Bugzilla – Bug 397
Custom WifiModes apparently not possible in infrastructure mode
Last modified: 2009-11-23 09:00:19 EST
I was trying, unsuccessfully, to use a custom WifiMode with NS 3. The code is something like:
WIMAX_DATA_RATE = 2000000 # (bit/s)
wimaxWifiMode = ns3.WifiModeFactory.CreateBpsk("wimax", False, 20000000, WIMAX_DATA_RATE, 12000000)
wifiDevice = ns3.WifiNetDevice()
mode = ns3.WifiModeValue(wimaxWifiMode)
manager = ns3.ConstantRateWifiManager(DataMode=mode, ControlMode=mode)
The end result is that the station can receive packets, but is unable to associate. Even if I change WIMAX_DATA_RATE to 6000000, which is basically the same default datarate value used by ns3.ConstantRateWifiManager, it still doesn't work. If I remove my custom mode and let ns3.ConstantRateWifiManager use its default one, then it works.
Now, while it is certainly possible that I have missed something, then I see code such as this in WifiPhy:
This leads me to suspect that WifiNetDevice will not work with other modes except the builtin ones. And that is a shame.
In related subject, I get the feeling a lot of standard data rates are missing from the builtin ns-3 modes. Quick googling shows data rates such as 1, 2, and 5.5 Mbit/s, see http://www.moonblinkwifi.com/differences_in_80211b_and_802.cfm
(In reply to comment #0)
> In related subject, I get the feeling a lot of standard data rates are missing
> from the builtin ns-3 modes. Quick googling shows data rates such as 1, 2, and
> 5.5 Mbit/s, see http://www.moonblinkwifi.com/differences_in_80211b_and_802.cfm
OK, so I get it now that WifiNetDevice is implementing 802.11a instead of b/g. Kind of strange, but not wrong :) But never mind this comment.
so, should I close this bug gustavo ? If not, can you try to rephrase it for me ?
Well, the main issue remains. In NS-2 wifi, at least when I used it a couple of years ago, it was rather simple to specify custom data rates and custom basic rates; you would just say how many bit/s data rate, and how many bit/s basic rate, and so on. In NS-3 it seems to be nigh impossible.
It would be a "nice to have" enhancement. But I don't have the skills to make it work, all the PHY level stuff is black magic to me. If no one else plans to provide a patch, I guess you can just close with WONTFIX.
we don't need to mark this issue as WONTFIX because we could improve the current situation but I see no point in making this bug P1. Hence, marking P3