In a Wynk

In our everyday lives, there are few things as magical as wireless networks.

Each time I swipe my credit card I find myself counting the seconds before the mobile phone in my pocket gives me a buzz. A few seconds for the transaction to go from the swiping device, over the city's telecom networks, across a satellite hovering 36,000 km away in the geostationary orbit, to check with a database sitting in a server on the other side of the world, before a digital confirmation finds its way back into my mobile phone -- all within about 10 seconds!

The magic works on much smaller scales as well. Bluetooth devices on speakers and earphones, IR remote controls for potato couches, and RFID tags for shoppers, workshops and marathon runners.

Last weekend I came across something new - Lenovo's app for high-speed, peer-to-peer sharing of files and folders: Shareit. I was walking out of the ADHM-2015 bib-distribution area when I saw a kiosk distributing free earphones. It was music company called Wynk and you had to download their app to get the earphones. The only hitch was that I had run out of my data quota for the month and I could not connect to the Google Playstore. "No problem", said the Wynk guy, "I can just share it from my mobile."

At first I thought this was another form of Bluetooth - near field communication and data transmission at 2.4 GHz. But no, this was not Bluetooth. Even with the WiFi and Bluetooth turned off, a file bigger than 15 MB jumped across thin air in less than three seconds! How did this happen?

Turns out that this 5 GHz band is not special to either Lenovo or Wynk. It is a part of the WiFi bandwidth that is less congested compared to the ones used by Bluetooth devices. So it is a lot faster but this transmission-frequency is efficient only at less than half the range of 2.4 GHz devices, which is less than 5 ft..

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LINKS

* List of 2.4 GHz Radio Use -- https://en.wikipedia.org/wiki/List_of_2.4_GHz_radio_use

* What is the difference between a 2.4 GHz and 5 GHz WiFi? -- http://www.howtogeek.com/222249/whats-the-difference-between-2.4-ghz-and-5-ghz-wi-fi-and-which-should-you-use/

* Lenovo Shareit FAQs - http://shareit.lenovo.com/faqs.html

Prepaid Cards in Japan

Multi-purpose prepaid travel cards embedded with an IC–chip is taking Japan closer to cashless transactions.

There are over ten IC chip car makers in Japan and all of them use Sony’s FeliCa technology. IC cards can store a wealth of information and up to 16 separate servicee applications can be read and authenticated in 0.1 seconds. The leading ones are -

Suica-card: Launched in November 2001 by JR (Japan Railways) East, serves the Kanto area, including the Tokyo-Yokohama conurbation. This is a contactless prepaid card that triggers automatic deduction at the ticket gates. An E-money feature added in 2004, allowing payment at vending machines, station kiosks, and shops around stations. 20 million in circulation, usable across 18,500 retails outlets. Service is also available on mobile phones from the bid three carriers – DoCoMo, AU and Softbank

Pasmo-card: The latest rage. Launched early this year by a consortium of over 100 train bus and subway companies across Kanto region. Goes with a catchy slogan, “Densha-mo, Bus-mo, Pasmo”. 3 million cards were sold in the first three weeks..