simulcast

Simulcast is the transmission of the same program across multiple channels or platforms at the same time. The term is a portmanteau of simultaneous and broadcast, and it applies to radio, television, and online streaming, among other media.

In radio, simulcasting allows a program to reach audiences over several stations or markets that share programming, often through a network affiliation or agreements with local stations. In television, simulcasting has long been used by networks to air the same show in different regions, and in satellite or cable distribution to reach tributary markets.

With digital distribution, simulcast commonly means delivering the identical stream to broadcast TV, over-the-top (OTT) platforms, and streaming services at once. It may also involve parallel feeds with different audio tracks or subtitles for multilingual audiences while preserving the same video content.

Technical considerations: Synchronization is critical to maintain timing and ad placement; latency differences between broadcast and internet streams can cause misalignment. Rights, licensing, and contractual obligations may restrict simultaneous airing in certain territories or on certain platforms. Operationally, delivering a single feed to multiple endpoints requires careful encoding, monitoring, and bandwidth management.

Benefits and limitations: Simulcasting expands reach, improves brand consistency, and can simplify scheduling. It can also increase costs due to higher bandwidth and processing, and introduces risk if one channel experiences issues that impact all streams.