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.""
this is not new information
by
Fnkmaster
·
· Score: 5, Insightful
This article rehashes what we already know - the purposes of Bluetooth and 802.11b are fundamentally different - Bluetooth supports what he calls a WPAN (Wireless Personal Area Network) and 802.11b is for WLANs.
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.
I don't know the exact details, but I've used older FHSS and DSSS WLAN technologies as well as 802.11b hardware and I believe it has something to do with the fact that one of Bluetooth or 802.11b is direct-signal and one is frequency-hopping and they therefore tend to obliterate each others signals intermittently. I can't personally testify to this, as I only have experience with 802.11b, but I will tell you that with a 2.4GHz portable phone that my mother bought and the old Proxim Symphony (FHSS if I remember correctly), the interference was a real problem in a practical situation. The 2.4GHz phone could not be used while sitting at the computer desk where the Symphony antenna lived, or the computer would lose connectivity. I finally ditched the wireless network in that apartment and moved to HPNA 2.0, a fabulous solution if your physical configuration doesn't allow good 2.4GHz transmission.
So yes, we would all love to have both Bluetooth and 802.11b work together in perfect harmony and we accept that they don't really compete, and there have been several/. articles with many postings to that effect. The real question is how do we make a technical solution to get the two standards to play nice with each other, if indeed the problems are as significant as I imagine they will be (based on anecdotal reports from others and based on my personal experience with 2.4GHz technology).
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).
Excellent Resources
by
webword
·
· Score: 5, Informative
These are my favorite resources on this subject...
But Bluetooth does nothing I want to do
by
Zeinfeld
·
· Score: 5, Interesting
The big idea of bluetooth appears to be to make my cell phone talk to my laptop. Rather than stick a bluetooth card in my laptop, buy a new $600 cell phone and then try to get the two to talk I would get a GPRS card for the laptop. Calling plans will soon adapt to that use, they have in Europe.
In the home there are very few devices that I would want to have on a wireless network that do not have an AC cord attached - so power consumption is not a big issue.
The other problem with Bluetooth is that it tries to define its own stack for everything. The developers appear to be part of some OSI holdout 'IP will go away' group.
On the security side 802.11b screwed it with WEP, only that does not matter that much because you can still use IPSEC. With Bluetooth the security model is homegrown as is the encryption algorithm. If someone wants to make a name for themselves in the crypto world go hack the Bluetooth crypto.
The author of the piece is a well known bluetooth developer. When a group like that suddenly starts saying 'we can work together' it is pretty much an admission that the other side has established a dominant market position that can't be reversed.
If there is genuinely a need for a low power Wireless lan then I would much prefer that someone do 'low power 802.11b' rather than attempt to reinvent the wheel.
--
Looking for an Information Security student project suggestion?
Try http://dotcrimeManifesto.com/
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.
Bluetooth and 802.11
by
SrlKlr
·
· Score: 4, Interesting
Bluetooth not only lowers throughput in a 802.11b network, but if too many pico net form, it can actaully bring it down. Bluetooth started as a wire replacement, but it seems to have many more possibilities today. The best solution for Bluetooth and 802.11 is move 802.11b to 802.11a. 802.11b uses 2.4 GHz to communicate (thats also what microwaves use). Because of that, 2.4 is not regulated throughout the world. 802.11a can reach speeds up to 54 Mbps, so it will be replacing 802.11b, which can only do 11 Mbps. The good thing about 802.11a is that it tranfers at 5 GHz, so there is no interference with Bluetooth. This seems to be the best fix between the two protocols, if only 802.11a was a bit cheaper...
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
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.
I don't know the exact details, but I've used older FHSS and DSSS WLAN technologies as well as 802.11b hardware and I believe it has something to do with the fact that one of Bluetooth or 802.11b is direct-signal and one is frequency-hopping and they therefore tend to obliterate each others signals intermittently. I can't personally testify to this, as I only have experience with 802.11b, but I will tell you that with a 2.4GHz portable phone that my mother bought and the old Proxim Symphony (FHSS if I remember correctly), the interference was a real problem in a practical situation. The 2.4GHz phone could not be used while sitting at the computer desk where the Symphony antenna lived, or the computer would lose connectivity. I finally ditched the wireless network in that apartment and moved to HPNA 2.0, a fabulous solution if your physical configuration doesn't allow good 2.4GHz transmission.
So yes, we would all love to have both Bluetooth and 802.11b work together in perfect harmony and we accept that they don't really compete, and there have been several
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
In the home there are very few devices that I would want to have on a wireless network that do not have an AC cord attached - so power consumption is not a big issue.
The other problem with Bluetooth is that it tries to define its own stack for everything. The developers appear to be part of some OSI holdout 'IP will go away' group.
On the security side 802.11b screwed it with WEP, only that does not matter that much because you can still use IPSEC. With Bluetooth the security model is homegrown as is the encryption algorithm. If someone wants to make a name for themselves in the crypto world go hack the Bluetooth crypto.
The author of the piece is a well known bluetooth developer. When a group like that suddenly starts saying 'we can work together' it is pretty much an admission that the other side has established a dominant market position that can't be reversed.
If there is genuinely a need for a low power Wireless lan then I would much prefer that someone do 'low power 802.11b' rather than attempt to reinvent the wheel.
Looking for an Information Security student project suggestion?
Try http://dotcrimeManifesto.com/
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.
Bluetooth not only lowers throughput in a 802.11b network, but if too many pico net form, it can actaully bring it down. Bluetooth started as a wire replacement, but it seems to have many more possibilities today. The best solution for Bluetooth and 802.11 is move 802.11b to 802.11a. 802.11b uses 2.4 GHz to communicate (thats also what microwaves use). Because of that, 2.4 is not regulated throughout the world. 802.11a can reach speeds up to 54 Mbps, so it will be replacing 802.11b, which can only do 11 Mbps. The good thing about 802.11a is that it tranfers at 5 GHz, so there is no interference with Bluetooth. This seems to be the best fix between the two protocols, if only 802.11a was a bit cheaper...
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).