Thanks Robert. That command is not working. This is what I get when I run that command (my wireless interface is wlan1)
*root@beaglebone:~# iwconfig wlan1 power off* *Error for wireless request "Set Power Management" (8B2C) :* * SET failed on device wlan1 ; Operation not permitted.* I tried this with two USB wifi adapters popular with BBB (this <https://www.amazon.com/Edimax-EW-7811Un-150Mbps-Raspberry-Supports/dp/B003MTTJOY%3Fpsc%3D1%26SubscriptionId%3DAKIAILSHYYTFIVPWUY6Q%26tag%3Dduckduckgo-d-20%26linkCode%3Dxm2%26camp%3D2025%26creative%3D165953%26creativeASIN%3DB003MTTJOY> and this <https://www.adafruit.com/products/814>). Does not work on both. I'm currently running *3.8.13-bone79 *kernel. Also tried adding this to my* /etc/network/interfaces* file. Still no luck. *allow-hotplug wlan1* *iface wlan1 inet dhcp* * wireless-power of*f Any suggestions? Thank you. On Tue, Nov 22, 2016 at 1:46 PM, Robert Nelson <robertcnel...@gmail.com> wrote: > On Tue, Nov 22, 2016 at 1:20 PM, <agm6...@gmail.com> wrote: > > Hello All, > > > > I'm using BeagleBone Black as a TCP client which sends a TCP packet > every 5 > > seconds and the same packet is echoed by the server immediately and I'm > > measuring the RTT (Round Trip Time). I'm using Edimax WiFi USB adapter. > The > > RTT measured was ridiculously high (400ms) and I eventually found out its > > because the BBB suspends power to the adapter every few milliseconds (if > > there is no activity). I can see the current toggling between 80mA and 0 > > through an ammeter. Its because of this toggle, the RTT shoots up. I have > > disabled the auto suspend for the USB. Some observations > > > > The same WIFI adapter plugged into a computer (Linux and windows) running > > the same code works fine (with and without change to the autosuspend > > settings). No toggling of power and a steady 40ms RTT is observed. Also > blue > > LED on adapter is stable. > > I powered the the USB through a hub(powered externally) and connected it > to > > BBB and it still exhibits the issue > > The toggling of power can be observed with the blue led on the edimax > > adapter which remains constant when connected to other computers but > blinks > > when connected to BBB. Cross checked with an ammeter. > > When I keep the adapter busy on BBB (by sending the packet every 500ms > > instead of 2s), the adapter consumes a steady 80mA and the RTT is stable > at > > 40ms > > > > > > I have played around with the autosuspend settings (by writing -1 to > > autosuspend for the usb device), powered through hub etc. but the problem > > persists. > > Have you disable power management? > > sudo iwconfig wlan0 power off > > > Regards, > > -- > Robert Nelson > https://rcn-ee.com/ > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/CALD0yU73B0u9Y7CD9NtcL5XSXZXxZ7Y176b%3DSTQmJO4qkgCDsA%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
