Knowledge Base

Bit-stream Access

Bit-stream access is when a wireline incumbent installs a high-speed access link to the customer's premises and then makes this access link available to third parties. This is done by installing ADSL equipment in the local access network which enables them to provide high-speed services to customers. Bit-stream access does not entail any third-party access to the copper pair in the local loop.

The incumbent may also provide transmission services to its competitors, using its Asynchronous Transfer Mode (ATM) or IP network, to carry competitors' traffic from the digital subscriber line access multiplexer (DSLAM) to a higher level in the network hierarchy where new entrants may already have a point of presence (e.g. a transit switch location). Bit-stream access handover points, as a result, can be at various levels.

Bit-stream Access Handover Levels

  • Handover at DSLAM
  • Handover at ATM-PoP
  • Handover at IP level

Why Use Bit-Stream Access

Bit-stream access is considered a key tool for opening competition in the broadband market in todays world. It enables competitors to offer their own products to consumers even if they do not operate the local loop (the last mile). Bit-stream access allows the new entrant to use the high-speed modems and other equipment provided by the incumbent and thus avoid maintenance and investments into the local loop. This affects the economics of the service and places restrictions on the type of modems that the customer of the new entrant can buy or rent.

The main elements defining Bit-stream access are the following:

  • High-speed access link to the customer premises (end-user part) provided by the incumbent and transmission capacity for broadband data in both directions, enabling new entrants to offer their own, value-added services to end-users;
  • New entrants have the possibility to differentiate their services by altering technical characteristics and/or the use of their own network.

Thus, bit-stream access is a wholesale product consisting of the access, which is typically ADSL,  and  the “backhaul” services of the (data) backbone network (ATM, IP backbone).

EU Regulation

Unlike unbundled access, the provision of bit-stream access services is not mandated under European Union law. However, where an incumbent operator provides bit-stream DSL services to its own services, subsidiary or third party, then, in accordance with community law, it must also provide such forms of access under transparent and non-discriminatory terms or conditions to others (Directive 98/10/EC Article 16).

Note: bit-stream access service allows the incumbent to retain control of the rate of deployment of high-speed access services, and the geographical regions in which these services are rolled out. From the regulatory point of view, such services are therefore seen as complementing the other forms of unbundled access, but not substituting them.

Article Copyright Wikipedia - Back to Knowledge Base

Click here for the original article.


Horizon Electronics
7925 Evies Way
Port Richey, FL 34668

If you would like a quote for an upcoming job, please fill our contact form here:

Nationwide Coverage

Copyright © 2024 - Horizon Electronics