Reply To:Wi-Fi Direct Question
Last Post: May 20, 2019:
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I can half answer your question. I've seen those HP Printer SSIDs around the place before. They appear to be ad-hoc networks, to enable people to 'easilly' connect to them. Just like an IBSS, it and any others would take turns at providing the beacons. I'd say that's what Netstumbler is picking up. As for the OUI, that's just the manufacturer of the nic. My little HP laptop has a Hon Hai one as well.
As for the other part, I know hidden in the standards somewhere is a method to transmit directly between stations in a BSS, although it's not really done. I had a reference to it on the forum here once I'm sure, but I can't find it anymore.
After reading a bit about Wi-Fi direct, it looks like basically using 802.11 to do the jobs that Bluetooth has traditionally been doing.
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I would not have been especially surprised to see client devices (?) listed as Ad-hoc, but to see them as AP (meaning Infrastructure) mode was surprizing.
I have never seen NS identify an Adhoc STA as an AP, even very briefly - it knows the mode from bits in the beacon.
All of the "listed as AP" devices I found have SSID's of the form "HP-xx- LaserJet 100" . The only Adhoc advertized printer was labelled "HP100-nn". I don't have direct access to the network, as its in a foreign country so investigating it is a little difficult to analyse.
Except for the exceptionally good interference tolerance that I have seen from some Bluetooth devices, I'm wondering if Wi-Fi direct will usurp BT in some markets ( i.e. handheld scanners, and mobile printers).
Thanks for your input - I'm glad someone else has seen this.
PS: I just checked the WFA public data base. At the moment the only WiFi Direct printers [i]that are listed[/i] are from Samsung.
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From the Samsung website, I found this explanation:
"If you set the printer as a [i]Group Owner[/i], the wireless devices, such
as notebook PC or smart phone, can connect to the printer
[u]as if it were an access point connection[/u]".So I guess I have a partial answer.
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And:
"If the connection is successful, the printer
distributes the IP Address to the mobile
device with internal DHCP server." -
I'd have to agree with you about the IBSS, in that I've not seen one detected as an AP in its own right. I found it strange, but just went along with it. I can't really help further with that product.
Playing with my new Wi-Spy is fun :)
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Just an addendum to this old post.
Yes the devices were/are beaconing like an AP.
From several admins and installers I have spoken with, they usually end up running around their installations, disabling the Wi-Fi Direct (WFD) , because it uses too much airtime and reduces network performance.
In a large building, such as a hospital, their may be hundreds of printers, and the WFD Beacons creates an intolerable amount of interference.
Unless a customer has no other AP's I suggest they disable WFD, regardless of the size of the network.
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