4 ms·
Reminds me of the time when it was declared that there was a physical barrier to sending more than 44kbps through a phone line.
by Tichy 14y ago
Reminds me of the time when it was declared that there was a physical barrier to sending more than 44kbps through a phone line.
- twoodfin 14y agoWasn't there? How much faster did modems over POTS really get? IIRC, even 56kbps only worked downstream, and only if you had a modern digital connection back to your telephone system.
- mikeash 14y agoYes, they were completely right, and improvements only happened by changing the game that was being played.
- takluyver 14y agoADSL connections over the same physical wire as a phone line can often get several Mbps.
- simonh 14y agoBut ADSL only goes as far as the exchange before being routed onto an IP backbone network. With modem signals the same signal goes over a voice circuit (albeit a virtual one) all the way to the receiving modem. They're not at all the same thing.
- InclinedPlane 14y agoThat's the point. People make sweeping assumptions about the limitations of something, and then someone else changes the ground underneath those assumptions and makes the cconclusions invalid. DSL, for example, is not much more difficult in terms of capital equipment cost compared to dialup and it doesn't require running a new line to the home, but the bandwidth available is a thousand times greater than the previous "hard" limit of phone land line based networking.
- Tichy 14y agoI'm not a technician, but I know that I now get 12MBps (via DSL) and they haven't exchanged the phone lines. So they must have come up with something.
- ori_b 14y agoThe physical copper wire is still the same, but you're no longer talking to the phone system on the other end of it, as I understand it. DSL is no longer using the "phone line". It's just using the phone cable. The battery analogy would be creating a fuel cell in a AA (or whatever) form factor. It circumvents the limits on battery technology by not being a battery, in spite of plugging into the same physical slot. (NB: I am not a DSL technician, I could be wrong).
- Tichy 14y agoMaybe, but the point is the constraint was never "use the phone system", only to use the cable.
- ori_b 14y agoThat's not the takeaway I got. What I got is that the (communication endpoint,fundamental energy storage) technology has to change before there can be large improvements in (network speed, energy storage capacity).
- Tichy 14y agoSure, but that article seems to make some assumptions about batteries that might be irrelevant. The requirement is not "a battery has to power the car", it is just "a clean energy source has to power an electric motor".
- raverbashing 14y agoYes, 56k is the limit to "phone lines" meaning the system between you and another phone subscriber, given the limitations of how voice is transmitted. ADSL works using the wire from your house to the phone company equipment. A much shorter path and with less interference (still, the wiring may be bad, which limits transmission rates)
- joenathan 14y agoThere is a big difference in moving some bits of data and moving a few thousand pounds, trying to draw a correlation as such is disingenuous.
- Tichy 14y agoI am not saying the same thing will happen with batteries, just that I wouldn't give up just yet.