Broadcast and cable communication systems

Broadcast vs Cable network vs Online distributors

This page explores the historical methods of signal distribution and reception systems, particularly within broadcast communication network, and delves into potential simulations of these systems.

• Terrestrial Broadcasting: A Broadcast Station transmits audio and/or video content to a wide audience using radio waves, known as over-the-air broadcasting. This system includes:

Television: Signals are sent from broadcast stations to be received by antennas. This could be analog or transitioned to digital formats like DTV and ATSC. Examples: Local TV stations, network affiliates like ABC, CBS, NBC.

Radio: Terrestrial radio broadcasting uses radio waves from land-based stations. It uses analog systems: Traditional AM (Amplitude Modulation) or FM (Frequency Modulation). AM varies the strength of the carrier wave, while FM varies the frequency for better quality but requires more bandwidth.

• Cable TV: Cable TV was a system for delivering television programming through RF signals via coaxial cables. It required;

Infrastructure: Physical cable networks to homes

Equipment: Subscribers needed equipment like set-top boxes (STBs) to decode and display the signals

Subscription: Access to cable TV typically required a subscription, akin to early online services.

• Satellite Broadcasting:

Satellite TV: Similar to cable, but uses satellites in orbit to transmit signals, providing a wider range of channels and sometimes exclusive content.

Satellite Radio: Under Digital Audio Radio Service (DARS), it involves digital transmission of audio signals from satellites to receivers on Earth.

• Internet Protocol television and streaming services:

Signal or content is received over an Internet stream or on a network utilizing the Internet Protocol.

There are preservation efforts by Radio Preservation Task Force, National Recording Preservation Board and Association of Recorded Sound Collections dedicated to project operates in fulfillment of the “to develop an online inventory of extant American radio archival collections.” Over 2000 radio collections are linked in this database and more to come. Lots of recordings and captures preserved on Archive.org as well, such as: Radio Show and Programs Archive.

Simulators

Name	Platform(s)	Years(s)	Region(s)	Enhancements	Active	Recommended
MyRetroTVs		'50s, '60s, '70s, '80s, '90s, '00s	United States of America	~	✓*	✓
swimelodeon		'90s	United States of America	?	?	?

Comparison

MyRetroTVs - 1996 news

MyRetroTVs

This website is for watching captured footage from TV channels or various videos from the eras of the '50s to '00s, eliminates the need for handpicking videos and creating a personal collection, which can be time-consuming and require a significant amount of storage space. This website simply gathers videos from specific sources such as YouTube playlists etc, so we can say that this website offers a simulated experience of watching TV channels from during those specific eras. It also supports some basic #Enhancements. While this is a great way to experience retro television, there's room for even deeper immersion. For example adding surfing channel collections playlists, this could be achieved by integrating with Archive.org's vast collection of VHS TV channel surfing captures. Also integration with EmuVR, perhaps with some kind of support for playlists support for libretro core, could be a great next step too.

swimelodeon

This website is for watching '90s Nicktoons, original Adult Swim, old-school cartoons and anime. placeholder text

Enhancements

Name		MyRetroTVs
Post-Processing	Filters	✓
	AI-powered filter compatible (Freestyle)	?
	Shader Chain	~*
	Inverse tone mapping compatible	?
Quality of life	Rewind	?
	Fast-Forward/Turbo Speed	?
	Savestates	?
	Video recording	?
	User Profile	✗
	Command Line Options	?
	Built-in Custom resolution/CRTSwitchRes For using this on Windows OS you need CRT Emudriver. Another option is using EDID editor tool such as "Custom Resolution Utility".	Exclusive to libretro cores and GroovyMAME at the moment. Also there is a project for achieving software emulators like libretro cores and GroovyMAME send the raw RGB data over a network to a core running on MiSTer, it basically turns the MiSTer into a GPU for the emulator allowing for easy setup and use with CRT TVs/Arcade monitors.
	Big Picture Mode	?
Misc	Netplay or SyncPlay	?
	AI Service With the help of OCR and other techniques, the AI service can provide a live translation of a video, or text-to-speech capabilities for the visually impaired among other things, either on demand or automatically.	Exclusive to libretro cores at the moment. So there is no support at the moment.
	EmuVR support	Exclusive to libretro cores at the moment. So there is no support at the moment.

