FTTx Headend

Fiber to the Home Custom Systems

Fiber-to-the-home systems need to be custom-tailored to each individual application. Thor manufactures custom RF over fiber systems for everything from small MDUs all the way up to whole cities. Typically, with a Fiber-to-the-Home system, the RF is on the 1550 nm band. Most GPON systems use the 1310 and 1490 bands for Ethernet communication. The reason that 1550 is reserved for the RF is that RF over fiber is particularly sensitive to loss. The RF optical signal needs to be much stronger than the corresponding GPON data signals. Optical channels in the 1550 nm band can be easily amplified with EDFA fiber amplifiers. EDFAs are needed on any FTTx application with more than 32 endpoints. Due to the nature of these systems, it is best to contact a sales representative to determine which equipment will best suit your needs.

Thor is able to design and deliver complete FTTx headend systems built to spec. Contact us today with the number of endpoints and the length of fiber runs, and we will be able to help you. In addition to RF, Thor can also provide GPON systems as well as AE if the application calls for it. Every application is different. Contact us today for a complete system proposal.

The following application drawing illustrates a standard CATV FTTH system for 4092 homes with an integrated GPON system. Such a system is scalable, allowing more endpoints to be added 500 at a time by incorporating more EDFAs. The primary optical transmitter has an internal EDFA that provides 8 identical optical outputs on 1550 nm. Each output is at 7 dBm, which is the ideal level to feed into the next EDFA. The primary EDFA bank amplifiers each have an internal 16 way coupler that provides 16 optical outputs. Each of these outputs is fed into a three-way CWDM for integration with a GPON system. Each one of these 16 ports has a corresponding OLT port to run the GPON system. From here, each of the 16 outputs runs to a 32-way coupler for the final split. The couplers allow each primary EDFA to deliver service to 512 homes.

A similar system used for distributing DirecTV without the GPON network can be seen below. The main difference is that DirecTV requires a minimum of 4 L-Band RF feeds. These feeds come off the LNB and are fed into a Single Wire Multiswitch (SWM) module. After the SWM module, there is 2-way RF communication between the SWM and the set-top box, so for FTTH applications, it makes the most sense to run all 4 RF feeds to the curb and have each optical receiver set feed a number of homes.

IMPORTANT NOTE*** (it is very important to interface our unit with SC/APC - Angle Polished Connector to avoid any light reflections.

If your fiber is terminated with the  SC, ST, FC /PC flat connector, you need to use an optical jumper from PC type to SC/APC for proper conversion.