how to configure different number Antennas for AP and STA in WiFi module

Anagha Thakur

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Mar 19, 2018, 10:59:58 AM3/19/18

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Hi,

I am using ns-3.27 WiFi 802.11ac.

I want to configure different number of antennas at AP and STA end. Is it possible to do so?

To do so, I think I will have to configure different WiFiPhy, is it possible?

Thanks!!

Best Regards,
Anagha

Rediet

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Apr 9, 2018, 5:11:23 AM4/9/18

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Hi,

Yes. You can reset attributes' values between two installation phases (i.e. for APs and STAs) by using the helpers.

BR,

Rediet

Anagha Thakur

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Apr 9, 2018, 10:30:46 AM4/9/18

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Hi Redlet,

Thank you very much for the response.

I have set the following parameters for 'WIFI_PHY_STANDARD_80211ac' in order to implement MiMo functionalities:

      wifiPhy.Set ("ShortGuardEnabled", BooleanValue (false));
        wifiPhy.Set ("Antennas", UintegerValue (3));
        wifiPhy.Set ("MaxSupportedTxSpatialStreams", UintegerValue (2));
        wifiPhy.Set ("MaxSupportedRxSpatialStreams", UintegerValue (2));

I am using YansWifiModel. And I am using VHT mode.
wifiHelper.SetRemoteStationManager ("ns3::ConstantRateWifiManager", "DataMode", StringValue("VhtMcs9"), "ControlMode", StringValue("VhtMcs0"));

But after setting these as well I am getting the same results (in terms of throughput or Congestion Window in case of Tcp application) as the one's without using MiMo.

It would be helpful if you could suggest me if any other parameter needs to be set along with the above parameters.

Thanks!!

Best Regards,
Anagha

Rediet

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Apr 9, 2018, 10:43:28 AM4/9/18

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Have you set a minimum of 2 spatial streams on both AP and STA sides? How about the NetDevice installation part, I assume that it was done after setting attributes...

Anagha Thakur

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Apr 10, 2018, 5:55:50 AM4/10/18

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Hi,

Yes, I am configuring these parameters before installing on the NetDevices.
And yes, I am installing the same wifiPhy for AP as well as STA. That means the same configuration is installed on both devices.

I have actually modified the TCP variant code for wired and wireless (WiFi) devices. Hence right now I have added only one AP-STA pair connected to a source through a router in my simulation. Later I want to use multiple STAs. For that I am using Yans WiFi model.

I am using BulkSendApplication and TcpSocketFactory for sending data.

With the attached code, I need to understand the MiMo effect in the simulations. But I couldn't even see increase in the throughput or changes in the congestion window behavior of the source node (connected to WiFi AP).

I don't have much knowledge about ns-3 WiFi module. Hence it has been little difficult for me to figure out the problem. I would like to know if I am missing any parameter or any setting to implement MiMo. Or should it actuially work with this code?

Thanks!!

Regards,
Anagha

scratch-simulator_0804.cc

Rediet

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Apr 10, 2018, 6:21:57 AM4/10/18

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I don't have the time to test the script but have you performed your comparison using 10Mbps data rate for the backhaul P2P link? If so, using MIMO over Wi-Fi won't change anything since the bottleneck is on your P2P link.

Anagha Thakur

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Apr 10, 2018, 6:36:54 AM4/10/18

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Okay!!

I am actually using data rate of 1Gbps for P2P links. Sorry for the confusion.

Hence, the source is sending data to intermediate router with P2P link of 1Gbps data rate and the router is sending it further to WiFi AP again on P2P link of 1Gbps.

- Anagha

Anagha Thakur

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Apr 10, 2018, 8:26:28 AM4/10/18

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Hi,

Thank you very much for the response.

With the higher data rates, Now I could see the difference in the behavior of congestion window and throughput values.

I have one last question to ask.
Is it possible to configure different number of antennas and spatial streams at AP (4 antennas, 2 streams) and STA (2 Antennas, 2 streams) ends.
To do so, do I need to configure two different YansWifiPhyHelper for both and install on net Devices?

Thanks!!

Regards,
Anagha

Rediet

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Apr 10, 2018, 9:11:58 AM4/10/18

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Yes you can. You'll just have to do wifiPhy.Set ([new parameters]) in between the two installation phases.

Anagha Thakur

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Apr 10, 2018, 9:41:43 AM4/10/18

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Okay. That would work.
Thank you very much for all the help!! :)

- Anagha

Mahesh

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Apr 12, 2018, 3:10:04 AM4/12/18

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Hi Anagha,

I am researching about the effects of TCP variants on multi-radio wireless networks. I had a query related to tracing TCP stats like CWND, RTT etc. The values are not being output to files. Can you please tell me where I am going wrong? Have attached my code.

Thanks,

Mahesh

test.cc

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