ATHN(4) FreeBSD Kernel Interfaces Manual ATHN(4)
NAME
athn - Atheros IEEE 802.11a/b/g/n wireless network device
SYNOPSIS
athn* at cardbus?
athn* at pci?
athn* at uhub? port ?
DESCRIPTION
The athn driver provides support for a wide variety of Atheros 802.11n
devices, ranging from the AR5008 up to the AR9287.
The AR5008 (codenamed Owl) is the first generation of Atheros 802.11n
solutions. It consists of two chips, a MAC/Baseband Processor and a
Radio-on-a-Chip. The MAC/Baseband Processor can be an AR5416 (PCI and
CardBus form factors) or an AR5418 (PCIe Mini Card form factor). The
radio can be an AR2122, AR2133, AR5122 or an AR5133 chip. The AR2122
chip operates in the 2GHz spectrum and supports up to 2 transmit paths
and 2 receiver paths (2T2R). The AR2133 chip operates in the 2GHz
spectrum and supports up to 3 transmit paths and 3 receiver paths (3T3R).
The AR5122 chip operates in the 2GHz and 5GHz spectra and supports up to
2 transmit paths and 2 receiver paths (2T2R). The AR5133 chip operates
in the 2GHz and 5GHz spectra and supports up to 3 transmit paths and 3
receiver paths (3T3R).
The AR9001 (codenamed Sowl) is a Mini-PCI 802.11n solution. It consists
of two chips, an AR9160 MAC/Baseband Processor and an AR9103 or AR9106
Radio-on-a-Chip. The AR9103 chip operates in the 2GHz spectrum and
supports up to 3 transmit paths and 3 receiver paths (3T3R). The AR9106
chip operates in the 2GHz and 5GHz spectra and supports up to 3 transmit
paths and 3 receiver paths (3T3R).
The AR9220, AR9223 and AR9280 (codenamed Merlin) are the first generation
of Atheros single-chip 802.11n solutions. The AR9220 and AR9223 exist in
PCI and Mini-PCI form factors. The AR9280 exists in PCIe (DT92), PCIe
Mini Card (XB92), half Mini Card (HB92) and USB 2.0 (AR9280+AR7010) form
factors. The AR9220 and AR9280 operate in the 2GHz and 5GHz spectra and
support 2 transmit paths and 2 receiver paths (2T2R). The AR9223
operates in the 2GHz spectrum and supports 2 transmit paths and 2
receiver paths (2T2R).
The AR9281 is a single-chip PCIe 802.11n solution. It exists in PCIe
Mini Card (XB91) and half Mini Card (HB91) form factors. It operates in
the 2GHz spectrum and supports 1 transmit path and 2 receiver paths
(1T2R).
The AR9285 (codenamed Kite) is a single-chip PCIe 802.11n solution that
targets the value PC market. It exists in PCIe half Mini Card (HB95)
form factor only. It operates in the 2GHz spectrum and supports a single
stream (1T1R). It can be combined with the AR3011 chip to form a combo
WiFi/Bluetooth device (WB195).
The AR9271 is a single-chip USB 2.0 802.11n solution. It operates in the
2GHz spectrum and supports a single stream (1T1R).
The AR2427 is a single-chip PCIe 802.11b/g solution similar to the other
AR9280 solutions but with 802.11n capabilities removed. It exists in
PCIe Mini Card form factor only. It operates in the 2GHz spectrum.
The AR9227 and AR9287 are single-chip 802.11n solutions that target mid-
tier PCs. The AR9227 exists in PCI and Mini-PCI form factors. The
AR9287 exists in PCIe half Mini Card (HB97) and USB 2.0 (AR9287+AR7010)
form factors. They operate in the 2GHz spectrum and support 2 transmit
paths and 2 receiver paths (2T2R).
The following table summarizes the supported chips and their
capabilities.
Chipset Spectrum TxR:S Bus
AR5008-2NG (AR5416+AR2122) 2GHz 2x2:2 PCI/CardBus
AR5008-3NG (AR5416+AR2133) 2GHz 3x3:2 PCI/CardBus
AR5008-2NX (AR5416+AR5122) 2GHz/5GHz 2x2:2 PCI/CardBus
AR5008-3NX (AR5416+AR5133) 2GHz/5GHz 3x3:2 PCI/CardBus
AR5008E-2NG (AR5418+AR2122) 2GHz 2x2:2 PCIe
AR5008E-3NG (AR5418+AR2133) 2GHz 3x3:2 PCIe
AR5008E-2NX (AR5418+AR5122) 2GHz/5GHz 2x2:2 PCIe
AR5008E-3NX (AR5418+AR5133) 2GHz/5GHz 3x3:2 PCIe
AR9001-2NG (AR9160+AR9103) 2GHz 2x2:2 PCI
AR9001-3NG (AR9160+AR9103) 2GHz 3x3:2 PCI
AR9001-3NX2 (AR9160+AR9106) 2GHz/5GHz 3x3:2 PCI
AR9220 2GHz/5GHz 2x2:2 PCI
AR9223 2GHz 2x2:2 PCI
AR9280 2GHz/5GHz 2x2:2 PCIe
AR9280+AR7010 2GHz/5GHz 2x2:2 USB 2.0
AR9281 2GHz 1x2:2 PCIe
AR9285 2GHz 1x1:1 PCIe
AR9271 2GHz 1x1:1 USB 2.0
AR2427 2GHz 1x1:1 PCIe
AR9227 2GHz 2x2:2 PCI
AR9287 2GHz 2x2:2 PCIe
AR9287+AR7010 2GHz 2x2:2 USB 2.0
These are the modes the athn driver can operate in:
BSS mode Also known as infrastructure mode, this is used when
associating with an access point, through which all
traffic passes. This mode is the default.
