Cable Modem is a #Broadband technology that utilises the existing coaxial cabling which was providing just the TV services before the technology. It is capable of offering high-speed connectivity as fast as Ethernet, which means it can run at the speed of greater than 10Mbps. However, since the connection must be permanently established, dialling multiple locations is not possible. Instead, it will directly connect to the Internet. Distance is not a limitation factor to it since the provider can easily amplify the signals if necessary.
The cable spectrum is already divided up into several hundred 6MHz blocks (capable of carrying around 30Mbps of data) to accommodate various TV channels. The provider needs only to assign one or more blocks for downstream data (for downloading) to the user. The lower end of the spectrum is divided into 2MHz blocks as upstream data (for uploading) instead, and the provider will assign one or more blocks to the user accordingly. Both upstream and downstream will be aggregated by a Cable Modem Termination System (CMTS) located at the cable provider. However, CMTS has limited number slots (typically 1000 of them) which allow a fix number of subscribers for the service.
There is no need to worry about the interference of the data and TV signals as the televisions already have their own filtering.