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Telesputnik uses FTTB (FTTx) technology to build its multiservice networks; in our region it is an innovative technology that has already proven itself worldwide.

If FTTH is a promising, but relatively expensive technology, then FTTB is the "optimal" technology, the most convenient for Russian cities of medium and large size.

What is commonly understood by FTTB? This technology is understood as a relatively deep penetration of optics to the subscriber, ie the work of optical node (OU) at an average of 100 ... 250 subscribers (for example, 9 ... 12-storey building with 4 ... 6 entrances). Usually not more than one coaxial amplifier is included after Op-Amp (Fig. 2).
FTTB technology features are:

Increased reliability. As we know from practice, the biggest number of failures is in coaxial networks, not in FTTB. Due to the presence of not more than one amplifier cascaded (for example, an amplifier per entrance hall), the probability of failure is low.

The simplicity of building parallel digital networks is the most important advantage of FTTB technology. In this case, a separate optical fiber is allocated for the parallel digital network (instead of the core for the reverse channel).

Ingress noise reduction is achieved by a small number of subscribers connected to a single OU. Moreover, when collective cable modems (CM) are used, the ingression noise (the main sources of noise in the reverse channel) coming from subscribers is actually eliminated, because CM is included at the input of the house amplifier, which does not include a reverse channel amplifier.

Higher rates of digital streams in reverse direction with the same number of frequency channels are exclusively due to the number of upstream receivers (reverse direction receivers) installed in the cable modem head-end station (CMTS). An increase in the number of upstream receivers (hence an increase in the total speeds in the reverse direction) while maintaining the carrier-to-noise ratio (C/N) was made possible by reducing the number of subscribers loaded per DUT.

The ease of implementation of new digital technologies superimposed on existing FTTB networks. A classic example is the new promising technology EttH (Ethernet to the Home), developed by Teleste (Finland) and becoming more and more widespread around the world. Figure 3A shows a fragment of a solution called Ethernet over Coaxial (EoC), which delivers Ethernet frames over the coaxial television cable of home distribution networks. The EoC solution does not require any additional cable, such as UTP, and provides access to the Ethernet network at the subscriber socket connected to the coaxial cable of the KTV operator. By the way, Teleste's EttH technology also allows FTTC network operators to do without laying FOCL to the house when building Ethernet networks. Fig. 3B shows a scheme of Virtual Fiber solution providing Ethernet delivery (100Mbit/s) over existing cable TV networks. Moreover, "virtual fiber" can work in KTV networks in parallel with Docsis.

The possibility of using cost-effective DT is achieved by the simple fact that a powerful house amplifier is installed after the DT, therefore, there are no stringent requirements for the DT output stage (namely, the value of its maximum output level is determined by the price policy of DT), both in terms of the gain and the output level.

Operation at low input optical power is achieved due to the fact that the downstream house amplifier actually does not contribute to the S/N reduction because of its high output level. It is the operation at low input optical powers that allows the use of a small number of optical transmitters (hence reducing the cost of the FOCL as a whole) with a large number of Op-Amps.
Thus, we can safely say that FTTB technology HFC network is the most profitable for the Russian operating conditions both in terms of price policy and in terms of implementation of high technical parameters.

It should also be added that when performing FTTB technology on the basis of universal platforms of AC series (Teleste), further economical upgrading to FTTH technology is possible due to a simple installation of a receiving optical module into the AC platform (in the initial supply it is a coaxial amplifier).