Currently broadband is provided by telecommunications operators to their subscribers via the same copper wires that have been used for telephony since its invention in the 19th century. However, new broadband services such as online gaming, high-definition TV and interactive applications require ever higher bandwidths that cannot be provided over copper infrastructure. To provide these services it is necessary to replace the copper infrastructure connecting the end-users to the local switches (the "local loop") by optical fibre. These new fibre-based access networks are referred to as "Next Generation Access networks" or "NGAs".