Difference Between ADSL and VDSL (With Table)

Nowadays, the technological community are experiencing significant expansion. DSL, or digital subscriber line, plays a critical part in the transmission of digital data over phone line in communication technology.

DSL is typically compared based on bandwidth, which is a measurement about how much data system could send and receive. Broadband speeds are usually expressed in millions  bits per second (Mbps) and billions of bits per second (GBPS) by Internet providers (Gbps). In general, the larger the bandwidth, the faster the internet connectivity.

DCL is commonly used in the technology industry for high-speed network access and network over voice lines. Some of the types are –

ADSL – Asymmetric Digital Subscriber Line

SDCL –Symmetric Digital Subscriber Line

VDSL – Very-high-bit-rate Subscriber Line


The main difference between ADSL and VDSL is that ADSL relies mostly on copper cable and earlier technologies, whereas VDSL includes fiber components and modern facilities. ADSL has a maximum speed of 20Mbps, whereas VDSL has a maximum speed of 40Mbps. Both ADSL and VDSL rely on your home’s existing copper wiring. ADSL and VDSL are notable for the type of internet connection selected by the globe due to their low cost and speedy accessibility. The strong demand for connectivity at the current times due to work from home and schooling services that are limited to the house.


The Asymmetric Subscriber Line is a type of telephone line that is extensively used in homes and companies for calling services. These are copper wire lines that may transfer voice signals from one telephonic line to the reception line. The internet signal is also carried on this line, albeit at a different frequency. As a result, the usage evaluates the state and disruption of the copper wire. The most recent form of this subscriber line, known as ADSL2+, is capable of offering internet services when placed in close proximity. As the transmission’s velocity range is determined by closeness.

The Very-high-bit-rate Subscriber Line is a novel technology that is utilised to successfully transport internet signals. It gives a far more effective and enhanced network accessibility experience. The optical node connected to the ISP and put near the user’s location offers a rapid connection. In the VDSL platform, fibre optic cables are employed. VDSL2 is the advanced assistance supplied by this subscriber line, with unique facilitation of the connectivity stretching from the customers location to roughly 1.2 kilomoteres.

Comparison Table Between ADSL and VDSL

Parameters of comparisonADSLVDSL
Full formAsymmetric Digital Subscriber Line· Very-high-bit-rate Subscriber Line
Internet speedComparatively Low bandwidthHigh bandwidth, Online accessibility without any lag
AvailabilityCommonly found and easily accessibleNot as widely popular as ADSL
SignalSignal service is moderate High speed internet connection
Data transmission rateUpstream rate – 64 Kbps to 1 Mbps
downstream rate – 500 Kbps to 8Mbps
upstream rate – 1.5 to 2.5 Mbps
downstream rate – 50 to 55 Mbps.
Servicesdata (only asymmetric) and POT(plain old telephone) servicedata (symmetric and asymmetric) and POT’s
Interspace accessibility18000 feet4500 feet

What is ADSL?

Cable modems face stiff competition from asymmetric digital subscriber lines (ADSL).ADSL requires two components: one for the consumer and one for the provider. The first is the transceiver, which is located at the customer’s location.
The DSL access multiplexer, or DSLAM, is a service provider that receives customer connections .DSL is a distance range technology, which means that as the length of the connection grows longer, the signal strength and connectivity speed diminish. The maximum distance between the modem and the DSLAM for ADSL device is about 18,000 feet.

In many regions, cable technology, which carries data through basic copper wires buried underground initially meant for television, now offers up to 300 Mbps of bandwidth, but ADSL speeds often top out at 100 Mbps. Furthermore, the length of the phone line required to connect to the user’s might restrict the maximum speed that a ADSL installation can provide.

What is VDSL?

 Many of the telephone companies’ primary feeds are being replaced with fiber-optic cable inspired by the VDSL applications.  Many phone providers are contemplating Fiber replacements, which means they will replace all current copper lines . However, VDSL’s impressive efficiency comes at a cost: It can only work for a limited distance of roughly 4500 feet over the copper wire.

The distance constraints can be elegantly avoided by installing a VDSL transceiver in your house and a VDSL router in the junction box. The gateway handles the analog-to-digital-to-analog conversion issue that prevents ADSL over fiber-optic connections from working. It transforms data from the transceiver into light pulses that may be transported through a fiber-optic network to the central office, where it is routed to the proper network to reach its eventual destination.

The VDSL design is constructed based on two contradictory technologies: quadrature amplitude modulation (QAM) and discrete multitone modulation (DMT). Equipment producers are the most typical users of DMT technology. Along with Internet connection, VDSL can provide services such as HDTVs and video-on-demand (VOD).

Main Differences Between ADSL and VDSL

  1. 1. VDSL apps have a higher bandwidth range than ADSL, so networked based applications like YouTube, Netflix, and other backup services can run smoothly.
  2. As, the availability of ADSL is economically feasible and easily available it is much more preferred by the general public than the VDSL
  3. The signal strength both varies according to the distance between the user’s application and the loop station. But in comparison, the VDSL application attenuates faster connectivity.
  4. The highest downstream bit rate for ADSL is 8Mbps, while the highest upstream bit rate is 1Mbps. VDSL, on the other hand, offers a downstream bit rate of 55 Mbps and a bit rate of 2.5 Mbps upstream.
  5. While VDSL can offer both asymmetric, symmetric data and POT services, on the other and hADSL can only provide asymmetric data and POT services.
  6. ADSL can transmit to a greater range than VDSL, with ADSL being able to cover up to 18000 feet while the VDSL could cover about 4500 feet.


In the virtual world, ADSL and VDSL are fundamentally the sorts of digital subscriber line technologies that are highly recommended. VDSL delivers better data rates for coaxed copper telephone lines over limited ranges, but ADSL gives lower data rates in comparison to VDSL, which covers a longer distance. VDSL has certain drawbacks, such as the fact that it is pricey and that signal speed decreases as distance rises.


  1. https://digital-library.theiet.org/content/journals/10.1049/ip-smt_20031072
  2. https://ieeexplore.ieee.org/abstract/document/679604/