BT range and interference with WiFi?

[BanjoFrog]

Hope this isn't a FAQ... but what's the expected range of a BT-enabled PPC when connecting to other BT devices? Also, does it interfere with WiFi networks?

[ctmagnus]

Generally around 10m/30 ft.

And you shouldn't have interference issues as BT and Wifi use different technologies to broadcast. iirc, one uses FHSS (frequency-hopping spread spectrum) and the other uses DSSS (distributed significant spread spectrum). I don't recall which uses which, though.

[Pony99CA]

Generally around 10m/30 ft.
Yes, but it depends on what Bluetooth class is being used. Class 1 has a range of 100 meters; Class 2 (the most common, I think), 10 meters; Class 3, 1 meter.

If I recall, the Loox was a Class 1 device, while iPAQs are Class 2. There are Bluetooth USB dongles available in both versions (I have a Belkin Class 1 dongle, but they also make a Class 2 version).

Steve

[ctmagnus]

Class 1, 1 meter.

Class 3, 1 meter. ;)

But it depends on the lower-class of device used. I.e., if you're using a class 1 dongle attached to your desktop/notebook and have a class 2 Pocket PC, then you'll only get around 10m/30 ft.

And as with other types of RF signals, there will most likely be interference (walls. furniture, large appliances and in this case, microwave ovens, baby monitors and 2.4GHZ cordless phones) that will degrade the signal and cause the effective range to be lower than optimal.

[Pony99CA]

Class 1, 1 meter.
Class 3, 1 meter. ;)
Fixed. :oops:

But it depends on the lower-class of device used. I.e., if you're using a class 1 dongle attached to your desktop/notebook and have a class 2 Pocket PC, then you'll only get around 10m/30 ft.
I've read that somebody using a mixed Class 1/Class 2 implementation got a range closer to 100 meters than 10 meters. I wasn't sure how that worked, either.

If Class 1 simply uses a more powerful transmitter, I could see a transmission range closer to Class 1, but I'd think it's receiving range would be dependent on the Class 2 device. If the Class 1 device also has a more sensitive antenna, then it might make sense.

Steve

[Kacey Green]

So then it would depend on the manufacturer, or if the class 1 device also has an amplifier in the receiver.

[ctmagnus]

If Class 1 simply uses a more powerful transmitter, I could see a transmission range closer to Class 1, but I'd think it's receiving range would be dependent on the Class 2 device.

Geometrically, yes. Picture a circle of 100 units radius/200 units diameter. That's the Class 1 device's range, with the device at the center. Then picture another circle of 10 units radius/20 units diameter. That's the Class 2 device's range.

Place the circles together such that the center of the larger circle lies anywhere within the smaller circle. That's the area where the two devices will communicate. If you move the center of the larger circle anywhere outside of the smaller circle, they will no longer communicate even if the circles overlap.

But then there's the real world. ;)

[Pony99CA]

If Class 1 simply uses a more powerful transmitter, I could see a transmission range closer to Class 1, but I'd think it's receiving range would be dependent on the Class 2 device.
Geometrically, yes. Picture a circle of 100 units radius/200 units diameter. That's the Class 1 device's range, with the device at the center. Then picture another circle of 10 units radius/20 units diameter. That's the Class 2 device's range.

Place the circles together such that the center of the larger circle lies anywhere within the smaller circle. That's the area where the two devices will communicate. If you move the center of the larger circle anywhere outside of the smaller circle, they will no longer communicate even if the circles overlap.
That's not necessarily true. Radio waves don't just die off completely; they just get weaker and weaker.

As I said, if the Class 1 device has a more powerful transmitter, the Class 2 device should be able to receive signals from the Class 1 device up to 100 meters away.

The issue is whether the Class 1 device would be able to receive transmissions from the Class 2 device farther than 10 meters away. If the Class 1 device also has a more sensitive antenna, it's quite possible that it could. That's why some radio antennas work better than others at picking up FM signals; the signals are there, the antenna just wasn't good enough at picking them up (or the electronics weren't good enough at processing the signal).

