I used to have that, I live in suburbs of Chicago. I thought thay stopped taking new customers, they still support existing customers, one of my friends still have it. You need a clear line of sight to Sears towers, they have the transmitter on it. I believe it uses microwave to communicate.
I naver had problem with it, it got little bit expensive onve I got cable modem available in my area. Cable modem was lot cheaper.
Looks like they are accepting new customers again.