COMPANY CONFIDENTIAL
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#iwpriv wifi0 SpurImmLvl 3
#iwpriv wifi0 GetSpurImmLvl
wifi0 GetSpurImmLvl:2
txchainmask
rxchainmask
#iwpriv wifi
N
txchainmask
mask
#iwpriv wifi
N
rxchainmask
mask
These parameters set the transmit and receive chainmask values. For MIMO devices, the chainmask indicates
how many streams are transmitted/received, and which chains are used. For some Atheros devices up to 3
chains can be used, while others are restricted to 2 or 1 chain. It’s important to note that the maximum number
of chains available for the device being used. For dual chain devices, chain 2 is not available. Similarly, single
chain devices will only support chain 0. The chains are represented in the bit mask as follows:
Chain 0 0x01
Chain 1 0x02
Chain 2 0x04
Selection of chainmask can affect several performance factors. For a 3 chain device, most of the time an RX
chainmask of 0x05 (or 0x03) is used for 2x2 stream reception. For near range operations, a TX chainmask of
0x05 (or 0x03) is used to minimize near range effects. For far range, a mask of 0x07 is used for transmit.
The default chainmask values are stored in EEPROM. This iwpriv command will override the current
chainmask settings. These commands have corresponding get commands
#iwpriv wifi0 txchainmask 0x05
#iwpriv wifi
N
rxchainmask 0x05
#iwpriv wifiN get_txchainmask
wifi0 get_txchainmask:5
#iwpriv wifiN get_rxchainmask mask
wifi0 get_rxchainmask:5
TXPowLim
#iwpriv ath
N
TXPowLim
limit
This command will set the current Tx power limit. This has the same effect as the
iwconfig ath0 txpower
command. The Tx power will be set to the minimum of the value provided and the regulatory limit. Note that
this value may be updated by other portions of the code, so the effect of the value may be temporary. The value
is in units of 0.5 db increments. This command has a corresponding get command, and its default value is 0.
#iwpriv ath0 TXPowLim 30
#iwpriv ath0 getTxPowLim
wifi0 getTxPowLim:30
TXPwrOvr
#iwpriv ath
N
TXPwrOvr
overrideLimit
This command is used to override the transmit power limits set by iwconfig or the TXPowLim command. This
is used for testing only, and is still limited by the regulatory power. A value of 0 disables this override. The
command has a corresponding get command, and its default value is 0.
#iwpriv ath0 TXPowOvr 30
#iwpriv ath0 getTxPowOvr
wifi0 getTxPowOvr:30
2.5.2.4 Protocol Layer
The Protocol Layer (or 802.11 layer) commands are used to configure settings that are made per VAP. These
include such things as security modes, QoS settings, WMM parameters, and any other setting that is specific
to the specific VAP vice the radio. These commands are grouped according to general categories to keep
associated commands in the same section.
