User domain

Written on 5:09 PM by ooe

For the user, there are two distinct installation options, BT-installed and self-installed. The two options not only identify who does the installation, but also the actual configuration in the user's premises. For BT-Installed, the master socket will (if necessary) be updated to the modern NTE5 that has a replaceable bottom half of the front plate. For broadband users this replaceable plate is replaced with a front plate that includes a splitter. The purpose of the splitter it to split the high ‘data’ frequencies from the lower ‘POTS’ frequencies. The user's existing POTS wiring is then connected to the POTS output from the splitter and there is no more modification to the user's POTS connections. The equipment that is attached to the data output from the splitter depends upon the product. However, there must be an ADSL modem connected with one of a number of interface options. In addition to the modem, there may also be the additional functionality of either a router or a set top box, though increasingly functionality is being incorporated into single pieces of equipment, e.g. a modem/router.

For self-installed, the master socket does not need be updated to the modern NTE5, and instead of using a splitter to separate the frequencies this separation is performed by a combination of filters. There is no need to modify the user's existing wiring because low pass filters are simply inserted for each telephone. This requires no more than unplugging each phone, plugging the filter into the master or extension socket, then plugging the telephone into the filter. The data equipment then simply plugs into a convenient master or extension socket. This equipment must include the functionality of a modem together with a high pass filter. Other equipment or functionality may also be required to provide the user with the connection and service required.

With both configurations, data between the user to the exchange is encoded and transmitted by the ADSL modem utilising the bandwidth above that required for the POTS service. It should be noted that the structure for carrying traffic on ADSL lines is ATM formatting.