How does Internet communication work on a coaxial cable?
$begingroup$
In buildings, it is common for the same cable (coax) to be used for pay-TV and the Internet.
It makes sense that I can transmit several TV channels on the same cable, since it can be modulated by the frequency and sends them. However, in Internet communication, data must be sent and received. There is no cable for the transmission and another for reception. So how is Internet communication on a coaxial cable?
signal coax internet
edited 48 mins ago
Peter Mortensen
1,60031422
asked 9 hours ago
LucasLucas
1061
New contributor
Lucas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
|
show 3 more comments
$begingroup$
In buildings, it is common for the same cable (coax) to be used for pay-TV and the Internet.
It makes sense that I can transmit several TV channels on the same cable, since it can be modulated by the frequency and sends them. However, in Internet communication, data must be sent and received. There is no cable for the transmission and another for reception. So how is Internet communication on a coaxial cable?
signal coax internet
edited 48 mins ago
Peter Mortensen
1,60031422
asked 9 hours ago
LucasLucas
1061
New contributor
Lucas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
4
$begingroup$
Have you tried looking this subject up? The idea of stack exchange is for questions which can't be answered by simple web searches.
$endgroup$
– Chris Stratton
9 hours ago
6
$begingroup$
It's not entirely simple, but the answer is en.m.wikipedia.org/wiki/DOCSIS
$endgroup$
– pjc50
9 hours ago
1
$begingroup$
Lucas, the same as for cable can be said for wireless communication...
$endgroup$
– Marcus Müller
9 hours ago
$begingroup$
@Chris, I do not consider this question trivial because I asked two professors, one PhD in engineering, and another master. one could not answer me and another said that there is a multiplexing by time (ie, the current would stop and wait to be able to change the direction.) what for this new information or it is wrong, or who answered me.
$endgroup$
– Lucas
5 hours ago
1
$begingroup$
@Lucas, I did not say the question was trivial, but that it could be answered a simple web search. It is the search which is simple, not the search results. And part if the point is that what you can find there is more comprehensive than would fit in a response here.
$endgroup$
– Chris Stratton
5 hours ago
|
show 3 more comments
$begingroup$
In buildings, it is common for the same cable (coax) to be used for pay-TV and the Internet.
It makes sense that I can transmit several TV channels on the same cable, since it can be modulated by the frequency and sends them. However, in Internet communication, data must be sent and received. There is no cable for the transmission and another for reception. So how is Internet communication on a coaxial cable?
signal coax internet
edited 48 mins ago
Peter Mortensen
1,60031422
asked 9 hours ago
LucasLucas
1061
New contributor
Lucas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
In buildings, it is common for the same cable (coax) to be used for pay-TV and the Internet.
It makes sense that I can transmit several TV channels on the same cable, since it can be modulated by the frequency and sends them. However, in Internet communication, data must be sent and received. There is no cable for the transmission and another for reception. So how is Internet communication on a coaxial cable?
signal coax internet
signal coax internet
edited 48 mins ago
Peter Mortensen
1,60031422
asked 9 hours ago
LucasLucas
1061
New contributor
Lucas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 48 mins ago
Peter Mortensen
1,60031422
asked 9 hours ago
LucasLucas
1061
New contributor
Lucas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 48 mins ago
Peter Mortensen
1,60031422
edited 48 mins ago
Peter Mortensen
1,60031422
edited 48 mins ago
Peter Mortensen
1,60031422
1,60031422
asked 9 hours ago
LucasLucas
1061
New contributor
Lucas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 9 hours ago
LucasLucas
1061
asked 9 hours ago
LucasLucas
1061
1061
New contributor
Lucas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
Lucas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Lucas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
4
$begingroup$
Have you tried looking this subject up? The idea of stack exchange is for questions which can't be answered by simple web searches.
$endgroup$
– Chris Stratton
9 hours ago
6
$begingroup$
It's not entirely simple, but the answer is en.m.wikipedia.org/wiki/DOCSIS
$endgroup$
– pjc50
9 hours ago
1
$begingroup$
Lucas, the same as for cable can be said for wireless communication...
