hipmatt’s rant on satellite vs. cable is full of mis-information so I thought I’d spend some time to clear things up. This is long so I’ll give you the main points first. You can read the explanations if interested.
1) Broadcast data and internet data are different animals.
2) Both cable and satellite have enough bandwidth to broadcast high quality HD programs.
3) The best way to judge which is better is to do what stocktradr did.
1) Broadcast data and internet data are different animals.
First of all, broadcast data (like TV programs) and internet data are handled in very different ways. With broadcast data, you’re trying to send the exact same data to everyone. All the TV shows are being sent to your house. Your cable/satellite box just chooses which of those shows to watch.
With internet data, you’re basically trying to send different data to everyone. One customer might be watching a youtube video. Another customer might be dowloading some songs from itunes, etc.
Each of these customers requires a certain amount of data bandwidth. For our purposes, we’ll define “bandwidth” as the data rate in megabits/second (Mbits/sec).
In the cable world, your cable is connected to the cable plant that broadcasts the TV shows and handles your internet traffic. But if your neighbor has cable, you’re probably connected to him too. You and your neigbors actually share a single connection to the cable plant. When you request data from youtube, that data is getting sent to you as well as all of your neighbors. And all your neighbor’s data is getting sent to you.
So lets say each neighbor requires 1 Mbit/sec of bandwidth to do their internet surfing. And lets say there’s 10 neighbors surfing the internet. This cable plant need (10 x 1) 10 Mbits/sec of bandwidth to accomodate these customers. This 10 Mbits/sec of internet data is going to all your neighbors. If there were 100 neighbors surfing the internet at the same time, then the cable plant would need 100 Mbits/sec of bandwidth. Then there would be 100 Mbits/sec of internet data going to all your neighbors.
Now suppose there were 10 million neighbors, all connected toghether, trying to surf the internet. Well, then the cable plant would need 10 million Mbits/sec of bandwidth to service all its customers. It turns out that cable plants can’t give you 10 million Mbits/sec of bandwidth over a single cable connection. A single cable connection has a limited bandwidth. So in this case, we’d run into a lot of problems.
To avoid this problem, cable companies have multiple connections and multiple cable plants. There are still many customers attached to each cable connection. But the cable companies limit the number of attachements so that internet traffic won’t overload the maximum bandwidth of that connection.
Satellites are a different story. They don’t broadcast over a single cable; instead they broadcast through the air. Cable companies avoid internet traffic overload by spreading the traffic over multiple cable connections. Satellites don’t have the option of spreading internet traffic over differnt air!
That’s the big difference between broadcast data and internet data. Its easy for a single satellite to send TV programs to millions of homes. But its impossible for it to
provide internet service for millions of homes.
2) Both cable and satellite have enough bandwidth to broadcast HD channels.
The assertion that satellite doesn’t have enough bandwidth to broadcast high quality HD programs is just ignorant. The fact is that both cable and satellite have more than enough bandwidth to do this.
A single channel from either satellite or cable has between 27-40 Mbits/sec of bandwidth. For comparison, HD-DVD’s peak at about 30Mbits/sec. Off air HD programs use 18Mbits/sec of bandwidth.
Both satellite and cable stuff multiple programs into a single channel. So with a 40 Mbit/sec bandwidth channel, they could offer 2 good quality 20 Mbit/sec HD programs (2 x 20 = 40). But it turns out that most consumers would rather have more channels and less quality. So in this case, the cable/satellite company might stuff three 13.3 Mbit/sec HD programs into a single channel (3 x 13.3 = 40).
So both cable and satellite are capable of offering more than enough bandwidth to support superb HD quality programs. But they don’t do that because the market values variety over quality.
3) The best way to judge which is better is to do what stocktradr did.
You have to realize that there’s no rules about how much bandwidth a cable/satellite provider has to allocate to each prgram. So one cable provider could be offering high quality HD programs while another offers low quality HD programs.
On top of that, bandwidth isn’t everything. The quality of your cable/satellite box matters too. A cheap box can give you soft images or introduce artifacts which degrade the quality of your picture. So if you’re looking for the best picture, bandwidth alone won’t give you the answer.
So the best way to compare satellite to cable is to actually compare the picture from a satellite to the picture from your cable company. Set both of them up the way you intend to watch them and see which one is better. And test the channels you watch the most since each channel can have a different bandwidth.
