Cable Broadband Communication


Cable MODEM is a device that uses coaxial cables of cable television to transmit data. Because the wiring of cable television is extensive and has wider bandwidth. It is possible to transmit data in higher rate with coaxial cables than twisted pairs. Therefore, using cable modems to connect the internet is a good solution. Currently, the largest cable MODEM market is in the U. S., in the arrival of the broadband era, xDSL is becoming its main competitor which ADSL MODEM is based on telephone line transmission.



DOCSIS/EuroDOCSIS 1.0/1.1/2.0/3.0/3.1



A complete cable modem system contains front end equipment called cable modem terminate system (CMTS) and client end system; the two equipment are connected by hybrid fiber coaxial (HFC) cables.
Once a cable modem receives the signal, it runs through a tuner, goes into PHY layer, which converts the RF signal into IF signal, then converted to baseband digital signal at the MAC layer. Finally the baseband digital data is parsed by personal computer to achieve certain user instructions.
With the DOCSIS3.1 standard, cable modem can achieve 320Mbps for upstream, 1.4Gbps for downstream communications.