One of the most amazing new solutions developed by Hitachi Cable is all-optical networking for MAN and RAN using next-generation GMX "oWAVE and eWAVE". Currently, to compensate for damping of optical signals as they travel down optical fibers in RANs using SONET/SDH technologies, transponders are placed along network rings at intervals of several kilometers to relay the signals. These transponders convert the optical signals (O) to electric signals (E) and back again before transmitting it down the next cable, thereby enabling long-distance transmission. In contrast, all-optical networks use digital wrapper technology (see explanation) and other methods allowing long-distance transmission and no E/O or O/E conversion occurs in the backbone ring.
These networks achieve long-distance transmission of up to 1,000 kilometers and, because no transponders are necessary, costs are lower than conventional optical networks. In addition, multiple protocols, including Ethernet, SONET, and ATM at different wavelengths can be used on the same backbone ring, which is not possible on conventional optical networks.
In addition, because there is no overhead from E/O or O/E conversion, delay is reduced and an environment more suitable for such real time content as IP telephony and video transmission is created.
These attributes have made oWAVE and eWAVE technologies the choice of major telecommunications carries for FTTH backbone lines for video transmission services and combined infrastructure using for voice, data, and video class compression5. Hitachi Cable is leveraging these technologies to build a product lineup that is raising eyebrows for its ability to provide revolutionary solutions for next-generation network services.
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