Data Over Cable Service Interface Specification(DOCSIS), developed by CableLabs and approved by the ITU, defines interface requirements for cable modems involved in high-speed data distribution (both MPEG and IP data) over cable television system networks. Other devices that recognize and support the DOCSIS standard include HDTVs and Web enabled set-top boxes for regular televisions.
There are two key components in the DOCSIS architecture: Cable Modem (CM) which is located at the customer premise, and Cable Modem Termination System (CMTS), which is located at the headend of service providers and used to aggregate traffic from multiple Cable Modems and then communicate with the backbone network. DOCSIS specifies modulation schemes and the protocol for exchanging bidirectional signals between these two components over cable.
There are three versions of DOCSIS implemented and deployed now:
DOCSIS 1.0 - High Speed Internet Access. Key features: Downstream traffic transfer rates between 27 and 36 Mbps over a radio frequency (RF) path in the 50 MHz to 750+ MHz range, and upstream traffic transfer rates between 320 Kbps and 10 Mbps (Average 5 Mbps) over a RF path between 5 and 42 MHz. But, because data over cable travels on a shared loop, individuals will see transfer rates drop as more users gain access.
DOCSIS 1.1 - Data, Voice, Gaming and Streaming. Key features: DOSCIS 1.1 is interoperable with DOCSIS 1.0. It enhanced QoS for multiple services such as voice and streaming; Improved security over DOCSIS 1.0; and more robust upstream data transmission (average 10 Mbps).
DOCSIS 2.0 - Added capacity for symmetric services by operating at 64 QAM and having new 6.4 MHz wide channel. It increased bandwidth for IP traffic by using enhanced modulation and improved error correction. The result for upstream transmission is 30 Mbps, which is 3 times better than DOCSIS 1.1 and 6 times than DOSCIS 1.0. DOSCIS 2.0 is interoperable and backward compatible with DOCSIS 1.x.
The latest DOCSIS specification eDOCSIS has been published to the industry. eDOCSIS stands for embedded DOCSIS, which would provide a subordinate function at the core chip level to the host device. And, rather than leveraging a home networking protocol, an eDOCSIS device would feed directly into a cable network’s DOCSIS channel. eDOCSIS is intended to solve end device (and traffic) management, configuration and security issues to significantly reduce cost in the service operation and to improve speed and quality of end customer services.
source: javvin
Asta-Net is the next cable TV operator which introduces DOCSIS 3.0 I-CMTS in cooperation with VECTOR.
The DOCSIS 3.0 I-CMTS data transmission system allows offering the Internet access services with data speed higher than 100 Mbit/s. It also makes possible to use the IP protocol for video transmission (IPTV services). The new system reduces the operational costs of cable TV operators by the power reduction and increases efficiency and reliability of the solution. It reduces the cost per each Mb of the network traffic.
Astra-Net has appreciated the advantages of DOCSIS 3.0. The company has been present in the Wielkopolska district since 1989. The company offers services in the area of cable TV, broadband Internet access, digital TV and telephony. The offered products have the highest quality and are based on the latest technological solutions responding for increasing customer needs.
“The deployment of the DOCSIS 3.0 system will allow us to offer fast data transmission services up to 200 Mbit/s and to broaden our offer with new services responding for needs of more and more demanding customers. Our competitiveness will be higher thanks to the deployed system. The reduction of the transmission cost is also very important for us, as well as the flexibility of downstream and upstream configuration”, said Mr. Zbigniew Ryczek, the President of the Astra-Net board of directors.
The DOCSIS 3.0 I-CMTS fast data transmission system arouses interest of cable operators offering TV, data and telephone services. VECTOR will be informing about the system introduction by the next cable operators.
source: VECTOR