When installing TRIAX EoC, there are a couple of things you might want to investigate before the actual installation. The system itself is very easy to install and configure, but depending on the existing coax installation, the result may vary in the end.
This article is a part of a small series of articles, that will help you pre-qualify an installation. The pre-qualification process will increase the quality of the complete installation at the end.
This article is about the usage of the frequencies, in the installation.
The TRIAX EoC system will coexist with the TV services that are already there. There are thou some scenarios that need to be considered.
First of all, are the services generated locally with a headend or are they delivered from an ISP (service provider)?
Locally generated services
If the services are generated locally with a headend, then it is possible to relocate any services that may interfere with the TRIAX EoC system. The recommendation is, to have the first TV QAM on S21 (306MHz).
ISP delivered services
If the services are delivered from an ISP, then it is not possible to relocate any services. The larger service providers normally also deliver internet services on the DOCSIS platform. This means, that there will be a return path signalling in the 1...200MHz range. The service provider usually doesn't filter out their DOCSIS signalling if the installation doesn't utilize the DOCSIS service, so this will interfere with the EoC system. In rare scenarios, there can be a TV QAM in the range as well. This TV QAM must possibly be preserved and broadcasted along with the other TV QAM, so all TV services are available.
Injection or combining of TV services?
Both options have their advantages. The most optimal solution is injection on the controller.
By injecting the TV services on the controller, you will be utilizing the build-in filters on both controller and endpoints. This will spare the TV/STB tuners from the EoC signalling, remember that the EoC signalling is bidirectional. Neighbouring endpoints will be transmitting at 100dBµV in the 1...200MHz range and TV/STB tuners will see this signalling if it isn't filtered out.
Combining is only a good idea if there are TV services below 300MHz. The filters in both the controller and endpoints allow 300...862MHz to be forwarded. There is not much to gain regarding attenuation if you compare injection and combining. The controller has the same attenuation as a 2-way (for the 32/2 controller) or 4-way (for the 64/4 controller) splitter. if you combine the TV services and EoC signalling, then we strongly recommend, that you filter out the EoC signalling towards the TV/STB.
Signal levels
When installing the TRIAX EoC system into an existing coax installation, you will be introducing passive components. These passive components add to the accumulated attenuation of the TV QAMs.
TV services may stop working on individual TV/STB due too to low signal levels. Especially in the high-frequency area, that is more sensitive to attenuation. Measuring the level of the TV signal at each TV/STB is highly recommended, to verify that the signal level is high enough, giving headroom for the added attenuation (depending on added passive components/outlet etc.).
We would highly recommend that you participate in our TRIAX Academy course “EoC Intermediate”. Further information and registration can be found on our website: TRIAX Academy