Raspberry Pi 3 and HostAPD throughput

Raspberry Pi 3 in a Pi2Go

Raspberry Pi 3 in a Pi2Go

The Raspberry Pi 3 has n-wireless (and bluetooth) onboard now.  I got this robot before Christmas “for my boys”.  I didn’t have much time with it before the holidays and couldn’t quite get it to work with a USB wifi dongle and USB storage (to hopefully store pictures from the camera.)

Anyway, I got the Raspberry Pi 3 (RPi3) yesterday and got hostapd working in a very short time using this RPI Wireless Hotspot.

I posted on Twitter that I got it working and got this tweet in reply:

So, here goes… I installed iperf on the RPi3 and locally on my laptop (Fedora 22 i7) with RT5370 USB dongle and Intel 7260 AC onboard.

Raspberry Pi 3 Aerial

Raspberry Pi 3 Aerial (picture from http://makezine.com/2016/02/28/meet-the-new-raspberry-pi-3/)

I can’t find the reference on the web but someone asked if an external aerial could be fitted because his Pis are used in industrial applications and need to be housed in metal cases.  This got me to think that there might be a problem with a robot like mine when it rotates.

This is using the USB dongle on the laptop with the aerial facing away at two feet:

root@robotpi:/home/pi# iperf -s
[root@qedu ~]# iperf -c 10.1.0.1
------------------------------------------------------------
Client connecting to 10.1.0.1, TCP port 5001
TCP window size: 85.0 KByte (default)
------------------------------------------------------------
[ 3] local 10.1.0.192 port 59856 connected with 10.1.0.1 port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0-10.0 sec 24.5 MBytes 20.5 Mbits/sec

This is using the USB dongle on the laptop with the aerial facing towards it:

[root@qedu ~]# iperf -c 10.1.0.1
------------------------------------------------------------
Client connecting to 10.1.0.1, TCP port 5001
TCP window size: 85.0 KByte (default)
------------------------------------------------------------
[ 3] local 10.1.0.192 port 60514 connected with 10.1.0.1 port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0-10.1 sec 24.1 MBytes 20.1 Mbits/sec

From ten feet with the aerial facing away from the laptop:

[root@qedu ~]# iperf -c 10.1.0.1
------------------------------------------------------------
Client connecting to 10.1.0.1, TCP port 5001
TCP window size: 85.0 KByte (default)
------------------------------------------------------------
[ 3] local 10.1.0.192 port 60792 connected with 10.1.0.1 port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0-10.0 sec 24.0 MBytes 20.1 Mbits/sec

Now, with the AC wireless:

[root@qedu ~]# iperf -c 10.1.0.1
------------------------------------------------------------
Client connecting to 10.1.0.1, TCP port 5001
TCP window size: 85.0 KByte (default)
------------------------------------------------------------
[ 3] local 10.1.0.153 port 56582 connected with 10.1.0.1 port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0-10.3 sec 20.4 MBytes 16.7 Mbits/sec
[root@qedu ~]# iperf -c 10.1.0.1
------------------------------------------------------------
Client connecting to 10.1.0.1, TCP port 5001
TCP window size: 85.0 KByte (default)
------------------------------------------------------------
[ 3] local 10.1.0.153 port 56600 connected with 10.1.0.1 port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0-10.1 sec 21.9 MBytes 18.2 Mbits/sec

Ouch!  The USB wireless-n dongle is faster than the onboard wireless-AC.

 

About c3iq

Opensource, Linux, Unix, Fish, Family
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