What frequency is internet over cable tv infrastructure? What range does it operate in?
Rogers tech support does not know, "out of the scope of what we know here"
It is 1000MHz?
Rogers tech support does not know, "out of the scope of what we know here"
It is 1000MHz?
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Titanium,
Cable Internet systems can typically operate ... up to 100 miles (160 km) via optical cables at this range. Copper is used for the local leg ie “last couple of miles” or so.
Bit rates can be 100Mbit/s as a data rate for home users. This data rate could need a signalling rate of up to 6 MHz or more depending on the amount of overhead and that must be multiplied by the number of channels. This is because the signal rate and data rate are different. Overheads are the extra data required to help with error correction and routing etc. In addition the signalling rate has to be twice the data rate sampled (Nyquist rate Shannons sampling theorem).
The signal itself is similar to FM but is phase modulated. The phase can be varied into 4 quadrants and the frequency also modulated to give more combinations on the same VHF/UHF signal. So each signalling bit can represent any 1 of 64 data bits. ie A "2 to the power of 7 bits". This is called QAM “Quadrature Amplitude Modulation” or QAM. Eg 64-QAM has 64 data bits per signal bit.
( ( 6MHz x 2 samples) +15% overhead) x 7 bit compression on the QAM. =/= 100Mbps
Read more on the attached wiki links.
Tony
Cable Internet systems can typically operate ... up to 100 miles (160 km) via optical cables at this range. Copper is used for the local leg ie “last couple of miles” or so.
Bit rates can be 100Mbit/s as a data rate for home users. This data rate could need a signalling rate of up to 6 MHz or more depending on the amount of overhead and that must be multiplied by the number of channels. This is because the signal rate and data rate are different. Overheads are the extra data required to help with error correction and routing etc. In addition the signalling rate has to be twice the data rate sampled (Nyquist rate Shannons sampling theorem).
The signal itself is similar to FM but is phase modulated. The phase can be varied into 4 quadrants and the frequency also modulated to give more combinations on the same VHF/UHF signal. So each signalling bit can represent any 1 of 64 data bits. ie A "2 to the power of 7 bits". This is called QAM “Quadrature Amplitude Modulation” or QAM. Eg 64-QAM has 64 data bits per signal bit.
( ( 6MHz x 2 samples) +15% overhead) x 7 bit compression on the QAM. =/= 100Mbps
Read more on the attached wiki links.
Tony
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I think it depends on your cable provider.
On my modem, before it's got a signal (e.g. if you unplug it from cable and restart) it runs a webserver you can connect to and see various system parameters. I forget if the cable frequency is one of them
On my modem, before it's got a signal (e.g. if you unplug it from cable and restart) it runs a webserver you can connect to and see various system parameters. I forget if the cable frequency is one of them
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Cable modems operate below 1000MHz (5-850 Mhz), the modulation scheme is QAM.