What is a digital cable signal?
Digital cable signals are used to transfer data via terrestrial cables. The primary advantage of the digital cable signal over the analog signal is the ability to transmit multiple data in the same bandwidth. Traditional cable systems use channels that each occupy 6MHz, but a digital cable signal that occupies the same bandwidth can transmit either two high -resolution channels or 10 standard definition channels (SD). Digital cable signals can also broadcast music stations, carry content on request and provide internet connection. The first digital cable systems were implemented in the 80s and most carriers offered some type of digital service by 2000.
Early cable systems have been designed to transmit air (OTA) to distant and inaccessible communities. For this purpose, they basically only reworked OTA analog signals via physical cables. Because each channel Ota occupied 4.8 MHz bandwidth and cable withYStems required a small amount of extra bandwidth for modulation, each channel was assigned 6MHz bandwidth. Over the years, 6MHz has remained a standard assignment of the bandwidth for cable TV channels. Since terrestrial cable systems have a limited amount of bandwidth, only the final number of 6MHz signals can bear.
At the end of the 80s. The first digital cable system was designed and tested. As a result of data compression, it has been shown that the 6MHz digital cable signal could transmit more data than a traditional analog signal. It took several years to accept this new technology, although higher demand for multiple channels, content on request, and other types of data have helped to stimulate the implementation of digital cable systems. The reason is that modern digital cable systems can carry more channels than older analog systems. Digital transmissions also allow other music channels, on requestBSAH and Internet data to be transmitted via the existing cable infrastructure.
The digital cable is not synonymous with high -resolution TV, although the digital cable signal is able to transmit HD programming. Each 6MHz channel block can be transmitted about 38Mbit/s data that can be divided in different ways. One 6MHz block can carry two full HD channels and digital cable signals are able to transmit in 720p or 1080i. Standard definition programming can also be done on a digital cable signal and each 6MHz block has enough space for about 10 SD channels, including video programming that corresponds to the improved definition TV (EDTV) 480p Standard.