India vs Australia, 1st Test - Live Cricket Score, Commentary

Series: Australia tour of India, 2017 Venue: Maharashtra Cricket Association Stadium, Pune Date & Time: Feb 23-Feb 27, 09:30 AM LOCAL

AUS 202/7 (81.1 Ovs)

CRR: 2.49

Day 1: 3rd Session - Australia opt to bat

Batsman

Mitchell Starc *

35.71

Steve O'Keefe

0.00

Bowler

ECO

Umesh Yadav *

9.1

2.40

Ravichandran Ashwin

1.63

Key Stats

Partnership: 6(16)

Last Wkt: Renshaw 68 (156)

Ovs Left: 8.5

Last 10 overs: 24 runs, 2 wkts

Toss: Australia(Batting)

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81.1

U Yadav to Starc, no run

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Runs Scored: 3

2 0 1 0 0 0

Score after 81 overs

AUS 202-7

O'Keefe

0(11)

Starc

5(13)

Ashwin

30-10-49-2

Mayank Srivastava says: The pitch clearly didn't have too many demons in it. Hope to see some aggression from the Australian bowlers after a rather mundane performance by their batsmen.

80.6

Ashwin to O'Keefe, no run, shimmies out very close to the pitch and jams it back to Ashwin

80.5

Ashwin to O'Keefe, no run, right through the gate and over the stumps! Dangerous shot to play on such a turning pitch. Pushed through the air and spitting in from outside off, O'Keefe shapes to force it through the covers and has the bounce to thank for his non-dismissal. Ripper!

80.4

Ashwin to O'Keefe, no run, flatter outside off, O'Keefe blocks from the crease

80.3

Ashwin to Starc, 1 run, looped up on middle and leg, trying to tempt Starc for the big hit. Starc does the wise thing of knocking it down to long-off for a single

80.2

Ashwin to Starc, no run, driven to short cover

80.1

Ashwin to Starc, 2 runs, tries to drive with the turn but fails to cover it completely and gets a thick outside edge which scoots wide of gully for a couple of runs

Ashwin will continue with the old ball..

Time for a breather. The Aussie stonewalling finally gives way to what was predicted to be the order of the day. Renshaw looked to be the one to hold fort but with him gone now, anything the tail gets with its wagging will be a bonus.

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Runs Scored: 1

1 0 0 0 0 0

Score after 80 overs

AUS 199-7

O'Keefe

0(8)

Starc

2(10)

U Yadav

9-2-22-2

79.6

U Yadav to O'Keefe, no run, feels with the hanging vertical blade outside his off stump and defends away from his body. To earn himself a drink

79.5

U Yadav to O'Keefe, no run, he goes full. Looking to mix things up here is Yadav. Squeezed out in form of a drive to mid-on

79.4

U Yadav to O'Keefe, no run, and again. Another one scissors back in sharply and whizzes past the inside edge on the defence to rap the thigh pad. Higher this time

79.3

U Yadav to O'Keefe, no run, another pad-pinner. 90mph again. Tails back in once again. The very late swing at serious pace and you cannot blame O'Keefe to get his defence late. Down leg reckons umpire Llong. Can't disagree

79.2

U Yadav to O'Keefe, no run, aims for the blockholer. Just the slightest of opportunity for O'Keefe to get under this. And he takes it well to dig it out

79.1

U Yadav to Starc, 1 run, 129kph, much slower than usual. Starc's bat handle rolls in his palm off the front footed defence. In the gap through the covers though

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Runs Scored: 3

0 1 W 0 0 2L

Score after 79 overs

AUS 198-7

O'Keefe

0(3)

Starc

1(9)

Ashwin

29-10-46-2

78.6

Ashwin to O'Keefe, leg byes, 2 runs, takes off. With the turn. And past the glancing bat. Nothing leg slip can do about it either. Takes everybody by surprise

78.5

Ashwin to O'Keefe, no run, the carrom ball. With a dragged back length. All the time on the planet to read it off the wicket and knock it out

78.4

Ashwin to O'Keefe, no run, forward and pushes it into the off-side

Steve O'Keefe, right handed bat, comes to the crease

78.3

Ashwin to Renshaw, out Caught by Vijay!! The final straw the Aussies were clutching. A rare moment of lapse in concentration here from Renshaw to end a top knock. Feels for a wide floater and pushes his hands at it. The pitch ensures that the ball rips extravaganlty but doesn't quite ensure that the bat isn't found. Second slip in operation to pluck it inches off the turf. Australia now officially into the tail. Renshaw c Vijay b Ashwin 68(156) [4s-10 6s-1]

Ashwin to Renshaw, THAT'S OUT!! Caught!!

