Frequently Asked Questions

When I run my experiment, the wireless channels do not seem to change as I specified, i.e. they are fixed.

Occasionally the controller that connects emucontrol-1 to the emulator hardware crashes. You can verify whether it is working correctly, by executing


If the ping fails, the controller is down and you should send mail to so we can reset it. If you get a ping response the controller is working correctly and your problem lies elsewhere. You should check your script or code to make sure you are controlling the channels correctly.

When I run emulatorDaemon on, why does it ask for passphrase.

If you are asked to provide passphrase, it means your ssl certificate is not set up correctly. Follow the instructions on the Setting up Account page carefully.

When I start "emuRun" on, a lot of warning/java exceptions show up.

Did you run "startDaemon" for nodes that is remotely controled by emucontrol-1?

Sometimes it takes forever to execute a command on the nodewX, such as make, ifconifg.

Use "sudo [command]". A few commands require root access to be executed.

Which OS image should I load in the NS-script?

We suggest to use FC6w-EMU for dell laptops. If you are using USRP, "gnuradio1" is the recommended desk image.

I want to use multipath feature. Do you support multipath between all nodes?

No. The channels between these nodes (in the same group) have multiple-path (up to 3). Group 1: pcemu107 and pcemu108
Group 2: pecmu113, pcemu114, and pcemu115

Is there any special configuration to use USRP?

Yes. To use USRP, a special command need to be sent to the node, so that it connects USRP instead of the wireless interface to the Emulator Hardware. If you are interested, please email for details.