Ubiquitous broadband access: A low-cost satellite solution

2007 ◽  
Author(s):  
Ali Grami
Keyword(s):  
Low Cost ◽  
Broadband Access ◽  
Satellite Solution

India Connected

2019 ◽  
Author(s):  
Ravi Agrawal
Keyword(s):  
Gender Inequality ◽  
Online Community ◽  
Low Cost ◽  
Caste System ◽  
The Internet ◽  
Broadband Access ◽  
Arranged Marriages ◽  
Rural Villages ◽  
Start Ups ◽  
Entire Economy

Former chief CNN India correspondent and award-wining journalist Ravi Agrawal takes readers on a journey across the Subcontinent, through its remote rural villages and its massive metropolises, seeking out the nexuses of change created by smartphones, and with them connection to the internet. As always with India, the numbers are staggering: in 2000, 20 million Indians had access to the internet; by 2017, 465 million were online, with three Indians discovering the internet every second. By 2020, India's online community is projected to exceed 700 million, and more than a billion Indians are expected to be online by 2025. In the course of a single generation, access to the internet has progressed from dial-up connections on PCs, to broadband access, wireless, and now 4G data on phones. The rise of low-cost smartphones and cheap data plans has meant the country leapfrogged the baby steps their Western counterparts took toward digital fluency. The results can be felt in every sphere of life, upending traditions and customs and challenging conventions. Nothing is untouched, from arranged marriages to social status to business start-ups, as smartphones move the entire economy from cash-based to credit-based. Access to the internet is affecting the progress of progress itself. As Agrawal shows, while they offer immediate and sometimes mind-altering access to so much for so many, smartphones create no immediate utopia in a culture still driven by poverty, a caste system, gender inequality, illiteracy, and income disparity. Internet access has provided greater opportunities to women and changed the way in which India's many illiterate poor can interact with the world, but it has also meant that pornography has become more readily available. Under a government keen to control content, it has created tensions. And in a climate of hypernationalism, it has fomented violence and even terrorism. The influence of smartphones on "the world's largest democracy" is nonetheless pervasive and irreversible, and India Connected reveals both its dimensions and its implications.

Best Practices in Designing Low-Cost Community Wireless Networks

2013 ◽  
pp. 215-235
Author(s):  
Tomas Dulik ◽  
Michal Bliznak ◽  
Roman Jasek
Keyword(s):  
Growth Rate ◽  
Wireless Networks ◽  
Best Practices ◽  
Success Factors ◽  
New Technologies ◽  
Low Cost ◽  
Broadband Access ◽  
The European Union ◽  
Internet Service ◽  
Non Profit

The Czech Republic (CR) has been ranked the 1st among the countries of the European Union (EU) countries in the growth rate of broadband access. The Internet penetration rate has increased by 48 percent between 2005 and 2011. This high growth rate is driven by the entry of new operators and the proliferation of Community Wireless Networks (CWNs). The CR holds the first place in EU in the number of newly entered operators. There are 1150 companies providing Internet access in 601 Czech towns and 5645 villages. In addition, a number of community wireless networks have emerged as an alternative of these commercial Internet Service Providers (ISPs). Their main purpose is to increase the affordability and penetration of broadband Internet in the country. This chapter discusses the contribution of CWNs to the proliferation and affordability of broadband access in the CR, focusing on the reasons for their success and popularity. Their key success factors include obtaining a non-profit status, engaging academics, and cooperating with government entities. They formed the CZFree.net forum for experts and volunteers to exchange information and best practices with respect to new technologies, design considerations, and technical and social issues. It also articulates on technology options and best practices for building low-cost CWNs. Furthermore, the chapter discusses the role of the Netural czFree eXchange association in aggregating their technical, financial, and personal resources of individual CWNs. Thanks to this association and the CZFree.net forum, CWNs in the CR have become influential competitors in the local telecommunication industry.

