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access network (AN)

There are various scenarios for the access network, also referred to as the connection or access network (AN). According to ITU-T G.982, it is a hybrid network consisting of the optical access network (OAN), which implements the connection to the core network, and the connection to the end customer, which is implemented by a copper twisted pair

The reference points of the optical access network are the interface node (SNI) on the core network side and the subscriber network interface (UNI) on the user side. The network consists of the optical distribution network (ODN) bounded by the optical line termination (OLT) and the optical network units (ONU). These units can be located up to 20 km apart.

In another scenario, the access network is directly connected to the core network through the local exchange (LEX). Such a network has no switching functions and is usually based on the existing copper cabling of the telephone network in the access area.

Access technologies in the access area

Access technologies in the access area

The access network for the provision of all services

In general, the access network should enable the subscriber to use all future interactive distribution services such as video-on-demand, information-on-demand, computer games, teleshopping as well as the selective video services and therefore have a high transmission speed.

Bandwidth requirements in the access network, according to DSL Forum and MPEG Industry Forum

Bandwidth requirements in the access network, according to DSL Forum and MPEG Industry Forum

Various xDSL processes have been developed for this network segment which guarantee broadband, bidirectional transmission on copper twisted pairs. The preferred methods are ADSL and HDSL.

In addition to using the existing telephone cable infrastructure, passive optical networks (PON) are used in the access area, the last mile. There are corresponding fiber optic concepts for the direct connection of the last 100 meters to the subscriber. Fiber to the Premises (FTTP), Fiber to the Terminal (FTTT), Fiber to the Home (FTTH), Fiber to the Building (FTTB) and Fiber to the Curb (FTTC) are some of them.

Access networks with connection to core network and subscriber

Access networks with connection to core network and subscriber

In addition, in the access area there is broadband wireless subscriber connection using WiMAX and Long Term Evolution (LTE). LTE technology uses the frequencies between 790 MHz and 862 MHz, which are referred to as the digital dividend in the access area. These frequencies have been freed up by the transmission of digital TV and can be used for broadband wireless access technologies such as those required for Mobile Internet and Mobile Broadband. There is also broadband satellite connectivity and Ethernet connectivity with Ethernet in the First Mile (EFM) and Long Reach Ethernet (LRE).

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Englisch: access network - AN
Updated at: 02.09.2017
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