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
Charter is also moving ahead with a bandwidth management plan that will involve both switched digital video (SDV) and analog reclamation to make room for high-definition television (HDTV) and Docsis 3.0 services.
Today, Charter’s top-end 16 Mbit/s service is available to about 80 percent of its Docsis footprint. Docsis 3.0 uses channel bonding techniques to produce shared speeds in excess of 100 Mbit/s.
“We are rolling [Docsis 3.0] out in the second half of the year, [but] we haven’t yet announced which markets,” Smit said, noting that Charter has already rolled those dollars into its overall capex number for 2008, estimated to reach $1.2 billion.
Charter is already testing SDV in Los Angeles using the BigBand Networks Inc. (Nasdaq: BBND) platform and expects to begin broader deployments later this year. (See Charter Charts First SDV Course .)
Smit said Charter will use “low-cost set-tops” to aid its all-digital effort, but he did not specify whether it will use DTAs.
Smit said the MSO also expects to migrate to all-digital in markets with the highest digital penetration. Comcast Corp. (Nasdaq: CMCSA, CMCSK), by way of example, expects to enlist its all-digital strategy in 20 percent of its markets by year’s end. Comcast is using simple digital terminal adapters (DTAs) to help with the strategy. (See DTAs on Parade .)
source: lightreading.com
This was a big week for broadband. The combined news of growth in HD, FTTH, Multimedia-over-Coax (MoCA) technology and DOCSIS 3.0 deployments shows just how important broadband infrastructure has become. Sure, the financial markets may knock things back a bit, but our growing dependence on broadband suggests that the industry isn’t likely to slow to a crawl. We have too much riding – literally – on our broadband pipes.
More DOCSIS 3.0
Comcast made a big splash this week by extending its DOCSIS 3.0 deployments into Boston and Philadelphia. With the technology comes a new tier of service: 50 Mbps downstream and 10 Mbps upstream.
More HD
According to research firm iSuppli, shipments of HDTVs shot past shipments of standard-def televisions in 2008. The forecast is for HDTV shipments to increase to 241.2 million by 2012.
More MoCA
Broadcom is getting in on the MoCA game with integration of the technology into its latest modem, router and set-top chipsets. Verizon currently uses MoCA for its multi-room DVR service. Will more operators finally start offering in-home TV networking? Broadcom seems to be betting on it.
More Fiber
Fiber is growing as a share of broadband access technologies around the world, according to the latest report from the OECD (via GigaOM). Both Japan and Korea have more fiber-based broadband connections than anything else, 45% and 39% respectively. In the US, 3% of connections are fiber-to-the-home.
source: connectedhome2go.com
I’ve been collecting content from panels, conversations, and demos, but it takes time to turn that raw information into coherent posts. So in the meantime, here’s a selection of photos from the Motorola booth on The Cable Show floor: 3D TV, new DOCSIS 3.0 retail modems, Internet apps on the set-top, and more.
source: connectedhome2go.com
Tru2way technology is being used to create a common software platform that will enable cable companies, consumer electronics companies, content developers, network programmers and others to extend interactivity to the TV set and other kinds of devices. The new Panasonic VIERA HDTVs are built with tru2way technology inside enabling consumers to access two-way digital cable programming, like video on demand, without a cable operator-supplied set-top box. Panasonic and Comcast have worked together to lead the development and deployment of tru2way technology and related products which are based upon specifications developed by CableLabs®, the industry’s research and development arm.
Comcast customers in the Chicago and Denver areas will be the first in the U.S. to have access to tru2way digital cable service with additional cities expected to go live in the coming months. The tru2way VIERA HDTVs will be available in the Chicago area at Abt Electronics in Glenview and at Circuit City locations and at Ultimate Electronics and Circuit City stores in the Denver area.
Let’s step back in time to January. I wrote about the launch of the tru2way
source: cabletechtalk.com