Wireless power transfer (WPT) offers a promising solution for powering distributed devices in smart cities, significantly simplifying system complexity and accelerating urban automation. In traditional WPT systems, far-field schemes are costly, energy-intensive, and inefficient, while near-field transmission offers higher efficiency but suffers from limited distance. To address the limited transmission distance of near-field WPT, this paper derives an electromagnetic model for WPT using reflective metasurfaces and presents the design of a high-performance 3-bit reconfigurable intelligent surface (RIS). Based on theoretical models, we investigate the effects of phase quantization and array size on focusing efficiency. Simulation results guide the subsequent fabrication of the RIS prototype. Experimental measurements on the fabricated prototype validate the beam-focusing effect and evaluate the overall WPT efficiency.

Millimeter-wave (MMW) radar is one of the indispensable sensors for advanced driver assistance systems (ADASs) and autonomous driving. This paper adopts inter-pulse frequency agility (FA) to synthesize a broadband signal, achieving broadband imaging without increasing the sampling rate. Meanwhile, given that Doppler division multiple access (DDMA) has higher transmission efficiency than time division multiple access (TDMA) and is widely used in automotive radar, this paper proposes a signal transmission framework that integrates DDMA and FA. Simulation results demonstrate that the proposed DDMA FA multiple-input multiple-output (DDMA-FA-MIMO) processing architecture can yield 30 to 40 times more detection points for a single target compared to traditional methods, preliminarily achieving target contour imaging.

Edge blockchains, the blockchains running on edge computing infrastructures, have attracted a lot of attention in recent years. Thanks to data privacy, scalable computing resources, and distributed topology nature of edge computing, edge blockchains are considered promising solutions to facilitating future blockchain applications. However, edge blockchains face unique security issues caused by the deployment of vulnerable edge devices and networks, including supply chain attacks and insecure consensus offloading, which are mostly not well studied in previous literature. This paper is the first survey that discusses the attacks and countermeasures of edge blockchains. We first summarize the three-layer architecture of edge blockchains: blockchain management, blockchain consensus, and blockchain lightweight client. We then describe seven specific attacks on edge blockchain components and discuss the countermeasures. At last, we provide future research directions on securing edge blockchains. This survey will act as a guideline for researchers and developers to design and implement secure edge blockchains.

The industrial Internet realizes intelligent control and optimized operation of the industrial system through network interconnection. The industrial Internet identifier is the core element to accomplish this task. The traditional industrial Internet identifier resolution technologies depend excessively on IP networks, and cannot meet the requirements of ubiquitous resource-restraint Internet of Things (IoT) devices. An industrial Internet identifier resolution management strategy based on multi-identifier network architecture is proposed in this paper, which supports content names, identities, locations, apart from the traditional IP address. The application of multiple types of identifiers not only solves the problem of IP addresses exhaustion, but also enhances the security, credibility, and availability of the industrial Internet identification resolution system. An inter-translation scheme between multiple identifiers is designed to support multiple identifiers and the standard ones. We present an addressing and routing algorithm for identifier resolution to make it convenient to put our strategy into practice.

As the information network plays a more and more important role globally, the traditional network theories and technologies , especially those related to network security, can no longer meet the network development requirements . Offering the system with secure and trusted services has become a new focus in network res earch . This paper first discusses the meaning of and aspects involved in the trusted network. According to this paper, the trusted network should be a network where the network s and users behaviors and their results are always predicted and manageable . The trustworthiness of a network mainly involves three aspects : service provider, information transmission and terminal user. This paper also analyzes the trusted network in terms of trusted model for network/user behaviors , architecture of trusted network, s ervice survivability and network manageability, which is designed to give ideas on solving the problems that may be faced in developing the trusted network.