78.2

Ashwin to Starc, 1 run, pushes it very softly to a deepish mid-off and takes him on. In getting to the safer end

78.1

Ashwin to Starc, no run, leans forward and with his head right over the ball's head, taps it out

Li-Fi

From Wikipedia, the free encyclopedia

(Redirected from LIFI)

LiFi works in complement with existing and emerging wireless systems.

Light Fidelity (Li-Fi) is a bidirectional, high-speed and fully networked wireless communication technology similar to Wi-Fi. The term was coined by Harald Haas^[1] and is a form of visible light communication and a subset of optical wireless communications (OWC) and could be a complement to RF communication (Wi-Fi or cellular networks), or even a replacement in contexts of data broadcasting.

It is wire and uv visible-light communication or infrared and near-ultraviolet instead of radio-frequency spectrum, part of optical wireless communications technology, which carries much more information and has been proposed as a solution to the RF-bandwidth limitations.^[2]

[hide]

Technology details[edit]

This OWC technology uses light from light-emitting diodes (LEDs) as a medium to deliver networked, mobile, high-speed communication in a similar manner to Wi-Fi.^[3] The Li-Fi market is projected to have a compound annual growth rate of 82% from 2013 to 2018 and to be worth over $6 billion per year by 2018.^[4]

Visible light communications (VLC) works by switching the current to the LEDs off and on at a very high rate,^[5] too quick to be noticed by the human eye. Although Li-Fi LEDs would have to be kept on to transmit data, they could be dimmed to below human visibility while still emitting enough light to carry data.^[6] The light waves cannot penetrate walls which makes a much shorter range, though more secure from hacking, relative to Wi-Fi.^[7]^[8] Direct line of sight is not necessary for Li-Fi to transmit a signal; light reflected off the walls can achieve 70 Mbit/s.^[9]^[10]

Li-Fi has the advantage of being useful in electromagnetic sensitive areas such as in aircraft cabins, hospitals and nuclear power plants without causing electromagnetic interference.^[7]^[11]^[8] Both Wi-Fi and Li-Fi transmit data over the electromagnetic spectrum, but whereas Wi-Fi utilizes radio waves, Li-Fi uses visible light. While the US Federal Communications Commission has warned of a potential spectrum crisis because Wi-Fi is close to full capacity, Li-Fi has almost no limitations on capacity.^[12] The visible light spectrum is 10,000 times larger than the entire radio frequency spectrum.^[13] Researchers have reached data rates of over 224 Gbit/s, which is much faster than typical fast broadband in 2013.^[14]^[15] Li-Fi is expected to be ten times cheaper than Wi-Fi.^[6] Short range, low reliability and high installation costs are the potential downsides.^[4]^[5]

PureLiFi demonstrated the first commercially available Li-Fi system, the Li-1st, at the 2014 Mobile World Congress in Barcelona.^[16]

Bg-Fi is a Li-Fi system consisting of an application for a mobile device, and a simple consumer product, like an IoT (Internet of Things) device, with color sensor, microcontroller, and embedded software. Light from the mobile device display communicates to the color sensor on the consumer product, which converts the light into digital information. Light emitting diodes enable the consumer product to communicate synchronously with the mobile device.^[17]^[18]

History[edit]

Harald Haas, coined the term "Li-Fi" at his TED Global Talk where he introduced the idea of "Wireless data from every light".^[19] He is Chairman of Mobile Communications at the University of Edinburgh and co-founder of pureLiFi.^[20]

The general term visible light communication (VLC), whose history dates back to the 1880s, includes any use of the visible light portion of the electromagnetic spectrum to transmit information. The D-Light project at Edinburgh's Institute for Digital Communications was funded from January 2010 to January 2012.^[21] Haas promoted this technology in his 2011 TED Global talk and helped start a company to market it.^[22] PureLiFi, formerly pureVLC, is an original equipment manufacturer (OEM) firm set up to commercialize Li-Fi products for integration with existing LED-lighting systems.^[23]^[24]

In October 2011, companies and industry groups formed the Li-Fi Consortium, to promote high-speed optical wireless systems and to overcome the limited amount of radio-based wireless spectrum available by exploiting a completely different part of the electromagnetic spectrum.^[25]

A number of companies offer uni-directional VLC products, which is not the same as Li-Fi - a term defined by the IEEE 802.15.7r1 standardization committee.^[26]

VLC technology was exhibited in 2012 using Li-Fi.^[27] By August 2013, data rates of over 1.6 Gbit/s were demonstrated over a single color LED.^[28] In September 2013, a press release said that Li-Fi, or VLC systems in general, do not require line-of-sight conditions.^[29] In October 2013, it was reported Chinese manufacturers were working on Li-Fi development kits.^[30]