$endgroup$
– Marcus Müller
9 hours ago
$begingroup$
@Chris, I do not consider this question trivial because I asked two professors, one PhD in engineering, and another master. one could not answer me and another said that there is a multiplexing by time (ie, the current would stop and wait to be able to change the direction.) what for this new information or it is wrong, or who answered me.
$endgroup$
– Lucas
5 hours ago
1
$begingroup$
@Lucas, I did not say the question was trivial, but that it could be answered a simple web search. It is the search which is simple, not the search results. And part if the point is that what you can find there is more comprehensive than would fit in a response here.
$endgroup$
– Chris Stratton
5 hours ago
|
show 3 more comments
4
$begingroup$
Have you tried looking this subject up? The idea of stack exchange is for questions which can't be answered by simple web searches.
$endgroup$
– Chris Stratton
9 hours ago
6
$begingroup$
It's not entirely simple, but the answer is en.m.wikipedia.org/wiki/DOCSIS
$endgroup$
– pjc50
9 hours ago
1
$begingroup$
Lucas, the same as for cable can be said for wireless communication...
$endgroup$
– Marcus Müller
9 hours ago
$begingroup$
@Chris, I do not consider this question trivial because I asked two professors, one PhD in engineering, and another master. one could not answer me and another said that there is a multiplexing by time (ie, the current would stop and wait to be able to change the direction.) what for this new information or it is wrong, or who answered me.
$endgroup$
– Lucas
5 hours ago
1
$begingroup$
@Lucas, I did not say the question was trivial, but that it could be answered a simple web search. It is the search which is simple, not the search results. And part if the point is that what you can find there is more comprehensive than would fit in a response here.
$endgroup$
– Chris Stratton
5 hours ago
4
4
$begingroup$
Have you tried looking this subject up? The idea of stack exchange is for questions which can't be answered by simple web searches.
$endgroup$
– Chris Stratton
9 hours ago
$begingroup$
Have you tried looking this subject up? The idea of stack exchange is for questions which can't be answered by simple web searches.
$endgroup$
– Chris Stratton
9 hours ago
6
6
$begingroup$
It's not entirely simple, but the answer is en.m.wikipedia.org/wiki/DOCSIS
$endgroup$
– pjc50
9 hours ago
$begingroup$
It's not entirely simple, but the answer is en.m.wikipedia.org/wiki/DOCSIS
$endgroup$
– pjc50
9 hours ago
1
1
$begingroup$
Lucas, the same as for cable can be said for wireless communication...
$endgroup$
– Marcus Müller
9 hours ago
$begingroup$
Lucas, the same as for cable can be said for wireless communication...
$endgroup$
– Marcus Müller
9 hours ago
$begingroup$
@Chris, I do not consider this question trivial because I asked two professors, one PhD in engineering, and another master. one could not answer me and another said that there is a multiplexing by time (ie, the current would stop and wait to be able to change the direction.) what for this new information or it is wrong, or who answered me.
$endgroup$
– Lucas
5 hours ago
$begingroup$
@Chris, I do not consider this question trivial because I asked two professors, one PhD in engineering, and another master. one could not answer me and another said that there is a multiplexing by time (ie, the current would stop and wait to be able to change the direction.) what for this new information or it is wrong, or who answered me.
$endgroup$
– Lucas
5 hours ago
1
1
$begingroup$
@Lucas, I did not say the question was trivial, but that it could be answered a simple web search. It is the search which is simple, not the search results. And part if the point is that what you can find there is more comprehensive than would fit in a response here.
$endgroup$
– Chris Stratton
5 hours ago
$begingroup$
@Lucas, I did not say the question was trivial, but that it could be answered a simple web search. It is the search which is simple, not the search results. And part if the point is that what you can find there is more comprehensive than would fit in a response here.
$endgroup$
– Chris Stratton
5 hours ago
|
show 3 more comments
3 Answers
3
active
oldest
votes
$begingroup$
Energy moves through the cable in both directions simultaneously. Just as different video signals are modulated on different channel frequencies, incoming and outgoing data streams are modulated on different carrier frequencies, and pass each other without interference.
answered 9 hours ago
AnalogKidAnalogKid
2,52937
$endgroup$
1
$begingroup$
@Lucas depending on the standard, both USB(USB 2 and lower) and ethernet (1000 base-T) use a bidirectional interface. In USB 2's case, it's half duplex so only the root or device can transmit at one time. In Ethernet's case some special processing is used to subtract the transmitted signal from the data so the other signal can be received.
