# TDMA support for the atheros driver



## francesco (May 27, 2009)

Hi guys,

I've read somewhere that FreeBSD has TDMA (Time Division Multiple Access) support for atheros based wifi cards. 

Anyone knows what is the status of this implementation and what features are available?

I would appreciate any pointers to get more info about this issue.

Thank you,

Francesco


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## richardpl (May 27, 2009)

It is implemented only on 8.0 CURRENT:
http://fxr.watson.org/fxr/source/net80211/ieee80211_tdma.c


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## francesco (Jun 3, 2009)

Thanks for your reply richardpl.

I installed 8.0 CURRENT (2009-05) but now I see a strange behaviour: when typing ifconfig ath0 I only get:


```
ath0: flags ..... metric 0 mtu 2900
      ether xx:xx:xx:xx:xx:xx
      media: IEEE 802.11 wireless ethernet autoselect 
      status: no carrier
```

I'm pretty sure I was getting more output when doing this with 7.2.

I'm also getting errors when trying to scan:

ifconfig ath0 list scan

ifconfig: unable to get scan results

Again, this was working fine on 7.2

Anyone knows what could be the problem here?

Thank you very much,

Francesco


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## richardpl (Jun 4, 2009)

RTFM of ath(4) man page for CURRENT.

CURRENT have multi-bss aka vap support.

By the way you need to read /usr/src/UPDATING too.


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## francesco (Jun 4, 2009)

Ok...I'm trying to create a wireless interface in tdma mode:


```
ifconfig wlan0 create wlandev ath0 wlanmode tdma
```

But I'm getting this error (on 8.0-CURRENT-200905) :


```
ath0: TDMA not supported
ifconfig: SIOCIFCREATE2: Operation not supported
```

What am I missing here?

man page of ath says: "The driver also support tdma operation when compiled with options AH_SUPPORT_TDMA (and the wlan module is built with options IEEE80211_SUPPORT_TDMA to enable the associated 802.11 support)"

How can I check if these options are enabled? How can I enable these options?

Thank you very much,

Francesco


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## richardpl (Jun 4, 2009)

Just add 
	
	



```
options IEEE80211_SUPPORT_TDMA
```
 to your custom kernel file, for more details look in FreeBSD Handbook.

After you add that option you need _just_ to recompile and reinstall kernel.

Note that if you use LKM aproach you just need to recompile and reinstall wlan.ko and if_ath.ko with IEEE80211_SUPPORT_TDMA defined - shortcut which doesnt need reboot  

Explained LKM approach doesnt work with GENERIC kernels.


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## francesco (Jun 4, 2009)

I've tried adding "options IEEE80211_SUPPORT_TDMA" to kernel configuration (under "device wlan"), recompiled it (as described in freebsd handbook) but I'm still getting the same error:


```
ath0: TDMA not supported
ifconfig: SIOCIFCREATE2: Operation not supported
```

uname shows that I'm using the new kernel.

Any idea?

Thank you,

Francesco


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## richardpl (Jun 4, 2009)

Your card doesnt have required capatibility.

It depends on ath_hal macversion greater than 0x78.
Your version should be displayed on ath0 attach on console.


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## francesco (Jun 5, 2009)

Thanks for your answer.

It's a shame that Ubiquiti SRC PCMCIA (AR5112 mac 5.9) are not supported, I love them 

Could you please advise on a good wifi PCMCIA supporting tdma?

Thanks,

Francesco


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## richardpl (Jun 5, 2009)

I dont think it is not supported, that chip just doesnt have such feature.

Sorry but I don't have any ath(4) card.
For more information you can ask FreeBSD developer(s).


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## eprueves (Apr 27, 2012)

Hi,

I know this thread is quite old but I have been trying to setup an ALIX3d3 board as a TDMA master. My card is Atheros AR5413. I was able to recompile the kernel, and got no errors until I bring the WLAN interface up. These are the commands that I used:


```
ifconfig wlan0 create wlandev ath0 wlanmode tdma
ifconfig wlan0 ssid freeBSDtdma tdmaslotlen 2500 tdmaslotcnt 2 tdmaslot 0
ifconfig wlan0 up
```

*A*fter the last command, the stuck beacon message starts coming up.


```
ath0: stuck beacon; resetting (bmiss count 4)
```

Any help here would be greatly appreciated. Thanks


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## wblock@ (Apr 27, 2012)

The freebsd-wireless mailing list is the best place to ask.


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## eprueves (Apr 28, 2012)

Thanks. *W*ill try your suggestion.


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