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Topic: Communicate with arduino over telephone line - max speed? (Read 865 times) previous topic - next topic

renasis

Hello,

I am interested in communicating with arduino over a telephone line. What is the maximum bytes per second that can be acheived? Is fsk the the fastest or are there other methods? Any example links would be appretiated also.

Thanks,

-ren

Coding Badly


By "telephone line" do you mean one end is controlled by a phone company?  Or do you mean a cable with two or four conductors and you control both ends?

CrossRoads

"telephone line", I believe the FCC limits the power you are supposed to put over lines so the max data rate achieved with a modem is 52Kbps.

Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
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Magician

Quote
The 56 kbit/s rate is only possible from the central office to the user site (downlink). In the United States, government regulation limits the maximum power output, resulting in a maximum data rate of 53.3 kbit/s. The uplink (from the user to the central office) still uses V.34 technology at 33.6 kbit/s.

56 kbit/s is also for North America T1 limitation, in Europe E1 - up to 64 kbit/s.
Modulation QAM.
More info :
http://en.wikipedia.org/wiki/Modem

retrolefty


Hello,

I am interested in communicating with arduino over a telephone line. What is the maximum bytes per second that can be achieved? Is fsk the the fastest or are there other methods? Any example links would be appreciated also.

Thanks,

-ren


First obvious thing to state is that an Arduino cannot directly communicate over a telephone line. A device called a modem (for modulator/demodulator) is required at both ends of the phone line. How fast a speed can be attained depends on the method and complexity of the modem. You mentioned FSK, I believe the fastest modem speed that used simple FSK is the old Bell 201 standard running at 1200 baud. The fastest modem I'm aware of is the 56K baud modems, however be aware that such 56K modems had to negotiate with the far modem to establish how fast they could actually work for that specific link at that specific time, so frequently, if not mostly, they linked up at lower speeds. 

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