About Li-Fi

[Shamonto Hasan Easha]

Hi,

I am a new member here, and I'd like to ask some questions to this forum. You people have heard about Li-Fi right? Would you please tell me about that in detail, how it works, pros and cons, and how to implement it in a country, especially in countrysides and villages?

 

Oh, one more thing, can microwave be used instead of IRs or visible electromagnetic waves, without losing speed? Does it cause any interference or something? And, how can I use it in smartphones, PCs, tablets and Laptops?

[Greg H.]

Microwave based wireless networking has been around for a while - I've seen it used to connect separate buildings on a corporate campus to one another, for example.

 

It does have drawbacks, like any networking technology - especially the requirement for line of sight (which I assume Li-Fi would share).

[Shamonto Hasan Easha]

Microwave based wireless networking has been around for a while - I've seen it used to connect separate buildings on a corporate campus to one another, for example.

 

It does have drawbacks, like any networking technology - especially the requirement for line of sight (which I assume Li-Fi would share).

But can we use microwaves instead of lights? I mean, they can cover greater distances than lights, since lights need to be reflected. Moreover, mobile phones use microwaves, and we get good network almost anywhere. So, wouldn't replacing with microwaves remove this drawback of requiring line of sight?

[Greg H.]

Microwave based networking equipment tends to be directional. You point two dishes at one another and communicate directly.

 

There are radio based WAN solutions which work as you describe, but they tend to be lower bandwidth and subject to interference from the same sorts of things that would interrupt radios in general.

[Shamonto Hasan Easha]

Microwave based networking equipment tends to be directional. You point two dishes at one another and communicate directly.

 

There are radio based WAN solutions which work as you describe, but they tend to be lower bandwidth and subject to interference from the same sorts of things that would interrupt radios in general.

So, about interference, does Li-Fi have one? I've seen on few websites that this can be implemented in every houses as regular LED lamps, yet transmitting data. And I also found, light on means 1 and light off means 0, i.e. binary logic. In a house, there will be other lights too, which are not involved in this transmission, and they are always lit, i.e. always 1. Provided those lights are LED bulbs, wouldn't they interfere in this transmission?

[Greg H.]

Honestly, I don't know. I'm not sure how Li-Fi works, aside from it shoots beams of light between the network nodes.

[Endy0816]

For the most part you can get rid of any 'noise' with filters and different encoding/error detection methods.

 

For microwave transmission we reflect them off the troposphere for over the horizon. Signal just degrades when you reflect it off something.

[EdEarl]

Just in case, see: http://en.wikipedia.org/wiki/Li-Fi

[Shamonto Hasan Easha]

For the most part you can get rid of any 'noise' with filters and different encoding/error detection methods.

 

For microwave transmission we reflect them off the troposphere for over the horizon. Signal just degrades when you reflect it off something.

So, microwaves aren't an option then. Would you please kindly reply about interference while using Li-Fi?

[EdEarl]

Interference from ambient light sources will depend on the optics of the receiver (analog of an antenna for microwaves). If the optics allow broadband input, any polarization, and 360 degree input, then there will be interference from all light sources. On the other hand, (for example) if the receiving element is focused in a single direction, narrow beam, for light polarized in one direction of a specific color (wavelength), then interference will be minimized. Or, one might allow 360 degree unpolarized multiple wavelength light and minimize interference by using spread spectrum electronics in the receiver and transmitter.

[Fuzzwood]

So, about interference, does Li-Fi have one? I've seen on few websites that this can be implemented in every houses as regular LED lamps, yet transmitting data. And I also found, light on means 1 and light off means 0, i.e. binary logic. In a house, there will be other lights too, which are not involved in this transmission, and they are always lit, i.e. always 1. Provided those lights are LED bulbs, wouldn't they interfere in this transmission?

Fog, bright sunlight, everything that would basically obscure your own vision. For the rest: your tv remote is a form of Li-Fi

[Shamonto Hasan Easha]

How do I make a Li-Fi device? What things would I need?