Host AP In this mode the driver acts as an access point (base
station) for other cards.
monitor mode In this mode the driver is able to receive packets without
associating with an access point. This disables the
internal receive filter and enables the card to capture
packets from networks which it wouldn't normally have
access to, or to scan for access points.
The athn driver can be configured to use Wired Equivalent Privacy (WEP)
or Wi-Fi Protected Access (WPA1 and WPA2). WPA2 is currently the most
secure encryption standard for wireless networks supported by OpenBSD.
It is strongly recommended that neither WEP nor WPA1 are used as the sole
mechanism to secure wireless communication, due to serious weaknesses.
WPA1 is disabled by default and may be enabled using the option
"wpaprotos wpa1,wpa2". For standard WPA networks which use pre-shared
keys (PSK), keys are configured using the "wpakey" option. WPA-
Enterprise networks require use of the wpa_supplicant package. The athn
driver offloads both encryption and decryption to the hardware for the
CCMP cipher.
The transmit speed is user-selectable or can be adapted automatically by
the driver depending on the number of hardware transmission retries.
In Host AP mode, the driver is compatible with clients using powersave,
except on AR7010 and AR9287 USB devices.
The athn driver can be configured at runtime with ifconfig(8) or on boot
with hostname.if(5).
FILES
For USB devices, the driver needs at least version 1.1p4 of the following
firmware files, which are loaded when an interface is attached:
/etc/firmware/athn-open-ar7010
/etc/firmware/athn-open-ar9271
A prepackaged version of the firmware can be installed using
fw_update(8). Firmware source code is available under a mix of BSD and
GPLv2 licences. A port which cross-compiles the firmware can be found in
/usr/ports/devel/open-ath9k-htc-firmware.
EXAMPLES
The following example scans for available networks:
# ifconfig athn0 scan
The following hostname.if(5) example configures athn0 to join network
"mynwid", using WPA key "mywpakey", obtaining an IP address using DHCP:
nwid mynwid wpakey mywpakey
inet autoconf
The following hostname.if(5) example creates a host-based access point on
boot:
mediaopt hostap
nwid mynwid wpakey mywpakey
inet 192.168.1.1 255.255.255.0
DIAGNOSTICS
athn0: device timeout A frame dispatched to the hardware for
transmission did not complete in time. The driver will reset the
hardware. This should not happen.
athn0: radio is disabled by hardware switch The radio transmitter is off
and thus no packet can go out. The driver will reset the hardware. Make
sure the laptop radio switch is on.
athn0: radio switch turned off The radio switch has been turned off
while the interface was up and running. The driver will turn the
interface down.
athn0: error N, could not read firmware ... For some reason, the driver
was unable to read the firmware file from the filesystem. The file might
be missing or corrupted.
SEE ALSO
arp(4), cardbus(4), ifmedia(4), intro(4), netintro(4), pci(4), usb(4),
hostname.if(5), ifconfig(8)
HISTORY
The athn driver first appeared in OpenBSD 4.7. Support for USB 2.0
devices first appeared in OpenBSD 4.9.
AUTHORS
The athn driver was written by Damien Bergamini
<
[email protected]> based on source code licensed under the ISC
released in 2008 by Atheros Communications for Linux.
Anthony J. Bentley <
[email protected]> added the open source USB
firmware and its cross-compiler to the ports tree.
Stefan Sperling <
[email protected]> implemented driver support for the
open source USB firmware.
CAVEATS
Support for 802.11n 40MHz channels and Tx aggregation is not yet
implemented. Additional work is required in ieee80211(9) before those
features can be supported.
On USB devices, Host AP mode is limited to 7 concurrent clients and does
not support power saving. Clients attempting to use power saving mode
may experience significant packet loss.
FreeBSD 14.1-RELEASE-p8 March 27, 2025 FreeBSD 14.1-RELEASE-p8