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

Giga Hertz

1,000,000,000 vibrations per second. This is one Giga Hertz (GHz).

GHz is just a tiny sliver of the electromagnetic spectrum (EM) that surrounds us. Yet, it has become so indispensible in our lives that most of us barely give it a second thought.

Just consider this:

* Bluetooth Devices used in personal area networks (wireless earphones, speakers, etc.,) use the frequency range 2.4 to 2.4835 GHz. The protocol divides the band into 79 channels (each 1 MHz wide) and changes channels up to 1600 times per second!

* Micowave Ovens cooks your food and heats your coffee using high power magnetrons to transmit EM radiation in the 2.4 GHz band.

* Telecom Towers - Use the range 1 GHz to 300 GHz. Interfering with the high power transmission of these towers can be fatal, as proven by this case of Darwin Awards, titled "Christmans Roast".

I am yet to figure out how we managed to get such precise control over anything that transmits signals at amazingly high frequencies...


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LINKS

* Connectivity failure while using Bluetooth and USB-3 devices simultaneously - http://www.bluetoothandusb3.com/

* EM interference at 2.4 GHz - https://en.wikipedia.org/wiki/Electromagnetic_interference_at_2.4_GHz

* Instructables - http://www.instructables.com/id/Car-motorcycle-or-bicycle-wifi-alarm-rang-500m-10-/

WiFi Internet Connectivity

We just graduated from a dongle to a wifi router.

I must thank BSNL, MTS, Reliance and Tata Docomo for forcing us to take this quantum leap. All four of them have been providing such pathetic internet connectivity in Noida that we never really experienced a broadband internet connection at home, until today.

BSNL had everything going for it. It was the first one to lay down optic cables and hubs in the neighborhood and it was offering the most competitive rates too. Unfortunately they also had a bunch of linemen moulded in the licence-permit Raj. Since they just could not kick the habit of demanding  "baksheesh"from customers, they always ensured that the last-mile connectivity was primed to fail, as frequently as possible.

The telecom corporates fared no better. The slick ad campaigns from Reliance, MTS and Tata Docomo offered high-speed internet of "up to 21 Mbps". In reality this meant that the speeds could be anywhere between 0 Kbps and 450 Kbps, well within their promised range!

Our new service provider, a franchisee for Triple Play, simply promises a download speed and then delivers it. We now have a plan for 4Mbps speed till 25GB for Rs. 800/month. Speedtest has consistently confirmed that - at least so far - they have exceeded promises.

Unlike last time with BSNL, we have picked a wireless router on our own from the online market. A Netgear N150 (JNR1010v2) marked with an MRP of Rs. 1600 was available in Atta Market for Rs. 1200. The same thing is on Snapdeal for Rs. 784!

How on earth do they figure a pricing strategy in a market like this?


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An attempt to make sense of the technical hocus-pocus:

Q. What is the radio frequency used by wifi routers?
A. Usually 2.4 GHz. for a maximum link speed of 150 Mbps. It is interesting to note that 'larger channel widths do not result in higher range, just faster speeds at close range'. So it is just as well that I did not buy a dual antenna N300 model for double the price!
Netgear's classification - details here.

Q. What is an "External 5dBi antenna"?
A. dBi stands for 'decibels relative to isotropic'. It represents  the direction and efficiency (Antenna Gain) with which a transmitter sends signals across distances. More here.

Q. The router conforms to four sets of international standards: Safety, EMC, Radio Spectrum and RoHS. What are these?
A. EMC = Electromagnetic Compatibility (European Standard - EN and International Electrotechnical Commission or IEC);
RoHS = Restriction of Hazardous Substances Directive  - also known as the "lead-free directive" it restricts the use of six substances in manufacturing.

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REFERENCES & LINKS

* http://www.explainthatstuff.com/wirelessinternet.html