Comparison and Analysis of Routing Protocols Based on OPNET for Fiber-Wireless Broadband Access Network

2014 ◽  
Vol 635-637 ◽  
pp. 1522-1525
Author(s):  
Chun Xin Xu ◽  
Fan Bo Meng ◽  
Miao Yu ◽  
Xiu Jun Zhang ◽  
Yun Feng Guo
Keyword(s):  
Routing Protocols ◽  
Performance Optimization ◽  
Ad Hoc ◽  
Transmission Rate ◽  
Low Cost ◽  
Access Network ◽  
Mesh Network ◽  
Self Healing ◽  
Broadband Access ◽  
Broadband Access Network

As a promising communication technology for smart grid system, Fiber-Wireless (FiWi) broadband access network integrating wireless and optical access technologies, is becoming a promising “last mile” access technology. As the front-end of FiWi broadband access network, Wireless Mesh Network (WMN) has the features of high transmission rate, wide coverage and low cost of networking, etc, which can make FiWi broadband access network have the advantages of self-healing, self-configuring and flexibility. As one of the key technologies in WMN, wireless routing protocols play an important role in the performance optimization of WMN, which directly influence FiWi broadband access network. Thus, this paper mainly studies the routing protocols in WMN based on OPNET network simulation platform. By simulation and analysis, this paper shows that Ad hoc On-demand Distance Vector (AODV) routing protocol has low data dropped and good performance in network delay. Dynamic Source Routing (DSR) protocol has low network load. Meanwhile, Optimized Link State Routing (OLSR) protocol has high network throughput.

Decomposition of the metastable beta titanium alloy Ti-15-3

1983 ◽  
Vol 41 ◽  
pp. 264-265
Author(s):  
Y. L. Chen ◽  
S. Fujlshiro
Keyword(s):  
Low Cost ◽  
High Strength ◽  
Alpha Phase ◽  
Thick Sheet ◽  
Omega Phase ◽  
Beta Titanium Alloy ◽  
Beta Titanium ◽  
Beta Matrix ◽  
Metastable Beta ◽  
Very High

Metastable beta titanium alloys have been known to have numerous advantages such as cold formability, high strength, good fracture resistance, deep hardenability, and cost effectiveness. Very high strength is obtainable by precipitation of the hexagonal alpha phase in a bcc beta matrix in these alloys. Precipitation hardening in the metastable beta alloys may also result from the formation of transition phases such as omega phase. Ti-15-3 (Ti-15V- 3Cr-3Al-3Sn) has been developed recently by TIMET and USAF for low cost sheet metal applications. The purpose of the present study was to examine the aging characteristics in this alloy.The composition of the as-received material is: 14.7 V, 3.14 Cr, 3.05 Al, 2.26 Sn, and 0.145 Fe. The beta transus temperature as determined by optical metallographic method was about 770°C. Specimen coupons were prepared from a mill-annealed 1.2 mm thick sheet, and solution treated at 827°C for 2 hr in argon, then water quenched. Aging was also done in argon at temperatures ranging from 316 to 616°C for various times.

Chromic Acid Etching of Polyethylene

1973 ◽  
Vol 31 ◽  
pp. 72-73
Author(s):  
J. D. Muzzy ◽  
R. D. Hester ◽  
J. L. Hubbard
Keyword(s):  
Chromic Acid ◽  
Low Cost ◽  
Acid Etching ◽  
Crystalline Morphology ◽  
Bulk Specimen ◽  
Morphological Studies ◽  
Perfect Form ◽  
Molecular Length ◽  
Lamellar Texture ◽  
Cost Studies

Polyethylene is one of the most important plastics produced today because of its good physical properties, ease of fabrication and low cost. Studies to improve the properties of polyethylene are leading to an understanding of its crystalline morphology. Polyethylene crystallized by evaporation from dilute solutions consists of thin crystals called lamellae. The polyethylene molecules are parallel to the thickness of the lamellae and are folded since the thickness of the lamellae is much less than the molecular length. This lamellar texture persists in less perfect form in polyethylene crystallized from the melt.Morphological studies of melt crystallized polyethylene have been limited due to the difficulty of isolating the microstructure from the bulk specimen without destroying or deforming it.

Glass Knife Geometry as Seen by the SEM

1971 ◽  
Vol 29 ◽  
pp. 454-455
Author(s):  
J. Temple Black
Keyword(s):  
Low Cost ◽  
Amorphous Material ◽  
Stress Concentrations ◽  
Basic Tool ◽  
Tool Materials ◽  
Optical Inspection ◽  
Surface Flaws ◽  
Slip Planes ◽  
Glass Knife ◽  
Diamond Knife

In ultramicrotomy, the two basic tool materials are glass and diamond. Glass because of its low cost and ease of manufacture of the knife itself is still widely used despite the superiority of diamond knives in many applications. Both kinds of knives produce plastic deformation in the microtomed section due to the nature of the cutting process and microscopic chips in the edge of the knife. Because glass has no well defined slip planes in its structure (it's an amorphous material), it is very strong and essentially never fails in compression. However, surface flaws produce stress concentrations which reduce the strength of glass to 10,000 to 20,000 psi from its theoretical or flaw free values of 1 to 2 million psi. While the microchips in the edge of the glass or diamond knife are generally too small to be observed in the SEM, the second common type of defect can be identified. This is the striations (also termed the check marks or feathers) which are always present over the entire edge of a glass knife regardless of whether or not they are visable under optical inspection. These steps in the cutting edge can be observed in the SEM by proper preparation of carefully broken knives and orientation of the knife, with respect to the scanning beam.

