Search for Devices looks for Bluetooth devices – but how many devices
can it found – for an example if there is about 50 devices (10 meters
from computer) will it display all 50 devices, and I can choose the
device I want to connect?

Maybe it depends from the device? But what it is the standard?

It can probably "see" all of them, but only connect to 7 at a time.

Look at Trust - Bluetooth information:
http://www.trust.com/service/help/bluetooth/#4
Under 4.3
"A master Bluetooth device can connect to a maximum of 7 slave devices."

-Dan

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LittleMoo napisa³(a):
I know that I can connect to 7 at a time - but I need to know that I
will see all of them - is there a maximum?

Your answer is 255 inactive + 7 active at a time.

Answer gotten from:
Bluetooth Communication & connection on Wikipedia:
http://en.wikipedia.org/wiki/Bluetooth#Communication_.26_connection

-Dan

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Thank you! And the final question could you recommend and BlueTooth
deviced that I can connect via USB compatybile with 255 inactive + 7
active at a time?

Any device that supports Bluetooth will support the 255 + 7 connections - if
you have a wireless card in your laptop then it might support bluetooth.
There isn't one device in particular that I could recommend, but a lot of
cell phones and PDA's use bluetooth.

-Dan

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### Wrong ####

Bluetooth needs the device to be in a discoverable mode to be found as part
of the security. As such if you are in a school with say 200 Bluetooth
devices and you try to discover them, you may discover none of them, or just
a few that happen to be in discoverable mode at the time.

David Hettel

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for everyone to see.  I'm sorry, but I don't answer questions
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confers no rights




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I was only going by the Bluetooth specs for this, not actual real-world
situations. In theory though if there were say 50 devices all in
discoverable mode and one laptop that has a Bluetooth USB adapter used as
the master device then the spec says that the laptop should be able to
(theoretically) "see" all of them. I don't know what the purpose of
something like this would be though.

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LittleMoo napisa³(a):
I need to identify people that have GSM/bloetooth with discoverable
mode, I don't want to connect them only identify. So are you sure that I
see all of them?

Most devices implement "discoverable" mode for only a few seconds at a time.
As such if you had a room full of 200 people, and you told them to put their
device into discoverable mode now, in theory you'd get a list of all of
them. Having actually used Bluetooth, I'd say it's very unlikely you'd get a
list of all of them in the above example If on the other hand you did not
tell them to put their device into discoverable mode, you simply had a room
full of 200 people with cell phones I would expect to see 0 found.

Does that help any?

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David Hettel napisa³(a):
Next example I told 200 people to switch on BlueTooth and make it
public. And after some days (people didn't change anything on their GSM)
people are seating at room for 2 hours and on my computer I click Search
for Devices - will I see all devices in the room?

"Make it public" is not a blue tooth command, if you told two hundred people
to switch there phone on and make it discoverable, and they attempted to do
it, I feel safe in saying no, you'll not find them all, nor even a great
number of then. It's very unlikely that you could get two hundred people to
do basically the same thing within 10 seconds of each other, in my
experience. Also as one who gives help with Bluetooth devices, it's unlikely
that all two hundred people would even know how to make their device
discoverable. This is something you might normally do once or twice a year
with a manual telling you how. It's generally not straight forward to
accomplish or simple. Normally it's buried several menus down in the device.
Different firmware on a device may also change where and how you do this, so
even if everyone had the same model of phone, different firmware can change
how you do this. Another potential problem is there is not one way of
displaying the Bluetooth devices discovered. Some devices may keep past
devices, and others if they are not refound will drop them from the display.
So say you "hunt" for devices and find 75, devices in the first 10 seconds,
in the next scan you find 50, some of the 50 may be the same as those found
in your first scan, but some of the first scan may no longer be in
discoverable mode, so they are removed from the list of those displayed. Do
you see the problem here, you may need to get all in the same mode, within 2
to 3 seconds of each other, to give your device time to talk to each one it
sees.

So yes in theory it may work, in reality I'd need to see in demonstrated
with a random group of users before I'd believe it. And I would never count
on it working.

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The first establishment is that one day I will configure all phones and
the second establishment is that people don't change anything (settings)
on their mobile phones.

And after some days they meet toogether in one room and I would like to
press Search for all devices in range (I can click it several times) and
for example for about 30 minutes I will find them all. Is it true or
not? (Of course - I will write application for it).


Does .Net 2.0 support bluetooth communication especially Search for all
devices?

For .Net development under Windows XP, 2000, etc. the short answer is no.
For .Net development under Windows CE (for Pocket PCs) you would be able to.

However - there is at least one way to use .Net under XP for Bluetooth
development, but it is not free. It's an SDK called BlueTools (about $100):
http://franson.com/bluetools/

You might be able to accomplish this by using WidComm drivers and the
Microsoft Bluetooth Stack drivers in a .Net application - but as there is
probably poor documentation of these drivers under XP at best then this
would be very hard to accomplish.

-Dan

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suspect someone stealing access
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Networking doesnt seem to load on xp
Wireless not starting
neighbor using wireless connection