Terrestrial Television Signal Type(s)

These networks can be categorized into different encoding or formatting Broadcast television systems for the transmission and reception of terrestrial television signals.

Analog Television Systems

During the 1st and 2nd generation of video game consoles, RF connection was the only way to connect a video game console to a TV. During the 3rd generation some consoles such as the NES had separate outputs for unmodulated signals and all consoles had the option by the 4th generation. By the 5th generation, composite video became the standard form of connecting a video game console

NTSC

NTSC was the first color television system to be widely adopted, NTSC works by transmitting a high frequency color signal on top of the legacy black and white image, the amplitude of this signal determines the saturation while the phase determines hue, this is a property that many early consoles and home computers took advantage of. Every nation using the NTSC system also used a 59.94hz field rate. Many filters exist to replicate this display on emulators.

PAL

PAL was created in Germany as a response to NTSC's susceptibility to hue fluctuations during poor reception conditions. The difference from NTSC is that the phase is inverted every other line, causing phase errors to cancel out, causing a less objectionable drop in saturation instead. The color signal is also in a higher frequency than NTSC, thanks to the larger channel bandwidth on European channel allocations. PAL was almost always used with a 50hz field rate.

PAL-M

PAL-M was only used in Brazil and should not be confused with PAL-60. PAL-M uses PAL encoding on NTSC channel allocations, as such the frequency of the color signal is lower than that of regular PAL, close but not the same as NTSC. As with NTSC PAL-M used a 59.94hz field rate.

SECAM

SECAM (also written as SÉCAM ) was developed in France for similar reasons as PAL. Unlike NTSC and PAL, which transmits a full color signal each line, SECAM alternates between two axes of the color signal, making a delay line mandatory for decoding (hence the name which translates roughly as Sequential color with memory). Also unlike NTSC and PAL this signal is frequency modulated, which makes it more robust to transmission errors. Aside from France, SECAM was used by the Soviet Union and its satellite states. For this reason SECAM is rarely found on video game consoles, most often opting to use a RGB SCART cable instead (in some cases such as the NES, the RGB signal comes from an internal PAL decoder, hence not being "pure" RGB). Rare exceptions are the French Atari 2600 and Soviet Sega Master System

MUSE

MUSE (Multiple sub-Nyquist Sampling Encoding), also known commercially as Hi-Vision (high definition television) was created in Japan in the eighties where it was used for HDTV transmissions as well as laserdisc. MUSE works in a completely different manner from the above systems and was never used for any video game console, and is only mentioned here as it was still an analog system :)

Samples

Comparison table

System	Refresh rate	Chroma subcarrier frequency	Usage	Effect of phase errors
NTSC	59.94	3.58 MHz	Most of the Americas, South Korea, Japan, Taiwan	Color shifts
PAL	50	4.43 MHz	Most of Europe, Australia, New Zealand	Desaturation
PAL-60	59.94	4.43 MHz	60Hz modes in PAL regions, never used in broadcasting	Desaturation
PAL-M	59.94	3.58 MHz	Brazil	Desaturation
SECAM	50		France	Immune

Analog Hidden Signals

Extended Data Services

Wide Screen Signaling

Vertical interval timecode

Vertical interval test signals

Video Encoded Invisible Light

Vertical blanking interval

Programme delivery control

Ghost-canceling reference

Electronic programming guides

Copy Generation Management System – Analog

See Copy protection page.

Captioning

Teletext

Zxnet's teletext viewer

Emulation

Name	Active	Recommended
zxnet	✓	✓
Teletext-capable version of JSBeeb	?	~
PagesFromCeefax	?	~

Digital Television Systems

Transmission of television signals using digital encoding, contrasting with the earlier analog television technology which utilized analog signals. At the time of its development, DTV was considered an innovative leap forward, marking the first significant evolution in television technology since the introduction of color television in the '50s.

