decreasing range of ble

RE: decreasing range of ble

AndrzejB — Sat, 04 Nov 2017 11:56:15 GMT

Yes, 10 meters wide faraday cage would be epic :D But seriously I meant microwave for example. You could throw transmitter and receiver inside of it, perform pairing and then take them out.

RE: decreasing range of ble

endnode — Sat, 04 Nov 2017 11:42:45 GMT

I've mentioned security security just to make sure what is the desired use case. I personally believe that only total noob would think this is feasible with this kind of radio but I'm still seeing this kind of question here on the forum as well as in the business so I needed to mention it;)

RE: decreasing range of ble

endnode — Sat, 04 Nov 2017 11:41:17 GMT

How you make Faraday cage with 10-meter diameter?;))) Once you are able to equip some room to the extend that it works as Faraday cage then you don't need any other security because it will basically be a vault in a bank;)))

RE: decreasing range of ble

AndrzejB — Sat, 04 Nov 2017 11:28:04 GMT

If it's security feature the transmitting device could be placed inside a faraday cage. As far as I know, any radio signal shouldn't get out of it.

RE: decreasing range of ble

endnode — Sat, 04 Nov 2017 11:20:12 GMT

As Andrzej wrote it's purely dependent on Tx Power, antenna's radiation characteristic, environment topology and receiver's sensitivity (which again consists of antenna's characteristic and sensitivity of the chip itself). It's good to know that 2.4GHz radio interacts with so many materials that whatever else then open space or shielded chamber is very hard to characterize and almost impossible to control. If you want to limit range then you might achieve it by differnt combinations of shielding and antenna design (especially if you are fine to achieve this in certain direction). If you think something like this could be a security feature then it is obviously NO GO because attacker will simply build/buy better receiving system and will listen from 20 meters or even further. Radio waves are not water, you cannot lock them to some 10-meter bubble;)

RE: decreasing range of ble

AndrzejB — Sat, 04 Nov 2017 11:12:53 GMT

The range depends on circumstances if there are walls between receive device and broadcaster the range will be different than in an open field. You must take your devices and experiment. The transmission power is set by sd_ble_gap_tx_power_set function.