Cable Television (TV) networks bear TV broadcasts from TV stations to cable TV subscriber homes. Digital TV broadcasts application VHF and UHF frequencies amid 47 MHz to 862 MHz. Each TV approach occupies 6 MHz bandwidth and articulate application 64/128/256 QAM afore combines calm with all added channels at the cable TV headend. Coaxial cables are acclimated to bear the TV RF signals to the subscriber homes. The abundance bandage beneath 47 MHz is acclimated to backpack acknowledgment aisle cartage from the subscribers to the cable TV headend.
In adjustment for the cable TV arrangement to supply top acceleration abstracts services, a set of cable arrangement advice interface and operation abutment standards alarm DOCSIS (Data Over Cable Account Interface Standards) are developed by the cable industry. There are four adaptation of DOCSIS; Versions 1.0, 1.1, 2.0 and 3.0. DOCSIS 1.0 enables cable TV operators to board internet admission up to 36 Mbps after over their HFC (Hybrid Fiber Coax) networks. Adaptation 1.1 adds QoS (Quality of Service) adequacy to accredit cable TV networks to bear articulation and alive casework (IP multicast). Adaptation 2.0 added the upstream acceleration (30 Mbps maximum) application 64 QAM accentuation and 6.4 MHz upstream approach bandwidth to board access in appeal of symmetric casework (e.g. IP telephony). DOCSIS 3.0 cogent increases the after acceleration (to 160 Mbps) and upstream acceleration (to 120Mbps) by bonding assorted upstream and after channels. Adaptation 3.0 aswell introduces abutment for IPv6.
PacketCable is addition cable industry standards developed to board packet based voice, video and added top acceleration multimedia account over HFC cable systems. PacketCable is a set of protocols developed to bear QoS added communications casework application packetized abstracts manual to a consumer’s home over the cable network. PacketCable arrangement architectonics abutment assessment superior VOIP (Voice over IP) casework and allows affiliation of a apparent analog buzz application an Embedded Multimedia Terminal Adapter (EMTA). It supports primary and accessory residential articulation band with array advancement capability. PacketCable leverages QoS adequacy of DOCSIS 1.1/2.0 and will abutment SIP (Session Initiation Protocol) in adaptation 2.0. While the antecedent account offerings for PacketCable artefact band are Packet Articulation and Packet Video, the continued appellation cold encompasses a ample ancestors of packet based casework such as Virtual Private Arrangement (VPN), absolute time alternate video sessions, multimedia telephony, alternate gaming and media streaming.
The two capital apparatus in DOCSIS are the Cable Modem (CM) in the subscriber apriorism and the Cable Modem Termination Systems (CMTS) in the cable abettor headend. DOCSIS specifies the concrete and MAC layers communications interfaces amid CM and CMTS. PacketCable networks use IP as the base for able-bodied multimedia architecture. PacketCable architectonics supports end-to-end functions including signaling for services, media carriage at capricious QoS levels, security, accessories of the applicant device, billing, and added arrangement administering functions. PacketCable VOIP blast account uses a managed IP arrangement instead of the accessible internet to backpack its articulation traffic. PacketCable blueprint for Articulation over IP (VoIP) call the basal functions that are about circumscribed assimilate a individual Class 5 axial appointment switch. These functions can be implemented beyond assorted elements or can be circumscribed assimilate a individual element, which leads to a low cost, awful flexible, scalable broadcast architecture.
With the deployment of DOCSIS and PacketCable arrangement architecture, cable operators can become abounding account providers of amateur play of voice, abstracts and multimedia services. Cable operators can aswell use their cable arrangement to board CableHome casework such as limited control, administration and analyze of customers’ home arrangement (router, firewall, arrangement abode translation, defended software download, etc) and added devices.