$endgroup$
– C_Elegans
5 hours ago
1
$begingroup$
Think about what happens when two people try to talk at the same time. Do their voices actually collide? To make it even clearer, say it is a young child and their father, so we might say different frequency bands are being used.
$endgroup$
– Chris Stratton
5 hours ago
1
$begingroup$
@Lucas the reason many interfaces use separate rx and tx lines is because of cost. Adding the extra processing and circuitry to be able to separate the two signals on one wire makes the hardware cost more. Granted, using separate lanes makes the cable cost more, but that tends to be less of an issue for how long the cables are (ethernet is pretty long, but USB, SATA and PCIe are not). Compare this to how much cable the cable company needs to lay, and it's a bit more reasonable that they would favor expensive hardware and cheap(er) cable
$endgroup$
– C_Elegans
5 hours ago
3
$begingroup$
It is very common. The telephone was invented in 1876.
$endgroup$
– AnalogKid
5 hours ago
3
$begingroup$
@Lucas as with most electronics questions, ignore the electrons - they will confuse you. The real signal carrier is the electromagnetic fields. It's much easier to understand it as a radio signal that has been contained in a tube.
$endgroup$
– pjc50
4 hours ago
|
show 1 more comment
$begingroup$
Internet over CATV is called DOCSIS (https://en.wikipedia.org/wiki/DOCSIS).
It uses several channels separated by frequency for downstream and upstream. Think about FM radio. How can you have several channels on radio? They just use different frequencies.
This is called "Frequency-division multiplexing"
(https://en.wikipedia.org/wiki/Frequency-division_multiplexing)
Here is an article that covers it: https://volpefirm.com/docsis101_rf-fundamentals/
answered 2 hours ago
user996142user996142
1111
New contributor
user996142 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
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add a comment |
$begingroup$
Radio Frequency communications operate the same when travelling through a coaxial cable as they do through open-air, they are just shielded from outside interference(called ingress) and leakage(called egress). As such, signals of differing frequencies can co-exist, with each travelling in different directions.
Amplification, however, is a different story. Since amplifiers work in only one direction, the incoming and outgoing signals need to be separated when amplification is necessary. This is performed by a device called a "diplex filter", which is sort of like a splitter/combiner that splits/combines based upon the frequency of the signal. In legacy CATV systems, downstream signals were generally about 50MHz(around the bottom of analog channel 2) and up, while upstream signals were from around 5MHz to 40MHz.
An amplifier assembly would(basically) consist of a diplex filter on one end separating the two frequency ranges, followed by an amplifier for each frequency range oriented in opposite directions, then a second diplex filter to merge the two frequency ranges to its original full spectrum signal.
answered 3 hours ago
HitekHitek
1
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Hitek is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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3 Answers
3
active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
Energy moves through the cable in both directions simultaneously. Just as different video signals are modulated on different channel frequencies, incoming and outgoing data streams are modulated on different carrier frequencies, and pass each other without interference.
answered 9 hours ago
AnalogKidAnalogKid
2,52937
$endgroup$
1
$begingroup$
@Lucas depending on the standard, both USB(USB 2 and lower) and ethernet (1000 base-T) use a bidirectional interface. In USB 2's case, it's half duplex so only the root or device can transmit at one time. In Ethernet's case some special processing is used to subtract the transmitted signal from the data so the other signal can be received.
$endgroup$
– C_Elegans
5 hours ago
1
$begingroup$
Think about what happens when two people try to talk at the same time. Do their voices actually collide? To make it even clearer, say it is a young child and their father, so we might say different frequency bands are being used.
