These players are namely smaller and very flexible companies, dealing mainly
with data transfer services, that envision a global networking environment with fully
converged digital services, including data, voice, and video, carried in digital format
over a single network by a single protocol. To alleviate bandwidth bottlenecks, optical
fibers, and thus optical nodes, are penetrating deeper into the first mile, promising to
bring fiber all the way to offices (FTTB), apartment buildings (FTTC), or individual
homes (FTTH). Unlike previous architectures, where fiber is used as a feeder to shorten
the lengths of copper and coaxial networks, these new deployments use optical fiber
throughout the access network and are capable of supporting Gbps data rates at costs
comparable to those of DSL and HFC networks, while eliminating all active electronic
devices from the signal pathway, thereby making the network structure passive, more
robust, and less expensive. This is the environment in which passive optical networks
(PONs) were born.
When Does This Solution Fit?
The main features of Ethernet PON systems can be summarized as follows:
?– EPONs extend the reach of LAN/HAN systems, inherently using Ethernet equipment
and allowing for native Ethernet frame transmission toward WAN systems,
where an increasing amount of Ethernet equipment (mainly multi-wavelength
10 Gbps systems) will give rise to back-to-back Ethernet carrier networks in the
future.
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