Posted by
Hemos
on from the making-wireless-really-work dept.
LupeROD writes "Here's a story that shoulders the responsibility of trying to convince us all that the spectrum wars between 802.11 and Bluetooth are bogus and the truth, be it obscured, is that 802.11 and Bluetooth are really compadres.""
Re:this is not new information
by
hattig
·
· Score: 5, Informative
This article does not address the _real_ issue that I have heard quite a few people bring up - that the intentions of the technologies and their use cases are orthogonal, but they use the same chunk of bandwidth and the nature of their frequency usage does not play nicely with each other.
Did you read a different article to the one I read? It does mention it, and describe why it ISN'T an issue, and that both these specifications live quite happily together.
2.4GHz is an open area of bandwidth - you have to expect interference. Home RF, DECT, Bluetooth, 802.11. Hence these technologies are designed to deal with interference, even high interference.
The use of one of the technologies in an area with the other technology only raises the noise level a bit. In fact, interference for each of these technologies is not caused by the other technology being present, but just by high levels of general interference (e.g., using it inside a nuclear reactor).
Bluetooth is noncompetitive (Re:WPAN?)
by
isdnip
·
· Score: 5, Informative
Well, no. Bluetooth does NOT add $5 to the cost of a device today, except perhaps for very large values of $5. That was the goal, but today it costs quite a bit more. It needs critical mass to come down that low, and critical mass is proving elusive.
Bluetooth's advantage is low power, making it suitable as a "cordless" technology. But 802.11 can be run with less power than the legal limit, again invading Bluetooth's turf. That's probably Bluetooth's Achilees Heel -- it's not that much better than 802.11 at what it's better at (low power).
Further putting a nail in Harold B's coffin is the actual Bluetooth spec. I've looked at it and IT STINKS. They have a preposterously complex protocol stack for doing simple things. They literally take the packets, serialize them, put in an RS-232 emulation protocol (control pins & stuff), stick Hayes AT modem commands atop that, and run packets atop THAT! Truly demented. Work done by a committee that had NO FREAKING CLUE what they were doing. That as much as anything explains the lack of interoperability. (802.11, at least, is easy to use, like other 802-family protocols.)
Which is too bad, because a $5 Bluetooth chip with micropower battery drain really would complement 802.11 and other things. But that's not what the corporate sponsors put out.
Interference
by
funky+womble
·
· Score: 4, Informative
There are interference problems between the original specs of bluetooth and 802.11b. There are working groups at IEEE trying to sort it out (search their website or search google for "802.11b bluetooth interference" and dig away).
Fortunately some modifications have been suggested to Bluetooth which should significantly reduce the problems. Let's just hope that these are incorporated into any mass-market bluetooth devices or it doesn't bode well for wireless internet access via 802.11b in some places, for example, coffee shops, where you are also likely to see a lot of mobile phones...
Frequency-hopping systems generally use frequencies from within a wider band but keep jumping between them, so they don't interfere with any one other user for a long period of time. Trouble is, this doesn't tie in very well with ethernet/TCP protocols where performance is seriously impacted by packet loss. (Sure, the packets are resent, but TCP treats packet loss as congestion and slows down).
Slashdot Mirror
These are my favorite resources on this subject...
Bluetooth Resource Center
A Businessman's Comparison of Bluetooth and Wi-Fi (802.11b)
Empirical Study for IEEE 802.11 Aand Bluetooth Interoperability (PDF)
Wi-Fi will not make Bluetooth obsolete
How to Download YouTube Videos
Did you read a different article to the one I read? It does mention it, and describe why it ISN'T an issue, and that both these specifications live quite happily together.
2.4GHz is an open area of bandwidth - you have to expect interference. Home RF, DECT, Bluetooth, 802.11. Hence these technologies are designed to deal with interference, even high interference.
The use of one of the technologies in an area with the other technology only raises the noise level a bit. In fact, interference for each of these technologies is not caused by the other technology being present, but just by high levels of general interference (e.g., using it inside a nuclear reactor).
Well, no. Bluetooth does NOT add $5 to the cost of a device today, except perhaps for very large values of $5. That was the goal, but today it costs quite a bit more. It needs critical mass to come down that low, and critical mass is proving elusive.
Bluetooth's advantage is low power, making it suitable as a "cordless" technology. But 802.11 can be run with less power than the legal limit, again invading Bluetooth's turf. That's probably Bluetooth's Achilees Heel -- it's not that much better than 802.11 at what it's better at (low power).
Further putting a nail in Harold B's coffin is the actual Bluetooth spec. I've looked at it and IT STINKS. They have a preposterously complex protocol stack for doing simple things. They literally take the packets, serialize them, put in an RS-232 emulation protocol (control pins & stuff), stick Hayes AT modem commands atop that, and run packets atop THAT! Truly demented. Work done by a committee that had NO FREAKING CLUE what they were doing. That as much as anything explains the lack of interoperability. (802.11, at least, is easy to use, like other 802-family protocols.)
Which is too bad, because a $5 Bluetooth chip with micropower battery drain really would complement 802.11 and other things. But that's not what the corporate sponsors put out.
Fortunately some modifications have been suggested to Bluetooth which should significantly reduce the problems. Let's just hope that these are incorporated into any mass-market bluetooth devices or it doesn't bode well for wireless internet access via 802.11b in some places, for example, coffee shops, where you are also likely to see a lot of mobile phones...
Frequency-hopping systems generally use frequencies from within a wider band but keep jumping between them, so they don't interfere with any one other user for a long period of time. Trouble is, this doesn't tie in very well with ethernet/TCP protocols where performance is seriously impacted by packet loss. (Sure, the packets are resent, but TCP treats packet loss as congestion and slows down).