Bluetooth Stack Test Methodology
A few people have asked how we tested the BlackBerry Bluetooth performance, so here it is.
I wrote an application for the BlackBerry called BlueBlaster and another application for OS X called MacBlaster. The BlueBlaster application accepts incoming connections from the MacBlaster application. Once a connection is received, the BlueBlaster program starts dumping data to the Mac via the Bluetooth serial link as quickly as possible.
This set of programs effectively isolated the Mac/BlackBerry performance from the rest of the Pulse system and allowed us to tune the connection for maximum performance. Once we knew what settings worked best on BlueBlaster we made the same adjustments to Pulse.
What we found is that BlueBlaster’s performance degraded substantially when we updated the BlackBerry OS version. That single change would drop the performance from 400 kps to 70 kps without exception.
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Impact of Blackberry OS Version on BlueBlaster Performance |
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| Model | Carrier | BB OS Version | Download(kps) | |||
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| 8700g | T-Mobile | 4.1.0.284 | 400 | |||
| 8700g | T-Mobile | 4.1.0.346 | 70 | |||
| 8700c | Cingular | 4.1.0.194 | 400 | |||
| 8700c | Cingular | 4.1.0.377 | 70 | |||
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The BlueBlaster download speed is faster than Pulse’s because our Pulse tests are limited by the carrier network performance. Since we’ve so far only been able to find GPRS BlackBerrys with firmware old enough to demonstrate the fast Bluetooth speed, our Pulse tests are limited to about 220 kps (EDGE network speeds).
We used the same code in each test, only changing the BlackBerry OS version in these tests. We saw the same problem across the boards with different BlackBerrys from different carriers. The use of the BlueBlaster application was significant in that it isolated the BlackBerry Bluetooth link from the rest of the system and eliminated the possibility of other bugs in our code causing the apparent slowdown.
Filed under: Pulse by Daniel
4 Responses to “Bluetooth Stack Test Methodology”
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I do BlackBerry programming for a career. I would love to see your sources for BlueBlaster & MacBlaster. Please drop me an email, as I could not find one on your website. Thanks!
[…] Just when we’re getting used to our Blackberry tethering via Bluetooth, news (and not the good kind either) travels downstream that the latest software release for Cingular and T-Mobile decreases the download speed significantly. Is it that RIM is intentionally making our BlackBerry 8700 slower or is it the carriers’ request to cut down on consumer tethering? More than likely it’s the first one seeing the problem didn’t exist in earlier releases of the 4.1 OS and it doesn’t exist in the Pearl’s 4.2 OS. According to the Brain Murmurs, which created the “Pulse” tethering application, data speeds went from a decent 200k to a crawling 65k. Hopefully, this is nothing more than some developer’s sick idea of how the fast the information superhighway should be, and we can all return to our regularly scheduled speeds in some future release of RIM’s OS. […]
[…] Just when we’re getting used to our Blackberry tethering via Bluetooth, news (and not the good kind either) travels downstream that the latest software release for Cingular and T-Mobile decreases the download speed significantly. Is it that RIM is intentionally making our BlackBerry 8700 slower or is it the carriers’ request to cut down on consumer tethering? More than likely it’s the first one seeing the problem didn’t exist in earlier releases of the 4.1 OS and it doesn’t exist in the Pearl’s 4.2 OS. According to the Brain Murmurs, which created the “Pulse” tethering application, data speeds went from a decent 200k to a crawling 65k. Hopefully, this is nothing more than some developer’s sick idea of how the fast the information superhighway should be, and we can all return to our regularly scheduled speeds in some future release of RIM’s OS. […]
[…] Just when we’re getting used to our Blackberry tethering via Bluetooth, news (and not the good kind either) travels downstream that the latest software release for Cingular and T-Mobile decreases the download speed significantly. Is it that RIM is intentionally making our BlackBerry 8700 slower or is it the carriers’ request to cut down on consumer tethering? More than likely it’s the first one seeing the problem didn’t exist in earlier releases of the 4.1 OS and it doesn’t exist in the Pearl’s 4.2 OS. According to the Brain Murmurs, which created the “Pulse” tethering application, data speeds went from a decent 200k to a crawling 65k. Hopefully, this is nothing more than some developer’s sick idea of how the fast the information superhighway should be, and we can all return to our regularly scheduled speeds in some future release of RIM’s OS. […]