The transition from analog to digital broadcasting started around 2000. This shift has led to the adoption of various digital television standards across the globe:

1. Digital Video Broadcasting (DVB): Utilizes coded orthogonal frequency-division multiplexing (OFDM) modulation and supports hierarchical transmission. It's adopted in Europe, Africa, Asia, and Australia, covering approximately 60 countries.
2. Advanced Television System Committee (ATSC): Employs eight-level vestigial sideband (8VSB) for terrestrial broadcasting. It has been adopted by nine countries including the United States, Canada, Mexico, South Korea, Bahamas, Jamaica, the Dominican Republic, Haiti, and Suriname.
3. Integrated Services Digital Broadcasting (ISDB): Designed for both fixed and mobile reception, using OFDM and two-dimensional interleaving. It supports hierarchical transmission of up to three layers with MPEG-2 video and Advanced Audio Coding. Japan and the Philippines use this standard, while ISDB-T International, adapted with H.264/MPEG-4 AVC, has been adopted in most of South America, as well as Botswana and Angola.
4. Digital Terrestrial Multimedia Broadcast (DTMB): Employs time-domain synchronous (TDS) OFDM technology, where a pseudo-random signal frame serves as both the guard interval (GI) of the OFDM block and the training symbol. This standard is in use in China, including Hong Kong and Macau.
5. Digital Multimedia Broadcasting (DMB): Developed in South Korea, this technology allows for the transmission of multimedia content like TV, radio, and data to mobile devices such as mobile phones, laptops, and GPS navigation systems.

Digital Hidden Signals

Electronic programming guides

DVB Content Protection & Copy Management

see copy protection page.

Captioning

Broadcast flag

Active Format Description

Teletext

Recordings of Broadcast Television

Early TV was broadcast live. Different means were invented for recording a broadcast.

Professional formats

Telerecordings, also known as Kinescopes, were means of recording a television program onto film. In 50hz territories, the film ran at 25fps and was synchronised with the image being drawn on a CRT. The image was slightly defocused to avoid recording a scanline structure, as that would beat against scanline structure of the telecine (a device used for transferring film to video) causing moire. Telerecordings were always in black and white, as the shadow mask used on color CRTs would cause moire when superimposed on the grain structure of color film. However, some telerecordings were made without filtering out the PAL subcarrier, which allowed modern methods to recover the "buried" color signal.

Quadruplex by Ampex was the first commercially successful format for recording video, released in 1956. Because a video signal requires significantly higher bandwidth than audio, and the tape speed needed for achieving such a bandwidth was impractical to achieve with linear recording (such as on an audio tape). The solution was to have a set of four magnetic heads rotating as 2 inch tape passed by them, hence the name Quadruplex, as a result the effective tape speed was over 1500 ips, or 100 times the linear tape speed. Audio was still recorded linearly. As technology progressed, smaller less cumbersome format took its place.

Sony's U-matic, released in 1971, was the first video format to store the tape inside a cassette instead of on a reel that required manual threading. While it never caught on as a home format due to its high price, it became popular for industrial and educational use. It also found significant use in newsgathering.

Home formats

While home video recording remained out of reach for two decades, home audio recording was a different matter. A number of otherwise lost programs exist in audio form due to watchers recording their favorite shows onto audio tapes, often by simply putting a microphone near the TV's speaker. More inventive persons would tape the audio signal electronically from the TV.

Several home video formats came out in the 1970s, however the two most important ones were Sony's Betamax (not to be confused with Betacam, which was a later professional format) and JVC's VHS in 1975 resp. 1976. While Betamax had a headstart, VHS came out victorious.

See also

• Preservation projects
• Online and Discontinued Online Services
• Set-top box emulators
• Game Room Simulations
• Auto-load next disc
• Arcade LaserDisc emulators#Comparisons - Domesday Duplicator project and difference between captures for Daphne/Singe and dumps for MAME.
• Copy protection

Home media or media content playback focused devices

• Home Media Player
• Portable media players
• Smart TVs, DVRs, smart TV boxes/digital media players/media boxes, smart blu-ray players

External links

• Wikipedia:Broadcasting
• Wikipedia:Broadcast television systems
• Wikipedia:Digital terrestrial television
• Wikipedia:Radio broadcasting
• Archive.org
• wrongdog reckons: My Nostalgia Machine - Recreating 80's broadcast TV with a Raspberry Pi - recreating over-the-air broadcast television the way he remember it from his childhood. In this video, He will wax nostalgic about the old-days and then show you how he built that simulator and talk about how it works. He use a Raspberry Pi 5, a Raspberry Pico, an old aerial rotator box and some custom code to create an accurate simulation of TV in the late 70s and early 80s. The source code for this project can be found here, more details on the project can be found here.
• VWestLife: Analog TV was smarter than you think