Packet switching and the communication networks of the eighties and beyond

1984 ◽  
Vol 9 (2) ◽  
pp. 67-73 ◽  
Author(s):  
G. Philip

Packet switched data communication services are now firmly established as a multi-million dollar industry. In the not too distant future, packet switching technology will be applied to the communication of voice as well. The availability of voice packet networks (whether separate or integrated with data) will have profound implications in providing cost-effective access to emerging voice-based computerised information services. Al though such networks are technically and economically feasible at the present time, there are a few minor problems to over come before they become widely available. This article ex amines the principles, economics, benefits and prospects of employing the packet switching principles in the transmission of voice.


2020 ◽  
Author(s):  
Yiding Lin ◽  
Danhao Ma ◽  
Rui-Tao Wen ◽  
Kwang Hong Lee ◽  
Govindo Syaranamual ◽  
...  

Abstract Photonic-integrated circuits (PICs) have become one of the most promising solutions to the burgeoning global data communication and are being envisioned to have revolutionary impact in many other emerging fields. This outlook requires future PICs to be significantly more broadband and cost-effective. The current germanium (Ge)-based active photonic devices in PICs are thus facing a new bandwidth-cost trade-off. Here, we demonstrate ultra-broadband, high-efficiency Ge photodetectors up to 1,630 nm operation wavelength and Ge0.99Si0.01 electro-absorption (EA) modulator arrays with an operating range of ~100 nm from 1,525 to 1,620 nm, using a CMOS-compatible recess-type silicon nitride (SiNx) stressor. The broadband operation could facilitate a wide (>100 nm) window for low-cost Ge modulator-detector co-integration, requiring only a single step of Ge epitaxy and two different SiNx depositions. The broad modulation and co-integration coverage can be entirely shifted to shorter (~1,300 nm) and longer (>1,700 nm) wavelengths with small amounts of Si or tin (Sn) alloying. This proof-of-concept work provides a pathway for PICs towards future low-cost and high-data-capacity communication networks, immediately accessible by designers through foundries.



2020 ◽  
pp. 87-97
Author(s):  
Sourish Chatterjee ◽  
Biswanath Roy

In an office space, an LED-based lighting system allows you to perform the function of a data transmitter. This article discusses the cost-effective design and development of a data-enabled LED driver that can transmit data along with its receiving part. In addition, this paper clearly outlines the application of the proposed VLC system in an office environment where ambient light interference is a severe issue of concern. The result shows satisfactory lighting characteristics in general for this area in terms of average horizontal illuminance and illuminance uniformity. At the same time, to evaluate real-time and static communication performance, Arduino interfaced MATLAB Simulink model is developed, which shows good communication performance in terms of BER (10–7) even in presence of ambient light noise with 6 dB signal to interference plus noise ratio. Our designed system is also flexible to work as a standalone lighting system, whenever data communication is not required.





2016 ◽  
Vol 6 (2) ◽  
pp. 1-10
Author(s):  
Chaima Bensaid ◽  
Sofiane Boukli Hacene ◽  
Kamel Mohamed Faraoun

Vehicular networks or VANET announce as the communication networks of the future, where the mobility is the main idea. These networks should be able to interconnect vehicles. The optimal goal is that these networks will contribute to safer roads and more effective in the future by providing timely information to drivers and concerned authorities. They are therefore vulnerable to many types of attacks among them the black hole attack. In this attack, a malicious node disseminates spurious replies for any route discovery in order to monopolize all data communication and deteriorate network performance. Many studies have focused on detecting and isolating malicious nodes in VANET. In this paper, the authors present two mechanisms to detect this attack. The main goal is detecting as well as bypass cooperative black hole attack. The authors' approaches have been evaluated by the detailed simulation study with NS2 and the simulation results shows an improvement of protocol performance.



2014 ◽  
Vol 513-517 ◽  
pp. 772-776
Author(s):  
Chen Wang ◽  
Hong Ai ◽  
Lie Wu ◽  
Yun Yang

The smart grid that the next-generation electric power system is studied intensively as a promising solution for energy crisis. One important feature of the smart grid is the integration of high-speed, reliable and secure data communication networks to manage the complex power systems effectively and intelligently. The goal of smart grid is to achieve the security of operation, economic efficient and environmental friendly. To achieve this goal, we proposed a fine-grained access control model for smart grid. In order to improve the security of smart grid, an access-trust-degree algorithm is proposed to evaluate the reliability of the user who want to access to the smart grid.





1995 ◽  
Vol 2 (5) ◽  
pp. 20-33 ◽  
Author(s):  
O. Spaniol ◽  
A. Fasbender ◽  
S. Hoff ◽  
J. Kaltwasser ◽  
J. Kassubek


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