Tu banner alternativo

Rate-Adaptive Digital Subscriber Line

In this article, we will delve into the fascinating world of Rate-Adaptive Digital Subscriber Line, exploring its origins, its impacts on today's society and its relevance throughout history. From its inception to the present day, Rate-Adaptive Digital Subscriber Line has exerted a significant influence on various aspects of life, from culture to technology. We will analyze its evolution over time, as well as the challenges and controversies it has faced throughout its career. Through a multidisciplinary approach, we will address different perspectives on Rate-Adaptive Digital Subscriber Line, providing a comprehensive view of its importance in the contemporary world. This article seeks to offer a complete and enriching look at Rate-Adaptive Digital Subscriber Line, with the aim of deepening its understanding and its implications for the present and the future.

Tu banner alternativo
This article is about the non-standardized DSL variant. For the rate-adaptive mode of ADSL, see ADSL § Operation. For RE-ADSL2, see ITU G.992.3 Annex L.

Rate-adaptive digital subscriber line (RADSL) is a pre-standard asymmetric digital subscriber line (ADSL) solution.[1] RADSL was introduced as proprietary technology by AT&T Paradyne, later GlobeSpan Technologies Inc.,[2] in June 1996.[3] In September 1999, RADSL technology was formally described by ANSI in T1.TR.59-1999.[4][5] RADSL supports downstream data rates of up to approximately 8 Mbit/s, upstream data rates up to approximately 1 Mbit/s, and can coexist with POTS voice on the same line.[5]

RADSL allows rate-adaptation while the connection is in operation — rate-adaptation during connection setup is possible in many other DSL variants, including G.dmt and its successors. Rate-adaptation while the connection is in operation is specified as an option in ADSL2, ADSL2+, and VDSL2, under the name seamless rate adaptation (SRA).[6]

Technology

RADSL specifies two alternative modulation schemes, quadrature amplitude modulation (QAM) and carrierless amplitude phase modulation (CAP).[1][5] RADSL is not interoperable with discrete multi-tone (DMT) modulation variants of ADSL, standardized in ANSI T1.413 Issue 2 and G.dmt (G.992.1).[5] Upstream and downstream are frequency-division duplexed, the upstream and downstream transmit PSD masks are identical to those in ANSI T1.413.[5]

In RADSL, the baud rate, center frequency, and constellation size of the downstream and upstream channels can be adjusted while the connection is in operation.[7] Using this technique the line is more tolerant of errors caused by noise and signal loss. As the parameters are adjusted, the bandwidth may be markedly decreased if there is a large amount of line noise or signal degradation.

See also

References

  1. ^ a b c d e f Vladimir Oksman (2 August 2004). "Fundamentals of Single-Carrier Modulation". In Philip Golden; Hervé Dedieu; Krista S. Jacobsen (eds.). Fundamentals of DSL Technology. CRC Press. p. 144. ISBN 978-0-203-31749-5.
  2. ^ "GlobeSpan Emerges From the Former AT&T Paradyne as a Separate Technology Licensing Business". PR Newswire. 1996-08-20. Retrieved 2014-03-06.
  3. ^ "AT&T Paradyne Announces High-Speed Modem Technology". New York Times. 1996-06-04. Retrieved 2014-03-06.
  4. ^ "T1.TR.59-1999 - Single-Carrier Rate Adaptive Digital Subscriber Line (RADSL)". ANSI. September 1999. Retrieved 2014-03-06.
  5. ^ a b c d e "Technical Report No. 59 - Single-Carrier Rate Adaptive Digital Subscriber Line (RADSL)" (PDF). ANSI. September 1999. Retrieved 2014-03-06.
  6. ^ "TR-197 - DQS: DSL Quality Management Techniques and Nomenclature" (PDF). Broadband Forum. August 2012. p. 29–30. Retrieved 2014-03-06.
  7. ^ "5.4.2.2.2 Link Initialization and Adaptation" (PDF). Technical Report No. 59 - Single-Carrier Rate Adaptive Digital Subscriber Line (RADSL). ANSI. September 1999. p. 104–105. Retrieved 2014-03-06.
Wikious
Boobota
Sagapedia