Simulcast Definition: The Tech Behind Efficient Meetings

Media and its transmission have undergone significant transformation in recent years. Just a decade ago, it was almost unimaginable that people could easily stream videos or audio from small-screen devices to large-screen TVs.

Whether you are watching a movie or sharing video content for a lecture or conference, Chromecast enhances the viewing experience. Now, you can easily cromecast MacBook to a TV and display files on the big screen.

However, technologies evolved even more, and today people can launch their own media channels and broadcast them across a wide audience via multiple platforms.

Suppose you want to start a broadcast, but your viewers are on different platforms. Do you really have to choose between TikTok and YouTube, Instagram and TikTok, and so on? Not at all!

Simulcast streaming technology allows you to run a live broadcast simultaneously on multiple applications from the same platform. Let’s clarify what this means.

What Is Simulcasting?

Simulcast is the simultaneous broadcasting of programs or events across multiple services using the Real-Time Messaging Protocol (RTMP). For example, airing a soccer match on both TV and radio at the same time is considered a simulcast.

The term “simulcast” originated in the United States when NBC and CBS began transmitting programs simultaneously on both radio and television in 1948. Today, simulcasting typically refers to content delivered digitally through websites and social platforms. Virtual events, webinars, speeches, sports matches, or entertainment content can all be streamed to multiple platforms at once.

To capture these events professionally, organizers may even hire an event photographer. Within simulcast systems, special repeaters are often used to ensure stable operation over long distances.

In video conferencing, simulcast refers to an architecture for data transmission between a server and endpoints:

• The server receives multiple (typically 3–5) video streams from each client, each containing the camera feed in different resolutions and quality levels.
• The server then delivers a version of each participant’s video stream that best matches the bandwidth and device capabilities of every endpoint.

How Does a Simulcast Work?

This architecture is a good choice when the layout places one participant in a larger video window, while others are displayed in smaller panes.

Advantages of Simulcast Architecture

• Multiple quality levels provide greater flexibility compared to earlier VC architectures.
• Reduces the server’s need to process video streams.

Disadvantages of Simulcast Architecture

• In practice, simulcast rarely uses channels and resources efficiently because all streams transmit the same image, just at different levels of detail. This leads to redundancy, as each participant in the conference sends a larger stream than necessary.
• Simulcast-based systems demand significant resources from users’ VC endpoints but use them inefficiently. In such systems, the main network load falls on the endpoints due to the need to simultaneously support multiple levels of video quality. This can result in performance issues, such as CPU thermal throttling, which negatively affects the stability of the streaming experience.

Endpoint Conference Comparison (4 Participants)

Server Conference Comparison (4 Participants)

Simulcast has been replaced by SVC architecture, which allows video quality to be adjusted without generating multiple separate streams.

What Is the Difference Between Simulcasting and Multicasting?

Simply put, both simulcasting and multicasting transmit the same signal simultaneously from different locations. The key difference lies in frequency usage: simulcasting uses the same frequency, while multicasting transmits on different frequencies.

What to Consider When Choosing a Simulcast Platform?

Streaming is widely recognized as the media of the future. According to recent surveys, 63% of millennials, which is the largest target audience on the Internet, regularly watch live streams, making them the most engaged demographic online. At the same time, leading streaming platforms have become integral to digital communication, especially in eSports and video game streaming.

Live streaming is gaining popularity not only among bloggers and content creators but also among everyday users. Many digital marketing agencies recommend it as a powerful tool to boost brand visibility and audience engagement. Today, there are many free streaming platforms, such as YouTube Live, Facebook Live, Instagram Live, and Periscope.

However, these platforms are primarily designed for B2C audiences and may lack the control and privacy needed for B2B (businesses) use cases. Live video is quickly becoming a must-have in digital marketing, helping brands connect with customer loyalty.

If you’re a business owner or IT professional looking to stream webinars, all-hands meetings, remote training, or e-learning sessions, TrueConf is the ideal solution. It enables you to reach a wide audience while keeping your content secure. With TrueConf, you can integrate video into your company’s communications in a way that supports your corporate identity and ensures data privacy: turning video into a reliable and effective marketing tool.