$endgroup$
– Chris Stratton
5 hours ago
1
$begingroup$
@Lucas the reason many interfaces use separate rx and tx lines is because of cost. Adding the extra processing and circuitry to be able to separate the two signals on one wire makes the hardware cost more. Granted, using separate lanes makes the cable cost more, but that tends to be less of an issue for how long the cables are (ethernet is pretty long, but USB, SATA and PCIe are not). Compare this to how much cable the cable company needs to lay, and it's a bit more reasonable that they would favor expensive hardware and cheap(er) cable
$endgroup$
– C_Elegans
5 hours ago
3
$begingroup$
It is very common. The telephone was invented in 1876.
$endgroup$
– AnalogKid
5 hours ago
3
$begingroup$
@Lucas as with most electronics questions, ignore the electrons - they will confuse you. The real signal carrier is the electromagnetic fields. It's much easier to understand it as a radio signal that has been contained in a tube.
$endgroup$
– pjc50
4 hours ago
|
show 1 more comment
$begingroup$
Energy moves through the cable in both directions simultaneously. Just as different video signals are modulated on different channel frequencies, incoming and outgoing data streams are modulated on different carrier frequencies, and pass each other without interference.
answered 9 hours ago
AnalogKidAnalogKid
2,52937
$endgroup$
1
$begingroup$
@Lucas depending on the standard, both USB(USB 2 and lower) and ethernet (1000 base-T) use a bidirectional interface. In USB 2's case, it's half duplex so only the root or device can transmit at one time. In Ethernet's case some special processing is used to subtract the transmitted signal from the data so the other signal can be received.
$endgroup$
– C_Elegans
5 hours ago
1
$begingroup$
Think about what happens when two people try to talk at the same time. Do their voices actually collide? To make it even clearer, say it is a young child and their father, so we might say different frequency bands are being used.
$endgroup$
– Chris Stratton
5 hours ago
1
$begingroup$
@Lucas the reason many interfaces use separate rx and tx lines is because of cost. Adding the extra processing and circuitry to be able to separate the two signals on one wire makes the hardware cost more. Granted, using separate lanes makes the cable cost more, but that tends to be less of an issue for how long the cables are (ethernet is pretty long, but USB, SATA and PCIe are not). Compare this to how much cable the cable company needs to lay, and it's a bit more reasonable that they would favor expensive hardware and cheap(er) cable
$endgroup$
– C_Elegans
5 hours ago
3
$begingroup$
It is very common. The telephone was invented in 1876.
$endgroup$
– AnalogKid
5 hours ago
3
$begingroup$
@Lucas as with most electronics questions, ignore the electrons - they will confuse you. The real signal carrier is the electromagnetic fields. It's much easier to understand it as a radio signal that has been contained in a tube.
$endgroup$
– pjc50
4 hours ago
|
show 1 more comment
$begingroup$
Energy moves through the cable in both directions simultaneously. Just as different video signals are modulated on different channel frequencies, incoming and outgoing data streams are modulated on different carrier frequencies, and pass each other without interference.
answered 9 hours ago
AnalogKidAnalogKid
2,52937
$endgroup$
Energy moves through the cable in both directions simultaneously. Just as different video signals are modulated on different channel frequencies, incoming and outgoing data streams are modulated on different carrier frequencies, and pass each other without interference.
answered 9 hours ago
AnalogKidAnalogKid
2,52937
answered 9 hours ago
AnalogKidAnalogKid
2,52937
answered 9 hours ago
AnalogKidAnalogKid
2,52937
answered 9 hours ago
AnalogKidAnalogKid
2,52937
2,52937
1
$begingroup$
@Lucas depending on the standard, both USB(USB 2 and lower) and ethernet (1000 base-T) use a bidirectional interface. In USB 2's case, it's half duplex so only the root or device can transmit at one time. In Ethernet's case some special processing is used to subtract the transmitted signal from the data so the other signal can be received.
$endgroup$
– C_Elegans
5 hours ago
1
$begingroup$
Think about what happens when two people try to talk at the same time. Do their voices actually collide? To make it even clearer, say it is a young child and their father, so we might say different frequency bands are being used.
