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..
* 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