B3P3 Flashcards
What is the local loop
Provides point to point connection between users premises and local exchange
Pair of telephone wires linking the exchange to users premises can be caked local loop or subscriber line.
What is a PCP
primary connection point – connects exchange and users premises
What is a distribution point
top of phone pole connecting houses
What is asymmetric DSL
Asymmetric in the sense that the downstream data rates are higher than upstream
Uses frequency division multiplexing to separate 3 types of transmission, analaogue phone system, upstream data and downstream data
What is Discrete Multitone transmission DMT
type of OFDM used in DSL
What is VDSL
An advanced form of DSL, which uses DMT and often has the same subchannel width as ADSL, but offers a much higher upper frequency limit. VDSL can be used symmetrically or asymmetrically. The ‘V’ stands for ‘very high bit rate’.
What is an OLT
OLT optical line terminal – the device the line is connected to
What is an ONT
ONT optical network terminal – users end
What is an active node
active node – between the exchange and users premises, also known as a point of presence with active equipment APOP
The word active indicates that an active note uses electrical power in order to perform aggregation and disaggregation
What are Passive optical networks (PONs)
Distinguished from active networks because:
• much more fibre is shared
• Nodes are passive nodes, they do not require power
They use splitters - a passive device that shares an optical signal from one fibre between two or more fibres.
What is a GPON gigabit capable passive optical network
capable of delivering data at speeds in the gigabit per second range
What is the purpose of a splitter
All a splitter can do is combine optical power in the upstream direction, or distribute power in the downstream direction
All downstream data packets are broadcast to all devices downsteam of the node. The ONTs extract only the data units that were addressed to them
