In 1994 I went and drew a chart of every possible way and strategy of getting internet in to a home.
Cable TV and Phone Lines being the most obvious, and using the water pipes or sewer also being options, and radio in various bands and arrangements from Micro Satellite dish, building neighborhood wifi mesh networks, various radio network topologies and immediately started working on all of these.
The idea that data could be pushed over a phone line and still leave the only analog phone line working unaffected is amazing. My first T1 1.544 Mbit/s lines in 1995/7 used PairGain transceivers (it seemed like cheating because they were using ADSL to provide it) , that connected to the CSU/DSU and then a Cisco 2500 router to finally get an ethernet. I say cheated because T1's use to be
Now they can push 300Mbit/s over these old phone lines.
line-modulation techniques for VDSL are:
- quadrature amplitude modulation (4-QAM)
- discrete multitone (DMT). a form of OFDM
The following list is a summary of existing OFDM-based standards and products. For further details, see the Usage section at the end of the article.
Wired version mostly known as Discrete Multi-tone Transmission (DMT)[edit]
- ADSL and VDSL broadband access via POTS copper wiring
- DVB-C2, an enhanced version of the DVB-C digital cable TV standard
- Power line communication (PLC)
- ITU-T G.hn, a standard which provides high-speed local area networking of existing home wiring (power lines, phone lines and coaxial cables)[13]
- TrailBlazer telephone line modems
- Multimedia over Coax Alliance (MoCA) home networking
- DOCSIS 3.1 Broadband delivery
https://en.wikipedia.org/wiki/VDSL
Very high-speed Digital Subscriber Line (VDSL)[1] and Very high-speed Digital Subscriber Line 2 (VDSL2)[2] are digital subscriber line (DSL) technologies providing data transmission faster than Asymmetric Digital Subscriber Line (ADSL).
VDSL offers speeds of up to 52 Mbit/s downstream and 16 Mbit/s upstream,[3] over a single flat untwisted or twisted pair of copper wires using the frequency band from 25 kHz to 12 MHz.[4] These rates mean that VDSL is capable of supporting applications such as high-definition television, as well as telephone services (voice over IP) and general Internet access, over a single connection. VDSL is deployed over existing wiring used for analog telephone service and lower-speed DSL connections. This standard was approved by the International Telecommunication Union (ITU) in November 2001.
Second-generation systems (VDSL2; ITU-T G.993.2 approved in February 2006)[5] use frequencies of up to 30 MHz to provide data rates exceeding 100 Mbit/s simultaneously in both the upstream and downstream directions. The maximum available bit rate is achieved at a range of about 300 metres (980 ft); performance degrades as the local loop attenuation increases.
| Version | Standard name | Common name | Downstream rate | Upstream rate | Approved on |
|---|---|---|---|---|---|
| VDSL | ITU G.993.1 | VDSL | 55 Mbit/s | 3 Mbit/s | 2001-11-29 |
| VDSL2 | ITU G.993.2 | VDSL2 | 200 Mbit/s | 100 Mbit/s | 2006-02-17 |
| VDSL2-Vplus | ITU G.993.2 Amendment 1 (11/15) | VDSL2 Annex Q VPlus/35b | 300 Mbit/s | 100 Mbit/s | 2015-11-06 |
VDSL2
The protocol is standardized in the International Telecommunication Union telecommunications sector (ITU-T) as Recommendation G.993.2. It was announced as finalized on 27 May 2005,[5] and first published on 17 February 2006. Several corrections and amendments were published from 2007 to 2011.[2]VDSL2 is an enhancement to VDSL designed to support the wide deployment of triple play services such as voice, video, data and high-definition television (HDTV) VDSL2 is intended to enable operators and carriers to gradually, flexibly, and cost-efficiently upgrade existing xDSL infrastructure.
VDSL2 permits the transmission of asymmetric and symmetric aggregate data rates up to 300+ Mbit/s downstream and upstream on twisted pairs using a bandwidth up to 35 MHz. It deteriorates quickly from a theoretical maximum of 350 Mbit/s at source to 100 Mbit/s at 500m (1640.42ft) and 50 Mbit/s at 1000m (3280.84ft), but degrades at a much slower rate from there, and outperforms VDSL. Starting from 1,600 m (1 mi) its performance is equal to ADSL2+.[
Bonding (ITU-T G.998.x) may be used to combine multiple wire pairs to increase available capacity, or extend the copper network's reach. Hybrid Access Networks can be used to combine xDSL with wireless networks. This enables network operators to provide faster Internet access services over long lines.
Vplus/35b
Vplus is a technology to achieve higher speeds over existing VDSL2 networks. It was developed by Alcatel-Lucent and standardised in November 2015 in ITU G.993.2 Amendment 1 as VDSL2 profile 35b.[2] It promises to deliver speeds of up to 300 Mbit/s downstream and 100 Mbit/s upstream on loops shorter than 250 m. On longer loops, Vplus falls back to VDSL2 17a vectoring performance.[8] Vplus uses the same tone spacing as VDSL2 17a to allow vectoring across Vplus (35b) and 17a lines, and thus mixed deployments and a smooth introduction of Vplus.
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