Reliable Data Forwarding in Wireless Sensor Networks: Delay and Energy Trade Off

eliable Data Forwarding in Wireless Sensor Networks: Delay and Energy Trade Of

A generic non-stationary MIMO channel model for different high-speed train scenarios

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.This paper proposes a generic non-stationary wideband geometry-based stochastic model (GBSM) for multiple-input multiple-output (MIMO) high-speed train (HST) channels. The proposed generic model can be applied on the three most common HST scenarios, i.e., open space, viaduct, and cutting scenarios. A good agreement between the statistical properties of the proposed generic model and those of relevant measurement data from the aforementioned scenarios demonstrates the utility of the proposed channel model

Optimizing Radio Access Network Selection in WLAN and 3G Networks

Abstract— this paper proposes a radio access network (RAN) selection algorithm for the next generation of wireless networks. The proposed algorithm uses mobile terminal measurements from different radio access technologies to obtain information for multi-criteria decision making between different RANs available to the mobile user. The proposed system uses a novel algorithm designed for decision-making under service parameters, Quality of Service (QoS), and service costs for the mobile user. The algorithm has been implemented within both client and server terminals. Also, an analysis of the results obtained using the new algorithm in 3G and wireless local area networks (WLANs), has been performed

Performance analysis of vertical handover using predictable LGD event based on IEEE 802.21.

Next Generation Wireless Networks (NGWN) aim to provide any service at any time and anywhere with seamless mobility between homogeneous and heterogeneous networks. IEEE defines the IEEE 802.21 standard to facilitate seamless handover, namely, Media Independent Handover (MIH). IEEE 802.21 provides layer two events to upper layers with a view to enhance the operability and enable them to make the right decision on time. Link Going Down (LGD) is a predictive event triggered when a link quality degradation is expected in the near future. Connectivity losses and quality decreases are usually foreseeable during the handover process. Therefore, in this paper, we analyze the performance of our effective prediction model for generating the Link Going Down (LGD) event. The network performance metrics, such as packet loss, end-to-end delay, and throughput, have been evaluated using the Network Simulator NS2

Structural and thermochemical properties of sodium magnesium phosphate glasses

Ternary phosphate based glasses with the general formula (50−x/2)Na2O–xMgO–(50−x/2)P2O5 (0 ⩽ x ⩽ 42.8 mol%), where the O/P ratio was varied from 3 to 3.75, have been prepared using a conventional melt quenching technique. Samples were investigated by means of density measurements, Fourier-transformed infrared (FTIR), Raman and 31P solid state magic angle spinning nuclear magnetic resonance (MAS-NMR) spectroscopies, differential scanning calorimetry (DSC), inductively coupled plasma atomic emission spectroscopy (ICP/AES) analysis and calorimetric dissolution.The depolymerization of metaphosphate chains are described by the decrease of Q2 tetrahedral sites allowing the formation of pyrophosphate groups (Q1) revealed by spectroscopic investigations. As a result, the increase of density and glass transition temperature when x rises. Calorimetric study shows that the dissolution phenomenon is endothermic for a lower MgO content and becomes exothermic when magnesium oxide is gradually incorporated, suggesting the disruption of phosphate chains with increasing O/P ratio