Hi guys,
maybe someone more experienced in reading .pcap files could help me. links at the bottom.
I have a single 802.11ac client (rivet killer 1535) and an AP (Linksys EA8500), and I have used a macbook air 2014 wireless diagnostics tool to sniff the packets from the air.
Just as the spec orders, every 100 ms. the AP sends out a Null Data Packet Announcement (NDPA) and the client sends back a beamforming feedback report.
The problem is that the beamforming report should describe a matrix of size Nr X Nc, but the values of Nr and Nc makes no sense!
Nc = the number of Space-Time-Streams, as it is specified in the NDP. this value should be between 2 and 8.
Nr = Min between the above and the number of antennas at the client.
(see 802.11ac-2013 page 57)
However, the value specified in the beamforming report is Nc=1! And on the other hand, the report includes the avg. SNR for Space-Time Streams [STS1,STS2,STS3..,STSNc] (see 802.11ac-2013 page 58), and there it shows 8 values, indicating Nc=8!
Can anyone shed some light on the matter?
802.11ac-2013 spec, full pcap and pcap with just the NDPA and beamforming reports can be found here:
https://drive.google.com/folderview?id=0B7X38eaciUXGM3ExZG1kRFFpWnM&usp=sharing
Thanks,
Uri
maybe someone more experienced in reading .pcap files could help me. links at the bottom.
I have a single 802.11ac client (rivet killer 1535) and an AP (Linksys EA8500), and I have used a macbook air 2014 wireless diagnostics tool to sniff the packets from the air.
Just as the spec orders, every 100 ms. the AP sends out a Null Data Packet Announcement (NDPA) and the client sends back a beamforming feedback report.
The problem is that the beamforming report should describe a matrix of size Nr X Nc, but the values of Nr and Nc makes no sense!
Nc = the number of Space-Time-Streams, as it is specified in the NDP. this value should be between 2 and 8.
Nr = Min between the above and the number of antennas at the client.
(see 802.11ac-2013 page 57)
However, the value specified in the beamforming report is Nc=1! And on the other hand, the report includes the avg. SNR for Space-Time Streams [STS1,STS2,STS3..,STSNc] (see 802.11ac-2013 page 58), and there it shows 8 values, indicating Nc=8!
Can anyone shed some light on the matter?
802.11ac-2013 spec, full pcap and pcap with just the NDPA and beamforming reports can be found here:
https://drive.google.com/folderview?id=0B7X38eaciUXGM3ExZG1kRFFpWnM&usp=sharing
Thanks,
Uri