A broadcast transmission is equivalent to a broadcast call or broadcasting, it is the simultaneous transmission from one point to all subscribers. Classic broadcast applications are radio and television.
In broadcast, the information is transmitted from the sender to the receivers and not in the opposite direction. In addition, the receiver can only choose from the information that is offered to him. There is no interactivity between sender and receiver. This is only possible via special return channels, such as DVB, which supports various return channels.
In broadcasting, a distinction is therefore made between enhanced broadcast and interactive broadcast. Enhanced Broadcast has no return channel and can only work interactively with local services such as Electronic Program Guide( EPG). Interactive Broadcast, on the other hand, has a return channel that is switched via the Internet or the telephone network. With interactive broadcast, there is therefore user interaction for televoting, for example.
Broadcast in local networks
In order to address certain classes of receivers or all connected stations simultaneously in a local network, multicast or broadcast is possible.
In local networks, a broadcast is a message that is sent to all devices in all networks. It is forwarded by each router to all connected networks. If all end devices in a particular network are to be addressed, this is referred to as multicast or network broadcast; in the case of IP networks, it is referred to as IP multicast.
IP broadcasts can be executed directly by the IP addresses. For example, the class A address 22.214.171.124 would go to all nodes in network 1 and the class C address 126.96.36.199 would go to all nodes in network 192.7.4.
Broadcast in mobile networks
Mobile networks always involve point-to-point connections over which television images are transmitted in unicast with streaming video to the receiver's smartphone. This technique is extremely bandwidth-intensive and affects the efficiency of mobile networks, since thousands of dedicated point-to-point connections have to be established for television transmissions. This is why LTE-Broadcast was developed, a technology that allows an unlimited number of users to receive the same television images simultaneously. LTE broadcast uses a fixed radio frequency for this purpose.