How to increase the transmition (range)of a Bluetooth device

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Asxetos

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how to increase the range on bluetooth devices

I recently bought two usb bluetooth keys (class2 csr bluecore2 chipset) to connect laptop-desktop for dialup sharing.
The problem is that they reside in different rooms, and i am missing about 3-4 meters of extra range for a good and steady connection.
I tried to adjust the persistent store settings with the casira tools (default transmit power etc) but no success.
Any help will be appreciated.
 

Hi Asxetos,

Do you use external antennas?
 

@ Mr Ghz

No external antennas available. The idea was to make the simplest (cheapest) possible connection.
Just two usb bluetooth dongles, one on the laptop, one on the desktop.

RF theory says that by removing the plastic enclosures (leave the internal minature antenna fully exposed) the range increases, but then that would not be practical. Would it?

If someone has experience with the bluesuite tools (pstool) i was wondering if the transmition power can be changed by modifing some settings.
 

no increase

The modules probably cannot be increased in power as the price is the main feature of this protocol. They would not design in costly higher capacity that would not be used.

Can you use some form of short cable that would allow the dongles to be placed higher in the air so that there are no obstructions between them?
 

I mess with rf all the time

The only "viable solution" is to bypass the internal antenna by connecting a thin coax cable an getting a rubber duck antena like those sold by lynx tech.
once you hava the coax with connector you can adapt a linear aplifier and then the sky is the limit.

There can be one problem though ,some times they use a discrete diplexer
for adapting the trasnmitter and receiver .This for cost reasons .It is always possible to put an RF switch .But you will have to locate the logic signal responsable for the transmit an receive!
 

The easiest solution is to get a usb extention cable. They can be around 5 meters. The alternate easy way is to get Class1 USB dongles.


Spartacus
 

You can extend the antenna from its 1/4wave with with a bit of wire soldered to the end to make a 1/2wave or full wave. This extra bit of wire can be moved around to get a better trans/recieve position.

P
 

Re: How to increase the transmition (range)of a Bluetooth de


Adjusting the power using the ps key settings may reduce the range by causing more RF feedback into the bluecore chip from the antenna. This affects the vco and makes the chip unstable and increases bit error.
Want more range, get a couple of class1 CSR MSI dongles from Scan.
The class2 usb dongles are only really useful in the same room.

P
 

Well... maybe strange question, maybe it is answered in Bluetooth docs that I not yet read completely... But anyway...

Is there a range limit that forced by allowable signal propagation delays? Imagine that I have nearly perfect directional antennas, fast T/R switch, whole kilowatt of RF power and good LNA - where Bluetooth will stop working due to propagation delays?
 

Velund:

...theorically, when the multipaths delay exceed the duration of symbol period you will have InterSymbol Interference (ISI), which will cause link degradation.

regards
 

I told about another thing - the same why DECT and GSM (for example) have limited range (~5km and ~70 km respectively if memory serves me correctly) even if signal is perfect. Signal turnaround time does not allow to fit into right timeslot anymore (To protocol gurus - am I correct?).

I understand that BlueTooth is quite different, but question was - is there anything in BT protocol that will limit range even in perfect condition (strong signal, no multipath etc)?
 

Re: How to increase the transmition (range)of a Bluetooth de

Could you change a atenna with some directivity??
 

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