återtransmission

Återtransmission, or retransmission, is the act of sending a signal, message, data, or content again after the initial delivery. The term is used in many fields to describe a process intended to improve reliability, coverage, or timeliness. While the exact meaning depends on the context, it generally refers to a second or repeated transmission of information that did not reach the intended recipient or needs to be delivered to a broader audience.

In data networks and telecommunications, retransmission describes resending data packets that were lost or corrupted during transit. Techniques such as automatic repeat request (ARQ), timeouts, acknowledgments, and error-correcting codes are used to trigger retransmission. Some schemes implement selective retransmission to minimize redundant data and reduce latency while maintaining accuracy.

In broadcasting and content delivery, retransmission denotes the rebroadcast of programming by another network, affiliate, or distribution channel. This can expand geographic reach, provide regional coverage, or comply with licensing arrangements. Digital streaming platforms may also offer retransmission of previously broadcast material to users on demand.

In medicine and epidemiology, retransmission describes the spread of a pathogen to new hosts after an initial outbreak. Retransmission can arise from waning immunity, incomplete vaccination, or persistent reservoirs. Understanding retransmission is important for modeling disease dynamics, planning vaccination campaigns, and implementing surveillance and containment strategies.

See also: retransmission protocols, ARQ, buffering, and disease transmission dynamics.