Over the past thirty years, the cable TV access network architecture has evolved significantly from pure coaxial network with many RF amplifier cascades into a majority Hybrid Fiber Coax (HFC) network with much shorter RF cascade while fiber goes deeper to customer’s premises. In new Greenfield (new‐built) and Brownfield (upgrade) projects, the Fiber to The Home (FTTH) architecture becomes prevalent and provide the ultimate speeds to access the internet.

However, transmitting several hundreds of high definition video program channels using data bandwidth and traffic over FTTH architecture could be cost‐prohibitive in many cases. Because of the switching network and system complexity involved, the logistic difficulty in replacing existing coaxial cable lines in some neighborhoods and also providing sufficient bandwidth for HD, 4K or even 8K videos, all fiber networks can be very capital intensive, especially for some smaller and medium services providers and network operators where they are trying to provide high speed internet and other advanced services to the customers either far away from the central office or reside in less density areas where penetration rate is generally low to offset the high investment.

An alternate cost-effective approach is to utilize the existing coaxial distribution network at the customer’s premises, and at the same time finding ways to overcome its limitations and provide a higher level of services to the ever bandwidth demanding end customers. The success will be based on choosing the right technology and architecture to deliver a reliable system in a cost‐effective way.

FTTH (Fiber to The Home) + Video Overlay architecture differs from traditional HFC or  FTTH + IPTV network in that Video Overlay utilize the RF coaxial cable at home. FTTH can be installed as a point‐to‐ point architecture, or as a passive optical network (PON). The former requires that the provider have an optical receiver for each customer home or MDU in the field. PON network utilizes a central transceiver and splitter to accommodate up to 32 or 64 clients. Optical electric converters, or OECs, are used to convert the signals to interface with cable wiring where necessary.

The combination of FTTH and Video Overlay architecture presents a cost-effective solution for the cable operators and services providers to offer the high-speed internet connection and high definition video services while maintaining the coaxial home network for their existing customers.

As can be seen in the diagram below, data and video CATV traffic are multiplexed into a SM (Single Mode) fibre. The distribution network is passive, with only optical splitters in the field. The CPE (Customer Premises Equipment) includes an ONU (Optical Network Unit) that delivers Fast or Gigabit Ethernet data and an optical receiver which convert the 1550nm video distribution signal to RF which further distributes to the in‐house coaxial cable system. Typically, the P2P or PON CPE (Customer Premises Equipment), installed in each apartment, provides both Ethernet data and CATV RF output ports. Sometime, the CPE and Optical receivers are two separate units.

Although each OLT (Optical Line Termination) can support up to 64 ONUs, typical FTTH deployments range from 8 to 32 splits, depending on the SLA (Service Level Agreement) and the take‐up rate.

CATV is implemented as an overlay on a 1550 nm wavelength. The CPE incorporates a CATV optical receiver with one or more high‐RF outputs (over 75 dBµV) for in‐home RF distribution.