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===== ath9k Antenna Diversity =====

This page documents how antenna diversity is supported by ath9k. 

 


===== What is Antenna Diversity ? =====

Adrian Chadd's excellent, detailed [[https://wiki.freebsd.org/dev/ath_hal(4)/AntennaDiversity|notes]]. 


===== Supported cards =====


==== WLAN Only ====
  * HB95  (AR9285) 
  * HB125 (AR9485) 
==== WLAN and BT ====


=== WB195 ===
|**WLAN** |**Bluetooth** |**Vendor ID** |**Device ID** |**Subvendor ID** |**Subdevice ID** |
|AR9285 |AR3011 |0x168c |0x002b |0x1a3b (Azurewave) |0x2c37 |


=== CUS198 ===
|**WLAN** |**Bluetooth** |**Vendor ID** |**Device ID** |**Subvendor ID** |**Subdevice ID** |
|AR9485 |AR3012 |0x168c |0x0032 |0x1a3b (Azurewave) |0x2086 |
|AR9485 |AR3012 |0x168c |0x0032 |0x1a3b (Azurewave) |0x1237 |
|AR9485 |AR3012 |0x168c |0x0032 |0x1a3b (Azurewave) |0x2126 |
|AR9485 |AR3012 |0x168c |0x0032 |0x1a3b (Azurewave) |0x126A |


=== CUS230 ===
|**WLAN** |**Bluetooth** |**Vendor ID** |**Device ID** |**Subvendor ID** |**Subdevice ID** |
|AR9485 |AR3012 |0x168c |0x0032 |0x1a3b (Azurewave) |0x2152 |
|AR9485 |AR3012 |0x168c |0x0032 |0x105b (Foxconn) |0xe075 |


=== WB225 ===
|**WLAN** |**Bluetooth** |**Vendor ID** |**Device ID** |**Subvendor ID** |**Subdevice ID** |
|AR9485 |AR3012 |0x168c |0x0032 |0x168c (Atheros) |0x3119 |
|AR9485 |AR3012 |0x168c |0x0032 |0x168c (Atheros) |0x3122 |
|AR9485 |AR3012 |0x168c |0x0032 |0x185f (WNC) |0x3119 |
|AR9485 |AR3012 |0x168c |0x0032 |0x185f (WNC) |0x3027 |
|AR9485 |AR3012 |0x168c |0x0032 |0x144d (Samsung) |0x4105 |
|AR9485 |AR3012 |0x168c |0x0032 |0x144d (Samsung) |0x4106 |
|AR9485 |AR3012 |0x168c |0x0032 |0x144d (Samsung) |0x410d |
|AR9485 |AR3012 |0x168c |0x0032 |0x144d (Samsung) |0x410e |
|AR9485 |AR3012 |0x168c |0x0032 |0x144d (Samsung) |0x410f |
|AR9485 |AR3012 |0x168c |0x0032 |0x144d (Samsung) |0xc706 |
|AR9485 |AR3012 |0x168c |0x0032 |0x144d (Samsung) |0xc680 |
|AR9485 |AR3012 |0x168c |0x0032 |0x144d (Samsung) |0xc708 |
|AR9485 |AR3012 |0x168c |0x0032 |0x17aa (Lenovo) |0x3218 |
|AR9485 |AR3012 |0x168c |0x0032 |0x17aa (Lenovo) |0x3219 |


=== WB335 ===

There are 3 types of WB335-based cards. 1-ANT cards share a LNA between WLAN/BT. 2-ANT cards have dedicated LNA for BT and WLAN and have antennae in both slots (MAIN and ALT), but WLAN RX diversity is disabled for some cards (based on vendor requirements). 
|**Type** |**No. of connected antennae** |**Shared LNA with BT** |**Antenna Diversity** |
|1-ANT |1 |Yes |No |
|2-ANT |2 |No |No |
|2-ANT |2 |No |Yes |

