Our BYOD environment supports laptops in the Upper School and iPads in the Middle School, so we’re searching for a wireless display solution which accommodates both. I tested AirParrot and Apple TV previously, and now I’m testing the Crestron AirMedia display adapter. Our goal is to have a classroom-based wireless display system where students and teachers alike can share on the projector or other display in order to work collaboratively.
About the AirMedia
One thing that differentiates the AirMedia right off the bat from an Apple TV solution is that the AirMedia has both HDMI, VGA and 1/8″ Audio Out. This makes it much more likely to play nicely with existing classroom projector and sound systems. Where the Apple TV is built to interact with your TV or home theatre system (hence the HDMI out carrying both video and audio, requiring something like the Kanex ATV adapter to separate them), the AirMedia is clearly meant to serve existing business/educational A/V infrastructure.
When connected, the AirMedia projects an IP address and an access code. Anyone wishing to present must download the AirMedia client (for Mac or PC) or App (for Android or iOS), enter the credentials given, and log in. Once one device is bound to the AirMedia and actively presenting, no other devices can connect until the projection is released, preventing accidental (or non!) hijacking of the display. The code is randomly generated each time a session is started, meaning that your access code from Monday’s class can’t be used on Tuesday.
Like the Apple TV, the AirMedia runs a network service which must be accessible from any devices that you wish to use. In other words, if you have it connected to your wired network, you won’t be able to access it from Wi-Fi unless you have your network properly configured. For testing purposes, I had my computer and the AirMedia on our Ethernet network. I’ll test with the iPad at home and report in a separate post.
To do each test, I used the device with the AirMedia as the primary display for normal daily operation, then threw some YouTube videos and streaming from ESPN.com at it to test the video smoothness.
Windows - Tested on a Lenovo Helix running 8.1. 2 GHz, 8 GB RAM.
Performance was seamless using the Windows device– operation on the display was nearly real-time with no noticeable lag. If I had the wireless network operation set up, I’d be using this as my main display with the Helix in tablet mode.
Mac – Tested on a Mid 2010 MacBook Pro running Mavericks. 2.4 GHz, 4 GB RAM.
Performance was noticeably laggy on the MacBook. The display continually ran 1-2 seconds behind input on the MacBook, and occasionally the videos would get choppy. Curious to see how this was taxing the OS, I noticed the following in Activity Monitor:
- Memory usage was pretty constant: around 30 MB of RAM being used at any given time. Given that the MacBook has half the RAM of the Windows machine, my first guess was that I was maxing the RAM out. Doesn’t look like it.
- CPU load was between 15-30% during normal operation. Jumped up to the high 60s (63-68%) when showing video. Again, that’s for the AirMedia process itself, so the actual rendering of video in Chrome isn’t factored in there.
Obviously, with a consistent 1-2 second lag, using the AirMedia as a primary display isn’t an option. If your students are using this to project on the main projector, that may not be a concern. In my quest for transparent/invisible technology usage, though, I don’t like the fact that everyone’s eyeballs would be on the screen being shared (i.e. projection) except the person manipulating it, who would have to be looking at their own computer. I’m less excited about this than the Windows performance, certainly.
Finally, while the Windows client works out of the box, the Mac client needed a little configuration to work with Mavericks. The initial install would only work for a few seconds before disconnecting because of a performance feature in Mavericks called App Nap. Turning App Nap off fixed the connection problem (Get Info on the AirMedia application, and “Prevent App Nap”), but in a BYOD environment, every student with Mavericks would have to configure this individually. Also, since the point of App Nap is to conserve battery power, this will have an adverse effect on the CPU power usage, but only while the AirMedia application is open. Crestron says that an update is coming soon.
AirMedia is spendy– near $1000 a unit. Compared with an Apple TV and AirParrot, I’m not seeing anything here that is worth the extra $800 (at least). In a managed environment, or a Windows-only environment, it may be an option, and the VGA output will work with more projectors out of the box. We’re unlikely to move forward with this device, though.