In April 2014, the Russian company Stins Coman announced the development of a Li-Fi wireless local network called BeamCaster. Their current module transfers data at 1.25 gigabytes per second but they foresee boosting speeds up to 5 GB/second in the near future.^[31] In 2014 a new record was established by Sisoft (a Mexican company) that was able to transfer data at speeds of up to 10 Gbit/s across a light spectrum emitted by LED lamps.^[32]

Recent integrated CMOS optical receivers for Li-Fi systems are implemented with avalanche photodiodes (APDs) which has a low sensitivity. ^[33] In July 2015, IEEE has operated the APD in Geiger-mode as a single photon avalanche diode (SPAD) to increase the efficiency of energy-usage and makes the receiver more sensitive. ^[34] Also this operation could be performed as quantum-limited sensitivity that makes receivers detect weak signals from far distance. ^[33]

Commercialization[edit]

There are some startup companies around the world working on LiFi technology. Visible Light Communication (VLC) is another term that is sometimes used for this technology. Here is the list of companies developing LiFi technology:

PureLiFi is the main company in this field. They are developing LiFi luminaries with a French company named Lucibel.
The main startup company in US working on this technology is VLNComm. They have been funded by US Department of Energy and National Science Foundation.
OLEDComm is a French company working on LiFi. They have some products for indoor positioning.
LightPointe is a manufacturer of point-to-point Gigabit Ethernet Free Space Optics and Hybrid Optical-Radio Bridges, has recently started working on VLC.
i2cat, located in Barcelona, Spain is also working on location based system using visible light communication.
ByteLight which is recently acquired by the LED manufacturer Acuty Brands is developing location based services.
Nakagawa Lab in Japan
Basic6
Velmenni
Zero1
Axrtek
There are many big companies entertaining this technology: Qualcomm, GE, Panasonic, Philips, Samsung, OSRAM

Standards[edit]

Like Wi-Fi, Li-Fi is wireless and uses similar 802.11 protocols; but it uses visible light communication (instead of radio frequency waves), which has much wider bandwidth.

One part of VLC is modeled after communication protocols established by the IEEE 802 workgroup. However, the IEEE 802.15.7 standard is out-of-date, it fails to consider the latest technological developments in the field of optical wireless communications, specifically with the introduction of optical orthogonal frequency-division multiplexing (O-OFDM) modulation methods which have been optimized for data rates, multiple-access and energy efficiency.^[35] The introduction of O-OFDM means that a new drive for standardization of optical wireless communications is required.

Nonetheless, the IEEE 802.15.7 standard defines the physical layer (PHY) and media access control (MAC) layer. The standard is able to deliver enough data rates to transmit audio, video and multimedia services. It takes into account optical transmission mobility, its compatibility with artificial lighting present in infrastructures, and the interference which may be generated by ambient lighting. The MAC layer permits using the link with the other layers as with the TCP/IP protocol.^{[citation needed]}

The standard defines three PHY layers with different rates:

The PHY 1 was established for outdoor application and works from 11.67 kbit/s to 267.6 kbit/s.
The PHY 2 layer permits reaching data rates from 1.25 Mbit/s to 96 Mbit/s.
The PHY 3 is used for many emissions sources with a particular modulation method called color shift keying (CSK). PHY III can deliver rates from 12 Mbit/s to 96 Mbit/s.^[36]

The modulation formats recognized for PHY I and PHY II are on-off keying (OOK) and variable pulse position modulation (VPPM). The Manchester coding used for the PHY I and PHY II layers includes the clock inside the transmitted data by representing a logic 0 with an OOK symbol "01" and a logic 1 with an OOK symbol "10", all with a DC component. The DC component avoids light extinction in case of an extended run of logic 0's.^{[citation needed]}

The first VLC smartphone prototype was presented at the Consumer Electronics Show in Las Vegas from January 7–10 in 2014. The phone uses SunPartner's Wysips CONNECT, a technique that converts light waves into usable energy, making the phone capable of receiving and decoding signals without drawing on its battery.^[37]^[38] A clear thin layer of crystal glass can be added to small screens like watches and smartphones that make them solar powered. Smartphones could gain 15% more battery life during a typical day. The first smartphones using this technology should arrive in 2015. This screen can also receive VLC signals as well as the smartphone camera.^[39] The cost of these screens per smartphone is between $2 and $3, much cheaper than most new technology.^[40]

Philips lighting company has developed a VLC system for shoppers at stores. They have to download an app on their smartphone and then their smartphone works with the LEDs in the store. The LEDs can pinpoint where they are located in the store and give them corresponding coupons and information based on which aisle they are on and what they are looking at.^[41]

Anderson

Thursday, 23 February 2017