Both unicast and multicast have their specific advantages. In this case, the choice of technology not only influences the network capacity, but also the end customer experience. We show you the differences and when which method makes sense.
Nowadays, network operators and utility companies have to offer their customers a reliable, scalable and high-quality TV service - and this with growing bandwidth requirements. The choice between unicast and multicast not only influences the efficiency of signal distribution, but also network utilization and the cost-effectiveness of operations.
What is unicast?
Unicast refers to a point-to-point transmission in which a signal is sent directly from a transmitter to a single receiver. Each viewer receives an individual data stream, even if several users are watching the same program.
The main challenge for network operators is the high bandwidth consumption, as each viewer receives their own stream. This can lead to bottlenecks, particularly in networks with limited resources. In addition, scalability is limited if many users access the service at the same time.
Unicast is particularly suitable for applications where individual content is required. Video-on-demand, replay TV and pay TV offerings rely on this transmission method, as each user receives a tailored program.
Another important aspect is the type of transmission. Unicast is often based on technologies such as HLS (HTTP Live Streaming) or DASH (Dynamic Adaptive Streaming over HTTP). These streaming protocols divide the video into small segments that the client retrieves and plays one after the other.
A major advantage of unicast is that it works independently of the internet provider's network. As soon as a consumer leaves the home network and streams via a mobile network or another WLAN, for example, unicast is required.
What is multicast?
Multicast enables point-to-group transmission, in which a single TV signal is sent to a large number of receivers. Instead of generating individual data streams, the signal is sent once and received by several endpoints simultaneously.
This method offers significant advantages for network operators. As the signal is only transmitted once via the network, the bandwidth consumption remains constant regardless of the number of viewers. This makes multicast highly scalable and particularly suitable for live TV. The lower latency also ensures stable and fast transmission.
A crucial point with multicast is the network dependency. Multicast can only be used within a defined network, for example in a network operator's fiber optic network.
In the classic cable network (DVB-C), the basic offer is almost always provided via multicast, as this method conserves network capacity and enables consistent quality.
Multicast is primarily used for the distribution of live TV signals in cable or fiber optic networks. TV transmissions in supply networks and corporate TV solutions also benefit from this technology.
Comparison of unicast and multicast for TV providers
| Criterion | Unicast | Multicast |
| Transmission type | Point-to-point | Point-to-Group |
| Signal receiver | Each receiver receives an individual signal | A signal is sent to several receivers at the same time |
| Bandwidth utilization | High bandwidth requirements for many viewers | Efficient bandwidth utilization |
| Grid dependency | Works everywhere, even mobile | Only within a defined network |
| Scalability | Limited; can lead to bottlenecks with high traffic | Very scalable; ideal for mass transmission |
| Application scenarios | Individual content (streaming on demand) | Live events, TV broadcasts |
| Technology | TCP/IP, frequent use of HTTP | IGMP (Internet Group Management Protocol), UDP |
| Latency | Potentially higher latency with many connections | Lower latency, as the signal is only sent once |
| Efficiency | Less efficient with multiple viewers | High efficiency through joint transmission |
| Error management | Individual troubleshooting for each user | Can be more difficult with incorrect transfers |
| Public vs. private | Rather private, user-dependent | Rather public, ideal for broadcast applications |
What does this mean for cable network operators and utility companies with their own TV offering?
The choice between unicast and multicast depends heavily on the planned use. Multicast is ideal for classic live TV services, as it saves network capacity and ensures stable transmission. Unicast, on the other hand, is the preferred choice for on-demand content, as individual streams are provided for each user.
Many network operators now rely on a combination of both technologies. Live TV is distributed via multicast to make efficient use of bandwidth, while replay TV and VoD run via unicast to enable flexible playback times and personalized content.
Netstream supports cable network operators and utility companies with a scalable, high-performance TV signal solution. Let's work together to design the best streaming infrastructure for your network.