$endgroup$
– Chris Stratton
5 hours ago
1
$begingroup$
@Lucas the reason many interfaces use separate rx and tx lines is because of cost. Adding the extra processing and circuitry to be able to separate the two signals on one wire makes the hardware cost more. Granted, using separate lanes makes the cable cost more, but that tends to be less of an issue for how long the cables are (ethernet is pretty long, but USB, SATA and PCIe are not). Compare this to how much cable the cable company needs to lay, and it's a bit more reasonable that they would favor expensive hardware and cheap(er) cable
$endgroup$
– C_Elegans
5 hours ago
3
$begingroup$
It is very common. The telephone was invented in 1876.
$endgroup$
– AnalogKid
5 hours ago
3
$begingroup$
@Lucas as with most electronics questions, ignore the electrons - they will confuse you. The real signal carrier is the electromagnetic fields. It's much easier to understand it as a radio signal that has been contained in a tube.
$endgroup$
– pjc50
4 hours ago
|
show 1 more comment
1
$begingroup$
@Lucas depending on the standard, both USB(USB 2 and lower) and ethernet (1000 base-T) use a bidirectional interface. In USB 2's case, it's half duplex so only the root or device can transmit at one time. In Ethernet's case some special processing is used to subtract the transmitted signal from the data so the other signal can be received.
$endgroup$
– C_Elegans
5 hours ago
1
$begingroup$
Think about what happens when two people try to talk at the same time. Do their voices actually collide? To make it even clearer, say it is a young child and their father, so we might say different frequency bands are being used.
$endgroup$
– Chris Stratton
5 hours ago
1
$begingroup$
@Lucas the reason many interfaces use separate rx and tx lines is because of cost. Adding the extra processing and circuitry to be able to separate the two signals on one wire makes the hardware cost more. Granted, using separate lanes makes the cable cost more, but that tends to be less of an issue for how long the cables are (ethernet is pretty long, but USB, SATA and PCIe are not). Compare this to how much cable the cable company needs to lay, and it's a bit more reasonable that they would favor expensive hardware and cheap(er) cable
$endgroup$
– C_Elegans
5 hours ago
3
$begingroup$
It is very common. The telephone was invented in 1876.
$endgroup$
– AnalogKid
5 hours ago
3
$begingroup$
@Lucas as with most electronics questions, ignore the electrons - they will confuse you. The real signal carrier is the electromagnetic fields. It's much easier to understand it as a radio signal that has been contained in a tube.
$endgroup$
– pjc50
4 hours ago
1
1
$begingroup$
@Lucas depending on the standard, both USB(USB 2 and lower) and ethernet (1000 base-T) use a bidirectional interface. In USB 2's case, it's half duplex so only the root or device can transmit at one time. In Ethernet's case some special processing is used to subtract the transmitted signal from the data so the other signal can be received.
$endgroup$
– C_Elegans
5 hours ago
$begingroup$
@Lucas depending on the standard, both USB(USB 2 and lower) and ethernet (1000 base-T) use a bidirectional interface. In USB 2's case, it's half duplex so only the root or device can transmit at one time. In Ethernet's case some special processing is used to subtract the transmitted signal from the data so the other signal can be received.
$endgroup$
– C_Elegans
5 hours ago
1
1
$begingroup$
Think about what happens when two people try to talk at the same time. Do their voices actually collide? To make it even clearer, say it is a young child and their father, so we might say different frequency bands are being used.
$endgroup$
– Chris Stratton
5 hours ago
$begingroup$
Think about what happens when two people try to talk at the same time. Do their voices actually collide? To make it even clearer, say it is a young child and their father, so we might say different frequency bands are being used.
$endgroup$
– Chris Stratton
5 hours ago
1
1
$begingroup$
@Lucas the reason many interfaces use separate rx and tx lines is because of cost. Adding the extra processing and circuitry to be able to separate the two signals on one wire makes the hardware cost more. Granted, using separate lanes makes the cable cost more, but that tends to be less of an issue for how long the cables are (ethernet is pretty long, but USB, SATA and PCIe are not). Compare this to how much cable the cable company needs to lay, and it's a bit more reasonable that they would favor expensive hardware and cheap(er) cable
$endgroup$
– C_Elegans
5 hours ago
$begingroup$
@Lucas the reason many interfaces use separate rx and tx lines is because of cost. Adding the extra processing and circuitry to be able to separate the two signals on one wire makes the hardware cost more. Granted, using separate lanes makes the cable cost more, but that tends to be less of an issue for how long the cables are (ethernet is pretty long, but USB, SATA and PCIe are not). Compare this to how much cable the cable company needs to lay, and it's a bit more reasonable that they would favor expensive hardware and cheap(er) cable
$endgroup$
– C_Elegans
5 hours ago
3
3
$begingroup$
It is very common. The telephone was invented in 1876.