Of course, this is just speculation on my part. I have no idea what the actual differences between Class 1 and Class 2 Bluetooth devices are. If you do, feel free to let us know. :-)

Steve

[Kacey Green]

Don't forget to try different manufacturers

[Jon Westfall]

never had a problem with interference, and BT range is usually pretty good even on a class 1 (i.e. if I'm below my home office in my house and my phone is up there, the BT headset will pick up while I sit in the living room!)

[Kacey Green]

I've got all sorts of 2.4 GHz stuff going on right now and only an occasional (once every ~3 weeks for 30 sec) microwave (usually which sets off the problems), an entire wifi network, a neighbor who isn't very polite about their wifi config (multi channel and signal strengths), bluetooth, cheap 2.4 GHz phones, and some stuff I don't know about.

[Kowalski]

the power usage of radio transmitters are proportional to square of the distance. therefore if the distance goes from 10 meters to 100 meters, the power consumption rises 100 times.
thats why there exists only afew mobile devices with 100 meter range

[Pony99CA]

thats why there exists only afew mobile devices with 100 meter range
Maybe your definition of "a few" is broader than mine, but I believe there are more than a few PDAs with WiFi, which has a 100-meter range. (I define "few" as about 3-7.)

Steve

[Kacey Green]

Steve, I think he may have been refering to BT, judging from the "few", I think most (all) wifi PDAs have at least a 100m range

Edit: see my post below for what was edited

[Kowalski]

she??!! the avatar on the left is the picture of my girlfriend, not me!

I believe there are more than a few PDAs with WiFi, which has a 100-meter range. (I define "few" as about 3-7.)
for wifi i can count more than 10, i have been refering BT for sure.

[Kacey Green]

I stand corrected I have corrected my post above, to match the gender, but I was right about the BT, so that stays!

[Kati Compton]

she??!! the avatar on the left is the picture of my girlfriend, not me!
Ah - I assumed you were female as well. Generally, as one's avatar is supposed to represent oneself, I assume that if the avatar is gendered, the poster is of that gender. Though there are others who use pictures of people of the opposite sex as well.

But anyway, that's off-topic...

[Pony99CA]

Steve, I think he may have been refering to BT, judging from the "few", I think most (all) wifi PDAs have at least a 100m range
Then maybe he should have said "Bluetooth devices", not "mobile devices". I'm not responsible for others' lack of clear communication. :-D

Steve

[Pony99CA]

she??!! the avatar on the left is the picture of my girlfriend, not me!
Ah - I assumed you were female as well. Generally, as one's avatar is supposed to represent oneself, I assume that if the avatar is gendered, the poster is of that gender.
I assumed he was male, as I generally do on geek boards unless there's an obvious clue (like the name "Kati" :-D). I wasn't sure if the avatar was a girl or a young boy, nor if it was kowalski's picture, a special friend or a child of his.

If pressed to guess, I would have guessed it was his picture and that he was a young (under 20) boy -- until he said he was an engineer, at least. :lol:

Maybe he should work on a better profile (and Web site, for that matter). :twisted:

UPDATE: I noticed he has changed his profile (interests now include "girls", so maybe I was right) and the empty Web site is gone. :way to go:

Steve

[Kowalski]

so you guys are happy now?
this is a photo from my last holiday 8)

I assume that if the avatar is gendered, the poster is of that gender so problem is solved

but I was right about the BT, so that stays! you are a kind person :D

Then maybe he should have said "Bluetooth devices", not "mobile devices". I'm not responsible for others' lack of clear communication
sorry for that, you are absolutely right

i dont have time for my website because i am very busy right now but at least i moved the link, and update my interests.

so if everyones happy, shall we continue and discuss about our subject?[/quote]

[Pony99CA]

so you guys are happy now?
this is a photo from my last holiday 8)
:rofl: Good one. However, don't worry about what we think of your avatar; ask Kati how many times somebody confused her cat avatar with a cracked egg. If you want your girlfriend as your avatar, go for it.

That said, may I suggest that we move further avatar discussion to the avatar thread (http://www.pocketpcthoughts.com/forums/viewtopic.php?t=4872).

We now return to our regularly scheduled topic....

Steve

[Pat Logsdon]

??!! the avatar on the left is the picture of my girlfriend, not me!
:rotfl:

Um... you may want to edit that post...it has an entirely different connotation now. :mrgreen:

Not that there's anything WRONG with that, of course. :D

ok, :nonono: