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ATH(4)			    Kernel Interfaces Manual			ATH(4)

NAME
       ath -- Atheros IEEE 802.11 wireless network driver

SYNOPSIS
       device ath
       device ath_hal
       device ath_rate_onoe
       device wlan

DESCRIPTION
       The  ath	driver provides	support	for wireless network adapters based on
       the Atheros AR5210, AR5211, and AR5212 chips.  Chip-specific support is
       provided	by the Atheros Hardware	Access Layer (HAL), that  is  packaged
       separately.

       Supported  features  include 802.11 and 802.3 frames, power management,
       BSS, IBSS, and host-based access	point operation	modes.	 All  host/de-
       vice interaction	is via DMA.

       The  ath	 driver	 encapsulates all IP and ARP traffic as	802.11 frames,
       however it can receive either 802.11 or 802.3 frames.   Transmit	 speed
       and  operating  mode is selectable and depends on the specific chipset.
       AR5210-based devices support 802.11a operation with transmit speeds  of
       6  Mbps,	 9  Mbps,  12 Mbps, 18 Mbps, 24	Mbps, 36 Mbps, 48 Mbps,	and 54
       Mbps.  AR5211-based devices support 802.11a and 802.11b operation  with
       transmit	 speeds	 as  above for 802.11a operation and 1Mbps, 2Mbps, 5.5
       Mbps and	11Mbps for 802.11b operation.	AR5212-based  devices  support
       802.11a,	 802.11b, and 802.11g operation	with transmit speeds appropri-
       ate to each.  All chips also support an Atheros Turbo  Mode  (TM)  that
       operates	in the 5Ghz frequency range with 2x the	transmit speeds.  Some
       chips also support Turbo	mode in	the 2.4Ghz range with 802.11g.	(These
       modes  are,  however,  only  interoperable with other Atheros-based de-
       vices.)	The actual transmit speed used is dependent on signal  quality
       and  the	 "rate	control"  algorithm employed by	the driver.  All chips
       support WEP encryption.	The AR5212 has hardware	support	for  the  AES-
       CCM,  TKIP,  and	Michael	cryptographic operations required for WPA.  To
       enable encryption, use ifconfig(8) as shown below.

       By default, the ath driver configures the card for BSS  operation  (aka
       infrastructure  mode).	This  mode requires the	use of an access point
       (base station).

       The ath driver also supports  the  standard  IBSS  point-to-point  mode
       where stations can communicate amongst themselves without the aid of an
       access point.

       The  driver  may	also be	configured to operate in hostap	mode.  In this
       mode a host may function	as an access  point  (base  station).	Access
       points  are different than operating in IBSS mode.  They	operate	in BSS
       mode.  They allow for easier roaming and	bridge	all  Ethernet  traffic
       such  that  machines  connected via an access point appear to be	on the
       local Ethernet segment.

       For more	information on configuring this	device,	see ifconfig(8).

       Devices supported by the	ath driver come	in either Cardbus or  mini-PCI
       packages.   Wireless cards in Cardbus slots may be inserted and ejected
       on the fly.

HARDWARE
       The following cards are among those supported by	the ath	driver:

       Card		    Chip      Bus	 Standard
       Aztech WL830PC	    AR5212    CardBus	 b/g
       Cisco AIR-CB21AG	    AR5115    Cardbus	 a/b/g
       Cisco AIR-PI21AG	    AR5115    PCI	 a/b/g
       D-Link DWL-A650	    AR5210    CardBus	 a
       D-Link DWL-AB650	    AR5211    CardBus	 a/b
       D-Link DWL-A520	    AR5210    PCI	 a
       D-Link DWL-AG520	    AR5212    PCI	 a/b/g
       D-Link DWL-AG650	    AR5212    CardBus	 a/b/g
       D-Link DWL-G520B	    AR5212    PCI	 b/g
       D-Link DWL-G650B	    AR5212    CardBus	 b/g
       Elecom LD-WL54AG	    AR5212    Cardbus	 a/b/g
       Elecom LD-WL54	    AR5211    Cardbus	 a
       Fujitsu E5454	    AR5212    Cardbus	 a/b/g
       Fujitsu FMV-JW481    AR5212    Cardbus	 a/b/g
       Fujitsu E5454	    AR5212    Cardbus	 a/b/g
       HP NC4000	    AR5212    PCI	 a/b/g
       I/O Data	WN-AB	    AR5212    CardBus	 a/b
       I/O Data	WN-AG	    AR5212    CardBus	 a/b/g
       I/O Data	WN-A54	    AR5212    CardBus	 a
       Linksys WMP55AG	    AR5212    PCI	 a/b/g
       Linksys WPC51AB	    AR5211    CardBus	 a/b
       Linksys WPC55AG	    AR5212    CardBus	 a/b/g
       NEC PA-WL/54AG	    AR5212    CardBus	 a/b/g
       Netgear WAG311	    AR5212    PCI	 a/b/g
       Netgear WAB501	    AR5211    CardBus	 a/b
       Netgear WAG511	    AR5212    CardBus	 a/b/g
       Netgear WG311T	    AR5212    PCI	 b/g
       Netgear WG511T	    AR5212    CardBus	 b/g
       Orinoco 8480	    AR5212    CardBus	 a/b/g
       Orinoco 8470WD	    AR5212    CardBus	 a/b/g
       Proxim Skyline 4030  AR5210    CardBus	 a
       Proxim Skyline 4032  AR5210    PCI	 a
       Samsung SWL-5200N    AR5212    CardBus	 a/b/g
       SMC SMC2536W-AG	    AR5212    CardBus	 a/b/g
       SMC SMC2735W	    AR5210    CardBus	 a
       Sony PCWA-C700	    AR5212    Cardbus	 a/b
       Sony PCWA-C300S	    AR5212    Cardbus	 b/g
       Sony PCWA-C500	    AR5210    Cardbus	 a
       3Com 3CRPAG175	    AR5212    CardBus	 a/b/g

       An     up     to	    date      list	can	 be	 found	    at
       http://customerproducts.atheros.com/customerproducts.

EXAMPLES
       Join an existing	BSS network (ie: connect to an access point):

	     ifconfig ath0 inet	192.168.0.20 netmask 0xffffff00

       Join a specific BSS network with	network	name "my_net":

	     ifconfig ath0 inet	192.168.0.20 netmask 0xffffff00	ssid my_net

       Join a specific BSS network with	WEP encryption:

	     ifconfig ath0 inet	192.168.0.20 netmask 0xffffff00	ssid my_net \
		     wepmode on	wepkey 0x8736639624

       Join/create an 802.11b IBSS network with	network	name "my_net":

	     ifconfig ath0 inet	192.168.0.22 netmask 0xffffff00	ssid my_net \
		     mode 11b mediaopt adhoc

       Create an 802.11g host-based access point:

	     ifconfig ath0 inet	192.168.0.10 netmask 0xffffff00	ssid my_ap \
		     mode 11g mediaopt hostap

       Create an 802.11a host-based access point with WEP enabled:

	     ifconfig ath0 inet	192.168.0.10 netmask 0xffffff00	ssid my_ap \
		     wepmode on	wepkey 0x1234567890 mode 11a mediaopt hostap

       Create a	host-based wireless bridge to fxp0:

	     Add BRIDGE	to the kernel config.
	     ifconfig ath0 inet	up ssid	my_ap media DS/11Mbps mediaopt hostap
	     sysctl net.link.ether.bridge.enable=1
	     sysctl net.link.ether.bridge.config="ath0 fxp0"
	     sysctl net.inet.ip.check_interface=0

       This will give you the same functionality as an access point.

DIAGNOSTICS
       ath%d:  unable  to attach hardware; HAL status %u  The Atheros Hardware
       Access Layer was	unable to configure the	hardware  as  requested.   The
       status	 code	 is    explained    in	  the	 HAL	include	  file
       sys/contrib/dev/ath/ah.h.

       ath%d: failed to	allocate descriptors: %d  The driver was unable	to al-
       locate contiguous memory	for  the  transmit  and	 receive  descriptors.
       This usually indicates system memory is scarce and/or fragmented.

       ath%d:  unable  to  setup a data	xmit queue!  The request to the	HAL to
       set up the transmit queue for normal data frames	failed.	  This	should
       not happen.

       ath%d:  unable to setup a beacon	xmit queue!  The request to the	HAL to
       set up the transmit queue for 802.11 beacon frames frames failed.  This
       should not happen.

       ath%d: 802.11 address: %s  The MAC address programmed in	the EEPROM  is
       displayed.

       ath%d:  hardware	 error;	resetting  An unrecoverable error in the hard-
       ware occurred.  Errors of this sort include unrecoverable  DMA  errors.
       The driver will reset the hardware and continue.

       ath%d:  rx  FIFO	 overrun;  resetting  The receive FIFO in the hardware
       overflowed before the data could	be transferred to the host.  This typ-
       ically occurs because the hardware ran short of receive descriptors and
       had no place to transfer	received data.	 The  driver  will  reset  the
       hardware	and continue.

       ath%d:  unable  to  reset hardware; hal status %u  The Atheros Hardware
       Access Layer was	unable to reset	the hardware as	requested.  The	status
       code is explained in the	 HAL  include  file  sys/contrib/dev/ath/ah.h.
       This should not happen.

       ath%d:  unable  to  start  recv logic  The driver was unable to restart
       frame reception.	 This should not happen.

       ath%d: device timeout  A	frame dispatched to the	hardware for transmis-
       sion did	not complete in	time.  The driver will reset the hardware  and
       continue.  This should not happen.

       ath%d: bogus xmit rate 0x%x  An invalid transmit	rate was specified for
       an outgoing frame.  The frame is	discarded.  This should	not happen.

       ath%d:  ath_chan_set:  unable to	reset channel %u (%u Mhz)  The Atheros
       Hardware	Access Layer was unable	to reset the hardware  when  switching
       channels	during scanning.  This should not happen.

       ath%d: unable to	allocate channel table	The driver was unable to allo-
       cate memory for the table used to hold the set of available channels.

       ath%d:  unable  to  collect  channel  list from hal  A problem occurred
       while querying the HAL to find the set of available  channels  for  the
       device.	This should not	happen.

       ath%d: failed to	enable memory mapping  The driver was unable to	enable
       memory-mapped I/O to the	PCI device registers.  This should not happen.

       ath%d:  failed to enable	bus mastering  The driver was unable to	enable
       the device as a PCI bus master for doing	DMA.  This should not happen.

       ath%d: cannot map register space	 The driver was	unable to map the  de-
       vice registers into the host address space.  This should	not happen.

       ath%d:  could  not  map interrupt  The driver was unable	to allocate an
       IRQ for the device interrupt.  This should not happen.

       ath%d: could not	establish interrupt  The driver	was unable to  install
       the device interrupt handler.  This should not happen.

SEE ALSO
       an(4),	arp(4),	 ath_hal(4),  card(4),	netintro(4),  pcic(4),	wi(4),
       wlan(4),	ifconfig(8), wicontrol(8)

HISTORY
       The ath device driver first appeared in FreeBSD 5.2.

CAVEATS
       Different regulatory domains have different default channels for	 adhoc
       mode.   See  ifconfig(8)	 for information on how	to change the channel.
       See wicontrol(8)	for information	on different regulatory	domains.  Dif-
       ferent regulatory domains may not be  able  to  communicate  with  each
       other  with  802.11a as different regulatory domains do not necessarily
       have overlapping	channels.

       Revision	A1 of the D-LINK DWL-G520 and DWL-G650 are based on an	Inter-
       sil PrismGT chip	and are	not supported by this driver.

BUGS
       Performance in lossy environments is suboptimal.	 The algorithm used to
       select  the  rate for transmitted packets is very simplistic.  There is
       no software retransmit; only hardware retransmit	is used.  Contributors
       are encouraged to replace the existing rate control  algorithm  with  a
       better  one  (hint: all the information needed is available to the dri-
       ver).

       The driver does not fully enable	power-save operation of	the chip; con-
       sequently power use is suboptimal.

       The driver honors the regulatory	domain programmed into the EEPROM of a
       device and does not support overriding this setting.  This is  done  to
       insure  compliance  with	local regulatory agencies when operating as an
       access point.  Unfortunately this also means that devices purchased for
       use in one locale may not be usable in another.	Changes	are planned to
       remove this restriction when operating in station mode.

FreeBSD	6.0		       December	29, 2004			ATH(4)

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