Huawei says it has developed a prototype DSL system capable of supporting symmetrical 1-Gbps transmission rates. The systems, appropriately named Giga DSL, uses a technique called time-division duplex (TDD)
The prototype Giga DSL system will support the 1-Gbps speeds over 100 m of twisted pair, as well as 500 Mbps over 200 m. Huawei envisions the technology as applicable to fiber to the node/cabinet/curb (FTTN/FTTC) and fiber to the building (FTTB) applications. However, some carriers deploying the technology likely would have to install fiber deeper into their networks to leverage the Giga DSL systems for 1 Gbps FTTN/FTTC.
The Giga DSL initiative complements Huawei’s work with the ITU-T G.fast project team, which targeted 500 Mbps over 100 m of twisted pair. Huawei says it recently worked to incorporate TDD-OFDM (orthogonal frequency division multiplexing) as a G.fast modulation mode.
Dr. Long Guozhu, Huawei's principal expert on DSL technology, said, "Huawei has taken the lead in developing a Giga DSL prototype because of our rich capabilities and industry-leading technical strengths in access networks. It was inevitable that spectrum expansion would help us improve the rate of a twisted pair at a short distance, but after the spectrum is expanded, a technical issue appears: How to design the high-speed physical layer and high-frequency analog front end (AFE). To tackle this issue, Huawei's FBB Innovation Lab used the core solution TDD-OFDM, which simplifies the physical-layer architecture and the AFE design, while at the same time makes it possible to be downward compatible with traditional ADSL/VDSL2 technologies."
The Giga DSL technology would potentially offer a step beyond Huawei’s latest DSL speed booster, node level vectoring (NLV). NLV, designed to support 100 Mbps over a single twisted pair in FTTC/FTTB applications, has been tested and commercially trialed, Huawei asserts.
Huawei did not reveal when Giga DSL might be available for trials and deployment.
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