IR (Infrared Communication) 

Dear Melleeman, I think one of the reasons is the infrared wave can be transmitted only light of sight. Therefore it is not the competitor of the current WiFi, 2G, 3G, 4G bands

Dear Blair, The infrared way contains heat. It is used for some heating application. The second application type of infrared is communication. In this case, the intensity of Infrared is very small. Therefore, it carried is very small of heat that does not make the surrounding environment hotter.

@@ezTCP Thank you. So why do we need a special electric transmitter if it is 'small intensity'? I know about frequencies and the range of the NIR, but, why can't other IR heat radiators, human body etc, affect the receiver? And if it is 'small intensity' how does the IR radiate across such large (relative) distances, 10s of metres, without a 'strong' original heat source? Normally even high output transmitters, small indoor house fires etc, output would not reach such distances. Is this not about heat, but about electricity?

Dear @@fractalnomics Unfortunately, We are sorry, We cannot answer your questions. We are not specialized on low-level wireless communication. We just apply it. The above video is made when We did an DIY project that uses our hardware platform, called PHPoC. To answer your question correctly, an expert on wireless communication is required. Best regards,

@@ezTCP Cheers. Thank you.

@@fractalnomics No, IR is not heat itself. IR is just an electromagnetic wave of a specific wave length range. Heat is simply the vibration of molecules, that’s it. The faster they vibrate the hotter they are. It just so happens that when these molecules vibrate faster they produce more IR radiation (as well as many other types of radiation). Yes IR communications devices are limited, they penetrate things poorly and they are very directional and subject to interference; as you alluded to; sources of heat will create interference. However, if you can see a traffic light on a bright day then I’m sure that your TV will recognise IR commands in a warm room, it’s the same principle. As long as the signal is tuned and at a threshold over the noise then the signal will be recognised. That’s why traffic lights have a shade over them to reduce interference from the sun. They are also tuned to specific frequency’s which results in the varying colours that we need to recognise. The universe is full of electromagnetic waves it’s just that we have evolved to see only those that penetrate physical objects poorly (light), that way we can understand the physical physics of our environment.

Just bcz u can't understand this accent of eng doesn't mean she has to change hers. She has an accent and let it be. U could've just wrote to give captions.