[Endy0816]

LED's, light sensors. Some means of converting the output of your sensors into data for your computer.

 

Here is something Arduino-based:

 

http://www.costayannakis.com/uncategorized/arduino-based-li-fi-system/

 

I'm sure there are a bunch of other projects out there. Main question is how complex you want to make it.

Edited February 23, 2014 by Endy0816

[Shamonto Hasan Easha]

LED's, light sensors. Some means of converting the output of your sensors into data for your computer.

 

Here is something Arduino-based:

 

http://www.costayannakis.com/uncategorized/arduino-based-li-fi-system/

 

I'm sure there are a bunch of other projects out there. Main question is how complex you want to make it.

Ok, I didn't understand most of this project. Could you please give me other links?

[openSauce]

Ok, I didn't understand most of this project. Could you please give me other links?

Hi Shamonto,

 

I am the author of the post @ http://www.costayannakis.com/uncategorized/arduino-based-li-fi-system/

 

Consumer LiFi systems, to my knowledge, are not available commercially and are still in the experimentation phase. If you are serious about LiFi you may have to consider creating your own device. My device had a maximum transfer rate of 1,000 bits and was more to show the theory of how an led can be used to transfer data. I have also transferred data via a laser to a printer as shown here:

These are both "line of sight" systems whereby if you break the line you lose some of the data.

 

I think you have to be clear in what you want to do and the purpose.

 

Feel free to ask me any question and I will endeavour to answer

[Shamonto Hasan Easha]

Hi Shamonto,

 

I am the author of the post @ http://www.costayannakis.com/uncategorized/arduino-based-li-fi-system/

 

Consumer LiFi systems, to my knowledge, are not available commercially and are still in the experimentation phase. If you are serious about LiFi you may have to consider creating your own device. My device had a maximum transfer rate of 1,000 bits and was more to show the theory of how an led can be used to transfer data. I have also transferred data via a laser to a printer as shown here:

These are both "line of sight" systems whereby if you break the line you lose some of the data.

 

I think you have to be clear in what you want to do and the purpose.

 

Feel free to ask me any question and I will endeavour to answer

I have seen the article about RONJA, it was quite impressive, but too big for a science project. And yes, I saw your one too, just want to know how do I achieve 700 Mbps with it, and how do I make that. The data is transferred from a smartphone, connected with the transceiver via USB or 3.5 mm jack to another, similarly. Could you please help me out by designing the circuit (and keeping costs minimum)?

[openSauce]

I have seen the article about RONJA, it was quite impressive, but too big for a science project. And yes, I saw your one too, just want to know how do I achieve 700 Mbps with it, and how do I make that. The data is transferred from a smartphone, connected with the transceiver via USB or 3.5 mm jack to another, similarly. Could you please help me out by designing the circuit (and keeping costs minimum)?

Hi S,

I was only able to achieve 1000bit/s without error and only done as a weekend project. You may need to engage/pay an engineer to design circuitry.

 

All the best bro

[Shamonto Hasan Easha]

Hi S,

I was only able to achieve 1000bit/s without error and only done as a weekend project. You may need to engage/pay an engineer to design circuitry.

 

All the best bro

Ok, I have designers ready but I need some specific components like LED Drivers, modulator, DAC, TIA, and lots of other things. How can I find one, and what are the components that work as these?

[openSauce]

Ok, I have designers ready but I need some specific components like LED Drivers, modulator, DAC, TIA, and lots of other things. How can I find one, and what are the components that work as these?

Not sure, I just used an arduino, LED and light sensor nothing as fancy as the above ^

[Shamonto Hasan Easha]

Not sure, I just used an arduino, LED and light sensor nothing as fancy as the above

So, I guess, you can't help me that way? Anyway, thanks for your help. I'd appreciate your help if I do need in future.