Wi-Fi direct concurrent connection

[Taceant Omnes]

Wi-Fi direct allows concurrent connection of a P2P device to a router
and to a P2P network as a group owner or P2P client. Using
wpa_supplicant v. 2.5 I managed to create a group with p2p_group_add
and then connect with an Android tablet. Separately I also managed to
connect to a wireless router. I did not succeed in having the two
connections simultaneously, with neither a Raspberry PI USB dongle nor
with a Netgear one.

Question 1: does wpa_supplicant support concurrent P2P connection as
described above?

Question 2: With a Google search I came across some blog/forum
accounts of people that managed to have concurrent connections to a
router (as a client) and to devices (as an AP) with the same Wi-Fi
dongle. To achieve this they run simultaneously hostapd (to create an
AP) and wpa_supplicant (to connect to a router). I have not tried this
yet. My question is what are the advantages/disadvantages of this
approach as compared with using P2P as I described above?


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P. S. “iw list” and “dmesg” output for a Raspberry PI USB dongle based
on a Broadcom chipset is below.

# iw list
Wiphy phy3
        max # scan SSIDs: 10
        max scan IEs length: 2048 bytes
        max # sched scan SSIDs: 0
        max # match sets: 0
        Retry short limit: 7
        Retry long limit: 4
        Coverage class: 0 (up to 0m)
        Device supports roaming.
        Supported Ciphers:
                * WEP40 (00-0f-ac:1)
                * WEP104 (00-0f-ac:5)
                * TKIP (00-0f-ac:2)
                * CCMP (00-0f-ac:4)
        Available Antennas: TX 0 RX 0
        Supported interface modes:
                 * IBSS
                 * managed
                 * AP
                 * P2P-client
                 * P2P-GO
                 * P2P-device
        Band 1:
                Capabilities: 0x1022
                        HT20/HT40
                        Static SM Power Save
                        RX HT20 SGI
                        No RX STBC
                        Max AMSDU length: 3839 bytes
                        DSSS/CCK HT40
                Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
                Minimum RX AMPDU time spacing: 16 usec (0x07)
                HT TX/RX MCS rate indexes supported: 0-7
                Bitrates (non-HT):
                        * 1.0 Mbps
                        * 2.0 Mbps (short preamble supported)
                        * 5.5 Mbps (short preamble supported)
                        * 11.0 Mbps (short preamble supported)
                        * 6.0 Mbps
                        * 9.0 Mbps
                        * 12.0 Mbps
                        * 18.0 Mbps
                        * 24.0 Mbps
                        * 36.0 Mbps
                        * 48.0 Mbps
                        * 54.0 Mbps
                Frequencies:
                        * 2412 MHz [1] (20.0 dBm)
                        * 2417 MHz [2] (20.0 dBm)
                        * 2422 MHz [3] (20.0 dBm)
                        * 2427 MHz [4] (20.0 dBm)
                        * 2432 MHz [5] (20.0 dBm)
                        * 2437 MHz [6] (20.0 dBm)
                        * 2442 MHz [7] (20.0 dBm)
                        * 2447 MHz [8] (20.0 dBm)
                        * 2452 MHz [9] (20.0 dBm)
                        * 2457 MHz [10] (20.0 dBm)
                        * 2462 MHz [11] (20.0 dBm)
                        * 2467 MHz [12] (disabled)
                        * 2472 MHz [13] (disabled)
                        * 2484 MHz [14] (disabled)
        Supported commands:
                 * new_interface
                 * set_interface
                 * new_key
                 * start_ap
                 * join_ibss
                 * set_pmksa
                 * del_pmksa
                 * flush_pmksa
                 * remain_on_channel
                 * frame
                 * set_channel
                 * start_p2p_device
                 * crit_protocol_start
                 * crit_protocol_stop
                 * connect
                 * disconnect
        Supported TX frame types:
                 * managed: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70
0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
                 * P2P-client: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70
0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
                 * P2P-GO: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70
0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
                 * P2P-device: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70
0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
        Supported RX frame types:
                 * managed: 0x40 0xd0
                 * P2P-client: 0x40 0xd0
                 * P2P-GO: 0x00 0x20 0x40 0xa0 0xb0 0xc0 0xd0
                 * P2P-device: 0x40 0xd0
        software interface modes (can always be added):
        valid interface combinations:
                 * #{ managed } <= 1, #{ P2P-device } <= 1, #{
P2P-client, P2P-GO } <= 1,
                   total <= 3, #channels <= 1
                 * #{ managed } <= 1, #{ AP } <= 1, #{ P2P-client } <=
1, #{ P2P-device } <= 1,
                   total <= 4, #channels <= 1
        Device supports scan flush.

# dmesg

[32471.157026] usb 1-3: new high-speed USB device number 4 using ehci-pci
[32471.273873] usb 1-3: New USB device found, idVendor=0a5c, idProduct=bd1e
[32471.273882] usb 1-3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[32471.273888] usb 1-3: Product: Remote Download Wireless Adapter
[32471.273892] usb 1-3: Manufacturer: Broadcom
[32471.273895] usb 1-3: SerialNumber: 000000000001
[32471.551505] brcmfmac: brcmf_c_preinit_dcmds: Firmware version =
wl0: Apr  3 2014 04:43:32 version 6.10.198.66 (r467479) FWID
01-32bd010e
[32496.612576] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[32497.762949] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
[33813.857788] brcmfmac: brcmf_inetaddr_changed: fail to get arp ip
table err:-23