“A television network available via direct cable channel, available through satellite broadcast, as well as via IPTV channel.”

Cable TV is also known as “CATV” (community antenna television). In addition to bringing television programs to those millions of people throughout the world who are connected to a community antenna, cable TV will likely become a popular way to interact with the World Wide Web and other new forms of multimedia information and entertainment services.

1.Most cable TV systems also carry local over-the-air television stations for distribution.
2.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.
3.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, for reception of local television stations’ programming by the headend.
Cable television headend and modulator

  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.

Cable television signals are then mixed in accordance with the cable system’s channel numbering scheme using a series of cable modulators (one for each channel), which is in turn fed into a frequency multiplexer or signal combiner. The mixed signals are sent into a broadband amplifier, then sent into the cable system by the trunk line and continuously re-amplified as needed.

24 In 1 Analog Fixed Channel Modulator Headend

SK-24M
The SK-24M is a 3RU rack mounted chassis that allows for installation of up to 24 pieces microprocessor-controlled fixed mini-modulators.Built-in active combiner eliminates unnecessary cabling and potential connection problem and ensures high output level . All modulators are perfect factory set to desired channel and proper offset.

Features:
1. Switching power supply for installation flexibility and precise voltage regulation
2. Two cooling fans for long life performance
3. 45dBmV chassis output level,no need extra combiner
4. SAW(surface acoustic wave) filtering on IF for superior in band C/N
5. Front panel access controls enables easy setup
6. Rear panel has a combiner loop for easy connection
7. One unit contains 24 pcs fixed adjacent channel modulator card 

For more, please access to https://www.soukacatv.com/24-in-1-analog-fixed-channel-modulator-headend_p11.html