Tuesday, October 7, 2008

Driving Pandora

I've been a fan of Pandora internet radio for a few years now. Pandora is great for discovering new music. With just a few clicks, you can create a custom music station out of your favorite artist, song, or album. Pandora will try to find similar songs and artists and play those on your personal station. You can fine tune the music they play by rating songs with a Tivo style thumbs up or thumbs down.

The folks at Pandora were quick to get on the iPhone bandwagon with a free Pandora iPhone app. (Thanks guys!) The app streams music over your WiFi network or over the AT&T network if WiFi isn't available. Recently I tested this on a drive from Tahoe to the Bay Area. I connected my iPhone to the car stereo through the AUX jack and fired up the Pandora app. We have good coverage of the Edge network at our place in Incline. I was curious as to how long the music would last. I was impressed, for almost the entire four hour dive we had continuous Pandora coverage. There were two notable exceptions. One is the stretch of road near Northstar, the ski resort between Truckee and Incline Village. That wasn't too surprising given the rural nature of that road. The other was near UC Davis. This was a bit more surprising since this is a pretty flat piece of Interstate 80. Maybe it was a bug in the Pandora application that caused the slight outage. I'm more inclined to think that it was a dead spot in the Edge network, given the fact that the music kept playing after a few minutes of silence.

Now most iPhone plans come with unlimited data. So streaming audio for 4 hours isn't going to cost me anything extra. The audio coming out of the phone seemed to be roughly equivalent to FM radio. I would guess that the bit rate was something like 128 kbs. How much data did I use on my drive? About 1/4 MByte GByte. [Corrected from MByte, thanks Pablo!]

128 kb/s * 1/8 bit/byte * 60 s/m * 60 m/h * 4 hr = 230,400 KB
Actually I find this to be surprisingly small. Given that AT&T charges $5 per month for a 1 MB data plan, this streaming would have only cost me $1.25 $1,150 (230 MB * $5.) Of course I have the unlimited data plan, so it didn't cost me any extra to listen to Pandora on my drive.

The kids have been asking for XM Radio, but I think I'll stick with Pandora for now. If I could only get XM Kids on Pandora...