Stardate 20010808.1229 (On Screen): This article discusses satellite as an alternative to DSL and Cable modems for consumer broadband access. It notes that it hasn't been very successful commercially. There are several good reasons why that is. One, as noted in the article, is the steep cost associated with it. Another, not mentioned, is that satellite broadband is only one-way. It's not a bidirectional medium. Data goes from the satellite ground station up to the satellite and then is bounced down to all its subscribers. The subscribers have to use a modem with a phone line for their uplink, and it's limited to phone-line speeds, 40 kilobits or less, and it ties up the phone line while in use. Cable and DSL both generally provide much more downlink bandwidth than uplink bandwidth, but both generally provide at least 256 kilobit uplink. The third problem with satellite is latency. The downlink has to bounce up to a geosynchronous satellite and back down again. That turns out to require more than a quarter of a second just for light speed delay, let alone any other latency in the system. The combination of the modem uplink and a long latency downlink makes a satellite link useless for a lot of what people want broadband for, to wit playing games such as CounterStrike. As a result, it is primarily interesting only to people who want a lot of downlink bandwidth, don't mind long latency, and live places where DSL and cable are not available. Small wonder they have about 2% of the customer base that cable modem has.
(discuss)
