CiNcH83 / bravia_atv2

BRAVIA Android TV Knowledge Base
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WLAN throughput often dropping to 1/4th of the available bandwidth #68

Open CiNcH83 opened 5 years ago

CiNcH83 commented 5 years ago

WLAN bandwidth frequently drops to <30mbps permanently. Streaming Blu-ray from NAS isn't feasible anymore then. Bandwidth is still enough for streaming services like Netflix though.

When bandwidth drops, WLAN signal strength is still shown as Excellent (-43 dBm) and link speed as 866mbps. Other devices connected to the same access point (FRITZ!WLAN Repeater 1750E configured as LAN bridge) still operate at full bandwidth. After disabling and re-enabling WLAN on BRAVIA, "full" bandwidth (~250mbps on BRAVIA) is available again.

Bandwidth has been measured via fast.com using Vewd internet browser on BRAVIA and via iPerf (analiti on BRAVIA, iPerf3 on QNAP NAS):

iperf3 -c 10.0.0.4 -i 1 -R
Connecting to host 10.0.0.4, port 5201
Reverse mode, remote host 10.0.0.4 is sending
[ 4] local 10.0.0.7 port 57534 connected to 10.0.0.4 port 5201
[ID] Interval       Transfer    Bandwidth
[ 4] 0.00-1.00 sec  3.05 MBytes 25.6 Mbits/sec
[ 4] 1.00-2.00 sec  3.25 MBytes 27.2 Mbits/sec
[ 4] 2.00-3.00 sec  3.30 MBytes 27.8 Mbits/sec
[ 4] 3.00-4.00 sec  3.34 MBytes 28.0 Mbits/sec
[ 4] 4.00-5.00 sec  3.42 MBytes 28.7 Mbits/sec
[ 4] 5.00-6.00 sec  3.32 MBytes 27.8 Mbits/sec
[ 4] 6.00-7.00 sec  3.35 MBytes 28.1 Mbits/sec
[ 4] 7.00-8.00 sec  3.36 MBytes 28.2 Mbits/sec
[ 4] 8.00-9.00 sec  3.40 MBytes 28.6 Mbits/sec
[ 4] 9.00-10.00 sec 3.38 MBytes 28.3 Mbits/sec
------------------------------------------------------------------------
[ID] Interval       Transfer     Bandwidth      Retr
[ 4] 0.00-10.00 sec 35.5 MBytes  29.8 Mbits/sec 61

I switched off my 5GHz WiFi in order to verify via spectrum analyzer that there is no interference on the used 80MHz channel 42 (5170-5250MHz): image

What is quite interesting is that when bandwidth drops to <30mbps, only the first 20MHz of the 80MHz wide channel are extensively being used: image

One can clearly see that there is not a lot of activity on the remainder of the 80MHz wide channel.

The problem seems to be much more severe after power-cycling the router/WiFi access point. Bandwidth drops to <30mbps on a daily basis (typically after every deep sleep standby). There seems to be a settling process which takes some days after which connection becomes more reliable. Same is true for #53. All other devices on the WiFi instantly connect and make use of the full channel bandwidth at any time.