Bad WIFI connectivity

[maniolias]

We've been using ethernet to connect my tinker boards to internet and everything was working fine. Now, we need to have Tinker to be able to connect to internet over WIFI.

The WIFI connectivity is acting strangely.

We first connect my tinker board to WIFI and run a speedtest:

Code:

Testing download speed................................................................................
Download: 5.57 Mbit/s
Testing upload speed................................................................................................
Upload: 7.67 Mbit/s

And perform a ping from another computer:

Code:

PING 192.168.2.140 (192.168.2.140): 56 data bytes
64 bytes from 192.168.2.140: icmp_seq=0 ttl=64 time=17.950 ms
64 bytes from 192.168.2.140: icmp_seq=1 ttl=64 time=18.188 ms
64 bytes from 192.168.2.140: icmp_seq=2 ttl=64 time=11.740 ms
64 bytes from 192.168.2.140: icmp_seq=3 ttl=64 time=9.345 ms
64 bytes from 192.168.2.140: icmp_seq=4 ttl=64 time=1.840 ms
64 bytes from 192.168.2.140: icmp_seq=5 ttl=64 time=2.769 ms
64 bytes from 192.168.2.140: icmp_seq=6 ttl=64 time=832.240 ms
64 bytes from 192.168.2.140: icmp_seq=7 ttl=64 time=13.193 ms
64 bytes from 192.168.2.140: icmp_seq=8 ttl=64 time=15.144 ms
64 bytes from 192.168.2.140: icmp_seq=9 ttl=64 time=1.853 ms
64 bytes from 192.168.2.140: icmp_seq=10 ttl=64 time=84.482 ms
64 bytes from 192.168.2.140: icmp_seq=11 ttl=64 time=1.933 ms
64 bytes from 192.168.2.140: icmp_seq=12 ttl=64 time=11.473 ms
64 bytes from 192.168.2.140: icmp_seq=13 ttl=64 time=163.019 ms
64 bytes from 192.168.2.140: icmp_seq=14 ttl=64 time=10.288 ms
64 bytes from 192.168.2.140: icmp_seq=15 ttl=64 time=1.810 ms
64 bytes from 192.168.2.140: icmp_seq=16 ttl=64 time=2.800 ms
64 bytes from 192.168.2.140: icmp_seq=17 ttl=64 time=1.750 ms
64 bytes from 192.168.2.140: icmp_seq=18 ttl=64 time=1.690 ms
64 bytes from 192.168.2.140: icmp_seq=19 ttl=64 time=12.199 ms
64 bytes from 192.168.2.140: icmp_seq=20 ttl=64 time=427.251 ms
64 bytes from 192.168.2.140: icmp_seq=21 ttl=64 time=2.859 ms
64 bytes from 192.168.2.140: icmp_seq=22 ttl=64 time=41.634 ms
64 bytes from 192.168.2.140: icmp_seq=23 ttl=64 time=3.772 ms
64 bytes from 192.168.2.140: icmp_seq=24 ttl=64 time=1.721 ms
64 bytes from 192.168.2.140: icmp_seq=25 ttl=64 time=9.478 ms
64 bytes from 192.168.2.140: icmp_seq=26 ttl=64 time=502.713 ms

First weird things is the huge ping time sometimes and the bad wifi speed (we expect around 20Mbit/s over a 2.4 GHz wifi).
For no reason after few minutes the connectivity seems to be even worse. Dit the speedtest again:

Code:

Testing download speed................................................................................
Download: 2.80 Mbit/s
Testing upload speed................................................................................................
Upload: 5.14 Mbit/s

And the ping :

Code:

Request timeout for icmp_seq 86
Request timeout for icmp_seq 87
64 bytes from 192.168.2.140: icmp_seq=86 ttl=64 time=2182.965 ms
64 bytes from 192.168.2.140: icmp_seq=87 ttl=64 time=1178.695 ms
64 bytes from 192.168.2.140: icmp_seq=88 ttl=64 time=177.714 ms
64 bytes from 192.168.2.140: icmp_seq=89 ttl=64 time=625.934 ms
64 bytes from 192.168.2.140: icmp_seq=90 ttl=64 time=1.863 ms
64 bytes from 192.168.2.140: icmp_seq=91 ttl=64 time=1.710 ms
64 bytes from 192.168.2.140: icmp_seq=92 ttl=64 time=346.937 ms
64 bytes from 192.168.2.140: icmp_seq=93 ttl=64 time=471.389 ms
64 bytes from 192.168.2.140: icmp_seq=94 ttl=64 time=402.202 ms
64 bytes from 192.168.2.140: icmp_seq=95 ttl=64 time=2.239 ms
64 bytes from 192.168.2.140: icmp_seq=96 ttl=64 time=3.350 ms
64 bytes from 192.168.2.140: icmp_seq=97 ttl=64 time=10.660 ms
64 bytes from 192.168.2.140: icmp_seq=98 ttl=64 time=25.655 ms
64 bytes from 192.168.2.140: icmp_seq=99 ttl=64 time=10.664 ms
64 bytes from 192.168.2.140: icmp_seq=100 ttl=64 time=6.700 ms
64 bytes from 192.168.2.140: icmp_seq=101 ttl=64 time=23.313 ms
64 bytes from 192.168.2.140: icmp_seq=102 ttl=64 time=13.242 ms
64 bytes from 192.168.2.140: icmp_seq=103 ttl=64 time=3.338 ms
64 bytes from 192.168.2.140: icmp_seq=104 ttl=64 time=399.058 ms
64 bytes from 192.168.2.140: icmp_seq=105 ttl=64 time=67.222 ms

Information about the WIFI network:
- professional grade router (Sophos AP55)
- ~55% of WIFI quality
- When the tinker board is connected the firewall see a good connection speed (72.2 Mbit/s) then it drops slowly to (6.5Mbit/s) and it sometimes get better, sometimes not. 
- Other WIFI device in the same area (computer, smartphones) have no problems

Software:
- TinkerOS 2.0.7 (first tests of 2.0.8 not conclusive)
- nmcli to establish connectivity 
- this script for speedtest (https://github.com/sivel/speedtest-cli/b...eedtest.py)

We did the test with many Tinker boards S and same results. Some devices speedtest are really bad (0.17Mbit/s) and huge ping (29000ms 48000ms). Sometimes it works fine after few reboots.

We're not sure if its an hardware or a software issue, we hope it's a software one.

[igorpec]

The same on a modern kernel: http://ix.io/1H7V

Download: 3.68 Mbit/s
Upload: 2.34 Mbit/s

Realtek 8811AU on USB as a reference. Router is also pro grade, cca. 10m away, but there is noise on 2.4G band

Download: 37.02 Mbit/s
Upload: 19.78 Mbit/s

But that doesn't necessarily means a problem is in hardware. IMHO just drivers are bad. Similar versions of this chip is found in Olimex Lime 64:

Download: 4.20 Mbit/s
Upload: 2.94 Mbit/s

[aronwarner11]

You are facing this problem just because of your cache memory. Do one thing clear all the cache in your browser and as well as from your system. And after that reset your WiFi's password. Then I assured you will generate a good WiFi connectivity.

[edwardpitt]

You are facing this problem just because of your cache memory. Do one thing clear all the cache in your browser and as well as from your system. And after that reset your WiFi's password. Then I assured you will generate a good WiFi connectivity.
Kaspersky issues. Call us at our toll free number 0800 820 3300

[KaithlynMoore]

You can always use WiFi dongels if you're going through connectivity problem.