A 16-QAM 45-Gbps 7-m Wireless Link Using InP HEMT LNA and GaAs SBD Mixers at 220-GHz-Band

This paper presents a 220-GHz-band 7-m wireless link with a 45-Gbps transmission data rate by using 16 quadrature amplitude modulation(16-QAM).Super-heterodyne transceiver modules are developed for transmission and reception of the modulated signals,which consist of a Schottky barrier diodes(SBD)based sub-harmonic mixer(SHM),an InP HEMT low noise amplifier(LNA),a waveguide band-pass filter(BPF),and a 108-GHz local oscillator(LO)multiplier chain.The transmitter features a peak transmit power of 1.41 dBm,and the IF frequency varies from 5 GHz to 20 GHz.Besides,the receiver features a conversion gain of 9.3 dB in average and a noise temperature of 3052.8 K.The measured results indicate that the transceiver modules enable data transmission of a 45-Gbps 16-QAM signal with Signal-Noise-Ratio(SNR)from 11.59 dB to 15.36 dB in a 7-m line-of-sight channel.

A Wireless LAN Bridging Solution Based on Campus Network

This paper presents a creative wireless LAN (WLAN) bridging solution, concentrating on the overall realization of a well designed interconnection. This solution integrates effective traffic insulation, intended access control, and required address translation without interfering with the vested interest of internet service provider (ISP). The specific solution can be widely applied on the campus-dorm (off campus)-ISP internetworking mode, where it is hard to implement wired link between campus network and dorm network in terms of cost and existing environmental constraints.

Advantages of solitonic shape pulses for full-optical wireless communication links

We propose the use of a power pulse shape of the widely known optical soliton, corresponding to the hyperbolic secant square function, for both conventional atmospheric optical communication systems and, especially, for new full-optical wireless communications. We analyze the performance of the proposed pulse in terms of peak-to-average optical power ratio （PAOPR） and bit error rate （BER）. During the analysis, we compare the proposed pulse shape against conventional rectangular and Gaussian pulse shapes with reduced duty cycle. Results show the noticeable superiority of the proposed pulse for atmospheric optical links.

Effective link quality estimation as a means to improved end-to-end packet delivery in high traffic mobile ad hoc networks

Accurate link quality estimation is a fundamental building block in quality aware multi hop routing. In an inherently lossy, unreliable and dynamic medium such as wireless, the task of accurate estimation becomes very challenging. Over the years ETX has been widely used as a reliable link quality estimation metric. However, more recently it has been established that under heavy traffic loads ETX performance gets significantly worse. We examine the ETX metric＇s behavior in detail with respect to the MAC layer and UDP data; and identify the causes of its unreliability. Motivated by the observations made in our analysis, we present the design and implementation of our link quality measurement metric xDDR - a variation of ETX. This article extends xDDR to support network mobility. Our experiments show that xDDR substantially outperforms minimum hop count, ETX and HETX in terms of end-to-end packet delivery ratio in static as well as mobile scenarios.

Design of Efficient Router with Low Power and Low Latency for Network on Chip

The NoC consists of processing element (PE), network interface (NI) and router. This paper proposes a hybrid scheme for Netwok of Chip (NoC), which aims at obtaining low latency and low power consumption by concerning wired and wireless links between routers. The main objective of this paper is to reduce the latency and power consumption of the network on chip architecture using wireless link between routers. In this paper, the power consumption is reduced by designing a low power router and latency is reduced by implementing a on-chip wireless communication as express links for transferring data from one subnet routers to another subnet routers. The average packet latency and normalized power consumption of proposed hybrid NoC router are analyzed for synthetic traffic loads as shuffle traffic, bitcomp traffic, transpose traffic and bitrev traffic. The proposed hybrid NoC router reduces the normalized power over the wired NoC by 12.18% in consumer traffic, 12.80% in AutoIndust traffic and 12.5% in MPEG2 traffic. The performance is also analyzed with real time traffic environments using Network simulator 2 tool.

In-situ manipulation of wireless link with reinforcement-learningdriven programmable metasurface in indoor environment

It is of great importance to control flexibly wireless links in the modern society,especially with the advent of the Internet of Things(IoT),fifth-generation communication(5G),and beyond.Recently,we have witnessed that programmable metasurface(PM)or reconfigurable intelligent surface(RIS)has become a key enabling technology for manipulating flexibly the wireless link;however,one fundamental but challenging issue is to online design the PM's control sequence in a complicated wireless environment,such as the real-world indoor environment.Here,we propose a reinforcement learning(RL)approach to online control of the PM and thus in-situ improve the quality of the underline wireless link.We designed an inexpensive one-bit PM working at around 2.442 GHz and developed associated RL algorithms,and demonstrated experimentally that it is capable of enhancing the quality of commodity wireless link by a factor of about 10 dB and beyond in multiple scenarios,even if the wireless transmitter is in the glancing angle of the PM in the realworld indoor environment.Moreover,we also prove that our RL algorithm can be extended to improve the wireless signals of receivers in dual-receiver scenario.We faithfully expect that the presented technique could hold important potentials in future wireless communication,smart homes,and many other fields.

A low-cost 10-Gbit/s millimeter-wave wireless link working at E-band

Test results for a 10-Gbps prototype demonstrator working at 71~76 GHz frequency band with a 2-bit/s/Hz spectral efficiency are reported.To overcome the speed limitation of the commercial DA/ADs,a two-channel analog IF multiplexing and demultiplexing topology is adopted as a trade-off between cost and spectrum efficiency.The same approach is also used to achieve up to 20 Gbps with a full 10-GHz bandwidth of the allocated commercial bands(71~76 GHz and 81~86 GHz).

Status adaptive routing with delayed rebroadcast scheme in AODV-based MANETs

An efficient solution is proposed in this article to determine the best reliable route and to prolong the lifetime of the mobile Ad-hoc networks （MANETs）. In the proposed solution, the route discovery process of the Ad-hoc on-demand distance vector routing protocol （AODV） has been modified using a novel delayed rebroadcast scheme. It combines the shortest route selection criterion of AODV with the real network status including the wireless link quality, the remaining power capacity, as well as the traffic load at each node. Simulation results show that the proposed scheme can significantly extend the network lifetime and provide fewer packet losses than the conventional AODV protocol.