Problems on simulating WiFi uplink and downlink throughput in infrastructure mode

[Willian He]

I am simulating the WiFi uplink and downlink throughput in infrastructure mode.

In my simulation, one AP node and two STA nodes are created.

The udpClient application is installed on the first STA and it sends UDP packets to AP on which udpServer application is installed .

The second STA has downlink traffic only. The AP sends UDP packets to the second STA, so udpClient application is installed on AP and udpServer app is installed on the second STA.

The physical layer rate is set to 24Mbps for both downlink and uplink, and uplink load is fix at 0.2Mbps.

RTS/CTS is enable, however, when I range the downlink load from 1Mbps to 20Mbps, the downlink throughput firstly increases and then decreases instead of getting saturated.

when the downlink load is 20Mbps, the downlink UDP packet loss ratio is extremely large(about 98%).

I am new to ns-3, can anybody tell me what's wrong? Great thanks in advance.

 

[Tommaso Pecorella]

Hi,

maybe you should consider that there's no such thing like "uplink" and "downlink" in Wi-Fi. There's only one channel and both up and down traffic are competing for resources.
If you want to see the channel status, you should check *all* the packets in the channel, including the failed transmissions. Check the MAC-level traces, there should be something telling you also the failed attempts.

Cheers,

T.

[Willian He]

Thanks a lot.

I got the problem solved now.