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CPE210 Frequent dropouts?

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CPE210 Frequent dropouts?

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Re:CPE210 Frequent dropouts?
2019-12-14 15:28:14 - last edited 2019-12-14 15:28:49

Yes, I suggest 20 MHz channel width.

 

Grounding is essential to mitigate against atmospheric discharges during lightning storms.

 

Regarding distance setting: IIRC manual setting can be made only with a precision of one digit after the decimal point; if you have V1 hardware you can set to »Auto« to force precision to be 2 digits after the decimal point. If there is no »Auto« setting (newer hardware), try manual setting of 0.1km.
 

To test the WiFi throughput, run the iperf built into the CPE (see the »Tools« menu). Start the iperf server on the remote CPE. The server will run until you stop it, you can even close the remote's »Speed Test« window while the server still will run. Then run the built-in iperf on the local client. This gives you pure WiFi throughput between the two CPEs.

 

To test Internet (uplink) speed I recommend dslreports.com, it is very accurate in my experience.

 

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#12
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Re:CPE210 Frequent dropouts?
2019-12-14 16:13:49

@R1D2 

Thanks. It is the V3 version. I will change tomorow to 20MHz and also do the speed test. It is just me working then so I will not upset my co-workers. Left a ping running overnight to see what we get for max-min values.

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#13
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Re:CPE210 Frequent dropouts?
2019-12-15 13:43:45

@R1D2 

Did some more testing today. I could indeed set i to 0.05Km

 

All values as reported by CPE 210 selftest, average of three measurements

0.1Km 132 down 43 up

1Km 74 down 45 up

0.05Km 132 down 34 up

Changed from 20/40 to 20

85 down 15 up

Changed to 40

136 down 40 up

 

Testing against a fileserver 10 packets of 1Mb each gives 80MBps reading, 40 writing

 

 

Seems like it is prioritising download. Is that correct?

 

BTW, the Mbps in the throughput graph. Is that Megabyte per second och megabits per second.?

 

 

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#14
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Re:CPE210 Frequent dropouts?
2019-12-15 16:11:30

 

AndersG wrote

Seems like it is prioritising download. Is that correct?

 

BTW, the Mbps in the throughput graph. Is that Megabyte per second och megabits per second.?

 

No, there is no »down/up« for a CPE. What you send »up« (send direction) on the remote CPE is »down« (receive direction) on the local CPE and vice versa. The difference between send/receive is probably caused by different read/write speeds or read-ahead/caching on a fileserver. It is unrelated to WiFi throughput.

 

Mbps (U.S.) or Mbit/s (Europe) is always megabits per sec., megabytes pre sec. would be MB/s.

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#15
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Re:CPE210 Frequent dropouts?
2019-12-15 17:03:27

@R1D2 "The difference between send/receive is probably caused by different read/write speeds or read-ahead/caching on a fileserver. It is unrelated to WiFi throughput."

 

But I see those when I do the speed test on the units as well? Ie if I select "bidirectional". If I test "unidirectional RX" I get: 

RX:171.54Mbps

 

And "unidirectional TX" I get 

TX:141.28Mbps

 

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#16
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Re:CPE210 Frequent dropouts?
2019-12-15 18:36:51 - last edited 2019-12-15 18:47:14

Ehm, yes, the distance precision is 2 digits after decimal point for manual and 3 digits if set to »Auto«, sorry. »Auto« works the better the larger the distance; for very short distances it computes wrong values. For the test I did manually set it to 0.01km, actual distance is 5m.

 

I get following the results in 802.11n-only mode.

 

20MHz channel width, WiFi speed index: MCS15 (144.4 Mbps WiFi rate, ~30% WiFi protocol overhead)

 

RX:

 

TX:

 

Bidirectional:

 

 

Link rates:

 

 

40MHz channel width, WiFi speed index: MCS15 (300 Mbps, ~30% WiFi protocol overhead)

 

RX:

 

TX:

 

Bidirectional:

 

Link rates:

 

There is some fluctuation of the results between the measurements due to interferences (17 APs around, 13 from neighbors, 3 indoor APs and 1 outdoor AP from me). Depending on activity of those foreign APs total throughput will decrease according to the amount of AirTime those APs need for sending data.

