The broadband connection providing Internet access, data, voice and video can be implemented by using various technology options. Telecommunications companies give their priority to the xDSL service, while Cable TV companies prefer using Cable Modem-based services. The rule of using FTTH for high speed broadband access is commonly used, since this technology is ultimate in bandwidth and flexible in upgrade.

 

While most of modern ADSL services are providing not that impressive 1.5-6 Mb/s, VDSL could deliver up to 50 Mb/s or more in scenarios where copper wires are sufficiently short. In order to support higher speed xDSL services, network designers are supposed to install curb/cabinet (FTTC) or switch to fiber-deep architecture (FTTN). While it might sound as a good idea to upgrade spectral coding and modulation techniques while reusing existing copper plant, it is not. At some point it would be more expensive to upgrade and manage new technology, then install fiber-all-the-way to the customers. Considering that, FTTH is now preferred choice for installation in new buildings. At the same time, some existing installations are considered to be ineffective or more expensive, so it is considered to use FTTH instead of existing architecture.

 

Most of the companies already implementing the plan of upgrading the whole infrastructure, but this process may be slowed down in some regions due economic reasons.
South Korea is one of the leaders of broadband xDSL services with most of the country having 8-10 Mbps provided by xDSL. South Korean market is already demanding high-speed broadband, so natural migration to FTTH has already began to satisfy the need of 50-100 Mbps connection.
Situation is different in the US, with high deployment of TV cables, antennas and tree and bus architecture. Due Cable TV companies Research and Development labs, Headend multi-channel video systems were consolidated with digital optical transmission technologies. At the same time, laser and optical fiber technologies were used for analog RF subcarrier.

 

All these adjustments were making possible higher quality analog video signal being transmitted before it would be converted back to traditional RF signal at the end of the optical fiber link.

 

The coax part of the video distribution plant has been significantly shortened in the HFC architecture. The same architecture is using the power of optical fiber transmission technologies. Entire networks bandwidth has been improved, eliminating some problems with the RF coax amplifiers. Different research results of the telecom research labs have improved video transmission quality by several orders of magnitude. Research has significantly helped in distribution and flexible trunking of the RF-video encoded optics signal over the HFC networks.
Upgrade of that size and scale made possible for Cable TV companies to extend their market, now providing TV and video services together with bandwidth Internet connection and data – making them full service providers. Furthermore, some of the companies combine the Data Centers, CO and the HE calling it Master Communications Centers. These MCCs have all the necessary equipment for data, video and telephony distribution and communications.
There is a time gap of 10 years between the first lab research of the xDSL and Cable Modem technologies to current state of deployment. Of course these technologies being compared all the time in literature, but even a side-by-side comparison could not tell the exact result. Many factors affect both of the architectures and designer should not forget best-case and worst-case scenarios. While typically xDSL is having lower speed, Cable Modem bandwidth is shared by a group of customers and speed of the bandwidth can be affected by these factors.
While thinking of network deployment, designer should always be aware of the costs of the equipment. It is absolutely possible to get the transmission of Gigabit per second over existing copper or coax cables using advanced modulation techniques and signal processing. But the cost increases would be significant and some limitations would be faced. Optical fiber price is dropping rapidly and it can potentially accommodate the nearly unlimited bandwidth without distance limitations. As a result, designers would agree that FTTH is the ultimate solution with ability to upgrade in future and provide services on demand.