The physical link between the CPE and central office parts of the network is based on a point-to-point (PtP) architecture. Within this architecture, the fiber-to-the-home (FttH) network enables the transport of two basic service types: communication through an Ethernet/IP network, and broadcast of (video) content through a CATV network overlay.

In the OPTISIS FttH network with RF overlay, each user is connected to a CATV distribution system. Therefore, in the simplest solution each user is connected to the central office with a single cable containing a fiber pair: one fiber for bidirectional voice and data and one fiber for the CATV overlay. Solutions that multiplex all signals (Ethernet/IP and CATV) on a single fiber can also be provided (single fiber solution).

The figure below provides a schematic overview of the Genexis CATV network overlay.

Four basic elements are of relevance:

• The optical transmitter translates the electrical (analog) signal of the head-end into an optical signal suitable for distribution. This signal is transmitted within the 1550nm wavelength band in order to allow optical amplification of this signal.
   
• The Erbium Doped Fiber Amplifier (EDFA) amplifies the optical signal to a level appropriate for connecting the head-end to a large number of end-users. Depending on the number of users and their physical location, one or more EDFAs can be used each with its own gain and power.
   
• The splitters arrange the actual distribution of the signal to the various end-users. These are fully passive devices, not requiring any electrical power feeding or maintenance.
   
• The optical CATV receiver, located at the end-user, translates the optical input signal into an electrical signal, suitable for direct connection to conventional TV and Radio equipment.

The network management system GAPS also offers control of the CATV network. Specifically, the optical CATV receiver can be enabled and disabled remotely via the management system.