Sunday, February 24, 2008

Latency


CNN and others are reporting that the Japanese have launched a satellite that is aimed at providing high speed internet service. While the pundits are abuzz with the idea, I think its lame. I don't care how much technology the Japanese (or anyone else for that matter) will stick in the bird, its gonna suck for internet service. Why? One word.

Latency.

See, a satellite like this has to orbit the Earth in geosynchronous orbit in order to keep above a stationary point on the planet. This orbit is at 22,500 miles and that's the problem. No matter what sort of gizmos you cram into the satellite, there's one thing you can't change.

The speed of light.

For you do to do a simple web search, you type in "www.google.com". The first thing your computer does it go lookup the name you typed into to see what IP address you are actually trying to reach. So, the request for the lookup has to go from your computer, up to the satellite, and down to the Earth station for the DNS query. Then the answer needs to go back up to the satellite and down to your PC. You just blew roughly 1/4 of a second doing that request. But it will take longer than that.

Now your computer has to do the actual request to the IP address of CNN.com to ask for the actual web page. Up and down, and then up and down back to you. Now that you have the html, your browser now will ask for the individual elements of the page, you know - images, imbedded flash, etc. More up and down, more waiting.

So, aside from the numbers, why am I so down on satellite internet access? I used to use it for access at the house. I live pretty far outside of town, and it took a while for us to get DSL service out here so for about 2 years I had satellite service and I gotta say, for typical browsing, dialup is faster. If you want to pull down large files, once you get the data flowing, its not that bad. But overall experience really sucks.

I think this satellite will be a nice backup in case a landline goes down, etc. but for general user access? Its DOA.

Seems that I'm not alone on this. Tom thinks along the same lines.

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