Reconfigurable Intelligent Surfaces for 6G -- Applications, Challenges and Solutions

It is expected that scholars will continuously strengthen the depth and breadth of theoretical research on RIS, and provide a higher theoretical upper bound for the engineering application of RIS. While making breakthroughs in academic research, it has also made rapid progress in engineering application research and industrialization promotion. This paper will provide an overview of RIS engineering applications, and make a systematic and in-depth analysis of the challenges and candidate solutions of RIS engineering applications. Future trends and challenges are also provided.Comment: 2

Functional analysis of the micro/nanostructures of dragonfly wing veins

This article studies the internal micro/nanostructures and reveals the relations between the structures and functions of dragonfly wing veins. Through SEM, we take the microscopic photos of the cross-sections of dragonfly wing veins. From these photos, we obtain the following results: (a) The micro/nanostructures vary along the axis of the vein, i.e., different cross-sections have different micro/nanostructures. (b) For a given cross-section, the micro/nanostructures are of multilevels and multiscales. (c) At large scale, the structures of the veins are of diversities and disorders. The larger is the size scale. The more complicated are the structures, and the higher are the diversities and disorders. At small scale, the structures of the veins are of unifications and orders. The smaller is the size scale, the simpler is the structures, and the higher are the unifications and orders. (d) At the micro scale, we may induce unified assembling mode for the vein’s structures, i.e., “nanofibers/nanolayers (or nanobunches)”. (e) Both the mechanical functions and biological functions of the micro/nanostructures of the veins are optimized synthetically

Energy-Efficient Non-Orthogonal Transmission under Reliability and Finite Blocklength Constraints

This paper investigates an energy-efficient non-orthogonal transmission design problem for two downlink receivers that have strict reliability and finite blocklength (latency) constraints. The Shannon capacity formula widely used in traditional designs needs the assumption of infinite blocklength and thus is no longer appropriate. We adopt the newly finite blocklength coding capacity formula for explicitly specifying the trade-off between reliability and code blocklength. However, conventional successive interference cancellation (SIC) may become infeasible due to heterogeneous blocklengths. We thus consider several scenarios with different channel conditions and with/without SIC. By carefully examining the problem structure, we present in closed-form the optimal power and code blocklength for energy-efficient transmissions. Simulation results provide interesting insights into conditions for which non-orthogonal transmission is more energy efficient than the orthogonal transmission such as TDMA.Comment: accepted by IEEE GlobeCom workshop on URLLC, 201

HIGH EFFICIENCY SLEEP SCHEDULE FOR BATTERY BASED ENDPOINTS IN LOW-POWER AND LOSSY NETWORKS

Techniques are described herein for a high efficiency sleep schedule method to save energy for Wireless Mesh Network (WMN). Nodes are not distinguished as Full Function Device (FFD) or Reduced Function Device (RFD), as the strategy depends on hop count and the parent node’s sleep schedule. This is an improvement over current WMNs, which do not account for power management for Battery Based Endpoint (BBP) devices

Shock-induced breaking of the nanowire with the dependence of crystallographic orientation and strain rate

The failure of the metallic nanowire has raised concerns due to its applied reliability in nanoelectromechanical system. In this article, the breaking failure is studied for the [100], [110], and [111] single-crystal copper nanowires at different strain rates. The statistical breaking position distributions of the nanowires have been investigated to give the effects of strain rate and crystallographic orientation on micro-atomic fluctuation in the symmetric stretching of the nanowires. When the strain rate is less than 0.26% ps-1, macro-breaking position distributions exhibit the anisotropy of micro-atomic fluctuation. However, when the strain rate is larger than 3.54% ps-1, the anisotropy is not obvious because of strong symmetric shocks