Spectraplot: A PC-based spectrum translation and display program

1988 ◽  
Vol 46 ◽  
pp. 918-919
Author(s):  
H. O. Colijn
Keyword(s):  
Low Cost ◽  
Transfer Program ◽  
File Transfer ◽  
Transfer Data ◽  
Error Checking ◽  
Data Files ◽  
The University

Many labs today wish to transfer data between their EDS systems and their existing PCs and minicomputers. Our lab has implemented SpectraPlot, a low- cost PC-based system to allow offline examination and plotting of spectra. We adopted this system in order to make more efficient use of our microscopes and EDS consoles, to provide hardcopy output for an older EDS system, and to allow students to access their data after leaving the university.As shown in Fig. 1, we have three EDS systems (one of which is located in another building) which can store data on 8 inch RT-11 floppy disks. We transfer data from these systems to a DEC MINC computer using “SneakerNet”, which consists of putting on a pair of sneakers and running down the hall. We then use the Hermit file transfer program to download the data files with error checking from the MINC to the PC.

Transmission Electron Microscopy of oriented Co84Cr14Ta2 thin films for longitudinal magnetic recording

1991 ◽  
Vol 49 ◽  
pp. 756-757
Author(s):  
T. P. Nolan
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Low Cost ◽  
Low Noise ◽  
Information Storage ◽  
High Coercivity ◽  
Magnetic Alloy ◽  
Magnetic Media ◽  
Transmission Electron

Thin film magnetic media are being used as low cost, high density forms of information storage. The development of this technology requires the study, at the sub-micron level, of morphological, crystallographic, and magnetic properties, throughout the depth of the deposited films. As the microstructure becomes increasingly fine, widi grain sizes approaching 100Å, the unique characterization capabilities of transmission electron microscopy (TEM) have become indispensable to the analysis of such thin film magnetic media.Films were deposited at 225°C, on two NiP plated Al substrates, one polished, and one circumferentially textured with a mean roughness of 55Å. Three layers, a 750Å chromium underlayer, a 600Å layer of magnetic alloy of composition Co84Cr14Ta2, and a 300Å amorphous carbon overcoat were then sputter deposited using a dc magnetron system at a power of 1kW, in a chamber evacuated below 10-6 torr and filled to 12μm Ar pressure. The textured medium is presently used in industry owing to its high coercivity, Hc, and relatively low noise. One important feature is that the coercivity in the circumferential read/write direction is significandy higher than that in the radial direction.

Influence of MBE Growth Conditions on Dislocation Densities of GaAs/Ge Epilayers Grown on Silicon Substrates

1985 ◽  
Vol 43 ◽  
pp. 364-365
Author(s):  
K.M. Hones ◽  
P. Sheldon ◽  
B.G. Yacobi ◽  
A. Mason
Keyword(s):  
High Efficiency ◽  
Lattice Mismatch ◽  
Low Cost ◽  
Growth Conditions ◽  
Nonradiative Recombination ◽  
Device Structure ◽  
Si Substrates ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Dislocation Type

There is increasing interest in growing epitaxial GaAs on Si substrates. Such a device structure would allow low-cost substrates to be used for high-efficiency cascade- junction solar cells. However, high-defect densities may result from the large lattice mismatch (∼4%) between the GaAs epilayer and the silicon substrate. These defects can act as nonradiative recombination centers that can degrade the optical and electrical properties of the epitaxially grown GaAs. For this reason, it is important to optimize epilayer growth conditions in order to minimize resulting dislocation densities. The purpose of this paper is to provide an indication of the quality of the epitaxially grown GaAs layers by using transmission electron microscopy (TEM) to examine dislocation type and density as a function of various growth conditions. In this study an intermediate Ge layer was used to avoid nucleation difficulties observed for GaAs growth directly on Si substrates. GaAs/Ge epilayers were grown by molecular beam epitaxy (MBE) on Si substrates in a manner similar to that described previously.

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