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#17
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Re:CPE210 Frequent dropouts?
2019-12-15 18:47:05

@R1D2 OK. Thanks. This gives me something to compare with. I did try having a go at the antenna alignment, but found it rather unresponsive. I could turn the antenna almost 90 degrees before I saw a drop down to -68dBm. It currently hovers between -48 and -57dBm. I was wondering if the metal window sill at one end might cause interference?

 

We mounted the antenna in the center, for aestethic reasons. I will try to get a picture tomorrow as it is a bit hard to explain.

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#18
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Re:CPE210 Frequent dropouts?-Solution
2019-12-15 18:53:32 - last edited 2019-12-15 19:38:07

Over 50m (you wrote ~300m first) a CPE sees even APs located in the opposite direction due to reflections. 50m is no big distance for a CPE. You could try to decrease Tx power on such a short distance, but it will need lots of tests to get best settings for ideal throughput and IMO it's questionable whether this is worth the time to gain just a few Mbits/s.

 

Remember: WLAN is a shared medium. You can't expect an ideal environment. See what happens with the CPE's throughput if I send data to another WLAN link in the same room during a speed test between the CPEs (still at 40 MHz channel width with WiFi rate 300 Mbps):

 

 

Throughput on second (different) WLAN:

 

$ iperf -t 600 -i 10 -c 192.168.5.10
------------------------------------------------------------
Client connecting to 192.168.5.10, TCP port 5001
TCP window size:  129 KByte (default)
------------------------------------------------------------
[  3] local 192.168.5.205 port 64342 connected with 192.168.5.10 port 5001
[ ID] Interval       Transfer     Bandwidth
[...]
[  3] 70.0-80.0 sec  22.0 MBytes  18.5 Mbits/sec
[  3] 80.0-90.0 sec  19.8 MBytes  16.6 Mbits/sec
[  3] 90.0-100.0 sec  20.0 MBytes  16.8 Mbits/sec
[  3] 100.0-110.0 sec  19.6 MBytes  16.5 Mbits/sec
[  3] 110.0-120.0 sec  11.4 MBytes  9.54 Mbits/sec
[  3] 120.0-130.0 sec  7.75 MBytes  6.50 Mbits/sec
[  3] 130.0-140.0 sec  19.6 MBytes  16.5 Mbits/sec
[  3] 140.0-150.0 sec  19.5 MBytes  16.4 Mbits/sec
[  3] 150.0-160.0 sec  19.9 MBytes  16.7 Mbits/sec
[  3] 160.0-170.0 sec   640 KBytes   524 Kbits/sec
[  3] 170.0-180.0 sec  13.9 MBytes  11.6 Mbits/sec
[  3] 180.0-190.0 sec  20.9 MBytes  17.5 Mbits/sec
[  3] 190.0-200.0 sec  19.5 MBytes  16.4 Mbits/sec
[  3] 200.0-210.0 sec  19.9 MBytes  16.7 Mbits/sec
[  3] 210.0-220.0 sec  20.5 MBytes  17.2 Mbits/sec

 

You can never predict which actual throughput you will get, since you never know who is sending data around your place on the same (or an overlapping) channel. That's why 20 MHz channel width (4 channels required) can result in better throughput than 40 MHz (8 channels required) in the 2.4 GHz frequency band.

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#19
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Re:CPE210 Frequent dropouts?
2019-12-16 07:26:02

@R1D2 

"You can never predict which actual throughput you will get, since you never know who is sending data around your place on the same (or an overlapping) channel. "

 

Absolutely! I will test some more during weekends and evenings.

 

Does this look right?

Client:

 

 

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#20
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Re:CPE210 Frequent dropouts?
2019-12-16 11:01:52

 

AndersG wrote

Does this look right?

 

No. AP has fixed 40 MHz channel width, Client has 20/40 MHz setting. Always use the same settings for both CPEs. Also make sure to use WPA2-PSK/AES.

 

40 MHz requires 8 channels, this includes channel 9 which is used by many other radio equipment (not necessarily WiFI). I suggest to set channel to »Auto«.

 

Client distance is 1km, AP distance is 0.05km.

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#21
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