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Multiple Bluetooth Connections in a limited area

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djsfantasi

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I want to use Bluetooth to connect multiple sound sources to a common amplifier, with a small defined area. The transmitter pairs might be up tp 150 feet of each other and a nearby Bluetooth pair might be within 150 feet to it's neighbor. There might be 6-10 pairs of Bluetooth transmitters within a 4,000 to 8,000 square foot area.

Am I going to run into problems?
 
first, bluetooth range is limited to 35ft (10 meters). bluetooth signals are 1Mhz wide, so there's not a huge problem with them sharing spectrum space, but if there are wifi devices present , or nearby, they will cause problems with the bluetooth links. the 2.4Ghz band is a very crowded chunk of spectrum, and also includes microwave ovens. i worked for almost 10 years at a major retailer's service center. out of all the failures of bluetooth audio devices, by far the most common was interference. the system worked fine at the service center, and in the store when the customer picked it up, but when they got home it would fail again. sometimes, the customer could fix the problem by putting the bluetooth receiver closer to the transmitter, or by moving their wifi devices further from the bluetooth equipment. the largest number of interference problems were in apartment complexes, where everybody has wifi, bluetooth devices, microwave ovens, cordless phones, and baby monitors, all of which share the same bit of spectrum. you can do a site survey with a Software Defined Radio that can operate in the 2.4Ghz band (the cheap SDR dongles don't go above 2.0Ghz, so you need to find one that does go to about 2.5Ghz. with that most SDR software can show you the signals present in the 2.4Ghz band, and with some, you can save a plot of the activity in a 24 hour period. that can give you a clue whether all of the bluetooth devices will or will not be interfered with. the only remaining problem is increasing the range by a factor of about 4.5. there may be antenna options (like a "cantenna" to extend the range (highly directional), or passive boosters that increase the antenna "aperture".
 
To clarify my situation, imagine about 10 zones. Each zone will have one Bluetooth transmitter and receiver. But, there will also be a WiFi network.

I estimated 150’ as the average distance between non-matched Bluetooth pairs. But the distance between the transmitter and receiver of one pair is about 15’. Which is within the range you specified. I can be pretty sure the Bluetooth pair will be within 15’ of each other.

My concern now is your comments regarding WiFi. Within a 2x5’ area,in each zone there are about five nodes in a WiFi network. Traffic over this network is light. Perhaps 64 bytes per minute. And it is unlikely (but not impossible) that WiFi traffic and Bluetooth traffic will be concurrent.

Am I going to run into a problem? Your answer is important.
 
one thing i discovered in my time at the service center is that because a wifi router transmits with more power and much wider bandwidth, it can cause interference from much larger distances. wifi range is 200 feet line of sight, so a wild guess at the distance it can caue interference to bluetooth would be about 100 feet. in an apartment complex, there could be 30 or more wifi routers in any 100 foot radius. in a dense residential area, there could be possibly 12 to 15 wifi routers within 100 feet
Within a 2x5’ area,in each zone there are about five nodes in a WiFi network. Traffic over this network is light. Perhaps 64 bytes per minute. And it is unlikely (but not impossible) that WiFi traffic and Bluetooth traffic will be concurrent.
wifi routers regularly "handshake" to maintain the connection, so even with very little data, the link isn't idle. the only way you will find out for sure is to build a couple of "zones" and see what happens,and then add one zone at a time until things begin to bottleneck. i'm pretty certain you may have a limit to the number of zones you can have before links start interfering with each other. one thing that will help is to limit the wifi devices to operation on 5Ghz (802.11a or 802.11ac mode). that will remove the wifi traffic as a source of interference with bluetooth. that doesn't guarantee that you won't have inteference from external sources, but it's a big step in the right direction.
 
If you install wifi analyser on an android device it'll give you a good idea what networks are around you. I'm in a tower and 2.4G is just unusable. I now use 5G (that's 5 GhZ wifi).

Mike.
 
If you install wifi analyser on an android device it'll give you a good idea what networks are around you. I'm in a tower and 2.4G is just unusable. I now use 5G (that's 5 GhZ wifi).

Mike.

Hola Pommie, Pommie

In Play Store there are many with that name. Which one do you actually suggest?
 
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