Virtualization is becoming a core feature of next-generation networks. Consider how the cable TV industry is looking to use a form of virtualization in its access networks. Traditionally, cable TV networks have used frequency division for both upstream and downstream communications.
Telco networks have used time division. But the latest development is that cable TV networks are looking at a way to use “full duplex” techniques in place of frequency division, a capability that could reduce the cost of rebuilding physical networks to boost bandwidth.
To use full duplex, a hybrid fiber coax network would have to operate in “passive HFC” mode, which means no use of active signal repeaters in the distribution network, in all likelihood.
It is hard to see how full duplex could work through any set of bandpass filters, standard in a radio frequency amplifier.
Full duplex would allow all spectrum to be used for upstream or downstream communications at the same time. And that would be a form of virtualization, separating logical channels from underlying physical network frequencies and channels.
Today’s Technology Duplex: Time Division Duplex
Today’s Technology Duplex: Frequency Division Duplex
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