Broadbandindia Magazine

A digital headend system can be an extremely rational and inexpensive way of offering variety and quality to the subscribers in a multi dwelling network.

A cable television headend is a master facility for receiving television signals for processing and distribution over a cable television system. The headend facility is normally unstaffed and surrounded by some type of security fencing and is typically a building or large shed housing electronic equipment used to receive and re-transmit video over the local cable infrastructure. One can also find head ends in power line communication (PLC) substations and Internet communications networks.

Digital headends serve as the main distribution point for all of your facility’s entertainment and education programming, providing a seamless integration into your hospital’s television system. Each system is custom engineered to the facility’s standard or high definition channel requirements, tested and shipped fully assembled to make installation quick and easy. Digital headend solutions provide more programming options than cable, while achieving considerable cost savings and better quality entertainment for your facility.

A digital headend system can be an extremely rational and inexpensive way of offering variety and quality to the subscribers in a multi dwelling network. A dedicated, non-movable dish is required for each satellite that the cable TV utility wishes to receive cable channels from for distribution over its system. For reception of signals from several adjacent satellites, a larger non-parabolic multi-satellite dish (such as the Simulsat) that can see up to 3 or more satellites is often used. Many digital cable systems use Digital headend which carry hundreds of channels on just a few satellites; this is commonly used by small systems to expand service without adding expensive new dishes or other equipment.

Most cable TV systems also carry local over-the-air television networks for distribution. Since each terrestrial channel represents a defined frequency, a dedicated commercial-grade receiving antenna is needed for each channel that the cable company wishes to receive and distribute. Smaller systems may use a broadband antenna to share several channels. These antenna are often built into a single tower structure called a master antenna television structure. Commercial TV pre-amplifiers strengthen the weakened terrestrial TV signals for distribution.

Some cable TV systems receive the local television stations’ programming by dedicated coaxial, microwave link or fiber-optic line, installed between the local station and the headend. A device called a modulator at the local station’s facilities feed their programming over this line to the cable TV headend, which in turn receives it with another device called a demodulator. It is then distri-buted through the cable TV headend to subscribers. This is usually more reliable than receiving the local stations’ broad-casts over the air with an antenna. How-ever, off-air reception is used as a backup by the headend in case of failure. In some cases systems receive local channels by satellite. Other sources of programming include those delivered via fiber optics, telephone wires, the Internet, microwave towers and local Public-access television channels that are sent to the cable headend on an upstream frequency over the cable system itself (known in the industry as “T”-channels), or via a dedicated line set up by the cable company, as mentioned earlier for reception of local television stations’ programming by the headend.

Digital Headend Solutions

Digital headend is the master distribution center of a CATV system by which incoming television signals from video sources (e.g., DBS satellites, local studios, video players) are received, selected, amplified, and re-modulated onto TV channels for transmission down the CATV system. The incoming signals for headend systems include satellite receivers, off-air receivers and other types of transmission links. The signals are received (selected) and processed using channel decoders. Digital head-ends commonly use modern receiver devi-ces that combine multi-ple receiver, decoding and decryption functions into one assembly. After the headend recei-ves, separates and converts incoming sig-nals into new formats, the signals are selected and encoded so they can be retransmitted (or stored) in the CATV network. These signals are modulated, amplified and combined so they can be sent on the CATV distribution system.

DVB-C digital headend solution to provide stable and reliable equipments and full set of dvb solution to cable network operators. This technology uses the DVB headend system to provide a series of stable and reliable DVB headend equipments and a full set of DVB solution to the cable network operators. It takes the advantage of the advanced IP processing technology to provide solid technical support to the cable network company in the field of from ASI signal to IP signal. In programs resource processing, MSO’s satellite receivers, encoders, adapters can receive and process the signal from digital satellite, local TV station, SDH separately, then transfer the signal to multiplexers, scramblers or multiplexing scrambler, modulators. MSO’s equipments do not only support ASI output, but also have IP output which will be convenient for the cable operator to use our IP technical group to build the digital TV headend. They also provide VOD, TSTV function, etc.

Features and Benefits

l      Each channel has an individual receiver and modulator.

l      All components are rack-mounted at the factory and shipped ready to connect to MATV system.

l      Frequency agile modulators allow easy changes to channel lineups.

l      Over 135 channels provide the perfect balance of news, entertainment and sports options.

l      Rack is open on the sides and back, reducing heat buildup and promoting long component life.

l      Average rack dimensions: 72″ H x 19″ L x 14″ W

l      Headend can be leased or purchased.

The example delivery system

The example of Digital headend delivery system like Drake & BBT provides a totally unique digital cable delivery platform designed to afford cable operators of any size the ability to effectively compete in the digital video marketplace. The system encompasses a powerful, end-to-end service architecture that offers video providers an affordable means to upgrade their existing analog networks with MPEG-4 and high definition (HD) cable TV services.

The Drake & BBT system is capable of delivering hundreds of HD and SD channels, enabling operators to offer premium services and increase revenue per subscriber in addition to existing analog channels. In partnership with Avail-TVN, the Drake/BBT system today allows cable operators to offer subscribers:

l      64 High Definition (HD) channels

l      250 Standard Definition (SD) channels

l      56 digital audio channels

l      Locally-provided analog channels

Drake & BBT provide a low-cost, yet powerful, headend architecture ideal for even the smallest of cable systems. This platform is designed to overlay existing hardware and provide a fully customizable migration path from analog to digital distribution, allowing operators to recover and manage broadband spectrum far more efficiently without the necessity of major new capital expenditures. This is the first manufactured digital platform to feature Beyond Broadband Technology LLC’s pioneering Solution, which establishes a secure communications path, which enables a highly secure package of content to be delivered through the network to subscriber homes. This headend architecture consists of customizable combinations of:

l      Drake Digital SCT2X4 (2 Sat/4 QAM) Headend Transcoder

l      Drake Digital OBM100 Out-of-Band Modulator

l      Drake Digital PC1201 Passive CombinerInter

l      TECH Headend Controller designed to work with the BBTSolution

The Drake & BBT digital headend system is easy to set up and can be preconfigured for plug and play capability. The system’s scalability allows operators to deploy only what they need now, and later grow to meet increasing demand, access new products and offer additional services. Drake & BBT now enable premium digital cable services at a price point lower than any system currently on the market.