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[svpcom]

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[iamfaith]

Dear svpcom,

I was able to receive data with your repo between the internal wifi card of raspberry pi zero and rt28xx wifi cards.

I just filter this address in Wireshark and catch the packet.

I have a question about a feature. I don't want encryption of video and I only use it for video transmitting. Can I remove the session key? I will this can reduce latency a lot.

[iamfaith]

Dear svpcom,

Does wifbroadcast support RX diversity? We may have 2 wifi adapters on the ground side. While we receive a data packet from two wifi cards, how could it select one of them with the best RSSI respect to the TX?

[svpcom]

Yes. It supports RX and TX diversity out of box. In case of RX it accept packets from all cards and remove duplicates. In case of TX it use card with best RSSI of RX packets

[iamfaith]

--> In case of TX it use card with best RSSI of RX packets

How to achieve this? For example, I have two RX cards, and do I need to start two processes with the command of wfb_rx with the same radio port?

[iamfaith]

Yes. It supports RX and TX diversity out of box. In case of RX it accept packets from all cards and remove duplicates. In case of TX it use card with best RSSI of RX packets

I think you are misunderstanding me. Could it support such scenarios such as we have two RX cards to receive packets from the same TX. But in some cases, the RX1 may lose some packets, but RX2 not. So we can combine the received packets together on the RX side(ground side). But it's different from what the single RX are receiving from multiple TX cards.

[svpcom]

You need only one wfb_rx process: wfb_rx accepts multiple wifi cards:

$ ./wfb_rx 
Local receiver: ./wfb_rx [-K rx_key] [-k RS_K] [-n RS_N] [-c client_addr] [-u client_port] [-p radio_port] [-l log_interval] interface1 [interface2] ...
Remote (forwarder): ./wfb_rx -f [-c client_addr] [-u client_port] [-p radio_port] interface1 [interface2] ...
Remote (aggregator): ./wfb_rx -a server_port [-K rx_key] [-k RS_K] [-n RS_N] [-c client_addr] [-u client_port] [-l log_interval]
Default: K='rx.key', k=8, n=12, connect=127.0.0.1:5600, radio_port=1, log_interval=1000
WFB version 21.2.4.28894-653b3c2c

https://github.com/svpcom/wifibroadcast/wiki/Setup-HOWTO

WFB support RX diversity via collection packets from multiple wifi cards. Also it support TX diversity (to select tx card based on rx rssi), but this requires python daemon (see HOWTO). I'll recommend to use python daemon because it run out-of-box and configure all channels automatically. Using standalone wfb_rx and wfb_tx only recommended for developers who known WFB internals and known what they want to get.

[iamfaith]

Dear svpcom,

I still can not figure out why the packet loss rate is so high. Same configuration for RX and TX as discussed before. But without wifibroadcast using wifi and gstreamer, everything is ok

[svpcom]

1. Check that you use free channel (I'll recommend to use 5.8GHz band)
2. Check that you video bitrate < 1/2 of radio bitrate. For MCS#1 max video bitrate is 7mbit/s. I'll recommend to use 4mbit/s
   Sample gstreamer pipeline for linux pc:

gst-launch-1.0 videotestsrc ! videoconvert ! video/x-raw,format=NV12,framerate=30/1,width=1280,height=720 ! timeoverlay ! vaapih264enc bitrate=4000 rate-control=cbr max-bframes=0 ! rtph264pay config-interval=1 ! udpsink host=127.0.0.1 port=5602