Controlling time division duplex operation

An intermediate distribution node for digital subscriber line access multiplex, the intermediate distribution node connected to a central node and supporting a plurality of subscriber devices, the intermediate distribution node comprising:

• an analogue optical interface for communication of analogue signals for all of the plurality of subscriber devices with the central node for digital subscriber line access multiplex;
• a plurality of subscriber interfaces for an electrical subscriber line connection to each one of the plurality of subscriber devices;
• an analogue demultiplexer/multiplexer connected between the analogue optical interface and the plurality of subscriber interfaces;
• and
• a plurality of switches, wherein each one of the plurality of switches is for each one of the plurality of subscriber devices, wherein each switch is controllable to selectively enable at least one of reception and transmission over the respective subscriber interface, controlled using an analogue control signal received from the central node.

A method implemented by a central node for controlling an intermediate distribution node for digital subscriber line access multiplex and supporting a plurality of subscriber devices, wherein the method comprising steps of:

• converting incoming digital signals to analogue signals in a plurality of converter devices for each one of a plurality of subscriber devices, wherein each converter device comprises an analogue to digital (A/D) converter and a digital to analogue (D/A) converter;
• generating an analogue control signal for controlling time division duplex operation at the intermediate distribution node;
• multiplexing the analogue signals and the analogue control signal to a combined analogue signal;
• and
• transmitting the combined analogue signal to the intermediate distribution node over an analogue optical interface.