$endgroup$
– AnalogKid
5 hours ago
$begingroup$
It is very common. The telephone was invented in 1876.
$endgroup$
– AnalogKid
5 hours ago
3
3
$begingroup$
@Lucas as with most electronics questions, ignore the electrons - they will confuse you. The real signal carrier is the electromagnetic fields. It's much easier to understand it as a radio signal that has been contained in a tube.
$endgroup$
– pjc50
4 hours ago
$begingroup$
@Lucas as with most electronics questions, ignore the electrons - they will confuse you. The real signal carrier is the electromagnetic fields. It's much easier to understand it as a radio signal that has been contained in a tube.
$endgroup$
– pjc50
4 hours ago
|
show 1 more comment
$begingroup$
Internet over CATV is called DOCSIS (https://en.wikipedia.org/wiki/DOCSIS).
It uses several channels separated by frequency for downstream and upstream. Think about FM radio. How can you have several channels on radio? They just use different frequencies.
This is called "Frequency-division multiplexing"
(https://en.wikipedia.org/wiki/Frequency-division_multiplexing)
Here is an article that covers it: https://volpefirm.com/docsis101_rf-fundamentals/
answered 2 hours ago
user996142user996142
1111
New contributor
user996142 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
add a comment |
$begingroup$
Internet over CATV is called DOCSIS (https://en.wikipedia.org/wiki/DOCSIS).
It uses several channels separated by frequency for downstream and upstream. Think about FM radio. How can you have several channels on radio? They just use different frequencies.
This is called "Frequency-division multiplexing"
(https://en.wikipedia.org/wiki/Frequency-division_multiplexing)
Here is an article that covers it: https://volpefirm.com/docsis101_rf-fundamentals/
answered 2 hours ago
user996142user996142
1111
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add a comment |
$begingroup$
Internet over CATV is called DOCSIS (https://en.wikipedia.org/wiki/DOCSIS).
It uses several channels separated by frequency for downstream and upstream. Think about FM radio. How can you have several channels on radio? They just use different frequencies.
This is called "Frequency-division multiplexing"
(https://en.wikipedia.org/wiki/Frequency-division_multiplexing)
Here is an article that covers it: https://volpefirm.com/docsis101_rf-fundamentals/
answered 2 hours ago
user996142user996142
1111
New contributor
user996142 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
Internet over CATV is called DOCSIS (https://en.wikipedia.org/wiki/DOCSIS).
It uses several channels separated by frequency for downstream and upstream. Think about FM radio. How can you have several channels on radio? They just use different frequencies.
This is called "Frequency-division multiplexing"
(https://en.wikipedia.org/wiki/Frequency-division_multiplexing)
Here is an article that covers it: https://volpefirm.com/docsis101_rf-fundamentals/
answered 2 hours ago
user996142user996142
1111
New contributor
user996142 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered 2 hours ago
user996142user996142
1111
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user996142 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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answered 2 hours ago
user996142user996142
1111
answered 2 hours ago
user996142user996142
1111
1111
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Radio Frequency communications operate the same when travelling through a coaxial cable as they do through open-air, they are just shielded from outside interference(called ingress) and leakage(called egress). As such, signals of differing frequencies can co-exist, with each travelling in different directions.
Amplification, however, is a different story. Since amplifiers work in only one direction, the incoming and outgoing signals need to be separated when amplification is necessary. This is performed by a device called a "diplex filter", which is sort of like a splitter/combiner that splits/combines based upon the frequency of the signal. In legacy CATV systems, downstream signals were generally about 50MHz(around the bottom of analog channel 2) and up, while upstream signals were from around 5MHz to 40MHz.
