated with the ionic ground state energy within a given group…

Advanced voice and data solutions for evolution of cellular network system

Dynamic Resource Allocation and Computation Offloading for Edge Computing System

In this work, we propose a dynamic optimization scheme for an edge computing system with multiple users, where the radio and computational resources, and offloading decisions, can be dynamically allocated with the variation of computation demands, radio channels and the computation resources. Specifically, with the objective to minimize the energy consumption of the considered system, we propose a joint computation offloading, radio and computational resource allocation algorithm based on Lyapunov optimization. Through minimizing the derived upper bound of the Lyapunov drift-plus-penalty function, the main problem is divided into several sub-problems at each time slot and are addressed sepa…

Towards Service-oriented 5G: Virtualizing the Networks for Everything-as-a-Service

It is widely acknowledged that the forthcoming 5G architecture will be highly heterogeneous and deployed with a high degree of density. These changes over the current 4G bring many challenges on how to achieve an efficient operation from the network management perspective. In this article, we introduce a revolutionary vision of the future 5G wireless networks, in which the network is no longer limited by hardware or even software. Specifically, by the idea of virtualizing the wireless networks, which has recently gained increasing attention, we introduce the Everything-as-a-Service (XaaS) taxonomy to light the way towards designing the service-oriented wireless networks. The concepts, chall…

Dynamic Packet Bundling for VoIP Transmission Over Rel'7 HSUPA with 10ms TTI Length

In this paper, the system level optimization of the voice over IP transmission in the HSUPA system, configured with a 10 ms TTI length, is analyzed. The study considers the release 7 improvements to HSUPA, in terms of the DPCCH gating concept. A dynamic activated MAC layer bundling of two VoIP packets in a single frame is proposed and compared against the single packet per frame transmission by means of quasi-static system level simulations.

VoIP end-to-end performance in HSPA with packet age aided HSDPA scheduling

In this paper, we present an enhanced VoIP scheduling for the high speed downlink packet access (HSDPA) in UMTS, which takes the age of the VoIP packet into account. The downlink capacity can be significantly improved by this way, especially for shorter uplink transmission delay. In order to quantify the achievable performance improvement, we present results obtained from extensive system-level uplink and downlink simulations. Inter alia, it is shown that using the proposed scheme can lead to an increase in the downlink cell capacity of up to 16%. By applying the proposed method, the downlink performance can be improved considerably while the uplink performance remains the same, which ensur…

Uplink DPCCH Gating of Inactive UEs in Continuous Packet Connectivity Mode for HSUPA

In order to further improve the packet performance in the UMTS FDD system, uplink dedicated physical control channel (DPCCH) gating as a scheme is proposed in 3GPP under the work item "continuous connectivity for packet data users". In this paper, the uplink DPCCH gating concept is described and analyzed on both a qualitative and a quantitative level. And the system performance of different gating patterns used in the scheme was investigated by analytical prediction and system level simulations with different channel profiles. As shown, the selection of the gating pattern has a significant influence on the system performance, which is correlated with the uplink data transmission activity an…

Fragmentation of anthracene C14H10, acridine C13H9N and phenazine C12H8N2 ions in collisions with atoms

International audience; We report experimental total, absolute, fragmentation cross sections for anthracene C14H10, acridine C13H9N, and phenazine C12H8N2 ions colliding with He at center-of-mass energies close to 100 eV. In addition, we report results for the same ions colliding with Ne, Ar, and Xe at higher energies. The total fragmentation cross sections for these three ions are the same within error bars for a given target. The measured fragment mass distributions reveal significant contributions from both delayed (≫10−12 s) statistical fragmentation processes as well as non-statistical, prompt (∼10−15 s), single atom knockout processes. The latter dominate and are often followed by sec…

Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: the challenge ahead

Goodson, William H. et al.

Nonstatistical fragmentation of large molecules

International audience; We present experimental evidence for the dominance of prompt single-atom knockout in fragmenting collisions between large polycyclic aromatic hydrocarbon cations and He atoms at center-of-mass energies close to 100 eV. Such nonstatistical processes are shown to give highly reactive fragments. We argue that nonstatistical fragmentation is dominant for any sufficiently large molecular system under similar conditions.