== On-Campus WiMAX ==

In this experiment, we'll explore what you can do with on-campus WiMAX. 

More than '''[wiki:SpiralFour#a4.GENIWiMAXMeso-ScaleDeployments a dozen campuses]''' are now participating in GENI WiMAX. While anybody can use GENI WiMAX remotely, if you are on or near a WiMAX campus you can also do interactive, mobile, and live experiments. 

== Experiment Background ==

In this experiment, we'll run a '''WebRTC''' video chat in which one participant is using a commodity laptop equipped with a USB WiMAX dongle. (The other participant is connected to the Internet over !WiFi). 

WebRTC is a new and evolving video standard for enabling voice, video, and data communications in the browser - without plugins. A diverse and vibrant ecosystem of applications using WebRTC has grown up and around the standard in the last year.

== Instrumenting the Experiment ==

We're using the  [http://witestlab.poly.edu/repos/omlapps/oml4js/ oml4js] library, a !JavaScript library for collecting measurements from a website and storing them using '''OML'''. While the video chat is active, measurements from the chat will be continuously streamed to a local OML server on the laptop. After the experiment is over, we'll push the results to iRODS and examine them more closely there.

== Experiment Procedure ==

The experiment procedure is as follows:

 * The first peer visits the [http://witestlab.poly.edu/~ffund/webrtc/webrtc-read-only/samples/js/demos/html/webrtc-oml.html URL] for the WebRTC app in Google Chrome. A bar at the top of the screen will ask if you are willing to let the browser access your camera; don't click allow until the second peer has joined the chat!
 * The second peer visits the same [http://witestlab.poly.edu/~ffund/webrtc/webrtc-read-only/samples/js/demos/html/webrtc-oml.html URL]
 * Both peers click "Allow" and should now see video streams from each other's webcams

== Post-Experiment ==

After the experiment, the OML-instrumented peer will send the measurement results to iRODS using the {{{iput}}} command. 


Inside iRODS, we'll use the iRODS web browser to visualize the results of our experiment.

== Reconfiguring the WiMAX BS ==

A major advantage of on-campus WiMAX (over using a regular cellular carrier) for experimentation, is that you can reconfigure the WiMAX BS. In this experiment, we'll try using WebRTC with and without link-layer retransmission (ARQ) and observe the effect of ARQ on latency, packet loss, and video rate.