An amplifier assembly would(basically) consist of a diplex filter on one end separating the two frequency ranges, followed by an amplifier for each frequency range oriented in opposite directions, then a second diplex filter to merge the two frequency ranges to its original full spectrum signal.
answered 3 hours ago
HitekHitek
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Radio Frequency communications operate the same when travelling through a coaxial cable as they do through open-air, they are just shielded from outside interference(called ingress) and leakage(called egress). As such, signals of differing frequencies can co-exist, with each travelling in different directions.
Amplification, however, is a different story. Since amplifiers work in only one direction, the incoming and outgoing signals need to be separated when amplification is necessary. This is performed by a device called a "diplex filter", which is sort of like a splitter/combiner that splits/combines based upon the frequency of the signal. In legacy CATV systems, downstream signals were generally about 50MHz(around the bottom of analog channel 2) and up, while upstream signals were from around 5MHz to 40MHz.
An amplifier assembly would(basically) consist of a diplex filter on one end separating the two frequency ranges, followed by an amplifier for each frequency range oriented in opposite directions, then a second diplex filter to merge the two frequency ranges to its original full spectrum signal.
answered 3 hours ago
HitekHitek
1
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Hitek is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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add a comment |
$begingroup$
Radio Frequency communications operate the same when travelling through a coaxial cable as they do through open-air, they are just shielded from outside interference(called ingress) and leakage(called egress). As such, signals of differing frequencies can co-exist, with each travelling in different directions.
Amplification, however, is a different story. Since amplifiers work in only one direction, the incoming and outgoing signals need to be separated when amplification is necessary. This is performed by a device called a "diplex filter", which is sort of like a splitter/combiner that splits/combines based upon the frequency of the signal. In legacy CATV systems, downstream signals were generally about 50MHz(around the bottom of analog channel 2) and up, while upstream signals were from around 5MHz to 40MHz.
An amplifier assembly would(basically) consist of a diplex filter on one end separating the two frequency ranges, followed by an amplifier for each frequency range oriented in opposite directions, then a second diplex filter to merge the two frequency ranges to its original full spectrum signal.
answered 3 hours ago
HitekHitek
1
New contributor
Hitek is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
Radio Frequency communications operate the same when travelling through a coaxial cable as they do through open-air, they are just shielded from outside interference(called ingress) and leakage(called egress). As such, signals of differing frequencies can co-exist, with each travelling in different directions.
Amplification, however, is a different story. Since amplifiers work in only one direction, the incoming and outgoing signals need to be separated when amplification is necessary. This is performed by a device called a "diplex filter", which is sort of like a splitter/combiner that splits/combines based upon the frequency of the signal. In legacy CATV systems, downstream signals were generally about 50MHz(around the bottom of analog channel 2) and up, while upstream signals were from around 5MHz to 40MHz.
An amplifier assembly would(basically) consist of a diplex filter on one end separating the two frequency ranges, followed by an amplifier for each frequency range oriented in opposite directions, then a second diplex filter to merge the two frequency ranges to its original full spectrum signal.
answered 3 hours ago
HitekHitek
1
New contributor
Hitek is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered 3 hours ago
HitekHitek
1
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answered 3 hours ago
HitekHitek
1
answered 3 hours ago
HitekHitek
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1
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Lucas is a new contributor. Be nice, and check out our Code of Conduct.
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Have you tried looking this subject up? The idea of stack exchange is for questions which can't be answered by simple web searches.
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– Chris Stratton
9 hours ago
6
$begingroup$
It's not entirely simple, but the answer is en.m.wikipedia.org/wiki/DOCSIS
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– pjc50
9 hours ago
1
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Lucas, the same as for cable can be said for wireless communication...
$endgroup$
– Marcus Müller
9 hours ago
$begingroup$
@Chris, I do not consider this question trivial because I asked two professors, one PhD in engineering, and another master. one could not answer me and another said that there is a multiplexing by time (ie, the current would stop and wait to be able to change the direction.) what for this new information or it is wrong, or who answered me.
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– Lucas
5 hours ago
1
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@Lucas, I did not say the question was trivial, but that it could be answered a simple web search. It is the search which is simple, not the search results. And part if the point is that what you can find there is more comprehensive than would fit in a response here.
$endgroup$
– Chris Stratton
5 hours ago