Lesson 6 Flashcards
Is the physical path that runs between two or more points
Circuit
Two Types of Circuits
Two-Wire Circuits, Four-Wire
Has two insulated electrical conductors
Two-Wire Circuit
What is each wire of the two-wire circuit used for?
transmission; return path
When oppositely directed portions of a single telephone conversation occur over the same electrical transmission channel or path
two-wire operation
Has two pairs of conductors
Four-Wire Circuit
What does PSTN stand for?
Public Switched Telephone Network
Types of four-wire circuits
Physical Four-Wire, Logical Four-Wire
Four-wire circuit where you can actually count four wires
Physical Four-Wire
Four-wire circuit where there are physically two wires but four individual paths are derived by spotting the frequency
Logical Four-Wire
Boosts attenuated signal back up to its original power level so it can continue to make its way across the network
Amplifier
Distance requirement between amplifiers for copper wires
6000 feet/ 1800 meters
Could only amplify a signal moving in one direction.
First-generation amplifiers
Length of local loops worldwide
less than 2 miles or 3.2 km
It terminates on a port (that is, a point of electrical or optical interface), and that port can be in a host computer (that is, a switching device used to establish connections), on a multiplexer, or in another device.
Circuit
Does not define the number of simultaneous conversations that can be carried
Circuit
Are generally deployed in the analog local loop, which is the last mile between the subscriber and the subscriber’s first point of access into the network.
Two-wire Circuits
When both directions are carried on the same pair of wires
Two wire Transmission
In telecommunication,
A ______ is a two way circuit using two paths so arranged that the respective signals are transmitted in one direction only by one path and in the other direction by the other path.
four wire circuit
Characterized by supporting transmission in two directions simultaneously, as opposed to four wire circuits, which have separate pairs for transmit and receive.
Two wire Circuit
Are also used with leased lines, where a customer may be connecting locations of its own that are separated by distance.
Four wire circuits
Refer to the number of wires in the internal cabling plan.
two pair and four pair
Have to do with the number of electrical conductors associated with a transmission line.
Two wire and four wire
It has two sets of one way transmission paths: one path for each direction and a complementary path to complete the electrical circuit.
Four wire circuits
Are used where there is distance between the termination points which requires that the signal be strengthened periodically.
Four wire circuits
The local loop is a two wire circuit for one reason only
to save copper
Whenever you release energy into space, it loses power as it’s traveling over a distance. So, because networks were designed to carry communications over a distance, we need tools to augment signals that have been losing power as they have traveled across the network, which are called
attenuated signals
The PSTN traditionally used
copper wires