2-ANT cards supporting WLAN RX diversity. 
|**WLAN** |**Bluetooth** |**Vendor ID** |**Device ID** |**Subvendor ID** |**Subdevice ID** |
|AR9565 |AR3012 |0x168c |0x0036 |0x144d |0x411a |
|AR9565 |AR3012 |0x168c |0x0036 |0x144d |0x411b |
|AR9565 |AR3012 |0x168c |0x0036 |0x144d |0x411c |
|AR9565 |AR3012 |0x168c |0x0036 |0x144d |0x411d |
|AR9565 |AR3012 |0x168c |0x0036 |0x144d |0x411e |
|AR9565 |AR3012 |0x168c |0x0036 |0x168c |0x3027 |
|AR9565 |AR3012 |0x168c |0x0036 |0x1028 |0x302c |
|AR9565 |AR3012 |0x168c |0x0036 |0x11ad |0x0642 |
|AR9565 |AR3012 |0x168c |0x0036 |0x11ad |0x0652 |
|AR9565 |AR3012 |0x168c |0x0036 |0x11ad |0x0612 |
|AR9565 |AR3012 |0x168c |0x0036 |0x11ad |0x0832 |
|AR9565 |AR3012 |0x168c |0x0036 |0x11ad |0x0692 |
|AR9565 |AR3012 |0x168c |0x0036 |0x1a3b |0x2130 |
|AR9565 |AR3012 |0x168c |0x0036 |0x1a3b |0x213b |
|AR9565 |AR3012 |0x168c |0x0036 |0x1a3b |0x2182 |
|AR9565 |AR3012 |0x168c |0x0036 |0x144f |0x7202 |
|AR9565 |AR3012 |0x168c |0x0036 |0x1b9a |0x2810 |
|AR9565 |AR3012 |0x168c |0x0036 |0x1b9a |0x28a2 |
|AR9565 |AR3012 |0x168c |0x0036 |0x185f |0x3027 |
|AR9565 |AR3012 |0x168c |0x0036 |0x185f |0xa120 |
|AR9565 |AR3012 |0x168c |0x0036 |0x105b |0xe07f |
|AR9565 |AR3012 |0x168c |0x0036 |0x105b |0xe081 |
|AR9565 |AR3012 |0x168c |0x0036 |0x17aa |0x3026 |
|AR9565 |AR3012 |0x168c |0x0036 |0x17aa |0x4026 |
|AR9565 |AR3012 |0x168c |0x0036 |0x1043 |0x85f2 |
|AR9565 |AR3012 |0x168c |0x0036 |0x1028 |0x020e |

CUS252 (AR9565 + xLNA) 
|**WLAN** |**Bluetooth** |**Vendor ID** |**Device ID** |**Subvendor ID** |**Subdevice ID** |
|AR9565 |AR3012 |0x168c |0x0036 |0x168c |0x3028 |
|AR9565 |AR3012 |0x168c |0x0036 |0x1a3b |0x2176 |


===== Enable WLAN/BT RX Antenna Diversity =====

To enable WLAN RX diversity using the ALT antenna, use the module parameter //bt_ant_diversity//. The Bluetooth interface has to be disabled when this feature is enabled in ath9k. Also, BTCOEX should be disabled, so the driver must **not** be loaded with //btcoex_enable=1//. 


<code>modprobe ath9k bt_ant_diversity=1</code>
This can also be turned on/off using the debugfs file //bt_ant_diversity//. 


<code>echo 1 > /sys/kernel/debug/ieee80211/phy0/ath9k/bt_ant_diversity
echo 0 > /sys/kernel/debug/ieee80211/phy0/ath9k/bt_ant_diversity</code>

===== Debug statistics =====

The debugfs file //antenna_diversity// can be used to see how the LNA combining algorithm is performing. 


<code>cat /sys/kernel/debug/ieee80211/phy*/ath9k/antenna_diversity

Current MAIN config : LNA1
Current ALT config  : LNA2
Average MAIN RSSI   : 40
Average ALT RSSI    : 16

Packet Receive Cnt:
-------------------
                          MAIN            ALT
TOTAL COUNT   :          30932             63
LNA1          :          30932              0
LNA2          :              0             63
LNA1 + LNA2   :              0              0
LNA1 - LNA2   :              0              0

LNA Config Attempts:
--------------------
                          MAIN            ALT
LNA1          :              5              0
LNA2          :              0              5
LNA1 + LNA2   :              0              0
LNA1 - LNA2   :              0              0</code>